/**
    options
        element         the element the menu is attached to
        id              the menu id
        items           array of menu items
        mainmenu        the main menu this menu is part of, if any
        offset          offset of the menu, in px
        parent          the supermenu, if any
        selected        the position of the selected item
        side            open to 'bottom' or 'right'
        size            'large', 'medium' or 'small'

    events:
        change_groupId  {id, value}     checked item of a group has changed
        click_itemId                    item not belonging to a group was clicked
        click_menuId    {id, value}     item not belonging to a group was clicked
        deselect_menuId {id, value}     item was deselected                             not needed, not implemented
        hide_menuId                     menu was hidden
        select_menuId   {id, value}     item was selected
*/
Ox.Menu = function(options, self) {

    var self = self || {},
        that = new Ox.Element({}, self)
            .defaults({
                element: null,
                id: '',
                items: [],
                mainmenu: null,
                offset: {
                    left: 0,
                    top: 0
                },
                parent: null,
                selected: -1,
                side: 'bottom',
                size: 'medium',
            })
            .options(options || {})
            .addClass(
                'OxMenu Ox' + Ox.toTitleCase(self.options.side) +
                ' Ox' + Ox.toTitleCase(self.options.size)
            )
            .click(click)
            .mouseenter(mouseenter)
            .mouseleave(mouseleave)
            .mousemove(mousemove)
            .bindEvent({
                key_up: selectPreviousItem,
                key_down: selectNextItem,
                key_left: selectSupermenu,
                key_right: selectSubmenu,
                key_escape: hideMenu,
                key_enter: clickSelectedItem
            }),
        itemHeight = self.options.size == 'small' ? 12 : (self.options.size == 'medium' ? 16 : 20),
        // menuHeight,
        scrollSpeed = 1,
        $item; // fixme: used?
        // fixme: attach all private vars to self

    // construct
    that.items = [];
    that.submenus = {};
    that.$scrollbars = [];
    that.$top = $('<div>')
        .addClass('OxTop')
        .appendTo(that.$element);
    that.$scrollbars.up = constructScrollbar('up')
        .appendTo(that.$element);
    that.$container = $('<div>')
        .addClass('OxContainer')
        .appendTo(that.$element);
    that.$content = $('<table>')
        .addClass('OxContent')
        .appendTo(that.$container);
    constructItems(self.options.items);
    that.$scrollbars.down = constructScrollbar('down')
        .appendTo(that.$element);
    that.$bottom = $('<div>')
        .addClass('OxBottom')
        .appendTo(that.$element);
    that.$layer = $('<div>')
        .addClass(self.options.mainmenu ? 'OxMainMenuLayer' : 'OxMenuLayer')
        .click(click);

    function click(event) {
        var item,
            position,
            $target = $(event.target),
            $parent = $target.parent();
        // necessary for highlight
        if ($parent.is('.OxCell')) {
            $target = $parent;
            $parent = $target.parent();
        }
        if ($target.is('.OxCell')) {
            position = $parent.data('position');
            item = that.items[position];
            if (!item.options('disabled')) {
                clickItem(position);
            } else {
                that.hideMenu();
            }
        } else {
            that.hideMenu();
        }
    }

    function clickItem(position) {
        var item = that.items[position],
            menu = self.options.mainmenu || self.options.parent || that,
            toggled;
        that.hideMenu();
        if (!item.options('items').length) {
            if (that.options('parent')) {
                that.options('parent').hideMenu().triggerEvent('click');
            }
            if (item.options('checked') !== null) {
                if (item.options('group')) {
                    //Ox.print('has group', item.options('group'))
                    toggled = self.optionGroups[item.options('group')].toggle(position);
                    //Ox.print('toggled', toggled)
                    if (toggled.length) {
                        toggled.forEach(function(pos) {
                            that.items[pos].toggleChecked();
                        });
                        //Ox.print('--triggering change event--');
                        menu.triggerEvent('change', {
                            id: item.options('group'),
                            checked: $.map(self.optionGroups[item.options('group')].checked(), function(v, i) {
                                return {
                                    id: that.items[v].options('id'),
                                    title: Ox.stripTags(that.items[v].options('title')[0])
                                };
                            })
                        });
                    }
                } else {
                    item.toggleChecked();
                    menu.triggerEvent('change', {
                        checked: item.options('checked'),
                        id: item.options('id'),
                        title: Ox.stripTags(item.options('title')[0])
                    });
                }
            } else {
                menu.triggerEvent('click', {
                    id: item.options('id'),
                    title: Ox.stripTags(item.options('title')[0])
                });
            }
            if (item.options('title').length == 2) {
                item.toggleTitle();
            }
        }
    }

    function clickSelectedItem() {
        // called on key.enter
        if (self.options.selected > -1) {
            clickItem(self.options.selected);
        } else {
            that.hideMenu();
        }
    }

    function constructItems(items) {

        that.$content.empty();
        scrollMenuUp();

        self.optionGroups = {};
        items.forEach(function(item, i) {
            if (item.group) {
                items[i] = $.map(item.items, function(v, i) {
                    return $.extend(v, {
                        group: item.group
                    });
                });
                self.optionGroups[item.group] = new Ox.OptionGroup(
                    items[i],
                    'min' in item ? item.min : 1,
                    'max' in item ? item.max : 1
                );
            }
        });
        items = Ox.flatten(items);

        that.items = [];
        items.forEach(function(item) {
            var position;
            if ('id' in item) {
                that.items.push(new Ox.MenuItem($.extend(item, {
                    menu: that,
                    position: position = that.items.length
                })).data('position', position).appendTo(that.$content)); // fixme: jquery bug when passing {position: position}? does not return the object?;
                if (item.items) {
                    that.submenus[item.id] = new Ox.Menu({
                        element: that.items[position],
                        id: Ox.toCamelCase(self.options.id + '/' + item.id),
                        items: item.items,
                        mainmenu: self.options.mainmenu,
                        offset: {
                            left: 0,
                            top: -4
                        },
                        parent: that,
                        side: 'right',
                        size: self.options.size,
                    });
                }
            } else {
                that.$content.append(constructSpace());
                that.$content.append(constructLine());
                that.$content.append(constructSpace());
            }
        });

        if (!that.is(':hidden')) {
            that.hideMenu();
            that.showMenu();
        }

    }

    function constructLine() {
        return $('<tr>').append(
            $('<td>', {
                'class': 'OxLine',
                colspan: 5
            })
        );
    }

    function constructScrollbar(direction) {
        var interval,
            speed = direction == 'up' ? -1 : 1;
        return $('<div/>', {
            'class': 'OxScrollbar Ox' + Ox.toTitleCase(direction),
            html: Ox.UI.symbols['triangle_' + direction],
            click: function() { // fixme: do we need to listen to click event?
                return false;
            },
            mousedown: function() {
                scrollSpeed = 2;
                return false;
            },
            mouseenter: function() {
                var $otherScrollbar = that.$scrollbars[direction == 'up' ? 'down' : 'up'];
                $(this).addClass('OxSelected');
                if ($otherScrollbar.is(':hidden')) {
                    $otherScrollbar.show();
                    that.$container.height(that.$container.height() - itemHeight);
                    if (direction == 'down') {
                        that.$content.css({
                            top: -itemHeight + 'px'
                        });
                    }
                }
                scrollMenu(speed);
                interval = setInterval(function() {
                    scrollMenu(speed);
                }, 100);
            },
            mouseleave: function() {
                $(this).removeClass('OxSelected');
                clearInterval(interval);
            },
            mouseup: function() {
                scrollSpeed = 1;
                return false;
            }
        });
    }

    function constructSpace() {
        return $('<tr>').append(
            $('<td>', {
                'class': 'OxSpace',
                colspan: 5
            })
        );
    }

    function getElement(id) {
        // fixme: needed?
        return $('#' + Ox.toCamelCase(options.id + '/' + id));
    }

    function getItemPositionById(id) {
        var position;
        Ox.forEach(that.items, function(item, i) {
            if (item.options('id') == id) {
                position = i;
                return false;
            }
        });
        return position;
    }

    function hideMenu() {
        // called on key_escape
        that.hideMenu();
    }

    function isFirstEnabledItem() {
        var ret = true;
        Ox.forEach(that.items, function(item, i) {
            if (i < self.options.selected && !item.options('disabled')) {
                return ret = false;
            }
        });
        return ret;
    }

    function isLastEnabledItem() {
        var ret = true;
        Ox.forEach(that.items, function(item, i) {
            if (i > self.options.selected && !item.options('disabled')) {
                return ret = false;
            }
        });
        return ret;
    }

    function mouseenter() {
        that.gainFocus();
    }

    function mouseleave() {
        if (self.options.selected > -1 && !that.items[self.options.selected].options('items').length) {
            selectItem(-1);
        }
    }

    function mousemove(event) {
        var item,
            position,
            $target = $(event.target);
            $parent = $target.parent();
        if ($parent.is('.OxCell')) {
            $target = $parent;
            $parent = $target.parent();
        }
        if ($target.is('.OxCell')) {
            position = $parent.data('position');
            item = that.items[position];
            if (!item.options('disabled') && position != self.options.selected) {
                selectItem(position);
            }
        } else {
            mouseleave();
        }
    }

    function scrollMenu(speed) {
        var containerHeight = that.$container.height(),
            contentHeight = that.$content.height(),
            top = parseInt(that.$content.css('top')) || 0,
            min = containerHeight - contentHeight + itemHeight,
            max = 0;
        top += speed * scrollSpeed * -itemHeight;
        if (top <= min) {
            top = min;
            that.$scrollbars.down.hide().trigger('mouseleave');
            that.$container.height(containerHeight + itemHeight);
            that.items[that.items.length - 1].trigger('mouseover');
        } else if (top >= max - itemHeight) {
            top = max;
            that.$scrollbars.up.hide().trigger('mouseleave');
            that.$container.height(containerHeight + itemHeight);
            that.items[0].trigger('mouseover');
        }
        that.$content.css({
            top: top + 'px'
        });
    }

    function scrollMenuUp() {
        if (that.$scrollbars.up.is(':visible')) {
            that.$content.css({
                top: '0px'
            });
            that.$scrollbars.up.hide();
            if (that.$scrollbars.down.is(':hidden')) {
                that.$scrollbars.down.show();
            } else {
                that.$container.height(that.$container.height() + itemHeight);
            }
        }
    }

    function selectItem(position) {
        var item;
        if (self.options.selected > -1) {
            //Ox.print('s.o.s', self.options.selected, that.items)
            item = that.items[self.options.selected]
            item.removeClass('OxSelected');
            /* disabled
            that.triggerEvent('deselect', {
                id: item.options('id'),
                title: Ox.stripTags(item.options('title')[0])
            });
            */
        }
        if (position > -1) {
            item = that.items[position];
            Ox.forEach(that.submenus, function(submenu, id) {
                if (!submenu.is(':hidden')) {
                    submenu.hideMenu();
                    return false;
                }
            });
            item.options('items').length && that.submenus[item.options('id')].showMenu(); // fixme: do we want to switch to this style?
            item.addClass('OxSelected');
            /* disabled
            that.triggerEvent('select', {
                id: item.options('id'),
                title: Ox.stripTags(item.options('title')[0])
            });
            */
        }
        self.options.selected = position;
    }

    function selectNextItem() {
        var offset,
            selected = self.options.selected;
        //Ox.print('sNI', selected)
        if (!isLastEnabledItem()) {
            if (selected == -1) {
                scrollMenuUp();
            } else {
                that.items[selected].removeClass('OxSelected');
            }
            do {
                selected++;
            } while (that.items[selected].options('disabled'))
            selectItem(selected);
            offset = that.items[selected].offset().top + itemHeight -
                    that.$container.offset().top - that.$container.height();
            if (offset > 0) {
                if (that.$scrollbars.up.is(':hidden')) {
                    that.$scrollbars.up.show();
                    that.$container.height(that.$container.height() - itemHeight);
                    offset += itemHeight;
                }
                if (selected == that.items.length - 1) {
                    that.$scrollbars.down.hide();
                    that.$container.height(that.$container.height() + itemHeight);
                } else {
                    that.$content.css({
                        top: ((parseInt(that.$content.css('top')) || 0) - offset) + 'px'
                    });
                }
            }
        }
    }

    function selectPreviousItem() {
        var offset,
            selected = self.options.selected;
        //Ox.print('sPI', selected)
        if (selected > - 1) {
            if (!isFirstEnabledItem()) {
                that.items[selected].removeClass('OxSelected');
                do {
                    selected--;
                } while (that.items[selected].options('disabled'))
                selectItem(selected);
            }
            offset = that.items[selected].offset().top - that.$container.offset().top;
            if (offset < 0) {
                if (that.$scrollbars.down.is(':hidden')) {
                    that.$scrollbars.down.show();
                    that.$container.height(that.$container.height() - itemHeight);
                }
                if (selected == 0) {
                    that.$scrollbars.up.hide();
                    that.$container.height(that.$container.height() + itemHeight);
                }
                that.$content.css({
                    top: ((parseInt(that.$content.css('top')) || 0) - offset) + 'px'
                });
            }
        }
    }

    function selectSubmenu() {
        //Ox.print('selectSubmenu', self.options.selected)
        if (self.options.selected > -1) {
            var submenu = that.submenus[that.items[self.options.selected].options('id')];
            //Ox.print('submenu', submenu, that.submenus);
            if (submenu && submenu.hasEnabledItems()) {
                submenu.gainFocus();
                submenu.selectFirstItem();
            } else if (self.options.mainmenu) {
                self.options.mainmenu.selectNextMenu();
            }
        } else if (self.options.mainmenu) {
            self.options.mainmenu.selectNextMenu();
        }
    }

    function selectSupermenu() {
        //Ox.print('selectSupermenu', self.options.selected)
        if (self.options.parent) {
            self.options.selected > -1 && that.items[self.options.selected].trigger('mouseleave');
            scrollMenuUp();
            self.options.parent.gainFocus();
        } else if (self.options.mainmenu) {
            self.options.mainmenu.selectPreviousMenu();
        }
    }

    self.onChange = function(key, value) {
        if (key == 'items') {
            constructItems(value);
        } else if (key == 'selected') {
            that.$content.find('.OxSelected').removeClass('OxSelected');
            selectItem(value);
        }
    }

    that.addItem = function(item, position) {
        
    };

    that.addItemAfter = function(item, id) {

    };

    that.addItemBefore = function(item, id) {

    };

    that.checkItem = function(id) {
        var item = that.getItem(id);
        if (item.options('group')) {
            var position = getItemPositionById(id),
                toggled = self.optionGroups[item.options('group')].toggle(position);
            if (toggled.length) {
                toggled.forEach(function(pos) {
                    that.items[pos].toggleChecked();
                });
            }
        } else {
            item.options({
                checked: true
            });
        }
    };

    that.getItem = function(id) {
        //Ox.print('id', id)
        var ids = id.split('_'),
            item;
        if (ids.length == 1) {
            Ox.forEach(that.items, function(v) {
                if (v.options('id') == id) {
                    item = v;
                    return false;
                }
            });
            if (!item) {
                Ox.forEach(that.submenus, function(submenu) {
                    item = submenu.getItem(id);
                    return !item;
                });
            }
        } else {
            item = that.submenus[ids.shift()].getItem(ids.join('_'));
        }
        return item;
    };

    that.getSubmenu = function(id) {
        var ids = id.split('_'),
            submenu;
        if (ids.length == 1) {
            submenu = that.submenus[id];
        } else {
            submenu = that.submenus[ids.shift()].getSubmenu(ids.join('_'));
        }
        //Ox.print('getSubmenu', id, submenu);
        return submenu;
    }

    that.hasEnabledItems = function() {
        var ret = false;
        Ox.forEach(that.items, function(item) {
            if (!item.options('disabled')) {
                return ret = true;
            }
        });
        return ret;
    };

    that.hideMenu = function() {
        if (that.is(':hidden')) {
            return;
        }
        Ox.forEach(that.submenus, function(submenu) {
            if (submenu.is(':visible')) {
                submenu.hideMenu();
                return false;
            }
        });
        selectItem(-1);
        scrollMenuUp();
        that.$scrollbars.up.is(':visible') && that.$scrollbars.up.hide();
        that.$scrollbars.down.is(':visible') && that.$scrollbars.down.hide();
        if (self.options.parent) {
            //self.options.element.removeClass('OxSelected');
            self.options.parent.options({
                selected: -1
            });
        }
        that.hide()
            .loseFocus()
            .triggerEvent('hide');
        that.$layer.hide();
        return that;
    };

    that.removeItem = function() {

    };

    that.selectFirstItem = function() {
        selectNextItem();
    };

    that.showMenu = function() {
        if (!that.is(':hidden')) {
            return;
        }
        if (!self.options.parent && !that.$layer.parent().length) {
            that.$layer.appendTo(Ox.UI.$body);
        }
        that.parent().length == 0 && that.appendTo(Ox.UI.$body);
        that.css({
            left: '-1000px',
            top: '-1000px',
        }).show();
        var offset = self.options.element.offset(),
            width = self.options.element.outerWidth(),
            height = self.options.element.outerHeight(),
            left = Ox.limit(
                offset.left + self.options.offset.left + (self.options.side == 'bottom' ? 0 : width),
                0, Ox.UI.$window.width() - that.width()
            ),
            top = offset.top + self.options.offset.top + (self.options.side == 'bottom' ? height : 0),
            menuHeight = that.$content.outerHeight(); // fixme: why is outerHeight 0 when hidden?
            menuMaxHeight = Math.floor(Ox.UI.$window.height() - top - 16);
        if (self.options.parent) {
            if (menuHeight > menuMaxHeight) {
                top = Ox.limit(top - menuHeight + menuMaxHeight, self.options.parent.offset().top, top);
                menuMaxHeight = Math.floor(Ox.UI.$window.height() - top - 16);
            }
        }
        that.css({
            left: left + 'px',
            top: top + 'px'
        });
        if (menuHeight > menuMaxHeight) {
            that.$container.height(menuMaxHeight - itemHeight - 8); // margin
            that.$scrollbars.down.show();
        } else {
            that.$container.height(menuHeight);
        }
        if (!self.options.parent) {
            that.gainFocus();
        }
        that.$layer.show();
        return that;
        //that.triggerEvent('show');
    };

    that.toggleMenu = function() {
        that.is(':hidden') ? that.showMenu() : that.hideMenu();
    };

    return that;

};