/**
 *  Menu.js
 *
 *  A menu object. This is the container to which you may add {@link Common.UI.MenuItem menu items}.
 *
 *  Created by Alexander Yuzhin on 1/28/14
 *  Copyright (c) 2014 Ascensio System SIA. All rights reserved.
 *
 */

/**
 *  Default template
 *
 *  <ul class="dropdown-menu" role="menu">
 *      <li><a href="#">item 1</a></li>-->
 *      <li><a href="#">item 2</a></li>-->
 *      <li class="divider"></li>-->
 *      <li><a href="#">item 3</a></li>
 *  </ul>
 *
 *  A useful classes of menu position
 *
 *  - `'pull-right'` using for layout menu by right side of a parent
 *
 *
 *  Example usage:
 *
 *      new Common.UI.Menu({
 *          items: [
 *              { caption: 'item 1', value: 1 },
 *              { caption: 'item 1', value: 2 },
 *              { caption: '--' },
 *              { caption: 'item 1', value: 3 },
 *          ]
 *      })
 *
 *  @property {Object} itemTemplate
 *
 *  Default template for items
 *
 *
 *  @property {Array} items
 *
 *  Arrow of the {Common.UI.MenuItem} menu items
 *
 *
 */

if (Common === undefined)
    var Common = {};

define([
    'common/main/lib/extend/Bootstrap',
    'common/main/lib/component/BaseView',
    'common/main/lib/component/MenuItem',
    'common/main/lib/component/Scroller'
], function () {
    'use strict';

    Common.UI.Menu = (function(){
        var manager = (function(){
            var active = [],
                menus = {};

            return {
                register: function(menu) {
                    menus[menu.id] = menu;
                    menu
                    .on('show:after', function(m) {
                        active.push(m);
                    })
                    .on('hide:after', function(m) {
                        var index = active.indexOf(m);

                        if (index > -1)
                            active.splice(index, 1);
                    });
                },

                unregister: function(menu) {
                    var index = active.indexOf(menu);

                    delete menus[menu.id];

                    if (index > -1)
                        active.splice(index, 1);

                    menu.off('show:after').off('hide:after');
                },

                hideAll: function() {
                    Common.NotificationCenter.trigger('menumanager:hideall');

                    if (active && active.length > 0) {
                        _.each(active, function(menu) {
                            menu.hide();
                        });
                        return true;
                    }
                    return false;
                }
            }
        })();

        return _.extend(Common.UI.BaseView.extend({
            options : {
                cls         : '',
                style       : '',
                itemTemplate: null,
                items       : [],
                menuAlign   : 'tl-bl',
                menuAlignEl : null,
                offset      : [0, 0],
                cyclic      : true
            },

            template: _.template([
                '<ul class="dropdown-menu <%= options.cls %>" style="<%= options.style %>" role="menu"></ul>'
            ].join('')),

            initialize : function(options) {
                Common.UI.BaseView.prototype.initialize.call(this, options);

                var me = this;

                this.id             = this.options.id || Common.UI.getId();
                this.itemTemplate   = this.options.itemTemplate || Common.UI.MenuItem.prototype.template;
                this.rendered       = false;
                this.items          = [];
                this.offset         = [0, 0];
                this.menuAlign      = this.options.menuAlign;
                this.menuAlignEl    = this.options.menuAlignEl;

                if (!this.options.cyclic) this.options.cls += ' no-cyclic';

                _.each(this.options.items, function(item) {
                    if (item instanceof Common.UI.MenuItem) {
                        me.items.push(item)
                    } else {
                        me.items.push(
                            new Common.UI.MenuItem(_.extend({
                                tagName : 'li',
                                template: me.itemTemplate
                            }, item))
                        );
                    }
                });

                if (this.options.el)
                    this.render();

                manager.register(this);
            },

            remove: function() {
                manager.unregister(this);
                Common.UI.BaseView.prototype.remove.call(this);
            },

            render: function(parentEl) {
                var me = this;

                this.trigger('render:before', this);

                this.cmpEl = $(this.el);

                if (parentEl) {
                    this.setElement(parentEl, false);

                    if (!me.rendered) {
                        this.cmpEl = $(this.template({
                            options : me.options
                        }));

                        parentEl.append(this.cmpEl);
                    }
                } else {
                    if (!me.rendered) {
                        this.cmpEl = this.template({
                            options : me.options
                        });
                        $(this.el).append(this.cmpEl);
                    }
                }

                var rootEl = this.cmpEl.parent(),
                    menuRoot = (rootEl.attr('role') === 'menu') ? rootEl : rootEl.find('[role=menu]');

                if (menuRoot) {
                    if (!me.rendered) {
                        _.each(me.items || [], function(item) {
                            menuRoot.append(item.render().el);

                            item.on('click',  _.bind(me.onItemClick, me));
                            item.on('toggle', _.bind(me.onItemToggle, me));
                        });
                    }

                    menuRoot.css({
                        'max-height': me.options.maxHeight||'none',
                        position    : 'fixed',
                        right       : 'auto',
                        left        : -1000,
                        top         : -1000
                    });

                    this.parentEl = menuRoot.parent();

                    this.parentEl.on('show.bs.dropdown',    _.bind(me.onBeforeShowMenu, me));
                    this.parentEl.on('shown.bs.dropdown',   _.bind(me.onAfterShowMenu, me));
                    this.parentEl.on('hide.bs.dropdown',    _.bind(me.onBeforeHideMenu, me));
                    this.parentEl.on('hidden.bs.dropdown',  _.bind(me.onAfterHideMenu, me));
                    this.parentEl.on('keydown.after.bs.dropdown', _.bind(me.onAfterKeydownMenu, me));
                    menuRoot.on('scroll', _.bind(me.onScroll, me));

                    menuRoot.hover(
                        function(e) { me.isOver = true;},
                        function(e) { me.isOver = false; }
                    );
                }

                this.rendered = true;

                this.trigger('render:after', this);

                return this;
            },

            isVisible: function() {
                return this.rendered && (this.cmpEl.is(':visible'));
            },

            show: function() {
                if (this.rendered && this.parentEl && !this.parentEl.hasClass('open')) {
                    this.cmpEl.dropdown('toggle');
                }
            },

            hide: function() {
                if (this.rendered && this.parentEl) {
                    if ( this.parentEl.hasClass('open') )
                        this.cmpEl.dropdown('toggle');
                    else if (this.parentEl.hasClass('over'))
                        this.parentEl.removeClass('over');
                }
            },

            insertItem: function(index, item) {
                var me = this,
                    el = this.cmpEl;

                if (!(item instanceof Common.UI.MenuItem)) {
                    item = new Common.UI.MenuItem(_.extend({
                        tagName : 'li',
                        template: me.itemTemplate
                    }, item));
                }

                if (index < 0 || index >= me.items.length)
                    me.items.push(item);
                else
                    me.items.splice(index, 0, item);

                if (this.rendered) {
                    var menuRoot = (el.attr('role') === 'menu')
                        ? el
                        : el.find('[role=menu]');

                    if (menuRoot) {
                        if (index < 0) {
                            menuRoot.append(item.render().el);
                        } else if (index === 0) {
                            menuRoot.prepend(item.render().el);
                        } else {
                            $('li:nth-child(' + (index+1) + ')', menuRoot).before(item.render().el);
                        }

                        item.on('click',  _.bind(me.onItemClick, me));
                        item.on('toggle', _.bind(me.onItemToggle, me));
                    }
                }
            },

            doLayout: function() {
                if (this.options.maxHeight > 0) {
                    if (!this.rendered) {
                        this.mustLayout = true;
                        return;
                    }

                    var me = this,
                        el = this.cmpEl;

                    var menuRoot = (el.attr('role') === 'menu') ? el : el.find('[role=menu]');

                    if (!menuRoot.is(':visible')) {
                        var pos = [menuRoot.css('left'), menuRoot.css('top')];
                        menuRoot.css({
                            left    : '-1000px',
                            top     : '-1000px',
                            display : 'block'
                        });
                    }

                    var $items = menuRoot.find('li');

                    if ($items.height() * $items.length > this.options.maxHeight) {
                        var scroll = '<div class="menu-scroll top"></div>';
                        menuRoot.prepend(scroll);

                        scroll = '<div class="menu-scroll bottom"></div>';
                        menuRoot.append(scroll);

                        menuRoot.css({
                            'box-shadow'        : 'none',
                            'overflow-y'        : 'hidden',
                            'padding-top'       : '18px'
//                            'padding-bottom'    : '18px'
                        });

                        menuRoot.find('> li:last-of-type').css('margin-bottom',18);

                        var addEvent = function( elem, type, fn ) {
                            elem.addEventListener ? elem.addEventListener( type, fn, false ) : elem.attachEvent( "on" + type, fn );
                        };

                        var eventname=(/Firefox/i.test(navigator.userAgent))? 'DOMMouseScroll' : 'mousewheel';
                        addEvent(menuRoot[0], eventname, _.bind(this.onMouseWheel,this));
                        menuRoot.find('.menu-scroll').on('click', _.bind(this.onScrollClick, this));
                    }

                    if (pos) {
                        menuRoot.css({
                            display : '',
                            left    : pos[0],
                            top     : pos[1]
                        });
                    }
                }
            },

            addItem: function(item) {
                this.insertItem(-1, item);
            },

            removeItem: function(item) {
                var me = this,
                    index = me.items.indexOf(item);

                if (index > -1) {
                    me.items.splice(index, 1);

                    item.off('click').off('toggle');
                    item.remove();
                }
            },

            removeItems: function(from, len) {
                if (from > this.items.length-1) return;
                if (from+len>this.items.length) len = this.items.length - from;

                for (var i=from; i<from+len; i++) {
                    this.items[i].off('click').off('toggle');
                    this.items[i].remove();
                }
                this.items.splice(from, len);
            },

            removeAll: function() {
                var me = this;

                _.each(me.items, function(item){
                    item.off('click').off('toggle');
                    item.remove();
                });

                me.items = [];
            },

            onBeforeShowMenu: function(e) {
                if (this.mustLayout) {
                    delete this.mustLayout;
                    this.doLayout.call(this);
                }

                this.trigger('show:before', this, e);
                this.alignPosition();
            },

            onAfterShowMenu: function(e) {
                this.trigger('show:after', this, e);
                if (this.$el.find('> ul > .menu-scroll').length) {
                    var el = this.$el.find('li .checked')[0];
                    if (el) {
                        var offset = el.offsetTop - this.options.maxHeight / 2;
                        this.scrollMenu(offset < 0 ? 0 : offset);
                    }
                }
            },

            onBeforeHideMenu: function(e) {
                this.trigger('hide:before', this, e);

                if (Common.UI.Scroller.isMouseCapture())
                    e.preventDefault();
            },

            onAfterHideMenu: function(e) {
                this.trigger('hide:after', this, e);
            },

            onAfterKeydownMenu: function(e) {
                if (e.keyCode == Common.UI.Keys.RETURN) {
                    var li = $(e.target).closest('li');
                    if (li.length<=0) li = $(e.target).parent().find('li .dataview');
                    if (li.length>0) li.click();
                    if (!li.hasClass('dropdown-submenu'))
                        Common.UI.Menu.Manager.hideAll();
                    if ( $(e.currentTarget).closest('li').hasClass('dropdown-submenu')) {
                        e.stopPropagation();
                    }
                } else if (e.keyCode == Common.UI.Keys.UP || e.keyCode == Common.UI.Keys.DOWN)  {
                    this.fromKeyDown = true;
                } else if (e.keyCode == Common.UI.Keys.ESC)  {
//                    Common.NotificationCenter.trigger('menu:afterkeydown', e);
//                    return false;
                }
            },

            onScroll: function(item, e) {
                if (this.fromKeyDown) {
                    var menuRoot = (this.cmpEl.attr('role') === 'menu')
                        ? this.cmpEl
                        : this.cmpEl.find('[role=menu]');

                    menuRoot.find('.menu-scroll.top').css('top', menuRoot.scrollTop() + 'px');
                    menuRoot.find('.menu-scroll.bottom').css('bottom', (-menuRoot.scrollTop()) + 'px');
                }
            },

            onItemClick: function(item, e) {
                if (!item.menu) this.isOver = false;
                if (item.options.stopPropagation) {
                    e.stopPropagation();
                    var me = this;
                    _.delay(function(){
                        me.$el.parent().parent().find('[data-toggle=dropdown]').focus();
                    }, 10);
                    return;
                }
                this.trigger('item:click', this, item, e);
            },

            onItemToggle: function(item, state, e) {
                this.trigger('item:toggle', this, item, state, e);
            },

            onScrollClick: function(e) {
                this.scrollMenu(/top/.test(e.currentTarget.className));
                return false;
            },

            onMouseWheel: function(e) {
                this.scrollMenu(((e.detail && -e.detail) || e.wheelDelta) > 0);
            },

            scrollMenu: function(up) {
                this.fromKeyDown = false;
                var menuRoot = (this.cmpEl.attr('role') === 'menu')
                        ? this.cmpEl
                        : this.cmpEl.find('[role=menu]'),
                    value = typeof(up)==='boolean'
                        ? menuRoot.scrollTop() + (up ? -20 : 20)
                        : up;

                menuRoot.scrollTop(value);

                menuRoot.find('.menu-scroll.top').css('top', menuRoot.scrollTop() + 'px');
                menuRoot.find('.menu-scroll.bottom').css('bottom', (-menuRoot.scrollTop()) + 'px');
            },

            setOffset: function(offsetX, offsetY) {
                this.offset[0] = _.isUndefined(offsetX) ? this.offset[0] : offsetX;
                this.offset[1] = _.isUndefined(offsetY) ? this.offset[1] : offsetY;
                this.alignPosition();
            },

            getOffset: function() {
                return this.offset;
            },

            alignPosition: function() {
                var menuRoot    = (this.cmpEl.attr('role') === 'menu')
                        ? this.cmpEl
                        : this.cmpEl.find('[role=menu]'),
                    menuParent  = this.menuAlignEl || menuRoot.parent(),
                    m           = this.menuAlign.match(/^([a-z]+)-([a-z]+)/),
                    offset      = menuParent.offset(),
                    docW        = Math.min($(document).width(), $('body').width()),
                    docH        = $(document).height() - 10, // Yep, it's magic number
                    menuW       = menuRoot.outerWidth(),
                    menuH       = menuRoot.outerHeight(),
                    parentW     = menuParent.outerWidth(),
                    parentH     = menuParent.outerHeight();

                var posMenu = {
                    'tl': [0, 0],
                    'bl': [0, menuH],
                    'tr': [menuW, 0],
                    'br': [menuW, menuH]
                };
                var posParent = {
                    'tl': [0, 0],
                    'tr': [parentW, 0],
                    'bl': [0, parentH],
                    'br': [parentW, parentH]
                };
                var left = offset.left - posMenu[m[1]][0] + posParent[m[2]][0] + this.offset[0];
                var top  = offset.top  - posMenu[m[1]][1] + posParent[m[2]][1] + this.offset[1];

                if (left + menuW > docW)
                    if (menuParent.is('li.dropdown-submenu')) {
                        left = offset.left - menuW + 2;
                    } else {
                        left = docW - menuW;
                    }

                if (top + menuH > docH)
                    top = docH - menuH;

                if (top < 0)
                    top = 0;

                if (this.options.additionalAlign)
                    this.options.additionalAlign.call(this, menuRoot, left, top);
                else
                    menuRoot.css({left: left, top: top});
            }
        }), {
            Manager: (function() {
                return manager;
            })()
        })
    })();
});