// vim: et:ts=4:sw=4:sts=4:ft=js

// OxJS (c) 2007-2011 Ox2620, dual-licensed (GPL/MIT), see oxjs.org for details

// todo: check http://ejohn.org/blog/ecmascript-5-strict-mode-json-and-more/
// also see https://github.com/tlrobinson/narwhal/blob/master/lib/util.js


/*@
Ox <f> The <code>Ox</code> object
    See <code>Ox.wrap</code> for details.
    (value) -> <o> wrapped value
    value <*> any value
@*/

Ox = function(val) {
    return Ox.wrap(val);
};

/*
================================================================================
Constants
================================================================================
*/

//@ Ox.AMPM <[str]> ['AM', 'PM']
Ox.AMPM = ['AM', 'PM'];
//@ Ox.DURATIONS <[str]> ['year', 'month', 'day', 'minute', 'second']
Ox.DURATIONS = ['year', 'month', 'day', 'minute', 'second'];
//@ Ox.EARTH_RADIUS <number> Radius of the earth in meters
Ox.EARTH_RADIUS = 6378137;
//@ Ox.EARTH_CIRCUMFERENCE <num> Circumference of the earth in meters
Ox.EARTH_CIRCUMFERENCE = Ox.EARTH_RADIUS * 2 * Math.PI;
//@ Ox.HTML_ENTITIES <object> HTML entities for ... (FIXME)
Ox.HTML_ENTITIES = {
    '"': '&quot;', '&': '&amp;', "'": '&apos;', '<': '&lt;', '>': '&gt;'
};
//@ Ox.KEYS <object> Names for key codes
// the dot notation ('0.numpad') allows for namespaced events ('key_0.numpad'),
// so that binding to 'key_0' will catch 'key0.numpad' too
Ox.KEYS = {
    0: 'section', 8: 'backspace', 9: 'tab', 12: 'clear', 13: 'enter',
    16: 'shift', 17: 'control', 18: 'alt', 20: 'capslock', 27: 'escape',
    32: 'space', 33: 'pageup', 34: 'pagedown', 35: 'end', 36: 'home',
    37: 'left', 38: 'up', 39: 'right', 40: 'down',
    45: 'insert', 46: 'delete', 47: 'help',
    48: '0', 49: '1', 50: '2', 51: '3', 52: '4',
    53: '5', 54: '6', 55: '7', 56: '8', 57: '9',
    65: 'a', 66: 'b', 67: 'c', 68: 'd', 69: 'e',
    70: 'f', 71: 'g', 72: 'h', 73: 'i', 74: 'j',
    75: 'k', 76: 'l', 77: 'm', 78: 'n', 79: 'o',
    80: 'p', 81: 'q', 82: 'r', 83: 's', 84: 't',
    85: 'u', 86: 'v', 87: 'w', 88: 'x', 89: 'y', 90: 'z',
    // fixme: this is usually 91: window.left, 92: window.right, 93: select
    91: 'meta.left', 92: 'meta.right', 93: 'meta.right',
    96: '0.numpad', 97: '1.numpad', 98: '2.numpad',
    99: '3.numpad', 100: '4.numpad', 101: '5.numpad',
    102: '6.numpad', 103: '7.numpad', 104: '8.numpad', 105: '9.numpad',
    106: 'asterisk.numpad', 107: 'plus.numpad', 109: 'minus.numpad',
    108: 'enter.numpad', 110: 'dot.numpad', 111: 'slash.numpad',
    112: 'f1', 113: 'f2', 114: 'f3', 115: 'f4', 116: 'f5',
    117: 'f6', 118: 'f7', 119: 'f8', 120: 'f9', 121: 'f10',
    122: 'f11', 123: 'f12', 124: 'f13', 125: 'f14', 126: 'f15', 127: 'f16',
    144: 'numlock', 145: 'scrolllock',
    186: 'semicolon', 187: 'equal', 188: 'comma', 189: 'minus',
    190: 'dot', 191: 'slash', 192: 'backtick', 219: 'openbracket',
    220: 'backslash', 221: 'closebracket', 222: 'quote', 224: 'meta'
    // see dojo, for ex.
},
Ox.MAP_TILE_SIZE = 256; // fixme: definitely not needed here
//@ Ox.MODIFIER_KEYS <obj> Names for modifier keys
// meta comes last so that one can differentiate between
// alt_control_shift_meta.left and alt_control_shift_meta.right
Ox.MODIFIER_KEYS = {
    altKey: 'alt', // Mac: option
    ctrlKey: 'control',
    shiftKey: 'shift',
    metaKey: 'meta', // Mac: command
}
//@ Ox.MONTHS <[str]> Names of months
Ox.MONTHS = [
    'January', 'February', 'March', 'April', 'May', 'June',
    'July', 'August', 'September', 'October', 'November', 'December'
];
//@ Ox.SHORT_MONTHS <[str]> Short names of months
Ox.SHORT_MONTHS = Ox.MONTHS.map(function(val) {
    return val.substr(0, 3);
});
//@ Ox.PATH <str> Path of Ox.js
Ox.PATH = Array.prototype.slice.apply(
    document.getElementsByTagName('script')
).filter(function(element) {
    return /Ox\.js$/.test(element.src);
})[0].src.replace('Ox.js', '');
//@ Ox.PREFIXES <[str]> <code>['K', 'M', 'G', 'T', 'P']</code>
Ox.PREFIXES = ['K', 'M', 'G', 'T', 'P'];
//@ Ox.SYMBOLS <obj> Unicode characters for symbols
Ox.SYMBOLS = {
    DOLLAR: '\u0024', 
    CENT: '\u00A2', POUND: '\u00A3', CURRENCY: '\u00A4', YEN: '\u00A5',
    BULLET: '\u2022', ELLIPSIS: '\u2026', PERMILLE: '\u2030',
    COLON: '\u20A1', CRUZEIRO: '\u20A2', FRANC: '\u20A3', LIRA: '\u20A4',
    NAIRA: '\u20A6',  PESETA: '\u20A7', WON: '\u20A9', SHEQEL: '\u20AA',
    DONG: '\u20AB', EURO: '\u20AC', KIP: '\u20AD', TUGRIK: '\u20AE',
    DRACHMA: '\u20AF', PESO: '\u20B1', GUARANI: '\u20B2', AUSTRAL: '\u20B3',
    HRYVNIA: '\u20B4', CEDI: '\u20B5', TENGE: '\u20B8', RUPEE: '\u20B9',
    CELSIUS: '\u2103', FAHRENHEIT: '\u2109', POUNDS: '\u2114', OUNCE: '\u2125',
    OHM: '\u2126', KELVIN: '\u212A', ANGSTROM: '\u212B', INFO: '\u2139',
    LEFT: '\u2190', UP: '\u2191', RIGHT: '\u2192', DOWN: '\u2193',
    HOME: '\u2196', END: '\u2198', RETURN: '\u21A9',
    REDO: '\u21BA', UNDO: '\u21BB', PAGEUP: '\u21DE', PAGEDOWN: '\u21DF',
    CAPSLOCK: '\u21EA', TAB: '\u21E5', SHIFT: '\u21E7', INFINITY: '\u221E',
    CONTROL: '\u2303', COMMAND: '\u2318', ENTER: '\u2324', ALT: '\u2325',
    DELETE: '\u2326', CLEAR:'\u2327',BACKSPACE: '\u232B', OPTION: '\u2387',
    NAVIGATE: '\u2388', ESCAPE: '\u238B', EJECT: '\u23CF',
    SPACE: '\u2423', DIAMOND: '\u25C6',
    STAR: '\u2605', SOUND: '\u266B', TRASH: '\u267A', FLAG: '\u2691',
    ANCHOR: '\u2693', GEAR: '\u2699', ATOM: '\u269B', WARNING: '\u26A0',
    CUT: '\u2702', BACKUP: '\u2707', FLY: '\u2708', CHECK: '\u2713',
    CLOSE: '\u2715', BALLOT: '\u2717', WINDOWS: '\u2756',
    EDIT: '\uF802', CLICK: '\uF803', APPLE: '\uF8FF'
};
//@ Ox.TYPES <[str]> list of types, as returned by <code>Ox.type()</code>
Ox.TYPES = [
    'Arguments', 'Array', 'Boolean', 'Date', 'Element', 'Function', 'Infinity',
    'NaN', 'Null', 'Number', 'Object', 'RegExp', 'String', 'Undefined'
];
//@ Ox.VERSION <str> OxJS version number
Ox.VERSION = '0.1.2';
//@ Ox.WEEKDAYS <[str]> Names of weekdays
Ox.WEEKDAYS = [
    'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'
];
//@ Ox.SHORT_WEEKDAYS <[str]> Short names of weekdays
Ox.SHORT_WEEKDAYS = Ox.WEEKDAYS.map(function(val) {
    return val.substr(0, 3);
});

/*
================================================================================
Core functions
================================================================================
*/

/*@
Ox.doc <f> Generates documentation for annotated JavaScript
    (source) <a> Array of documentation objects
    source <s> JavaScript source code
    > Ox.doc("//@ Ox.foo <string> just some string")
    [{"name": "Ox.foo", "summary": "just some string", "type": "string"}]
@*/

Ox.doc = (function() {
    var re = {
            item: /^(.+?) <(.+?)> (.+)$/,
            multiline: /^\/\*\@.*?\n([\w\W]+)\n.*?\@\*\/$/,
            script: /\n(\s*<script>s*\n[\w\W]+\n\s*<\/script>s*)/g,
            singleline: /^\/\/@\s*(.*?)\s*$/,
            test: /\n(\s*> .+\n.+?)/g,
            usage: /\(.*?\)/
        },
        types = {
            a: 'array', b: 'boolean', d: 'date',
            e: 'element', f: 'function', n: 'number',
            o: 'object', r: 'regexp', s: 'string',
            u: 'undefined', '*': 'any', '!': 'event'
        }
    return function(source) {
        var blocks = [],
            items = [],
            tokens = [];
        Ox.tokenize(source).forEach(function(token) {
            var match;
            token.source = source.substr(token.offset, token.length);
            if (token.type == 'comment' && (match =
                re.multiline(token.source) || re.singleline(token.source)
            )) {
                blocks.push(match[1]);
                tokens.push([]);
            } else if (tokens.length) {
                tokens[tokens.length - 1].push(token);
            }
        });
        /*
        var blocks = Ox.map(Ox.tokenize(source), function(token) {
                // filter out tokens that are not comments
                // or don't match the doc comment pattern
                var match;
                token.source = source.substr(token.offset, token.length);
                return token.type == 'comment' && (match = 
                    re.multiline(token.source) || re.singleline(token.source)
                ) ? match[1] : null;
            }),
            items = [];
        */
        blocks.forEach(function(block, i) {
            var item, lastItem,
                lines = block
                    .replace(re.script, encodeLinebreaks)
                    .replace(re.test, encodeLinebreaks)
                    .split('\n');
            // create a tree and parse its root node
            item = parseNode(parseTree(lines));

            ///*
            item.source = [];
            var tokenBuffer = [], tokenFlag = false;
            tokens[i].forEach(function(token) {
                if (['linebreak', 'whitespace'].indexOf(token.type) > -1) {
                    tokenBuffer.push(token);
                } else {
                    if (!tokenFlag) {
                        item.source.push(token);
                        tokenFlag = true;
                    } else {
                        item.source = Ox.merge(item.source, tokenBuffer, [token]);
                    }
                    tokenBuffer = [];
                }
            });
            //*/

            if (/^[A-Z]/.test(item.name)) {
                items.push(item);
            } else {
                lastItem = items[items.length - 1];
                lastItem.properties = lastItem.properties || [];
                lastItem.properties.push(item);
                lastItem.source = Ox.merge(lastItem.source, item.source);
            }
        });
        function decodeLinebreaks(match, submatch) {
            return (submatch || match).replace(/\u21A9/g, '\n');
        }
        function encodeLinebreaks(match, submatch) {
            return '\n' + (submatch || match).replace(/\n/g, '\u21A9');
        }
        function getIndent(str) {
            var indent = -1;
            while (str[++indent] == ' ') {}
            return indent;
        }
        function parseItem(str) {
            var matches = re.item(str);
            // to tell a variable with default value, like
            //     name <string|'<a href="...">foo</a>'> summary
            // from a line of description with tags, like
            //     some <a href="...">description</a> text
            // we need to check if there is either no forward slash
            // or if the second last char is a single or double quote
            return matches && (
                matches[2].indexOf('/') == -1 ||
                '\'"'.indexOf(matches[2].substr(-2, 1)) > -1
            ) ? Ox.extend({
                name: parseName(matches[1].trim()),
                summary: matches[3].trim()
            }, parseType(matches[2])) : null;
        }
        function parseName(str) {
            var matches = re.usage(str);
            return matches ? matches[0] : str;
        }
        function parseNode(node) {
            var item = parseItem(node.line), subitem;
            Ox.print(node, node.line, 'item', item);
            node.nodes && node.nodes.forEach(function(node) {
                var key, line = node.line, subitem;
                if (!/^#/.test(node.line)) {
                    if (/^<script>/.test(line)) {
                        item.examples = [parseScript(line)];
                    } else if (/^>/.test(line)) {
                        item.examples = item.examples || [];
                        item.examples.push(parseTest(line));
                    } else if ((subitem = parseItem(line))) {
                        if (/^\(/.test(subitem.name)) {
                            item.usage = item.usage || [];
                            item.usage.push(parseNode(node));
                        } else if (subitem.types[0] == 'event') {
                            item.events = item.events || [];
                            item.events.push(parseNode(node));                            
                        } else {
                            key = item.types[0] == 'function' ?
                                'arguments' : 'properties'
                            item[key] = item[key] || [];
                            item[key].push(parseNode(node));                            
                        }
                    } else {
                        item.description = item.description ?
                            item.description + ' ' + line : line
                    }
                }
            });
            return item;
        }
        function parseScript(str) {
            // remove script tags and extra indentation
            var lines = decodeLinebreaks(str).split('\n'),
                indent = getIndent(lines[1]);
            return {
                statement: Ox.map(lines, function(line, i) {
                    return i && i < lines.length - 1 ?
                        line.substr(indent) : null;
                }).join('\n')
            };
        }
        function parseTest(str) {
            var lines = decodeLinebreaks(str).split('\n');
            return {
                statement: lines[0].substr(2),
                // result: JSON.parse(lines[1].trim())
                result: lines[1].trim()
            };
        }
        function parseTree(lines) {
            // parses indented lines into a tree structure, like
            // {line: "...", nodes: [{line: "...", nodes: [...]}]}
            var branches = [],
                indent,
                node = {
                    // chop the root line
                    line: lines.shift().trim()
                };
            if (lines.length) {
                indent = getIndent(lines[0]);
                lines.forEach(function(line) {
                    if (getIndent(line) == indent) {
                        // line is a child,
                        // make it the root line of a new branch
                        branches.push([line]);
                    } else {
                        // line is a descendant of the last child,
                        // add it to the last branch
                        branches[branches.length - 1].push(line);
                    }
                });
                node.nodes = branches.map(function(lines) {
                    return parseTree(lines);
                });
            }
            return node;
        }
        function parseType(str) {
            // returns {types: [""]}
            // or {types: [""], default: ""}
            // or {types: [""], parent: ""}
            var isArray,
                ret = {types: []},
                split,
                type;
            // only split by ':' if there is no default string value
            if ('\'"'.indexOf(str.substr(-2, 1)) == -1) {
                split = str.split(':');
                str = split[0];
                if (split.length == 2) {
                    ret.parent = split[1];
                }
            }
            str.split('|').forEach(function(str) {
                var unwrapped = unwrap(str);
                if (unwrapped in types) {
                    ret.types.push(wrap(types[unwrapped]))
                } else if (
                    (type = Ox.filter(Ox.values(types), function(type) {
                        return Ox.startsWith(type, unwrapped);
                    })).length
                ) {
                    ret.types.push(wrap(type[0]))
                } else {
                    ret.default = str;
                }
            });
            function unwrap(str) {
                return (isArray = /^\[.+\]$/.test(str)) ?
                    str = str.substr(1, str.length - 2) : str;
            }
            function wrap(str) {
                return isArray ? '[' + str + ']' : str;
            }
            return ret;
        }
        return items;
    };
}())

Ox.get = function(url, callback) {
    var req = new XMLHttpRequest();
    req.open('GET', url, true);
    req.onreadystatechange = function() {
        if (req.readyState == 4) {
            if (req.status == 200) {
                callback(req.responseText);
            } else {
                throw new Error('URL ' + url + ', status ' + req.status);
            }
        }
    };
    req.send();                
};

Ox.getJSON = function(url, callback) {
    Ox.get(url, function(data) {
        callback(JSON.parse(data));
    });
}

/*@
Ox.getset <f> Generic getter and setter function
    See examples for details.
    # Usage --------------------------------------------------------------------
    Ox.getset(options, args=[])                              -> <o> all options
    Ox.getset(options, args=[key])                           -> <*> options[key]
    Ox.getset(options, args=[key, value], callback, context) -> <f|o> context
        sets options[key] to value and calls fn(key, value)
        if the key/value pair was added or modified
    Ox.getset(options, args=[{key: value}], callback, context) -> <f|o> context
        sets multiple options and calls fn(key, value)
        for every key/value pair that was added or modified
    # Arguments ----------------------------------------------------------------
    options  <obj> Options object (key/value pairs)
    args     <arr> The arguments "array" of the caller function
    callback <fun> Callback function 
        The callback is called for every key/value pair that was added or
        modified.
        key      <s> Key
        value    <*> Value
    context  <obj> The parent object of the caller function (for chaining)
    # Examples -----------------------------------------------------------------
    <script>
        var object = new function() {
            var options = {},
                setOption = function(key, value) {},
                that = this;
            that.options = function() {
                return Ox.getset(options, arguments, setOption, that);
            }
            return that;
        };
    </script>
    > object.options("key", "val").options("key")
    "val"
    > object.options({foo: "foo", bar: "bar"}).options()
    {"key": "val", "foo": "foo", "bar": "bar"}
@*/

Ox.getset = function(obj, args, callback, context) {
    var obj_ = Ox.clone(obj), ret;
    if (args.length == 0) {
        // getset([])
        ret = obj;
    } else if (args.length == 1 && !Ox.isObject(args[0])) {
        // getset([key])
        ret = obj[args[0]];
    } else {
        // getset([key, val]) or getset([{key: val, ...}])
        args = Ox.makeObject(args);
        obj = Ox.extend(obj, args);
        Ox.forEach(args, function(val, key) {
            if (!obj_ || !Ox.isEqual(obj_[key], val)) {
                callback && callback(key, val);
            }
        });
        ret = context;                            
    }
    return ret;
}

/*@
Ox.load <f> Loads a module
    (module, callback)          -> <u> undefined
    (module, options, callback) -> <u> undefined
    module   <s> Module name
    options  <o> Module options
    callback <f> Callback function
        success <b> If true, the module has been loaded successfully
@*/

Ox.load = function(module, options, callback) {
    // fixme: no way to load multiple modules
    // problem: where do multiple options go?
    // [{name: "", options: {}}, {name: "", options: {}}] isn't pretty
    callback = arguments[arguments.length - 1];
    options = arguments.length == 3 ? arguments[1] : {};
    Ox.loadFile(Ox.PATH + 'Ox.' + module + '/Ox.' + module + '.js', function() {
        Ox.load[module](options, callback);
    });
};

/*@
Ox.loadFile <f> Loads a file (image, script or stylesheet)
    (file="script.js", callback)      -> <u> undefined
    (file="stylesheet.css", callback) -> <u> undefined
    (file="image.png", callback)      -> <e> DOM element
    file     <s> Local path or remote URL
    callback <f> Callback function
@*/

Ox.loadFile = (function() {
    // fixme: this doesn't handle errors yet
    var cache = {};
    return function (file, callback) {
        var element,
            request,
            type = file.split('.').pop();
            isImage = type != 'css' && type != 'js';
        if (!cache[file]) {
            if (isImage) {
                element = new Image();
                element.onload = addFileToCache;
                element.src = file;
            } else {
                if (!findFileInHead()) {
                    element = document.createElement(type == 'css' ? 'link' : 'script');
                    element[type == 'css' ? 'href' : 'src'] = file;
                    element.type = type == 'css' ? 'text/css' : 'text/javascript';
                    if (type == 'css') {
                        element.rel = 'stylesheet';
                        waitForCSS();
                    } else {
                        element.onload = addFileToCache;
                    }
                    document.head.appendChild(element);
                } else {
                    addFileToCache();
                }
            }
        } else {
            callback();
        }
        function addFileToCache() {
            if (isImage) {
                // for an image, save the element itself,
                // so that it remains in the browser cache
                cache['file'] = element;
                callback(element);
            } else {
                cache['file'] = true;
                callback();
            }
        }
        function findFileInHead() {
            return Array.prototype.slice.apply(
                document.getElementsByTagName(type == 'css' ? 'link' : 'script')
            ).map(function(element) {
                return element[type == 'css' ? 'href' : 'src'] == file;
            }).reduce(function(prev, curr) {
                return prev || curr; 
            }, false);
        }
        function waitForCSS() {
            var error = false;
            try {
                element.sheet.cssRule;
            } catch(e) {
                error = true;
                setTimeout(function() {
                    waitForCSS();
                }, 25);
            }
            !error && addFileToCache();
        }
    };
}());

/*@
Ox.print <f> Prints its arguments to the console
    (arg, ...) -> <s> String
        The string contains the timestamp, the name of the caller function, and
        any arguments, separated by spaces
    arg <*> any value
    > Ox.print("foo").substr(-3)
    "foo"
@*/

Ox.print = function() {
    var args = Ox.makeArray(arguments),
        date = new Date();
    args.unshift(
        Ox.formatDate(date, '%H:%M:%S.') + (+date).toString().substr(-3),
        arguments.callee.caller.name || '(anonymous)'
    );
    window.console && window.console.log.apply(window.console, args);
    return args.join(' ');
};

/*@
Ox.uid <f> Returns a unique id
    () -> <n> Unique id
    > Ox.uid() != Ox.uid()
    true
@*/
Ox.uid = (function() {
    var uid = 0;
    return function() {
        return uid++;
    };
}());

/*@
Ox.wrap <f> Wraps a value so that one can directly call any Ox function on it
    Additionally, chain() allows for chaining, and value() returns the
    original value. See examples for details.
    (value) -> <o> wrapped value
        chain <f> wrap the return value to allow chaining
        value <f> unwrap the value wrapped by chain()
    value <*> any value
    > Ox.wrap("foobar").repeat(2)
    "foobarfoobar"
    > Ox.wrap("foobar").chain().reverse().toTitleCase().value()
    "Raboof"
    > Ox.wrap("foobar").value()
    "foobar"
@*/

Ox.wrap = function(val, chained) {
    var wrapper = {
        chain: function() {
            wrapper.chained = true;
            return wrapper;
        },
        chained: chained || false,
        value: function() {
            return val;
        }
    };
    Object.getOwnPropertyNames(Ox).forEach(function(name) {
        if (name[0] == name[0].toLowerCase() && Ox.isFunction(Ox[name])) {
            wrapper[name] = function() {
                var args = Array.prototype.slice.call(arguments), ret;
                args.unshift(val);
                ret = Ox[name].apply(Ox, args);
                return wrapper.chained ? Ox.wrap(ret, true) : ret;
            };
        }
    });
    return wrapper;
};

/*
================================================================================
Array and Object functions
================================================================================
*/

/*@
Ox.avg <f> returns the average of an array's values, or an object's properties
    (collection) -> <n> average
    collection <[n]|o> An array or object with numerical values
    > Ox.avg([-1, 0, 1])
    0
    > Ox.avg({a: 1, b: 2, c: 3})
    2
@*/
Ox.avg = function(obj) {
    return Ox.sum(obj) / Ox.len(obj);
};

Ox.clone = function(obj) {
    /***
    returns a copy of an array or object
    >>> (function() { a = ['val']; b = Ox.clone(a); a[0] = null; return b[0]; }())
    'val'
    >>> (function() { a = {key: 'val'}; b = Ox.clone(a); a.key = null; return b.key; }())
    'val'
    ***/
    return Ox.isArray(obj) ? obj.slice() : Ox.extend({}, obj);
};

Ox.compact = function(arr) {
    /***
    returns an array without null or undefined values
    >>> Ox.compact([null,,1,,2,,3])
    [1, 2, 3]
    ***/
    return Ox.map(arr, function(val) {
        return Ox.isUndefined(val) ? null : val;
    });
};

Ox.count = function(arr) {
    /***
    >>> Ox.count(['foo', 'bar', 'foo']).foo
    2
    ***/
    var obj = {};
    arr.forEach(function(v) {
        obj[v] = (obj[v] || 0) + 1;
    });
    return obj;
};

Ox.each = function(obj, fn) {
    // fixme: deprecate!
    /*
    Ox.each() works for arrays, objects and strings,
    like $.each(), unlike [].forEach()
    >>> Ox.each([0, 1, 2], function(i, v) {})
    [0, 1, 2]
    >>> Ox.each({a: 1, b: 2, c: 3}, function(k, v) {}).a
    1
    >>> Ox.each('foo', function(i, v) {})
    'foo'
    */
    var i, isArray = Ox.isArray(obj);
    for (i in obj) {
        i = isArray ? parseInt(i) : i;
        // fixme: should be (v, k), like [].forEach()
        if (fn(i, obj[i]) === false) {
            break;
        }
    }
    return obj;
};

Ox.every = function(obj, fn) {
    /*
    Ox.every() works for arrays, objects and strings, unlike [].every()
    >>> Ox.every([0, 1, 2], function(v, i) { return i == v; })
    true
    >>> Ox.every({a: 1, b: 2, c: 3}, function(v) { return v == 1; })
    false
    >>> Ox.every("foo", function(v) { return v == 'f'; })
    false
    >>> Ox.every([true, true, true])
    true
    */
    return Ox.filter(Ox.values(obj), fn || function(v) {
        return v;
    }).length == Ox.len(obj);
};

Ox.extend = function() {
    /*
    >>> Ox.extend({a: 1, b: 1, c: 1}, {b: 2, c: 2}, {c: 3}).c
    3
    */
    var obj = arguments[0];
    Ox.forEach(Array.prototype.slice.call(arguments, 1), function(arg, i) {
        Ox.forEach(arg, function(val, key) {
            obj[key] = val;
        });
    });
    return obj;
};

Ox.filter = function(obj, fn) {
    /***
    Ox.filter works for arrays, objects and strings, unlike [].filter()
    >>> Ox.filter([2, 1, 0], function(v, i) { return v == i; })
    [1]
    >>> Ox.keys(Ox.filter({a: 'c', b: 'b', c: 'a'}, function(v, k) { return v == k; }))
    ['b']
    >>> Ox.filter(' hello world ', function(v) { return v != ' '; })
    'helloworld'
    ***/
    var type = Ox.typeOf(obj),
        ret = type == 'array' ? [] : type == 'object' ? {} : '';
    Ox.forEach(obj, function(v, k) {
        if (fn(v, k)) {
            if (type == 'array') {
                ret.push(v);
            } else if (type == 'object') {
                ret[k] = v;
            } else {
                ret += v;
            }
        }
    });
    return ret;
};

Ox.find = function(arr, str) {
    /*
    returns an array with two arrays as elements:
    an array of elements of arr that begin with str,
    and an array of elements of arr that contain,
    but do not begin with str
    >>> Ox.find(["foo", "bar", "foobar", "barfoo"], "foo")
    [["foo", "foobar"], ["barfoo"]]
    */
    var arrLowerCase = arr.map(function(v) {
            return v.toLowerCase();
        }),
        ret = [[], []];
    str && arrLowerCase.forEach(function(v, i) {
        var index = v.indexOf(str.toLowerCase());
        index > -1 && ret[index == 0 ? 0 : 1].push(arr[i]);
    });
    return ret;
};

Ox.flatten = function(arr) {
    /*
    >>> Ox.flatten([1, [2, [3], 4], 5])
    [1, 2, 3, 4, 5]
    */
    var ret = [];
    arr.forEach(function(v) {
        if (Ox.isArray(v)) {
            Ox.flatten(v).forEach(function(v) {
                ret.push(v);
            });
        } else {
            ret.push(v);
        }
    });
    return ret;
}

/*@
Ox.forEach <f> forEach loop
    <code>Ox.forEach()</code> loops over arrays, objects and strings.
    Returning <code>false</code> from the iterator function acts like a
    <code>break</code> statement (unlike <code>[].forEach()</code>, like
    <code>$.each()</code>). The arguments of the iterator function are
    <code>(value, key)</code> (like <code>[].forEach()</code>, unlike
    <code>$.each()</code>).
    (collection, callback) <a|o|s> The collection
    collection <a|o|s> An array, object or string
    callback <f> Callback function
        value <*> Value
        key <n|s> Key
@*/
Ox.forEach = function(obj, fn) {
    /*
    Ox.forEach() works for arrays, objects and strings,
    like $.each(), unlike [].forEach()
    The arguments of the iterator function are (value, key),
    like [].forEach(), unlike $.each()
    >>> Ox.forEach('foo', function(v, i) {})
    'foo'
    >>> Ox.forEach([0, 1, 2], function(v, i) {})
    [0, 1, 2]
    >>> Ox.forEach({a: 1, b: 2, c: 3}, function(v, k) {}).a
    1
    */
    var isObject = Ox.isObject(obj), key;
    for (key in obj) {
        key = isObject ? key : parseInt(key);
        if (/*hasOwnProperty.call(obj, key) && */fn(obj[key], key) === false) {
            break;
        }
    }
    return obj;
};

Ox.getObjectById = function(arr, id) {
    /***
    >>> Ox.getObjectById([{id: "foo", title: "Foo"}, {id: "bar", title: "Bar"}], "foo").title
    "Foo"
    ***/
    var ret = null;
    Ox.forEach(arr, function(v) {
        if (v.id == id) {
            ret = v;
            return false;
        }
    });
    return ret;
};

Ox.getPositionById = function(arr, id) {
    /***
    >>> Ox.getPositionById([{id: "foo", title: "Foo"}, {id: "bar", title: "Bar"}], "bar")
    1
    ***/
    var ret = -1;
    Ox.forEach(arr, function(v, i) {
        if (v.id == id) {
            ret = i;
            return false;
        }
    });
    return ret;
};

Ox.isEmpty = function(val) {
    return Ox.len(val) == 0;
};

Ox.isEqual = function(obj0, obj1) {
    /*
    >>> Ox.isEqual(false, false)
    true
    >>> Ox.isEqual(0, 0)
    true
    >>> Ox.isEqual(NaN, NaN)
    false
    >>> Ox.isEqual('', '')
    true
    >>> Ox.isEqual([1, 2, 3], [1, 2, 3])
    true
    >>> Ox.isEqual({a: 1, b: [2, 3], c: {d: '4'}}, {a: 1, b: [2, 3], c: {d: '4'}})
    true
    >>> Ox.isEqual(function(arg) { return arg; }, function(arg) { return arg; });
    true
    */
    var ret = false;
    if (obj0 === obj1) {
        ret = true;
    } else if (typeof(obj0) == typeof(obj1)) {
        if (obj0 == obj1) {
            ret = true;
        } else if (Ox.isArray(obj0) && obj0.length == obj1.length) {
            ret = true;
            Ox.forEach(obj0, function(v, i) {
                ret = Ox.isEqual(v, obj1[i]);
                return ret;
            });
        } else if (Ox.isDate(obj0)) {
            ret = obj0.getTime() == obj1.getTime();
        } else if (Ox.isObject(obj0)) {
            ret = Ox.isEqual(Ox.keys(obj0), Ox.keys(obj1)) &&
                Ox.isEqual(Ox.values(obj0), Ox.values(obj1));
        } else if (Ox.isFunction(obj0)) {
            ret = obj0.toString() == obj1.toString();
        }
    }
    return ret;
};

Ox.keys = function(obj) {
    /*
    works for arrays, objects and strings, unlike Object.keys()
    >>> Ox.keys([1, 2, 3])
    [0, 1, 2]
    >>> Ox.keys({a: 1, b: 2, c: 3})
    ["a", "b", "c"]
    >>> Ox.keys('abc')
    [0, 1, 2]
    >>> Ox.keys([,])
    [0]
    */
    var keys = [];
    Ox.forEach(obj, function(v, k) {
        keys.push(k);
    });
    return keys.sort();
};

Ox.last = function(arr, val) {
    /***
    >>> Ox.last([1, 2, 3])
    3
    >>> Ox.last([1, 2, 3], 4)
    [1, 2, 4]
    ***/
    var ret;
    if (arguments.length == 1) {
        ret = arr[arr.length - 1];
    } else {
        arr[arr.length - 1] = val;
        ret = arr;
    }
    return ret;
};

Ox.len = function(obj) {
    /*
    >>> Ox.len([1, 2, 3])
    3
    >>> Ox.len({a: 1, b: 2, c: 3})
    3
    >>> Ox.len('abc')
    3
    >>> Ox.len(function(x, y) { return x + y; })
    2
    >>> Ox.len([,])
    1
    */
    return Ox.isObject(obj) ? Ox.values(obj).length : obj.length;
};

Ox.loop = function() {
    var length = arguments.length,
        fn = arguments[length - 1],
        step = length == 4 ? arguments[2] : 1,
        stop = arguments[length > 2 ? 1 : 0],
        start = length > 2 ? arguments[0] : 0,
        i;
    for (i = start; i < stop; i += step) {
        fn(i);
    }
};

Ox.makeArray = function(obj) {
    /*
    >>> (function() { return Ox.makeArray(arguments); }('foo', 'bar'))
    ['foo', 'bar']
    */
    return Array.prototype.slice.call(obj);
};

Ox.makeObject = function(obj) {
    /*
    >>> (function() { return Ox.makeObject(arguments); }({foo: 'bar'})).foo
    'bar'
    >>> (function() { return Ox.makeObject(arguments); }('foo', 'bar')).foo
    'bar'
    >>> (function() { return Ox.makeObject(arguments); }('foo')).foo
    undefined
    >>> (function() { return Ox.makeObject(arguments); }()).foo
    undefined
    */
    var ret = {};
    if (Ox.isObject(obj[0])) {
        // ({foo: 'bar'})
        ret = obj[0];
    } else if (obj.length) {
        // ('foo', 'bar')
        ret[obj[0]] = obj[1]
    }
    return ret;
};

Ox.map = function(obj, fn) {
    /*
    Ox.map() works for arrays, objects and strings,
    unlike [].map()
    >>> Ox.map([1, 1, 1], function(v, i) { return v == i; })
    [false, true, false]
    >>> Ox.map({a: 'a', b: 'a', c: 'a'}, function(v, k) { return v == k; }).a
    true
    >>> Ox.map("111", function(v, i) { return v == i; })
    [false, true, false]
    >>> Ox.map([,], function(v, i) { return i; })
    [0]
    */
    // fixme: return null to filter out is a bit esoteric
    var isObject = Ox.isObject(obj),
        ret = isObject ? {} : [];
    Ox.forEach(obj, function(val, key) {
        if ((v = fn(val, key)) !== null) {
            ret[isObject ? key : ret.length] = v;
        }
    });
    return ret;
};

Ox.max = function(obj) {
    /*
    >>> Ox.max([-1, 0, 1])
    1
    >>> Ox.max({a: 1, b: 2, c: 3})
    3
    */
    return Math.max.apply(Math, Ox.values(obj));
};

Ox.min = function(obj) {
    /*
    >>> Ox.min([-1, 0, 1])
    -1
    >>> Ox.min({a: 1, b: 2, c: 3})
    1
    */
    return Math.min.apply(Math, Ox.values(obj));
};

Ox.merge = function(arr) {
    /*
    >>> Ox.merge(['foo'], ['bar'], ['baz'])
    ['foo', 'bar', 'baz']
    */
    Ox.forEach(Array.prototype.slice.call(arguments, 1), function(arg) {
        Ox.forEach(arg, function(val) {
            arr.push(val);
        });
    });
    return arr;
};

Ox.range = function(start, stop, step) {
    /*
    >>> Ox.range(3)
    [0, 1, 2]
    >>> Ox.range(3, 0)
    [3, 2, 1]
    >>> Ox.range(1, 2, 0.5)
    [1, 1.5]
    */
    stop = arguments.length > 1 ? stop : arguments[0];
    start = arguments.length > 1 ? start : 0;
    step = step || (start <= stop ? 1 : -1);
    var arr = [], i;
    for (i = start; step > 0 ? i < stop : i > stop; i += step) {
        arr.push(i);
    }
    return arr;
};

Ox.serialize = function(obj) {
    /*
    >>> Ox.serialize({a: 1, b: 2, c: 3})
    'a=1&b=2&c=3'
    */
    var arr = [];
    Ox.forEach(obj, function(val, key) {
        val !== '' && arr.push(key + '=' + val);
    });
    return arr.join('&');
};

Ox.setPropertyOnce = function(arr, str) {
    /*
    >>> Ox.setPropertyOnce([{selected: false}, {selected: false}], 'selected')
    0
    >>> Ox.setPropertyOnce([{selected: false}, {selected: true}], 'selected')
    1
    >>> Ox.setPropertyOnce([{selected: true}, {selected: true}], 'selected')
    0
    */
    var pos = -1;
    Ox.forEach(arr, function(v, i) {
        if (pos == -1 && arr[i][str]) {
            pos = i;
        } else if (pos > -1 && arr[i][str]) {
            delete arr[i][str];
        }
    });
    if (pos == -1) {
        arr[0][str] = true;
        pos = 0;
    }
    return pos;
};

Ox.shuffle = function(arr) {
    /*
    >>> Ox.shuffle([1, 2, 3]).length
    3
    */
    var shuffle = arr;
    return shuffle.sort(function() {
        return Math.random() - 0.5;
    });
};

Ox.some = function(obj, fn) {
    /*
    Ox.some() works for arrays, objects and strings, unlike [].some()
    >>> Ox.some([2, 1, 0], function(i, v) { return i == v; })
    true
    >>> Ox.some({a: 1, b: 2, c: 3}, function(v) { return v == 1; })
    true
    >>> Ox.some("foo", function(v) { return v == 'f'; })
    true
    */
    return Ox.filter(Ox.values(obj), fn).length > 0;
};

Ox.sort = function(arr) {
    /*
    >>> Ox.sort(['10', '9', 'B', 'a'])
    ['9', '10', 'a', 'B']
    */
    var len, matches = {}, sort = {};
    // find leading numbers
    arr.forEach(function(val, i) {
        var match = /^\d+/(val);
        matches[val] = match ? match[0] : '';
    });
    // get length of longest leading number
    len = Ox.max(Ox.map(matches, function(val) {
        return val.length;
    }));
    // pad leading numbers, and make lower case
    arr.forEach(function(val) {
        sort[val] = (
            matches[val] ?
            Ox.pad(matches[val], len) + val.toString().substr(matches[val].length) :
            val
        ).toLowerCase();
    });
    return arr.sort(function(a, b) {
        var ret = 0;
        if (sort[a] < sort[b]) {
            ret = -1;
        } else if (sort[a] > sort[b]) {
            ret = 1;
        }
        return ret;
    });
};

Ox.sum = function(obj) {
    /*
    >>> Ox.sum([-1, 0, 1])
    0
    >>> Ox.sum({a: 1, b: 2, c: 3})
    6
    */
    var sum = 0;
    Ox.forEach(obj, function(val) {
        sum += val;
    });
    return sum;
};

Ox.toArray = function(obj) {
    // fixme: can this be thrown out?
    /*
    >>> Ox.toArray('foo')
    ['foo']
    >>> Ox.toArray(['foo'])
    ['foo']
    */
    var arr;
    if (Ox.isArray(obj)) {
        arr = obj;
    } else if (Ox.isArguments(obj)) {
        arr = Ox.makeArray(obj);
    } else {
        arr = [obj];
    }
    return arr;
};

Ox.unique = function(arr) {
    /*
    >>> Ox.unique([1, 2, 3, 1])
    [1, 2, 3]
    */
    var unique = [];
    Ox.forEach(arr, function(val) {
        unique.indexOf(val) == -1 && unique.push(val);
    });
    return unique;
};

Ox.unserialize = function(str) {
    /*
    >>> Ox.unserialize('a=1&b=2&c=3').c
    '3'
    */
    var arr, obj = {};
    Ox.forEach(str.split('&'), function(val) {
        arr = val.split('=');
        obj[arr[0]] = arr[1];
    });
    return obj;
};

Ox.values = function(obj) {
    /*
    >>> Ox.values([1, 2, 3])
    [1, 2, 3]
    >>> Ox.values({a: 1, b: 2, c: 3})
    [1, 2, 3]
    >>> Ox.values('abc')
    ['a', 'b', 'c']
    >>> Ox.values([1,])
    [1]
    */
    // fixme: why doesn't this use map?
    var values = [];
    Ox.forEach(obj, function(val) {
        values.push(val);
    });
    return values;
};

Ox.walk = function(obj, fn) {
    /*
    >>> a = 0; Ox.walk({a: 1, b: {c: 2, d: 3}}, function(v, k) { a += Ox.isNumber(v) ? v : 0}); a
    6
    */
    Ox.forEach(obj, function(val, key) {
        fn(val, key, obj);
        Ox.walk(obj[key], fn);
    });
};

Ox.zip = function() {
    /*
    >>> Ox.zip([[0, 1], [2, 3], [4, 5]])
    [[0, 2, 4], [1, 3, 5]]
    >>> Ox.zip([0, 1, 2], [3, 4, 5])
    [[0, 3], [1, 4], [2, 5]]
    */
    var args = arguments.length == 1 ? arguments[0] : Ox.makeArray(arguments),
        arr = [];
    args[0].forEach(function(v, i) {
        arr[i] = [];
        args.forEach(function(v_, i_) {
            arr[i].push(v_[i]);
        });
    });
    return arr;
};

/*
================================================================================
Color functions
================================================================================
*/

/*@
Ox.hsl <f> Takes RGB values and returns HSL values
    (rgb) <[n]> HSL values
    rgb <[n]> RGB values
    > Ox.hsl([0, 0, 0])
    [0, 0, 0]
    > Ox.hsl([255, 255, 255])
    [0, 0, 1]
    > Ox.hsl([0, 255, 0])
    [120, 1, 0.5]
@*/
Ox.hsl = function(rgb) {
    rgb = rgb.map(function(v) {
        return v / 255;
    });
    var max = Ox.max(rgb),
        min = Ox.min(rgb),
        hsl = [0, 0, 0];
    hsl[2] = 0.5 * (max + min);
    if (max == min) {
        hsl[0] = 0;
        hsl[1] = 0;
    } else {
        if (max == rgb[0]) {
            hsl[0] = (60 * (rgb[1] - rgb[2]) / (max - min) + 360) % 360;
        } else if (max == rgb[1]) {
            hsl[0] = 60 * (rgb[2] - rgb[0]) / (max - min) + 120;
        } else if (max == rgb[2]) {
            hsl[0] = 60 * (rgb[0] - rgb[1]) / (max - min) + 240;
        }
        if (hsl[2] <= 0.5) {
            hsl[1] = (max - min) / (2 * hsl[2]);
        } else {
            hsl[1] = (max - min) / (2 - 2 * hsl[2]);
        }
    }
    return hsl;
};

/*@
Ox.rgb <f> Takes HSL values and returns RGB values
    (hsl) <[n]> RGB values
    hsl <[n]> HSL values
    > Ox.rgb([0, 0, 0])
    [0, 0, 0]
    > Ox.rgb([0, 0, 1])
    [255, 255, 255]
    > Ox.rgb([120, 1, 0.5])
    [0, 255, 0]
@*/

Ox.rgb = function(hsl) {
    hsl[0] /= 360;
    var rgb = [0, 0, 0],
        v1, v2, v3;
    if (hsl[1] == 0) {
        rgb = [hsl[2], hsl[2], hsl[2]];
    } else {
        if (hsl[2] < 0.5) {
            v2 = hsl[2] * (1 + hsl[1]); 
        } else {
            v2 = hsl[1] + hsl[2] - (hsl[1] * hsl[2]);
        }
        v1 = 2 * hsl[2] - v2;
        rgb.forEach(function(v, i) {
            v3 = hsl[0] + (1 - i) * 1/3;
            if (v3 < 0) {
                v3++;
            } else if (v3 > 1) {
                v3--;
            }
            if (v3 < 1/6) {
                rgb[i] = v1 + ((v2 - v1) * 6 * v3);
            } else if (v3 < 0.5) {
                rgb[i] = v2;
            } else if (v3 < 2/3) {
                rgb[i] = v1 + ((v2 - v1) * 6 * (2/3 - v3));
            } else {
                rgb[i] = v1;
            }
        });
    }
    return rgb.map(function(v) {
        return v * 255;
    });
};

/*
================================================================================
Date functions
================================================================================
*/

/*@
Ox.getDateInWeek <f> Get the date that falls on a given weekday in the same week
    # Usage
    (date, weekday)      -> <dat> Date
    (date, weekday, utc) -> <dat> Date
    # Arguments
    date    <d> Date
    weekday <n|s> 1-7 (Monday-Sunday) or name, full ("Monday") or short ("Sun")
    utc     <b> If true, all dates are UTC
    # Examples
    > Ox.formatDate(Ox.getDateInWeek(new Date("January 1 2000"), "Sunday"), "%A, %B %e, %Y")
    "Sunday, January  2, 2000"
    > Ox.formatDate(Ox.getDateInWeek(new Date("Jan 1 2000"), "Fri"), "%A, %B %e, %Y")
    "Friday, December 31, 1999"
    > Ox.formatDate(Ox.getDateInWeek(new Date("1/1/2000"), 1), "%A, %B %e, %Y")
    "Monday, December 27, 1999"
@*/

Ox.getDateInWeek = function(date, weekday, utc) {
    /*
    */
    date = Ox.makeDate(date);
    Ox.print(date, Ox.getDate(date, utc), Ox.formatDate(date, '%u', utc), date)
    var sourceWeekday = Ox.getISODay(date, utc),
        targetWeekday = Ox.isNumber(weekday) ? weekday :
            Ox.map(Ox.WEEKDAYS, function(v, i) {
                return v.substr(0, 3) == weekday.substr(0, 3) ? i + 1 : null;
            })[0];
    Ox.print(date, Ox.getDate(date, utc), sourceWeekday, targetWeekday)
    return Ox.setDate(date, Ox.getDate(date, utc) - sourceWeekday + targetWeekday, utc);
}

/*@
Ox.getDayOfTheYear <f> Get the day of the year for a given date
    # Usage
    (date)      -> <d> Date
    (date, utc) -> <d> Date
    # Arguments
    date <d> Date
    utc  <b> If true, all dates are UTC
    # Examples
    > Ox.getDayOfTheYear(new Date("12/31/2000"))
    366
    > Ox.getDayOfTheYear(new Date("12/31/2002"))
    365
    > Ox.getDayOfTheYear(new Date("12/31/2004"))
    366
@*/

Ox.getDayOfTheYear = function(date, utc) {
    date = Ox.makeDate(date);
    var month = Ox.getMonth(date, utc),
        year = Ox.getFullYear(date, utc);
    return Ox.sum(Ox.map(Ox.range(month), function(i) {
        return Ox.getDaysInMonth(year, i + 1);
    })) + Ox.getDate(date, utc);
};

Ox.getDaysInMonth = function(year, month, utc) {
    /*
    >>> Ox.getDaysInMonth(2000, 2)
    29
    >>> Ox.getDaysInMonth("2002", "Feb")
    28
    >>> Ox.getDaysInMonth(new Date('01/01/2004'), "February")
    29
    */
    year = Ox.makeYear(year);
    month = Ox.isNumber(month) ? month :
        Ox.map(Ox.MONTHS, function(v, i) {
            return v.substr(0, 3) == month.substr(0, 3) ? i + 1 : null;
        })[0];
    return new Date(year, month, 0).getDate();
}

Ox.getDaysInYear = function(year, utc) {
    /*
    >>> Ox.getDaysInYear(1900)
    365
    >>> Ox.getDaysInYear('2000')
    366
    >>> Ox.getDaysInYear(new Date('01/01/2004'))
    366
    */
    return 365 + Ox.isLeapYear(Ox.makeYear(year, utc));
};

Ox.getFirstDayOfTheYear = function(date, utc) {
    /*
    Decimal weekday of January 1 (0-6, Sunday as first day)
    >>> Ox.getFirstDayOfTheYear(new Date("01/01/2000"))
    6
    */
    date = Ox.makeDate(date);
    date = Ox.setMonth(date, 0, utc);
    date = Ox.setDate(date, 1, utc);
    return Ox.getDay(date, utc)
};

Ox.getISODate = function(date, utc) {
    /*
    >>> Ox.getISODate(new Date("01/01/2000"))
    "2000-01-01T00:00:00Z"
    */
    return Ox.formatDate(Ox.makeDate(date), '%FT%TZ', utc);
};

Ox.getISODay = function(date, utc) {
    /*
    Decimal weekday (1-7, Monday as first day)
    >>> Ox.getISODay(new Date("01/01/2000"))
    6
    >>> Ox.getISODay(new Date("01/02/2000"))
    7
    >>> Ox.getISODay(new Date("01/03/2000"))
    1
    */
    return Ox.getDay(Ox.makeDate(date), utc) || 7;
};

Ox.getISOWeek = function(date, utc) {
    /*
    see http://en.wikipedia.org/wiki/ISO_8601
    >>> Ox.getISOWeek(new Date("01/01/2000"))
    52
    >>> Ox.getISOWeek(new Date("01/02/2000"))
    52
    >>> Ox.getISOWeek(new Date("01/03/2000"))
    1
    */
    date = Ox.makeDate(date);
    // set date to Thursday of the same week
    return Math.floor((Ox.getDayOfTheYear(Ox.setDate(
        date, Ox.getDate(date, utc) - Ox.getISODay(date, utc) + 4, utc
    ), utc) - 1) / 7) + 1;
};

Ox.getISOYear = function(date, utc) {
    /*
    see http://en.wikipedia.org/wiki/ISO_8601
    >>> Ox.getISOYear(new Date("01/01/2000"))
    1999
    >>> Ox.getISOYear(new Date("01/02/2000"))
    1999
    >>> Ox.getISOYear(new Date("01/03/2000"))
    2000
    */
    date = Ox.makeDate(date);
    // set date to Thursday of the same week
    return Ox.getFullYear(Ox.setDate(
        date, Ox.getDate(date, utc) - Ox.getISODay(date, utc) + 4, utc
    ));
};

Ox.getTime = function() {
    // fixme: needed?
    return +new Date();
}

Ox.getTimezoneOffset = function() {
    return new Date().getTimezoneOffset() * 60000;
}

Ox.getTimezoneOffsetString = function(date) {
    /*
    Time zone offset string ('-1200' - '+1200')
    >>> Ox.getTimezoneOffsetString(new Date('01/01/2000')).length
    5
    */
    var offset = (Ox.makeDate(date)).getTimezoneOffset();
    return (offset < 0 ? '+' : '-') +
        Ox.pad(Math.floor(Math.abs(offset) / 60), 2) +
        Ox.pad(Math.abs(offset) % 60, 2);
};

Ox.getWeek = function(date, utc) {
    /*
    Week of the year (0-53, Sunday as first day)
    >>> Ox.getWeek(new Date("01/01/2000"))
    0
    >>> Ox.getWeek(new Date("01/02/2000"))
    1
    >>> Ox.getWeek(new Date("01/03/2000"))
    1
    */
    date = Ox.makeDate(date);
    return Math.floor((Ox.getDayOfTheYear(date, utc) +
        Ox.getFirstDayOfTheYear(date, utc) - 1) / 7);
};

Ox.isLeapYear = function(year, utc) {
    /*
    >>> Ox.isLeapYear(1900)
    false
    >>> Ox.isLeapYear('2000')
    true
    >>> Ox.isLeapYear(new Date('01/01/2004'))
    true
    */
    year = Ox.makeYear(year, utc);
    return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
};

Ox.makeDate = function(date) {
    return Ox.isDate(date) ? date :
        Ox.isUndefined(date) ? new Date() : new Date(date);
};

Ox.makeYear = function(date, utc) {
    return Ox.isDate(date) ? Ox.getFullYear(date, utc) : parseInt(date);
};

[
    'FullYear', 'Month', 'Date', 'Day',
    'Hours', 'Minutes', 'Seconds', 'Milliseconds'
].forEach(function(noun) {
    Ox['get' + noun] = function(date, utc) {
        return Ox.makeDate(date)['get' + (utc ? 'UTC' : '') + noun]()
    }
    Ox['set' + noun] = function(date, num, utc) {
        // new Date(date) makes a clone, so that
        // setSomething() doesn't have side effects
        return new Date(
            Ox.makeDate(date)
        )['set' + (utc ? 'UTC' : '') + noun](num);
        // fixme: maybe we _want_ set to have side effects?
    }
});

/*
================================================================================
DOM functions
================================================================================
*/

/*@
Ox.canvas <function> Generic canvas object
    Returns an object with the properties: <code>canvas</code>,
    <code>context</code>, <code>data</code> and <code>imageData</code>.
    # Usage --------------------------------------------------------------------
    Ox.canvas(width, height) -> <object> canvas
    Ox.canvas(image)         -> <object> canvas
    # Arguments ----------------------------------------------------------------
    width  <n> Width in px
    height <n> Height in px
    image  <e> Image object
@*/

Ox.canvas = function() {
    // Ox.canvas(img) or Ox.canvas(width, height)
    var c = {}, isImage = arguments.length == 1,
        image = isImage ? arguments[0] : {
            width: arguments[0], height: arguments[1]
        };
    c.context = (c.canvas = Ox.element('<canvas>').attr({
        width: image.width, height: image.height
    })[0]).getContext('2d');
    isImage && c.context.drawImage(image, 0, 0);
    c.data = (c.imageData = c.context.getImageData(
        0, 0, image.width, image.height
    )).data;
    return c;
};

/*@
Ox.documentReady <function> Calls a callback function once the DOM is ready
    (callback) -> <boolean> If true, the document was ready
    callback <function> Callback function
@*/
Ox.documentReady = (function() {
    var callbacks = [];
    document.onreadystatechange = function() {
        if (document.readyState == 'complete') {
            //Ox.print('document has become ready', callbacks);
            callbacks.forEach(function(callback) {
                callback();
            });
            delete callbacks;
        }
    };
    return function(callback) {
        if (document.readyState == 'complete') {
            callback();
            return true;
        } else {
            callbacks.push(callback);
            return false;
        }
    }
}());

/*@
Ox.element <f> Generic HTML element, mimics jQuery
    (str) -> <o> Element object
    str <s> Tagname ('<tagname>') or selector ('tagname', '.classname', '#id')
    > Ox.element("<div>").addClass("red").addClass("red")[0].classname
    "red"
    > Ox.element("<div>").attr({id: "red"}).attr("id")
    "red"
    > Ox.element("<div>").css("color", "red").css("color")
    "red"
    > Ox.element("<div>").html("red").html()
    "red"
@*/
Ox.element = function(str) {
    return {
        //@ 0 <e> The DOM element itself
        0: str[0] == '<' ? document.createElement(str.substr(1, str.length - 2)) :
            str[0] == '.' ? document.getElementsByClassName(str.substr(1))[0] :
            str[0] == '#' ? document.getElementById(str.substr(1)) :
            document.getElementsByTagName(str)[0],
        /*@
        addClass <f> Adds a class name
            (className) -> <o> This element
            className <s> Class name
        @*/
        addClass: function(str) {
            this[0].className = this[0].className ? Ox.unique(
                (this[0].className + ' ' + str).split(' ')
            ) : str;
            return this;
        },
        /*@
        append <f> Appends another element to this element
            (element) -> <o> This element
            element <o> Another element
        @*/
        append: function(element) {
            this[0].appendChild(element[0]);
            return this;
        },
        /*@
        appendTo <f> appends this element object to another element object
            (element) -> <o> This element
            element <o> Another element
        @*/
        appendTo: function(element) {
            element[0].appendChild(this[0]);
            return this;
        },
        /*@
        attr <f> Gets or sets an attribute
            (key)          -> <s> Value
            (key, value)   -> <o> This element
            ({key, value}) -> <o> This element
            key   <str> Attribute name
            value <str> Attribute value
        @*/
        attr: function() {
            var ret, that = this;
            if (arguments.length == 1 && Ox.isString(arguments[0])) {
                ret = this[0].getAttribute(arguments[0]);
            } else {
                Ox.forEach(Ox.makeObject(arguments), function(v, k) {
                    that[0].setAttribute(k, v);
                });
                ret = this;
            }
            return ret;
        },
        /*@
        css <f> Gets or sets a CSS attribute
            (key)          -> <s> Value
            (key, value)   -> <o> This element
            ({key, value}) -> <o> This element
            key   <str> Attribute name
            value <str> Attribute value
        @*/
        css: function() {
            var ret, that = this;
            if (arguments.length == 1 && Ox.isString(arguments[0])) {
                ret = this[0].style[arguments[0]];
            } else {
                Ox.forEach(Ox.makeObject(arguments), function(v, k) {
                    that[0].style[k] = v;
                });
                ret = this;
            }
            return ret;
        },
        /*@
        html <f> Gets or sets the inner HTML
            ()     -> <s> The inner HTML
            (html) -> <o> This element
            html <s> The inner HTML
        @*/
        html: function(str) {
            var ret;
            if (Ox.isUndefined(str)) {
                ret = this[0].innerHTML;
            } else {
                this[0].innerHTML = str;
                ret = this;
            }
            return ret;
        },
        /*@
        mousedown <f> Binds a function to the mousedown event
            (callback) -> <o> This element
            callback <f> Callback function
                event <o> The DOM event
        @*/
        mousedown: function(callback) {
            this[0].onmousedown = callback;
            return this;
        },
        /*@
        removeClass <f> Removes a class name
            (className) -> <o> This element
            className <s> Class name
        @*/
        removeClass: function(str) {
            this[0].className = Ox.filter(
                this[0].className.split(' '), function(className) {
                    return className != str;
                }
            ).join(' ');
            return this;
        }
    }
};

/*
================================================================================
Encoding functions
================================================================================
*/

(function() {

    var aliases = {'I': '1', 'L': '1', 'O': '0', 'U': 'V'},
        digits = '0123456789ABCDEFGHJKMNPQRSTVWXYZ';

    function cap(width, height) {
        // returns maximum encoding capacity of an image
        return parseInt(width * height * 3/8) - 4;
    }

    function seek(data, px) {
        // returns this, or the next, opaque pixel
        while (data[px * 4 + 3] < 255) {
            if (++px * 4 == data.length) {
                throwPNGError('de');
            }
        }
        return px;
    }

    function xor(byte) {
        // returns "1"-bits-in-byte % 2
        var xor = 0;
        Ox.range(8).forEach(function(i) {
            xor ^= byte >> i & 1;
        });
        return xor;
    }

    function throwPNGError(str) {
        throw new RangeError(
            'PNG codec can\'t ' +
            (str == 'en' ? 'encode data' : 'decode image')
        );
    }

    function throwUTF8Error(byte, pos) {
        throw new RangeError(
            'UTF-8 codec can\'t decode byte 0x' +
            byte.toString(16).toUpperCase() + ' at position ' + pos
        );
    }

    Ox.encodeBase32 = function(num) {
        // see http://www.crockford.com/wrmg/base32.html
        /*
        >>> Ox.encodeBase32(15360)
        'F00'
        >>> Ox.encodeBase32(33819)
        '110V'
        */
        return Ox.map(num.toString(32), function(char) {
            return digits[parseInt(char, 32)];
        }).join('');
    }

    Ox.decodeBase32 = function(str) {
        /*
        >>> Ox.decodeBase32('foo')
        15360
        >>> Ox.decodeBase32('ilou')
        33819
        >>> Ox.decodeBase32('?').toString()
        'NaN'
        */
        return parseInt(Ox.map(str.toUpperCase(), function(char) {
            var index = digits.indexOf(aliases[char] || char);
            return (index == -1 ? ' ' : index).toString(32);
        }).join(''), 32);
    }

    Ox.encodeBase64 = function(num) {
        /*
        >>> Ox.encodeBase64(32394)
        'foo'
        */
        return btoa(Ox.encodeBase256(num)).replace(/=/g, '');
    }

    Ox.decodeBase64 = function(str) {
        /*
        >>> Ox.decodeBase64('foo')
        32394
        */
        return Ox.decodeBase256(atob(str));
    }

    Ox.encodeBase128 = function(num) {
        /*
        >>> Ox.encodeBase128(1685487)
        'foo'
        */
        var str = '';
        while (num) {
            str = Ox.char(num & 127) + str;
            num >>= 7;
        }
        return str;
    }

    Ox.decodeBase128 = function(str) {
        /*
        >>> Ox.decodeBase128('foo')
        1685487
        */
        var num = 0, len = str.length;
        Ox.forEach(str, function(char, i) {
            num += char.charCodeAt(0) << (len - i - 1) * 7;
        });
        return num;
    }

    Ox.encodeBase256 = function(num) {
        /*
        >>> Ox.encodeBase256(6713199)
        'foo'
        */
        var str = '';
        while (num) {
            str = Ox.char(num & 255) + str;
            num >>= 8;
        }
        return str;
    }

    Ox.decodeBase256 = function(str) {
        /*
        >>> Ox.decodeBase256('foo')
        6713199
        */
        var num = 0, len = str.length;
        Ox.forEach(str, function(char, i) {
            num += char.charCodeAt(0) << (len - i - 1) * 8;
        });
        return num;
    }

    Ox.encodeDeflate = function(str) {
        // encodes string, using deflate
        /*
        in fact, the string is written to the rgb channels of a canvas element,
        then the dataURL is decoded from base64, and some head and tail cut off
        */
        str = Ox.encodeUTF8(str);
        var len = str.length, c = Ox.canvas(Math.ceil((4 + len) / 3), 1), data;
        str = Ox.pad(Ox.encodeBase256(len), 4, Ox.char(0)) + str +
                Ox.repeat('\u00FF', (4 - len % 4) % 4); // simpler? Ox.pad()?
        /* fixme: why does map not work here?
        c.data = $.map(c.data, function(v, i) {
            return i % 4 < 3 ? str.charCodeAt(i - parseInt(i / 4)) : 255;
        });
        */
        for (i = 0; i < c.data.length; i += 1) {
            c.data[i] = i % 4 < 3 ? str.charCodeAt(i - parseInt(i / 4)) : 255;
        }
        c.context.putImageData(c.imageData, 0, 0);
        Ox.print(c.canvas.toDataURL())
        data = atob(c.canvas.toDataURL().split(',')[1]);
        Ox.print('data', data);
        return data.substr(8, data.length - 20);
    }

    Ox.decodeDeflate = function(str) {
        var image = new Image();
        image.src = 'data:image/png;base64,' + btoa('\u0089PNG\r\n\u001A\n' +
                str + Ox.repeat('\u0000', 4) + 'IEND\u00AEB`\u0082');
        Ox.print(image.src);
        while (!image.width) {} // block until image data is available
        str = Ox.map(Ox.canvas(image).data, function(v, i) {
            return i % 4 < 3 ? Ox.char(v) : '';
        }).join('');
        return Ox.decodeUTF8(str.substr(4, Ox.decodeBase256(str.substr(0, 4))));
    }

    Ox.encodeHTML = function(str) {
        /*
        >>> Ox.encodeHTML('\'<"&">\'')
        '&apos;&lt;&quot;&amp;&quot;&gt;&apos;'
        >>> Ox.encodeHTML('äbçdê')
        '&#x00E4;b&#x00E7;d&#x00EA;'
        */
        return Ox.map(str, function(v) {
            var code = v.charCodeAt(0);
            return code < 128 ? (v in Ox.HTML_ENTITIES ? Ox.HTML_ENTITIES[v] : v) :
                '&#x' + Ox.pad(code.toString(16).toUpperCase(), 4) + ';';
        }).join('');
    };

    Ox.decodeHTML = function(str) {
        /*
        >>> Ox.decodeHTML('&apos;&lt;&quot;&amp;&quot;&gt;&apos;')
        '\'<"&">\''
        >>> Ox.decodeHTML('&#x0027;&#x003C;&#x0022;&#x0026;&#x0022;&#x003E;&#x0027;')
        '\'<"&">\''
        >>> Ox.decodeHTML('&auml;b&ccedil;d&ecirc;')
        'äbçdê'
        >>> Ox.decodeHTML('&#x00E4;b&#x00E7;d&#x00EA;')
        'äbçdê'
        */
        // relies on dom, but shorter than using this:
        // http://www.w3.org/TR/html5/named-character-references.html 
        return Ox.element('<div>').html(str)[0].childNodes[0].nodeValue;
    };

    Ox.encodePNG = function(img, str) {
        // encodes string into image, returns new image url
        /*
        the message is compressed with deflate (by proxy of canvas),
        then the string (four bytes length) + (length bytes message)
        is encoded bitwise into the r/g/b bytes of all opaque pixels
        by flipping, if necessary, the least significant bit, so that
        (number of "1"-bits of the byte) % 2 is the bit of the string
        wishlist:
        - only use deflate if it actually shortens the message
        - in deflate, strip and later re-insert the chunk types
        - encode a decoy message into the least significant bit
          (and flip the second least significant bit, if at all)
        - write an extra png chunk containing some key
        */
        //str = Ox.encodeDeflate(str); currently broken
        str = Ox.encodeUTF8(str);
        var c = Ox.canvas(img), len = str.length, px = 0;
        if (len == 0 || len > cap(img.width, img.height)) {
            throwPNGError('en')
        }
        len = Ox.pad(Ox.encodeBase256(len), 4, Ox.char(0));
        Ox.forEach(Ox.map(len + str, function(byte) {
            return Ox.map(Ox.range(8), function(i) {
                return byte.charCodeAt(0) >> 7 - i & 1;
            }).join('');
        }).join(''), function(bit, i) {
            var index = parseInt((px = seek(c.data, px)) * 4 + i % 3),
                byte = c.data[index];
            c.data[index] = bit == xor(byte) ? byte :
                    byte & 254 | !(byte & 1);
            px += i % 3 == 2;
        });
        c.context.putImageData(c.imageData, 0, 0);
        return c.canvas.toDataURL();
    }

    Ox.decodePNG = function(img) {
        // decodes image, returns string
        var bits = '', data = Ox.canvas(img).data, flag = false, i = 0,
            len = 4, max = cap(img.width, img.height), px = 0, str = '';
        do {
            bits += xor(data[parseInt((px = seek(data, px)) * 4 + i % 3)]);
            px += i % 3 == 2;
            if (++i % 8 == 0) {
                str += Ox.char(parseInt(bits, 2));
                bits = '';
                len--;
                if (len == 0 && !flag) {
                    len = Ox.decodeBase256(str);
                    if (len <= 0 || len > max) {
                        Ox.print(len);
                        throwPNGError('de');
                    }
                    str = '';
                    flag = true;
                }
            }
        } while (len);
        try {
            //return Ox.decodeDeflate(str); currently broken
            return Ox.decodeUTF8(str);
        } catch(e) {
            Ox.print(e.toString());
            throwPNGError('de');
        }
    }

    Ox.encodeUTF8 = function(str) {
        /*
        see http://en.wikipedia.org/wiki/UTF-8
        >>> Ox.encodeUTF8('foo')
        'foo'
        >>> Ox.encodeUTF8('¥€$')
        '\u00C2\u00A5\u00E2\u0082\u00AC\u0024'
        */
        return Ox.map(str, function(chr) {
            var code = chr.charCodeAt(0),
                str = '';
            if (code < 128) {
                str = chr;
            } else if (code < 2048) {
                str = String.fromCharCode(code >> 6 | 192) +
                    String.fromCharCode(code & 63 | 128);
            } else {
                str = String.fromCharCode(code >> 12 | 224) +
                    String.fromCharCode(code >> 6 & 63 | 128) +
                    String.fromCharCode(code & 63 | 128);
            }
            return str;
        }).join('');
    }

    Ox.decodeUTF8 = function(str) {
        /*
        >>> Ox.decodeUTF8('foo')
        'foo'
        >>> Ox.decodeUTF8('\u00C2\u00A5\u00E2\u0082\u00AC\u0024')
        '¥€$'
        */
        var bytes = Ox.map(str, function(v) {
                return v.charCodeAt(0);
            }),
            i = 0,
            len = str.length,
            str = '';
        while (i < len) {
            if (bytes[i] <= 128) {
                str += String.fromCharCode(bytes[i]);
                i++;
            } else if (
                bytes[i] >= 192 && bytes[i] < 240 &&
                i < len - (bytes[i] < 224 ? 1 : 2)
            ) {
                if (bytes[i + 1] >= 128 && bytes[i + 1] < 192) {
                    if (bytes[i] < 224) {
                        str += String.fromCharCode((bytes[i] & 31) << 6 |
                            bytes[i + 1] & 63);
                        i += 2;
                    } else if (bytes[i + 2] >= 128 && bytes[i + 2] < 192) {
                        str += String.fromCharCode((bytes[i] & 15) << 12 |
                            (bytes[i + 1] & 63) << 6 | bytes[i + 2] & 63);
                        i += 3;
                    } else {
                        throwUTF8Error(bytes[i + 2], i + 2);
                    }
                } else {
                    throwUTF8Error(bytes[i + 1], i + 1);
                }
            } else {
                throwUTF8Error(bytes[i], i);
            }
        }
        return str;
    };

})();

/*
================================================================================
Format functions
================================================================================
*/

Ox.formatArea = function(num, dec) {
    return Ox.formatNumber(Ox.round(num / 1000000, dec)) + ' km\u00B2';
}

Ox.formatColor = function() {
    
};

Ox.formatCurrency = function(num, str, dec) {
    /*
    >>> Ox.formatCurrency(1000, '$', 2)
    '$1,000.00'
    */
    return str + Ox.formatNumber(num, dec);
};

Ox.formatDate = function(date, str, utc) {
    // fixme: date and utc are optional, date can be date, number or string

    /*
    See http://developer.apple.com/documentation/Darwin/Reference/ManPages/man3/strftime.3.html
    and http://en.wikipedia.org/wiki/ISO_8601
    >>> _date = new Date("2005-01-02 00:03:04")
    "Sun Jan 02 2005 00:03:04 GMT+0100 (CET)"
    >>> Ox.formatDate(_date, "%A") // Full weekday
    "Sunday"
    >>> Ox.formatDate(_date, "%a") // Abbreviated weekday
    "Sun"
    >>> Ox.formatDate(_date, "%B") // Full month
    "January"
    >>> Ox.formatDate(_date, "%b") // Abbreviated month
    "Jan"
    >>> Ox.formatDate(_date, "%C") // Century
    "20"
    >>> Ox.formatDate(_date, "%c") // US time and date
    "01/02/05 12:03:04 AM"
    >>> Ox.formatDate(_date, "%D") // US date
    "01/02/05"
    >>> Ox.formatDate(_date, "%d") // Zero-padded day of the month
    "02"
    >>> Ox.formatDate(_date, "%e") // Space-padded day of the month
    " 2"
    >>> Ox.formatDate(_date, "%F") // Date
    "2005-01-02"
    >>> Ox.formatDate(_date, "%G") // Full ISO-8601 year
    "2004"
    >>> Ox.formatDate(_date, "%g") // Abbreviated ISO-8601 year
    "04"
    >>> Ox.formatDate(_date, "%H") // Zero-padded hour (24-hour clock)
    "00"
    >>> Ox.formatDate(_date, "%h") // Abbreviated month
    "Jan"
    >>> Ox.formatDate(_date, "%I") // Zero-padded hour (12-hour clock)
    "12"
    >>> Ox.formatDate(_date, "%j") // Zero-padded day of the year
    "002"
    >>> Ox.formatDate(_date, "%k") // Space-padded hour (24-hour clock)
    " 0"
    >>> Ox.formatDate(_date, "%l") // Space-padded hour (12-hour clock)
    "12"
    >>> Ox.formatDate(_date, "%M") // Zero-padded minute
    "03"
    >>> Ox.formatDate(_date, "%m") // Zero-padded month
    "01"
    >>> Ox.formatDate(_date, "%n") // Newline
    "\n"
    >>> Ox.formatDate(_date, "%p") // AM or PM
    "AM"
    >>> Ox.formatDate(_date, "%Q") // Quarter of the year
    "1"
    >>> Ox.formatDate(_date, "%R") // Zero-padded hour and minute
    "00:03"
    >>> Ox.formatDate(_date, "%r") // US time
    "12:03:04 AM"
    >>> Ox.formatDate(_date, "%S") // Zero-padded second
    "04"
    >/> Ox.formatDate(_date, "%s") // Number of seconds since the Epoch
    "1104620584"
    >>> Ox.formatDate(_date, "%T") // Time
    "00:03:04"
    >>> Ox.formatDate(_date, "%t") // Tab
    "\t"
    >>> Ox.formatDate(_date, "%U") // Zero-padded week of the year (00-53, Sunday as first day)
    "01"
    >>> Ox.formatDate(_date, "%u") // Decimal weekday (1-7, Monday as first day)
    "7"
    >>> Ox.formatDate(_date, "%V") // Zero-padded ISO-8601 week of the year
    "53"
    >>> Ox.formatDate(_date, "%v") // Formatted date
    " 2-Jan-2005"
    >>> Ox.formatDate(_date, "%W") // Zero-padded week of the year (00-53, Monday as first day)
    "00"
    >>> Ox.formatDate(_date, "%w") // Decimal weekday (0-6, Sunday as first day)
    "0"
    >>> Ox.formatDate(_date, "%X") // US time
    "12:03:04 AM"
    >>> Ox.formatDate(_date, "%x") // US date
    "01/02/05"
    >>> Ox.formatDate(_date, "%Y") // Full year
    "2005"
    >>> Ox.formatDate(_date, "%y") // Abbreviated year
    "05"
    >/> Ox.formatDate(_date, "%Z") // Time zone name
    "CET"
    >/> Ox.formatDate(_date, "%z") // Time zone offset
    "+0100"
    >/> Ox.formatDate(_date, "%+") // Formatted date and time
    "Sun Jan  2 00:03:04 CET 2005"
    >>> Ox.formatDate(_date, "%%")
    "%"
    >>> delete _date
    true
    >>> Ox.formatDate(new Date("01/01/2000"), "%W")
    "00"
    >>> Ox.formatDate(new Date("01/02/2000"), "%W")
    "00"
    >>> Ox.formatDate(new Date("01/03/2000"), "%W")
    "01"
    */

    date = Ox.makeDate(date);
    var format = [
        ['%', function() {return '%{%}';}],
        ['c', function() {return '%x %X';}],
        ['X', function() {return '%r';}],
        ['x', function() {return '%D';}],
        ['D', function() {return '%m/%d/%y';}],
        ['F', function() {return '%Y-%m-%d';}],
        ['h', function() {return '%b';}],
        ['R', function() {return '%H:%M';}],
        ['r', function() {return '%I:%M:%S %p';}],
        ['T', function() {return '%H:%M:%S';}],
        ['v', function() {return '%e-%b-%Y';}],
        ['\\+', function() {return '%a %b %e %H:%M:%S %Z %Y';}],
        ['A', function(d) {return Ox.WEEKDAYS[(Ox.getDay(d, utc) + 6) % 7];}],
        ['a', function(d) {return Ox.SHORT_WEEKDAYS[(Ox.getDay(d, utc) + 6) % 7];}],
        ['B', function(d) {return Ox.MONTHS[Ox.getMonth(d, utc)];}],
        ['b', function(d) {return Ox.SHORT_MONTHS[Ox.getMonth(d, utc)];}],
        ['C', function(d) {return Math.floor(Ox.getFullYear(d, utc) / 100).toString();}],
        ['d', function(d) {return Ox.pad(Ox.getDate(d, utc), 2);}],
        ['e', function(d) {return Ox.pad(Ox.getDate(d, utc), 2, ' ');}],
        ['G', function(d) {return Ox.getISOYear(d, utc);}],
        ['g', function(d) {return Ox.getISOYear(d, utc).toString().substr(-2);}],
        ['H', function(d) {return Ox.pad(Ox.getHours(d, utc), 2);}],
        ['I', function(d) {return Ox.pad((Ox.getHours(d, utc) + 11) % 12 + 1, 2);}],
        ['j', function(d) {return Ox.pad(Ox.getDayOfTheYear(d, utc), 3);}],
        ['k', function(d) {return Ox.pad(Ox.getHours(d, utc), 2, ' ');}],
        ['l', function(d) {return Ox.pad(((Ox.getHours(d, utc) + 11) % 12 + 1), 2, ' ');}],
        ['M', function(d) {return Ox.pad(Ox.getMinutes(d, utc), 2);}],
        ['m', function(d) {return Ox.pad((Ox.getMonth(d, utc) + 1), 2);}],
        ['p', function(d) {return Ox.AMPM[Math.floor(Ox.getHours(d, utc) / 12)];}],
        ['Q', function(d) {return Math.floor(Ox.getMonth(d, utc) / 4) + 1;}],
        ['S', function(d) {return Ox.pad(Ox.getSeconds(d, utc), 2);}],
        ['s', function(d) {return Math.floor(d.getTime() / 1000);}],
        ['U', function(d) {return Ox.pad(Ox.getWeek(d, utc), 2);}],
        ['u', function(d) {return Ox.getISODay(d, utc);}],
        ['V', function(d) {return Ox.pad(Ox.getISOWeek(d, utc), 2);}],
        ['W', function(d) {return Ox.pad(Math.floor((Ox.getDayOfTheYear(d, utc) +
            (Ox.getFirstDayOfTheYear(d, utc) || 7) - 2) / 7), 2);}],
        ['w', function(d) {return Ox.getDay(d, utc);}],
        ['Y', function(d) {return Ox.getFullYear(d, utc);}],
        ['y', function(d) {return Ox.getFullYear(d, utc).toString().substr(-2);}],
        ['Z', function(d) {return d.toString().split('(')[1].replace(')', '');}],
        ['z', function(d) {return Ox.getTimezoneOffsetString(d);}],
        ['n', function() {return '\n';}],
        ['t', function() {return '\t';}],
        ['\\{%\\}', function() {return '%';}]
    ];
    format.forEach(function(v) {
        var regexp = new RegExp('%' + v[0], 'g');
        if (regexp.test(str)) {
            str = str.replace(regexp, v[1](date));
        }
    });
    return str;
};

Ox.formatDuration = function(sec, dec, format) {
    /*
    >>> Ox.formatDuration(123456.789, 3)
    "1:10:17:36.789"
    >>> Ox.formatDuration(12345.6789)
    "03:25:46"
    >>> Ox.formatDuration(12345.6789, true)
    "0:03:25:46"
    >>> Ox.formatDuration(3599.999, 3)
    "00:59:59.999"
    >>> Ox.formatDuration(3599.999)
    "01:00:00"
    */
    var format = arguments.length == 3 ? format : (Ox.isString(dec) ? dec : "short"),
        dec = (arguments.length == 3 || Ox.isNumber(dec)) ? dec : 0,
        sec = dec ? sec : Math.round(sec),
        val = [
            Math.floor(sec / 31536000),
            Math.floor(sec % 31536000 / 86400),
            Math.floor(sec % 86400 / 3600),
            Math.floor(sec % 3600 / 60),
            format == "short" ? Ox.formatNumber(sec % 60, dec) : sec % 60
        ],
        str = {
            medium: ["y", "d", "h", "m", "s"],
            long: ["year", "day", "hour", "minute", "second"]
        },
        pad = [0, 3, 2, 2, dec ? dec + 3 : 2];
    while (!val[0] && val.length > (format == "short" ? 3 : 1)) {
        val.shift();
        str.medium.shift();
        str.long.shift();
        pad.shift();
    }
    while (format != "short" && !val[val.length - 1] && val.length > 1) {
        val.pop();
        str.medium.pop();
        str.long.pop();
    }
    return Ox.map(val, function(v, i) {
        return format == "short" ? Ox.pad(v, pad[i]) :
                v + (format == "long" ? " " : "") + str[format][i] +
                (format == "long" && v != 1 ? "s" : "");
    }).join(format == "short" ? ":" : " ");
};

Ox.formatNumber = function(num, dec) {
    /*
    >>> Ox.formatNumber(123456789, 3)
    "123,456,789.000"
    >>> Ox.formatNumber(-2000000 / 3, 3)
    "-666,666.667"
    >>> Ox.formatNumber(666666.666)
    "666,667"
    */
    var str = Math.abs(num).toFixed(dec || 0),
        spl = str.split('.'),
        arr = [];
    while (spl[0]) {
        arr.unshift(spl[0].substr(-3));
        spl[0] = spl[0].substr(0, spl[0].length - 3);
    }
    spl[0] = arr.join(',');
    return (num < 0 ? '-' : '') + spl.join('.');
};

Ox.formatOrdinal = function(num) {
    /*
    >>> Ox.formatOrdinal(1)
    "1st"
    >>> Ox.formatOrdinal(2)
    "2nd"
    >>> Ox.formatOrdinal(3)
    "3rd"
    >>> Ox.formatOrdinal(4)
    "4th"
    >>> Ox.formatOrdinal(11)
    "11th"
    >>> Ox.formatOrdinal(12)
    "12th"
    >>> Ox.formatOrdinal(13)
    "13th"
    */
    var str = num.toString(),
        end = str[str.length - 1],
        ten = str.length > 1 && str[str.length - 2] == '1';
    if (end == '1' && !ten) {
        str += 'st';
    } else if (end == '2' && !ten) {
        str += 'nd';
    } else if (end == '3' && !ten) {
        str += 'rd';
    } else {
        str += 'th';
    }
    return str;
};

Ox.formatPercent = function(num, total, dec) {
    /*
    >>> Ox.formatPercent(1, 1000, 2)
    "0.10%"
    */
    return Ox.formatNumber(num / total * 100, dec) + '%'
};

Ox.formatResolution = function(arr, str) {
    /*
    >>> Ox.formatResolution([1920, 1080], 'px')
    "1920 x 1080 px"
    */
    return arr[0] + ' x ' + arr[1] + (str ? ' ' + str : '');
}

Ox.formatString = function (str, obj) {
    /* 
    >>> Ox.formatString('{0}{1}', ['foo', 'bar'])
    "foobar"
    >>> Ox.formatString('{a}{b}', {a: 'foo', b: 'bar'})
    "foobar"
    */
    return str.replace(/\{([^}]+)\}/g, function(str, match) {
        return obj[match];
    });
}

Ox.formatValue = function(num, str, bin) {
    /*
    >>> Ox.formatValue(0, "B")
    "0 KB"
    >>> Ox.formatValue(123456789, "B")
    "123.5 MB"
    >>> Ox.formatValue(1234567890, "B", true)
    "1.15 GiB"
    */
    var base = bin ? 1024 : 1000,
        len = Ox.PREFIXES.length,
        val;
    Ox.forEach(Ox.PREFIXES, function(chr, i) {
        if (num < Math.pow(base, i + 2) || i == len - 1) {
            val = Ox.formatNumber(num / Math.pow(base, i + 1), i) +
                ' ' + chr + (bin ? 'i' : '') + str;
            return false;
        }
    });
    return val;
};

Ox.formatUnit = function(num, str) {
    return num + ' ' + str;
};

/*
================================================================================
Geo functions
================================================================================
*/

(function() {

    function rad(point) {
        return {
            lat: Ox.rad(point.lat),
            lng: Ox.rad(point.lng)
        };
    }

    Ox.crossesDateline = function(point0, point1) {
        return point0.lng > point1.lng;
    }

    Ox.getArea = function(point0, point1) {
        /*
            area of a ring between two latitudes:
            2 * PI * r^2 * abs(sin(lat0) - sin(lat1))
            see http://mathforum.org/library/drmath/view/63767.html
        */
        /*
        2 * Math.PI *
        Math.pow(Ox.EARTH_RADIUS, 2) *
        Math.abs(Math.sin(Ox.rad(0)) - Math.sin(Ox.rad(1))) *
        Math.abs(Ox.rad(0) - Ox.rad(1)) /
        (2 * Math.PI)
        */
        if (Ox.crossesDateline(point0, point1)) {
            point1.lng += 360;
        }
        var point0 = rad(point0),
            point1 = rad(point1);
        return Math.pow(Ox.EARTH_RADIUS, 2) *
            Math.abs(Math.sin(point0.lat) - Math.sin(point1.lat)) *
            Math.abs(point0.lng - point1.lng);
    };

    Ox.getBearing = function(point0, point1) {
        /*
        >>> Ox.getBearing({lat: -45, lng: 0}, {lat: 45, lng: 0})
        0
        */
        var point0 = rad(point0),
            point1 = rad(point1),
            x = Math.cos(point0.lat) * Math.sin(point1.lat) -
                Math.sin(point0.lat) * Math.cos(point1.lat) *
                Math.cos(point1.lng - point0.lng),
            y = Math.sin(point1.lng - point0.lng) *
                Math.cos(point1.lat);
        return (Ox.deg(Math.atan2(y, x)) + 360) % 360;
    };

    Ox.getCenter = function(point0, point1) {
        /*
        >>> Ox.values(Ox.getCenter({lat: -45, lng: -90}, {lat: 45, lng: 90}))
        [0, 0]
        */
        var point0 = rad(point0),
            point1 = rad(point1),
            x = Math.cos(point1.lat) *
                Math.cos(point1.lng - point0.lng),
            y = Math.cos(point1.lat) *
                Math.sin(point1.lng - point0.lng),
            d = Math.sqrt(
                Math.pow(Math.cos(point0.lat) + x, 2) + Math.pow(y, 2)
            ),
            lat = Ox.deg(
                Math.atan2(Math.sin(point0.lat) + Math.sin(point1.lat), d)
            ),
            lng = Ox.deg(
                point0.lng + Math.atan2(y, Math.cos(point0.lat) + x)
            );
        return {lat: lat, lng: lng};
    };

    Ox.getDegreesPerMeter = function(lat) {
        /***
        return degrees per meter at a given latitude
        >>> Ox.EARTH_CIRCUMFERENCE == 360 / Ox.getDegreesPerMeter(0)
        true
        ***/
        return 360 / Ox.EARTH_CIRCUMFERENCE / Math.cos(lat * Math.PI / 180);
    };

    Ox.getDistance = function(point0, point1) {
        /*
        >>> Ox.EARTH_CIRCUMFERENCE == Ox.getDistance({lat: -45, lng: -90}, {lat: 45, lng: 90}) * 2
        true
        */
        var point0 = rad(point0),
            point1 = rad(point1);
        return Math.acos(
    	    Math.sin(point0.lat) * Math.sin(point1.lat) + 
    	    Math.cos(point0.lat) * Math.cos(point1.lat) *
    	    Math.cos(point1.lng - point0.lng)
    	) * Ox.EARTH_RADIUS;
    };

    Ox.getLatLngByXY = function(xy) {
        /*
        >>> Ox.values(Ox.getLatLngByXY({x: 0.5, y: 0.5}))
        [0, 0]
        */
        function getVal(val) {
            return (val - 0.5) * 2 * Math.PI;
        }
        return {
            lat: -Ox.deg(Math.atan(Ox.sinh(getVal(xy.y)))),
            lng: Ox.deg(getVal(xy.x))
        }
    };

    Ox.getMetersPerDegree = function(lat) {
        /***
        returns meters per degree at a given latitude
        >>> Ox.EARTH_CIRCUMFERENCE == Ox.getMetersPerDegree(0) * 360
        true
        ***/
        return Math.cos(lat * Math.PI / 180) * Ox.EARTH_CIRCUMFERENCE / 360;
    };

    Ox.getXYByLatLng = function(latlng) {
        /*
        >>> Ox.values(Ox.getXYByLatLng({lat: 0, lng: 0}))
        [0.5, 0.5]
        */
        function getVal(val) {
            return (val / (2 * Math.PI) + 0.5)
        }
        return {
            x: getVal(Ox.rad(latlng.lng)),
            y: getVal(Ox.asinh(Math.tan(Ox.rad(-latlng.lat))))
        };
    };

}());

Ox.Line = function(point0, point1) {

    var self = {
            points: [point0, point1]
        },
        that = this;

    function rad() {
        return self.points.map(function(point) {
            return {
                lat: Ox.rad(point.lat()),
                lng: Ox.rad(point.lng())
            };
        });
    }

    that.getArea = function() {
        
    };

    that.getBearing = function() {
    };

    that.getDistance = function() {
        var points = rad();
        return Math.acos(
    	    Math.sin(point[0].lat) * Math.sin(point[1].lat) + 
    	    Math.cos(point[0].lat) * Math.cos(point[1].lat) *
    	    Math.cos(point[1].lng - point[0].lng)
    	) * Ox.EARTH_RADIUS; 
    };

    that.getMidpoint = function() {
        var points = rad(),
            x = Math.cos(point[1].lat) *
                Math.cos(point[1].lng - point[0].lng),
            y = Math.cos(point[1].lat) *
                Math.sin(point[1].lng - point[0].lng),
            d = Math.sqrt(
                Math.pow(Math.cos(point[0].lat) + x, 2) + Math.pow(y, 2)
            ),
            lat = Ox.deg(
                Math.atan2(Math.sin(points[0].lat) + Math.sin(points[1].lat), d)
            ),
            lng = Ox.deg(
                points[0].lng + Math.atan2(y, math.cos(points[0].lat) + x)
            );
        return new Point(lat, lng);
    };

    that.points = function() {
        
    };

    return that;

};

Ox.Point = function(lat, lng) {

    var self = {lat: lat, lng: lng},
        that = this;

    that.lat = function() {
        
    };

    that.latlng = function() {
        
    };

    that.lng = function() {
        
    };

    that.getMetersPerDegree = function() {
        return Math.cos(self.lat * Math.PI / 180) *
            Ox.EARTH_CIRCUMFERENCE / 360;
    }

    that.getXY = function() {
        return [
            getXY(Ox.rad(self.lng)),
            getXY(Ox.asinh(Math.tan(Ox.rad(-self.lat))))
        ];
    };

    return that;

};

Ox.Rectangle = function(point0, point1) {

    var self = {
            points: [
                new Point(
                    Math.min(point0.lat(), point1.lat()),
                    point0.lng()
                ),
                new Point(
                    Math.max(point0.lat(), point1.lat()),
                    point1.lng()
                )
            ]
        },
        that = this;

    that.contains = function(rectangle) {
        
    }

    that.crossesDateline = function() {
        return self.points[0].lng > self.points[1].lng;
    }

    that.getCenter = function() {
        return new Ox.Line(self.points[0], self.points[1]).getMidpoint();
    };

    that.intersects = function(rectangle) {
        
    };

    return that;

};


/*
================================================================================
HTML functions
================================================================================
*/

Ox.parseEmailAddresses = function(html) {
    return html.replace(
        /\b([0-9A-Z\.\+\-_]+@(?:[0-9A-Z\-]+\.)+[A-Z]{2,6})\b/gi,
        '<a href="mailto:$1" title="mailto:$1">$1</a>'
    );
};

Ox.parseHTML = (function() {
    /*
    >>> Ox.parseHTML('http://foo.com, bar')
    '<a href="http://foo.com" title="http://foo.com">foo.com</a>, bar'
    >>> Ox.parseHTML('(see: www.foo.com)')
    '(see: <a href="http://www.foo.com" title="http://www.foo.com">www.foo.com</a>)'
    >>> Ox.parseHTML('foo@bar.com')
    '<a href="mailto:foo@bar.com" title="mailto:foo@bar.com">foo@bar.com</a>'
    >>> Ox.parseHTML('<a href="http://foo.com" onmouseover="alert()">foo</a>')
    '<a href="http://foo.com" title="http://foo.com">foo</a>'
    >>> Ox.parseHTML('<a href="javascript:alert()">foo</a>')
    '&lt;a href=&quot;javascript:alert()&quot;&gt;foo&lt;/a&gt;'
    >>> Ox.parseHTML('[http://foo.com foo]')
    '<a href="http://foo.com" title="http://foo.com">foo</a>'
    >>> Ox.parseHTML('<rtl>foo</rtl>')
    '<div style="direction: rtl">foo</div>'
    >>> Ox.parseHTML('<script>alert()</script>')
    '&lt;script&gt;alert()&lt;/script&gt;'
    */
    var defaultTags = [
            'a', 'b', 'blockquote', 'cite', 'code',
            'del', 'em', 'i', 'img', 'ins',
            'li', 'ol', 'q', 'rtl', 's',
            'strong', 'sub', 'sup', 'ul', '[]'
        ],
        parse = {
            a: {
                '<a [^<>]*?href="(https?:\/\/.+?)".*?>': '<a href="{1}" title="{1}">',
                '<\/a>': '</a>'
            },
            img: {
                '<img [^<>]*?src="(https?:\/\/.+?)".*?>': '<img src="{1}">'
            },
            rtl: {
                '<rtl>': '<div style="direction: rtl">',
                '<\/rtl>': '</div>'
            },
            '*': function(tag) {
                var ret = {};
                ret['<(/?' + tag + ')>'] = '<{1}>';
                return ret;
            }
        },
        tab = '\t';

    return function(html, tags, wikilinks) {
        var matches = [],
            tags = tags || defaultTags;
        // html = Ox.clean(html); fixme: can this be a parameter?
        if (tags.indexOf('[]') > -1) {
            html = html.replace(/\[(https?:\/\/.+?) (.+?)\]/gi, '<a href="$1">$2</a>');
            tags = tags.filter(function(tag) {
                return tag != '[]';
            });
        }
        tags.forEach(function(tag) {
            var p = parse[tag] || parse['*'](tag);
            Ox.forEach(p, function(replace, regexp) {
                html = html.replace(new RegExp(regexp, 'gi'), function() {
                    matches.push(Ox.formatString(replace, arguments));
                    return tab + (matches.length - 1) + tab; 
                });
            });
        });
        html = Ox.encodeHTML(html);
        html = Ox.parseURLs(html);
        html = Ox.parseEmailAddresses(html);
        matches.forEach(function(match, i) {
            html = html.replace(new RegExp(tab + i + tab, 'gi'), match);
        });
        html = html.replace(/\n/g, '<br/>\n')
        // close extra opening (and remove extra closing) tags
        // return $('<div>').html(html).html();
        // fixme: this converts '&quot;' to '"' 
        return Ox.element('<div>').html(html).html();
    }

}());

Ox.parseURL = (function() {
    // fixme: leak memory, like now, or create every time? ... benchmark??
    var a = document.createElement('a'),
        keys = ['hash', 'host', 'hostname', 'origin',
            'pathname', 'port', 'protocol', 'search'];
    return function(str) {
        var ret = {};
        a.href = str;
        keys.forEach(function(key) {
            ret[key] = a[key];
        });
        return ret;
    };
}());

Ox.parseURLs = function(html) {
    return html.replace(
        /\b((https?:\/\/|www\.).+?)([\.,:;!\?\)\]]*?(\s|$))/gi,
        function(str, url, pre, end) {
            url = (pre == 'www.' ? 'http://' : '' ) + url;
            return Ox.formatString(
                '<a href="{url}" title="{url}">{host}</a>{end}',
                {
                    end: end,
                    host: Ox.parseURL(url).hostname,
                    url: url
                }
            );
        }
    );
};

/*
================================================================================
Math functions
================================================================================
*/

Ox.asinh = function(x) {
    /*
    fixme: no test
    */
    return Math.log(x + Math.sqrt(x * x + 1));
};

Ox.deg = function(rad) {
    /*
    >>> Ox.deg(2 * Math.PI)
    360
    */
    return rad * 180 / Math.PI;
};

Ox.divideInt = function(num, by) {
    /*
    >>> Ox.divideInt(100, 3)
    [33, 33, 34]
    >>> Ox.divideInt(100, 6)
    [16, 16, 17, 17, 17, 17]
    */
    var arr = [],
        div = parseInt(num / by),
        mod = num % by,
        i;
    for (i = 0; i < by; i++) {
        arr[i] = div + (i > by - 1 - mod);
    }
    return arr;
}

Ox.limit = function(num, min, max) {
    /*
    >>> Ox.limit(1, 2, 3)
    2
    >>> Ox.limit(2, 1)
    1
    */
    var len = arguments.length;
    max = arguments[len - 1];
    min = len == 3 ? min : 0;
    return Math.min(Math.max(num, min), max);
};

Ox.log = function(num, base) {
    /*
    >>> Ox.log(100, 10)
    2
    >>> Ox.log(Math.E)
    1
    */
    return Math.log(num) / Math.log(base || Math.E);
};

Ox.mod = function(num, by) {
    /*
    >>> Ox.mod(11, 10)
    1
    >>> Ox.mod(-11, 10)
    9
    */
    var mod = num % by;
    return mod >= 0 ? mod : mod + by;
};

Ox.rad = function(deg) {
    /*
    >>> Ox.rad(360)
    2 * Math.PI
    */
    return deg * Math.PI / 180;
};

Ox.random = function() {
    /*
    >>> Ox.random(3) in {0: 0, 1: 0, 2: 0, 3: 0}
    true
    >>> Ox.random(1, 2) in {1: 0, 2: 0}
    true
    */
    var len = arguments.length,
        min = len == 1 ? 0 : arguments[0],
        max = arguments[len - 1];
    return min + parseInt(Math.random() * (max - min + 1));
};

Ox.round = function(num, dec) {
    /*
    >>> Ox.round(2 / 3, 6)
    0.666667
    >>> Ox.round(1 / 2, 3)
    0.5
    */
    var pow = Math.pow(10, dec || 0);
    return Math.round(num * pow) / pow;
};

Ox.sinh = function(x) {
    /*
    fixme: no test
    */
    return (Math.exp(x) - Math.exp(-x)) / 2;
};

Ox.MAX_LATITUDE = Ox.deg(Math.atan(Ox.sinh(Math.PI)));
Ox.MIN_LATITUDE = -Ox.MAX_LATITUDE;

/*
================================================================================
RegExp functions
================================================================================
*/

Ox.regexp = {
    'accents': '¨´`ˆ˜',
    'letters': 'a-z¨´`ˆ˜äåáàâãæçëéèèñïíìîöóòôõøœßúùûÿ'
};

/*
================================================================================
String functions
================================================================================
*/

Ox.basename = function(str) {
    /*
    fixme: this should go into Path functions
    >>> Ox.basename("foo/bar/foo.bar")
    "foo.bar"
    >>> Ox.basename("foo.bar")
    "foo.bar"
    */
    return str.replace(/^.*[\/\\]/g, '');
};

Ox.char = String.fromCharCode;

Ox.clean = function(str) {
    /*
    >>> Ox.clean("foo  bar")
    "foo bar"
    >>> Ox.clean(" foo  bar ")
    "foo bar"
    >>> Ox.clean(" foo \n bar ")
    "foo\nbar"
    */
    return Ox.map(str.split('\n'), function(str) {
        return Ox.trim(str.replace(/\s+/g, ' '));
    }).join('\n');
};

Ox.contains = function(str, chr) {
    /*
    >>> Ox.contains("foo", "bar")
    false
    >>> Ox.contains("foobar", "bar")
    true
    >>> Ox.contains(['foo', 'bar'], 'foo')
    true
    // fixme: rename to Ox.has or Ox.isIn?
    // then it'd become convenient for arrays
    */
    return str.indexOf(chr) > -1;
};

Ox.endsWith = function(str, sub) {
    /*
    >>> Ox.endsWith("foobar", "bar")
    true
    */
    return new RegExp(sub + '$').test(str);
};

Ox.highlight = function(txt, str) {
    // fixme: move to ox.ui
    return str ? txt.replace(
        new RegExp('(' + str + ')', 'ig'),
        '<span class="OxHighlight">$1</span>'
    ) : txt;
};

Ox.isValidEmail = function(str) {
    /*
    >>> Ox.isValidEmail("foo@bar.com")
    true
    >>> Ox.isValidEmail("foo.bar@foobar.co.uk")
    true
    >>> Ox.isValidEmail("foo@bar")
    false
    >>> Ox.isValidEmail("foo@bar..com")
    false
    */
    return !!/^[0-9A-Z\.\+\-_]+@(?:[0-9A-Z\-]+\.)+[A-Z]{2,6}$/i(str);
}

Ox.pad = function(str, len, pad, pos) {
    // fixme: slighly obscure signature
    // fixme: weird for negative numbers
    /*
    >>> Ox.pad(1, 2)
    "01"
    >>> Ox.pad("abc", 6, ".", "right")
    "abc..."
    >>> Ox.pad("foobar", 3, ".", "right")
    "foo"
    >>> Ox.pad("abc", 6, "123456", "right")
    "abc123"
    >>> Ox.pad("abc", 6, "123456", "left")
    "456abc"
    */
    str = str.toString().substr(0, len);
    pad = Ox.repeat(pad || '0', len - str.length);
    pos = pos || 'left';
    str = pos == 'left' ? pad + str : str + pad;
    str = pos == 'left' ?
        str.substr(str.length - len, str.length) :
        str.substr(0, len);
    return str;
};

Ox.repeat = function(obj, num) {
    /*
    works for arrays, numbers and strings
    >>> Ox.repeat(1, 3)
    "111"
    >>> Ox.repeat("foo", 3)
    "foofoofoo"
    >>> Ox.repeat([1, 2], 3)
    [1, 2, 1, 2, 1, 2]
    */
    var ret;
    if (Ox.isArray(obj)) {
        ret = num >= 1 ? Ox.map(Ox.range(obj.length * num), function(v, i) {
            return obj[i % obj.length]
        }) : [];
    } else {
        ret = num >= 1 ? new Array(num + 1).join(obj.toString()) : '';
    }
    return ret;
};

Ox.reverse = function(str) {
    /*
    Ox.reverse("foo")
    oof
    */
    return str.toString().split('').reverse().join('');
};

Ox.startsWith = function(str, sub) {
    /*
    >>> Ox.startsWith("foobar", "foo")
    true
    // fixme:
    // !!(/^sub/(str)) is shorter than
    // Ox.startsWith(str, sub) anyway
    // new RegExp('^' + sub).test(str) is longer though...
    */
    return new RegExp('^' + sub).test(str);
};

Ox.stripTags = function(str) {
    /*
    >>> Ox.stripTags("f<span>o</span>o")
    "foo"
    */
    return str.replace(/(<.*?>)/gi, '');
};

Ox.substr = function(str, start, stop) {
    /***
    Ox.substr behaves like str[start:stop] in Python
    (or like str.substring() with negative values for stop)
    // fixme: needed?
    >>> Ox.substr('foobar', 1)
    "oobar"
    >>> Ox.substr('foobar', -1)
    "r"
    >>> Ox.substr('foobar', 1, 3)
    "oo"
    >>> Ox.substr('foobar', -3, 5)
    "ba"
    >>> Ox.substr('foobar', 1, -2)
    "oob"
    >>> Ox.substr('foobar', -4, -1)
    "oba"
    ***/
    stop = Ox.isUndefined(stop) ? str.length : stop;
    return str.substring(
        start < 0 ? str.length + start : start,
        stop < 0 ? str.length + stop : stop
    );
};

Ox.toCamelCase = function(str) {
    /*
    >>> Ox.toCamelCase("foo-bar-baz")
    "fooBarBaz"
    >>> Ox.toCamelCase("foo/bar/baz")
    "fooBarBaz"
    >>> Ox.toCamelCase("foo_bar_baz")
    "fooBarBaz"
    */
    return str.replace(/[\-_\/][a-z]/g, function(str) {
        return str[1].toUpperCase();
    });
};

Ox.toDashes = function(str) {
    /*
    >>> Ox.toDashes("fooBarBaz")
    "foo-bar-baz"
    */
    return str.replace(/[A-Z]/g, function(str) {
        return '-' + str.toLowerCase();
    });
};

Ox.tokenize = (function() {

    // see https://github.com/mozilla/narcissus/blob/master/lib/jslex.js
    // and https://developer.mozilla.org/en/JavaScript/Reference

    var identifier = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_',
        linebreak = '\n\r',
        number = '0123456789',
        operator = [
            // arithmetic
            '+', '-', '*', '/', '%', '++', '--',
            // assignment
            '=', '+=', '-=', '*=', '/=', '%=',
            '&=', '|=', '^=', '<<=', '>>=', '>>>=',
            // bitwise
            '&', '|', '^', '~', '<<', '>>', '>>>',
            // comparison
            '==', '!=', '===', '!==', '>', '>=', '<', '<=',
            // conditional
            '?', ':',
            // grouping
            '(', ')', '[', ']', '{', '}',
            // logical
            '&&', '||', '!',
            // other
            '.', ',', ';'
        ],
        whitespace = ' \t',
        word = {
            constant: [
                // Math
                'E', 'LN2', 'LN10', 'LOG2E', 'LOG10E', 'PI', 'SQRT1_2', 'SQRT2',
                // Number
                'MAX_VALUE', 'MIN_VALUE', 'NEGATIVE_INFINITY', 'POSITIVE_INFINITY'
            ],
            keyword: [
                'break',
                'case', 'catch', 'class', 'const', 'continue',
                'debugger', 'default', 'delete', 'do',
                'else', 'enum', 'export', 'extends',
                'false', 'finally', 'for', 'function',
                'if', 'implements', 'import', 'in', 'instanceof', 'interface',
                'let', 'module',
                'new', 'null',
                'package', 'private', 'protected', 'public',
                'return',
                'super', 'switch', 'static',
                'this', 'throw', 'true', 'try', 'typeof',
                'var', 'void',
                'yield',
                'while', 'with',
            ],
            method: [
                // Array
                'concat',
                'every',
                'filter', 'forEach',
                'join',
                'lastIndexOf',
                'indexOf', 'isArray',
                'map',
                'pop', 'push',
                'reduce', 'reduceRight', 'reverse',
                'shift', 'slice', 'some', 'sort', 'splice',
                'unshift',
                // Date
                'getDate', 'getDay', 'getFullYear', 'getHours', 'getMilliseconds',
                'getMinutes', 'getMonth', 'getSeconds', 'getTime', 'getTimezoneOffset',
                'getUTCDate', 'getUTCDay', 'getUTCFullYear', 'getUTCHours', 'getUTCMilliseconds',
                'getUTCMinutes', 'getUTCMonth', 'getUTCSeconds',
                'now',
                'parse',
                'setDate', 'setFullYear', 'setHours', 'setMilliseconds', 'setMinutes',
                'setMonth', 'setSeconds', 'setTime',
                'setUTCDate', 'setUTCFullYear', 'setUTCHours', 'setUTCMilliseconds', 'setUTCMinutes',
                'setUTCMonth', 'setUTCSeconds',
                'toDateString', 'toJSON', 'toLocaleDateString', 'toLocaleString', 'toLocaleTimeString',
                'toTimeString', 'toUTCString',
                'UTC',
                // Function
                'apply', 'bind', 'call', 'isGenerator',
                // JSON
                'parse', 'stringify',
                // Math
                'abs', 'acos', 'asin', 'atan', 'atan2',
                'ceil', 'cos',
                'exp',
                'floor',
                'log',
                'max', 'min',
                'pow',
                'random', 'round',
                'sin', 'sqrt',
                'tan',
                // Number
                'toExponential', 'toFixed', 'toLocaleString', 'toPrecision',
                // Object
                'create',
                'defineProperty', 'defineProperties',
                'freeze',
                'getOwnPropertyDescriptor', 'getOwnPropertyNames', 'getPrototypeOf',
                'hasOwnProperty',
                'isExtensible', 'isFrozen', 'isPrototypeOf', 'isSealed',
                'keys',
                'preventExtensions', 'propertyIsEnumerable',
                'seal',
                'toLocaleString', 'toString',
                'valueOf',
                // RegExp
                'exec', 'test',
                // String
                'charAt', 'charCodeAt', 'concat',
                'fromCharCode',
                'indexOf',
                'lastIndexOf', 'localeCompare',
                'match',
                'replace',
                'search', 'slice', 'split', 'substr', 'substring',
                'toLocaleLowerCase', 'toLocaleUpperCase', 'toLowerCase', 'toUpperCase', 'trim'
            ],
            object: [
                'Array',
                'Boolean',
                'Date', 'decodeURI', 'decodeURIComponent',
                'encodeURI', 'encodeURIComponent', 'Error', 'eval', 'EvalError',
                'Function',
                'Infinity', 'isFinite', 'isNaN',
                'JSON',
                'Math',
                'NaN', 'Number',
                'Object',
                'parseFloat', 'parseInt',
                'RangeError', 'ReferenceError', 'RegExp',
                'String', 'SyntaxError',
                'TypeError',
                'undefined', 'URIError',
                'window'
            ],
            property: [
                // Function
                'constructor', 'length', 'prototype',
                // RegExp
                'global', 'ignoreCase', 'lastIndex', 'multiline', 'source'
            ]
        };

    return function(source) {

        //source = source.replace(/\r\n/g, '\n').replace(/\r/g, '\n');

        var cursor = 0,
            tokenize = {
                comment: function() {
                    while (char = source[++cursor]) {
                        if (next == '/' && char == '\n') {
                            break;
                        } else if (next == '*' && char == '*' && source[cursor + 1] == '/') {
                            cursor += 2;
                            break;
                        }
                    }
                },
                identifier: function() {
                    var str;
                    while (identifier.indexOf(source[++cursor]) > -1) {}
                    str = source.substring(start, cursor);
                    Ox.forEach(word, function(value, key) {
                        if (value.indexOf(str) > -1) {
                            type = key;
                            return false;
                        }
                    });
                },
                linebreak: function() {
                    while (linebreak.indexOf(source[++cursor]) > -1) {}
                },
                number: function() {
                    while ((number + '.').indexOf(source[++cursor]) > -1) {}
                },
                operator: function() {
                    if (operator.indexOf(char + source[++cursor]) > -1) {
                        if (operator.indexOf(char + next + source[++cursor]) > 1) {
                            ++cursor;
                        }
                    }
                },
                regexp: function() {
                    while ((char = source[++cursor]) != '/') {
                        char == '\\' && ++cursor;
                        if (cursor == source.length) {
                            break;
                        }
                    }
                    while (identifier.indexOf(source[++cursor]) > -1) {}
                },
                string: function() {
                    var delimiter = char;
                    while ((char = source[++cursor]) != delimiter) {
                        char == '\\' &&  ++cursor;
                        if (cursor == source.length) {
                            break;
                        }
                    }
                    ++cursor;
                },
                whitespace: function() {
                    while (whitespace.indexOf(source[++cursor]) > -1) {}
                }
            },
            tokens = [],
            type;

        while (cursor < source.length) {
            var char = source[cursor],
                next = source[cursor + 1],
                start = cursor;
            if (char == '/' && (next == '/' || next == '*')) {
                type = 'comment';
            } else if (identifier.indexOf(char) > -1) {
                type = 'identifier';
            } else if (linebreak.indexOf(char) > -1) {
                type = 'linebreak';
            } else if (number.indexOf(char) > -1) {
                type = 'number';
            } else if (char == "'" || char == '"') {
                type = 'string';
            } else if (whitespace.indexOf(char) > -1) {
                type = 'whitespace';
            } else if (char == '/') {
                type = isRegExp() ? 'regexp' : 'operator';
            } else if (operator.indexOf(char) > -1) {
                type = 'operator';
            }
            tokenize[type]();
            tokens.push({
                length: cursor - start,
                offset: start,
                type: type,
            });
        }

        function isRegExp() {
            // checks if a forward slash is the beginning of a regexp,
            // as opposed to the beginning of an operator
            // see http://www.mozilla.org/js/language/js20-2000-07/rationale/syntax.html#regular-expressions
            var index = tokens.length,
                isRegExp = false
                offset = 0;
            // scan back to the previous significant token,
            // or the beginning of the source
            while (
                typeof tokens[--index] != 'undefined' &&
                ['comment', 'linebreak', 'whitespace'].indexOf(tokens[index].type) > -1
            ) {
                offset += tokens[index].length;
            }
            if (typeof tokens[index] == 'undefined') {
                // source begins with forward slash
                isRegExp = true;
            } else {
                prevToken = tokens[index];
                prevString = source.substr(cursor - prevToken.length - offset, prevToken.length);
                isRegExp = (
                    prevToken.type == 'keyword' &&
                    ['false', 'null', 'true'].indexOf(prevString) == -1
                ) || (
                    prevToken.type == 'operator' && 
                    ['++', '--', ')', ']', '}'].indexOf(prevString) == -1
                );
            }
            return isRegExp;
        }

        return tokens;

    };

}()); 

Ox.toSlashes = function(str) {
    /*
    >>> Ox.toSlashes("fooBarBaz")
    "foo/bar/baz"
    */
    return str.replace(/[A-Z]/g, function(str) {
        return '/' + str.toLowerCase();
    });
};

Ox.toTitleCase = function(str) {
    /*
    >>> Ox.toTitleCase("foo")
    "Foo"
    >>> Ox.toTitleCase("Apple releases iPhone, IBM stock plummets")
    "Apple Releases iPhone, IBM Stock Plummets"
    */
    return Ox.map(str.split(' '), function(v) {
        var sub = v.substr(1),
            low = sub.toLowerCase();
        if (sub == low) {
            v = v.substr(0, 1).toUpperCase() + low;
        }
        return v;
    }).join(" ");
};

Ox.toUnderscores = function(str) {
    /*
    >>> Ox.toUnderscores("fooBarBaz")
    "foo_bar_baz"
    */
    return str.replace(/[A-Z]/g, function(str) {
        return '_' + str.toLowerCase();
    });
};

Ox.trim = function(str) { // is in jQuery, and in JavaScript itself
    /*
    Ox.trim(" foo ")
    "foo"
    */
    return str.replace(/^\s+|\s+$/g, "");
};

Ox.truncate = function(str, len, pad, pos) {
    /*
    >>> Ox.truncate("anticonstitutionellement", 16, "...", "center")
    "anticon...lement"
    */
    var pad = pad || {},
        pos = pos || "right",
        strlen = str.length,
        padlen = pad.length,
        left, right;
    if (strlen > len) {
        if (pos == "left") {
            str = pad + str.substr(padlen + strlen - len);
        } else if (pos == "center") {
            left = Math.ceil((len - padlen) / 2);
            right = Math.floor((len - padlen) / 2);
            str = str.substr(0, left) + pad + str.substr(-right);
        } else if (pos == "right") {
            str = str.substr(0, len - padlen) + pad;
        }
    }
    return str;
};

Ox.words = function(str) {
    /*
    > Ox.words("The key/value pairs are read-only--aren't they?")
    ["the", "key", "value", "pairs", "are", "read-only", "aren't", "they"]
    */
    var arr = str.toLowerCase().split(/\b/),
        chr = "-'",
        len = arr.length,
        startsWithWord = !!/\w/(arr[0]);
    arr.forEach(function(v, i) {
        // find single occurrences of "-" or "-"
        // that are not at the beginning or end of the string
        // and join the surrounding words with them
        if (
            i > 0 && i < len - 1 &&
            v.length == 1 && chr.indexOf(v) > -1
        ) {
            arr[i + 1] = arr[i - 1] + arr[i] + arr[i + 1];
            arr[i - 1] = arr[i] = '';
        }
    });
    // remove elements that have been emptied above
    arr = arr.filter(function(v) {
        return v.length;
    });
    // return words, not spaces or punctuation
    return arr.filter(function(v, i) {
        return i % 2 == !startsWithWord;
    });
}

Ox.wordwrap = function(str, len, sep, bal, spa) {
    // fixme: bad API, sep/bal/spa should be in options object
    /*
    >>> Ox.wordwrap("Anticonstitutionellement, Paris s'eveille", 25, "<br/>")
    "Anticonstitutionellement, <br/>Paris s'eveille"
    >>> Ox.wordwrap("Anticonstitutionellement, Paris s'eveille", 16, "<br/>")
    "Anticonstitution<br/>ellement, Paris <br/>s'eveille"
    >>> Ox.wordwrap("These are short words", 16, "<br/>", true)
    "These are <br/>short words"
    */
    var str = str === null ? '' : str.toString(),
        len = len || 80,
        sep = sep || "<br/>",
        bal = bal || false,
        spa = Ox.isUndefined(spa) ? true : spa,
        words = str.split(" "),
        lines;
    if (bal) {
        // balance lines: test if same number of lines
        // can be achieved with a shorter line length
        lines = Ox.wordwrap(str, len, sep, false).split(sep);
        if (lines.length > 1) {
            // test shorter line, unless
            // that means cutting a word
            var max = Ox.max(Ox.map(words, function(word) {
                return word.length;
            }));
            while (len > max) {
                len--;
                if (Ox.wordwrap(str, len, sep, false).split(sep).length > lines.length) {
                    len++;
                    break;
                }
            }
        }
    }
    lines = [""];
    Ox.forEach(words, function(word) {
        if ((lines[lines.length - 1] + word + " ").length <= len + 1) {
            // word fits in current line
            lines[lines.length - 1] += word + " ";
        } else {
            if (word.length <= len) {
                // word fits in next line
                lines.push(word + " ");
            } else {
                // word is longer than line
                var chr = len - lines[lines.length - 1].length;
                lines[lines.length - 1] += word.substr(0, chr);
                for (var pos = chr; pos < word.length; pos += len) {
                    lines.push(word.substr(pos, len));
                }
                lines[lines.length - 1] += " ";
            }
        }
    });
    if (!spa) {
        lines = Ox.map(lines, function(line) {
            return Ox.trim(line);
        });
    }
    return Ox.trim(lines.join(sep));    
};

/*
================================================================================
Type functions
================================================================================
*/

Ox.isArguments = function(val) {
    /*
    >>> Ox.isArguments((function() { return arguments; }()))
    true
    */
    return !!(val && val.toString() == '[object Arguments]');
}

Ox.isArray = function(val) { // is in jQuery
    /*
    >>> Ox.isArray([])
    true
    */
    return val instanceof Array;
}

Ox.isBoolean = function(val) {
    /*
    >>> Ox.isBoolean(false)
    true
    */
    return typeof val == 'boolean';
};

Ox.isDate = function(val) {
    /*
    >>> Ox.isDate(new Date())
    true
    */
    return val instanceof Date;
};

Ox.isElement = function(val) {
    /*
    >>> Ox.isElement(document.createElement())
    true
    */
    return !!(val && val.nodeType == 1);
};

Ox.isFunction = function(val) { // is in jQuery
    /*
    >>> Ox.isFunction(function() {})
    true
    >>> Ox.isFunction(/ /)
    false
    */
    return typeof val == 'function' && !Ox.isRegExp(val);
};

Ox.isInfinity = function(val) {
    /*
    >>> Ox.isInfinity(Infinity)
    true
    >>> Ox.isInfinity(-Infinity)
    true
    >>> Ox.isInfinity(NaN)
    false
    */
    return typeof val == 'number' && !isFinite(val) && !Ox.isNaN(val);
};

Ox.isNaN = function(val) {
    /*
    >>> Ox.isNaN(NaN)
    true
    */
    return val !== val;
}

Ox.isNull = function(val) {
    /*
    >>> Ox.isNull(null)
    true
    */
    return val === null;
};

Ox.isNumber = function(val) {
    /*
    >>> Ox.isNumber(0)
    true
    >>> Ox.isNumber(Infinity)
    false
    >>> Ox.isNumber(-Infinity)
    false
    >>> Ox.isNumber(NaN)
    false
    */
    return typeof val == 'number' && isFinite(val);
};

Ox.isObject = function(val) {
    /*
    >>> Ox.isObject({})
    true
    >>> Ox.isObject([])
    false
    >>> Ox.isObject(new Date())
    false
    >>> Ox.isObject(null)
    false
    */
    return typeof val == 'object' && !Ox.isArguments(val) &&
        !Ox.isArray(val) && !Ox.isDate(val) && !Ox.isNull(val);
};

Ox.isRegExp = function(val) {
    /*
    >>> Ox.isRegExp(/ /)
    true
    */
    return val instanceof RegExp;
};

Ox.isString = function(val) {
    /*
    >>> Ox.isString('')
    true
    */
    return typeof val == 'string';
};

/*@
Ox.isUndefined <f> Tests if a value is undefined
    (value) -> <b> If true, the value is undefined
    value <*> any value
    > Ox.isUndefined()
    true
@*/

Ox.isUndefined = function(val) {
    // fixme: void 0 is also nice
    return typeof val == 'undefined';
};

/*@
Ox.typeOf <f> Returns the type of a value
    (value) -> <s> type
    value <*> Any value
    # Examples
    > (function() { return Ox.typeOf(arguments); }())
    "arguments"
    > Ox.typeOf([])
    "array"
    > Ox.typeOf(false)
    "boolean"
    > Ox.typeOf(new Date())
    "date"
    > Ox.typeOf(document.createElement())
    "element"
    > Ox.typeOf(function() {})
    "function"
    > Ox.typeOf(Infinity)
    "infinity"
    > Ox.typeOf(NaN)
    "nan"
    > Ox.typeOf(null)
    "null"
    > Ox.typeOf(0)
    "number"
    > Ox.typeOf({})
    "object"
    > Ox.typeOf(/ /)
    "regexp"
    > Ox.typeOf('')
    "string"
    > Ox.typeOf()
    "undefined"
@*/

Ox.typeOf = function(val) {
    var ret;
    Ox.forEach(Ox.TYPES, function(type) {
        if (Ox['is' + type](val)) {
            ret = type.toLowerCase();
            return false;
        }
    });
    return ret;
};