'use strict';

/*@
Ox.api <f> Turns an array into a list API
    <code>Ox.api</code> takes an array and returns a function that allows you to
    run complex queries against it. See the examples below for details.
    (items, options) -> <f> List API
    items <[o]> An array of objects (key/value stores)
    options <o> Options object
        enums <o> Enumerables, for example <code>{size: ['S', 'M', 'L', 'XL']}</code>
        sums <[s]> List of keys to be included in totals
        unique <s|'id'> The name of the unique key
    <script>
        Ox.test.api = Ox.api([
            {id: 'foo', n: 2},
            {id: 'bar', n: 2},
            {id: 'baz', n: 1}
        ], {
            sums: ['n']
        });
        Ox.test.apiResults = {
            0: Ox.test.api(),
            1: Ox.test.api({
                keys: []
            }),
            2: Ox.test.api({
                keys: ['id'],
                sort: ['-n', '+id']
            }),
            3: Ox.test.api({
                keys: [],
                query: {
                    conditions: [
                        {key: 'id', operator: '!^', value: 'f'},
                        {key: 'n', operator: '>', value: 1}
                    ],
                    operator: '&'
                }
            }),
            4: Ox.test.api({
                keys: [],
                query: {
                    conditions: [
                        {key: 'id', operator: '=', value: 'O'},
                        {key: 'n', operator: '=', value: [1, 2]}
                    ],
                    operator: '|'
                },
                sort: ['+id']
            }),
            5: Ox.test.api({
                keys: [],
                query: {
                    conditions: [
                        {key: 'id', operator: '=', value: 'f'},
                        {
                            conditions: [
                                {key: 'id', operator: '=', value: 'a'},
                                {key: 'id', operator: '=', value: 'z'}
                            ],
                            operator: '&'
                        }
                    ],
                    operator: '|'
                },
                sort: ['+id']
            }),
            6: Ox.test.api({
                keys: [],
                range: [1, 2],
                sort: ['+id']
            }),
            7: Ox.test.api({
                positions: ['foo', 'bar'],
                sort: ['+id']
            })
        };
        Ox.test.api = Ox.api([
            {i: 0, size: 'S'},
            {i: 1, size: 'M'},
            {i: 2, size: 'L'}
        ], {
            enums: {size: ['S', 'M', 'L']},
            unique: 'i'
        });
        Ox.test.apiResults[8] = Ox.test.api({
            keys: ['size'],
            query: {
                conditions: [{key: 'size', operator: '>=', value: 'M'}],
                operator: '&'
            },
            sort: [{key: 'size', operator: '-'}]
        });
    </script>
    > Ox.test.apiResults[0].data
    {items: 3, n: 5}
    > Ox.test.apiResults[1].data
    {items: [{id: 'foo', n: 2}, {id: 'bar', n: 2}, {id: 'baz', n: 1}]}
    > Ox.test.apiResults[2].data
    {items: [{id: 'bar'}, {id: 'foo'}, {id: 'baz'}]}
    > Ox.test.apiResults[3].data
    {items: [{id: 'bar', n: 2}]}
    > Ox.test.apiResults[4].data
    {items: [{id: 'baz', n: 1}, {id: 'foo', n: 2}]}
    > Ox.test.apiResults[5].data
    {items: [{id: 'baz', n: 1}, {id: 'foo', n: 2}]}
    > Ox.test.apiResults[6].data
    {items: [{id: 'baz', n: 1}]}
    > Ox.test.apiResults[7].data
    {positions: {foo: 2, bar: 0}}
    > Ox.test.apiResults[8].data
    {items: [{i: 2, size: 'L'}, {i: 1, size: 'M'}]}
@*/
Ox.api = function(items, options) {

    var enums = options.enums ? parseEnums(options.enums) : {},
        sums = options.sums || [],
        unique = options.unique || 'id';

    function parseEnums(enums) {
        // make enumerable strings lowercase
        return Ox.map(enums, function(values) {
            return values.map(function(value) {
                return value.toLowerCase();
            });
        });
    }

    function parseConditions(conditions) {
        // make string values lowercase,
        // and replace enumerable strings used with the
        // <, !<, <=, !<=, >, !>, >= or !>= operator
        // with their index
        return conditions.map(function(condition) {
            var key = condition.key,
                operator = condition.operator,
                values = Ox.toArray(condition.value);
            if (condition.conditions) {
                condition.conditions = parseConditions(condition.conditions);
            } else {
                values = values.map(function(value) {
                    if (Ox.isString(value)) {
                        value = value.toLowerCase();
                    }
                    if (enums[key] && (
                        operator.indexOf('<') > -1
                        || operator.indexOf('>') > -1
                    )) {
                        value = enums[key].indexOf(value);
                    }
                    return value;
                });
                condition.value = Ox.isArray(condition.value)
                    ? values : values[0];
            }
            return condition;
        });
    }

    function parseSort(sort) {
        // translate 'foo' to {key: 'foo', operator: '+'}
        return sort.map(function(sort) {
            return Ox.isString(sort) ? {
                key: sort.replace(/^[\+\-]/, ''),
                operator: sort[0] == '-' ? '-' : '+'
            } : sort;
        });
    }

    function testCondition(item, condition) {
        var key = condition.key,
            operator = condition.operator.replace('!', ''),
            value = condition.value,
            not = condition.operator[0] == '!',
            itemValue = item[key],
            test = {
                '=': function(a, b) {
                    return Ox.isArray(b) ? a >= b[0] && a < b[1]
                        : Ox.isString(a) ? a.indexOf(b) > -1
                        : a === b;
                },
                '==': function(a, b) { return a === b; },
                '<': function(a, b) { return a < b; },
                '<=': function(a, b) { return a <= b; },
                '>': function(a, b) { return a > b; },
                '>=': function(a, b) { return a >= b; },
                '^': function(a, b) { return Ox.starts(a, b); },
                '$': function(a, b) { return Ox.ends(a, b); },
            };
        if (Ox.isString(itemValue)) {
            itemValue = itemValue.toLowerCase();
        }
        if (enums[key] && (
            operator.indexOf('<') > -1
            || operator.indexOf('>') > -1
        )) {
            itemValue = enums[key].indexOf(itemValue);
        }
        return test[operator](itemValue, value) == !not;
    }

    function testQuery(item, query) {
        var match = true;
        Ox.forEach(query.conditions, function(condition) {
            if (condition.conditions) {
                match = testQuery(item, condition);
            } else {
                match = testCondition(item, condition)
            }
            if (
                (query.operator == '&' && !match)
                || (query.operator == '|' && match)
            ) {
                return false;
            }
        });
        return match;
    }

    return function(options, callback) {
        var data,
            result = {data: {}, status: {code: 200, text: 'ok'}},
            sort = {};
        options = options || {};
        if (options.query) {
            // find
            options.query.conditions = parseConditions(options.query.conditions);
            result.data.items = items.filter(function(item) {
                return testQuery(item, options.query);
            });
        } else {
            result.data.items = Ox.clone(items);
        }
        if (options.sort) {
            // sort
            options.sort = parseSort(options.sort);
            Ox.forEach(enums, function(values, key) {
                sort[key] = function(value) {
                    return values.indexOf(value.toLowerCase());
                };
            })
            result.data.items = Ox.sortBy(result.data.items, options.sort, sort);
        }
        if (options.positions) {
            // return positions
            data = {positions: {}};
            options.positions.forEach(function(id) {
                data.positions[id] = Ox.getIndex(result.data.items, unique, id)
            });
            result.data = data;
        } else if (!options.keys) {
            // return totals
            data = {};
            sums.forEach(function(key) {
                data[key] = Ox.sum(result.data.items.map(function(item) {
                    return item[key];
                }));
            })
            data.items = result.data.items.length;
            result.data = data;
        } else {
            // return items
            if (!Ox.isEmpty(options.keys)) {
                // filter keys
                if (options.keys.indexOf(unique) == -1) {
                    options.keys.push(unique);
                }
                result.data.items = result.data.items.map(function(item) {
                    var ret = {};
                    options.keys.forEach(function(key) {
                        ret[key] = item[key];
                    });
                    return ret;
                });
            }
            if (options.range) {
                // apply range
                result.data.items = Ox.sub(
                    result.data.items, options.range[0], options.range[1]
                );
            }
        }
        callback && callback(result);
        return result;
    };

};

/*@
Ox.compact <f> Removes <code>null</code> or <code>undefined</code> values
    > Ox.compact([null,,1,,2,,3])
    [1, 2, 3]
@*/
Ox.compact = function(arr) {
    return arr.filter(function(val) {
        return !Ox.isNull(val) && !Ox.isUndefined(val);
    });
};

/*@
Ox.flatten <f> Flattens an array
    > Ox.flatten([1, [2, [3], 2], 1])
    [1, 2, 3, 2, 1]
@*/
Ox.flatten = function(arr) {
    // fixme: can this work for objects too?
    var ret = [];
    arr.forEach(function(val) {
        if (Ox.isArray(val)) {
            Ox.flatten(val).forEach(function(val) {
                ret.push(val);
            });
        } else {
            ret.push(val);
        }
    });
    return ret;
};

/*@ 
Ox.merge <f> Merges an array with one or more other arrays
    For convenience, literals are treated as arrays with one element
    > Ox.merge([1], [2, 3, 2], [1])
    [1, 2, 3, 2, 1]
    > Ox.merge(1, [2, 3, 2], 1)
    [1, 2, 3, 2, 1]
@*/
Ox.merge = function(arr) {
    arr = Ox.toArray(arr);
    Ox.forEach(Array.prototype.slice.call(arguments, 1), function(arg) {
        Ox.forEach(Ox.toArray(arg), function(val) {
            arr.push(val);
        });
    });
    return arr;
};

/*@
Ox.range <f> Python-style range
    (stop) -> <[n]> range
        Returns an array of integers from <code>0</code> (inclusive) to
        <code>stop</code> (exclusive).
    (start, stop) -> <[n]> range
        Returns an array of integers from <code>start</code> (inclusive) to
        <code>stop</code> (exclusive).
    (start, stop, step) -> <[n]> range
        Returns an array of numbers from <code>start</code> (inclusive) to
        <code>stop</code> (exclusive), incrementing by <code>step</code>.
    start <n> Start value
    stop <n> Stop value
    step <n> Step value
    > Ox.range(3)
    [0, 1, 2]
    > Ox.range(1, 4)
    [1, 2, 3]
    > Ox.range(3, 0)
    [3, 2, 1]
    > Ox.range(1, 2, 0.5)
    [1, 1.5]
    > Ox.range(-1, -2, -0.5)
    [-1, -1.5]
@*/
Ox.range = function() {
    var arr = [];
    Ox.loop.apply(null, Ox.merge(Ox.makeArray(arguments), function(i) {
        arr.push(i);
    }));
    return arr;
};

(function() {

    function getSortValues(arr, fn) {
        var arr_ = fn ? arr.map(fn) : arr,
            len, matches = {}, sort = {};
        // find leading numbers
        arr.forEach(function(val, i) {
            var match;
            if (Ox.isString(val)) {
                match = /^\d+/.exec(arr_[i]);
                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, make lowercase,
        // and remove leading non-word characters
        arr.forEach(function(val, i) {
            sort[val] = Ox.isString(arr_[i])
                ? (
                    matches[val]
                    ? arr_[i].replace(
                        matches[val], Ox.pad(matches[val], len)
                    )
                    : arr_[i]
                ).toLowerCase().replace(/^\W+/, '')
                : arr_[i];
        });
        return sort;
    }

    /*@
    Ox.sort <f> Sorts an array, handling leading digits and ignoring capitalization
        (arr) -> <a> Sorted array
        (arr, fn) -> Sorted array
        arr <a> Array
        fn <f|u> Optional map function that returns the value for the array element
        > Ox.sort(['"z"', '10', '9', 'B', 'a'])
        ['9', '10', 'a', 'B', '"z"']
        > Ox.sort([{id: 0, name: '80 Days'}, {id: 1, name: '8 Women'}], function(v) {return v.name})
        [{id: 1, name: '8 Women'}, {id: 0, name: '80 Days'}]
    @*/
    Ox.sort = function(arr, fn) {
        var sort = getSortValues(fn ? arr.map(fn) : arr);
        return arr.sort(function(a, b) {
            a = fn ? fn(a) : a;
            b = fn ? fn(b) : b;
            var ret = 0;
            if (sort[a] < sort[b]) {
                ret = -1;
            } else if (sort[a] > sort[b]) {
                ret = 1;
            }
            return ret;
        });
    };

    /*@
    Ox.sortBy <f> Sorts an array of objects by given properties
        (arr, by) -> <a> Sorted array
        arr <[o]> Array of objects
        by <[s]> Array of object keys (asc: 'foo' or '+foo', desc: '-foo')
        fn <o> Optional functions, per key, that return the sort value
        > Ox.sortBy([{x: 1, y: 1}, {x: 1, y: 2}, {x: 2, y: 2}], ['+x', '-y'])
        [{x: 1, y: 2}, {x: 1, y: 1}, {x: 2, y: 2}]
        > Ox.sortBy([{id: 0, name: '80 Days'}, {id: 1, name: '8 Women'}], ['name'])
        [{id: 1, name: '8 Women'}, {id: 0, name: '80 Days'}]
    @*/
    Ox.sortBy = function(arr, by, fn) {
        var length = by.length, values = {};
        by = by.map(function(v) {
            return Ox.isString(v) ? {
                key: v.replace(/^[\+\-]/, ''),
                operator: v[0] == '-' ? '-' : '+'
            } : v;
        });
        fn = fn || {};
        by.map(function(v) {
            return v.key;
        }).forEach(function(key) {
            values[key] = getSortValues(arr.map(function(v) {
                return v[key];
            }), fn[key]);
        });
        return arr.sort(function(a, b) {
            var aValue, bValue, index = 0, key, ret = 0;
            while (ret == 0 && index < length) {
                key = by[index].key;
                aValue = values[key][a[key]];
                bValue = values[key][b[key]];
                if (aValue < bValue) {
                    ret = by[index].operator == '+' ? -1 : 1;
                } else if (aValue > bValue) {
                    ret = by[index].operator == '+' ? 1 : -1;
                } else {
                    index++;
                }
            }
            return ret;
        });
    };

}());

/*@
Ox.unique <f> Returns an array without duplicate values
    > Ox.unique([1, 2, 3, 2, 1])
    [1, 2, 3]
    > Ox.unique([NaN, NaN])
    []
@*/
Ox.unique = function(arr) {
    return Ox.filter(arr, function(val, i) {
        return arr.indexOf(val) == i;
    });
};

/*@
Ox.zip <f> Zips an array of arrays
    > 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]]
@*/
Ox.zip = function() {
    var args = arguments.length == 1 ? arguments[0] : Ox.makeArray(arguments),
        arr = [];
    args[0].forEach(function(v, i) {
        arr[i] = [];
        args.forEach(function(v) {
            arr[i].push(v[i]);
        });
    });
    return arr;
};