define([
    'jquery',
    'underscore',
    'backbone',
    'common',
    'app/collections/group-discussions',
    'app/views/group-discussion'
], function($, _, Backbone, Common, GroupDiscussions, ItemView) {
    'use strict';

    var View = Backbone.View.extend({
        el: '#group-discussions',

        initialize: function(options) {
            this.collection = new GroupDiscussions();
            this.listenTo(this.collection, 'add', this.addOne);
            this.listenTo(this.collection, 'reset', this.reset);

            this.$loadingTip = this.$('.loading-tip');
            this.$listContainer = this.$('#group-discussion-list');
            this.$emptyTip = this.$('.no-discussion-tip');
            this.$error = this.$('.error');

            var _this = this;
            $(window).resize(function() {
                _this.setConMaxHeight();
            });

            $(document).click(function(e) {
                var target = e.target || event.srcElement;
                var $popup = _this.$el,
                    $popup_switch = $('#group-discussions-icon');

                if ($('#group-discussions:visible').length &&
                    !$popup.is(target) &&
                    !$popup.find('*').is(target) &&
                    !$popup_switch.is(target)) {
                    _this.hide();
                }
            });
        },

        events: {
            'click .close': 'hide',
            'submit form': 'formSubmit'
        },

        addOne: function(item, collection, options) {
            var view = new ItemView({
                model: item
            });
            if (options.prepend == true) {
                this.$listContainer.append(view.render().el);
            } else {
                this.$listContainer.prepend(view.render().el);
            }
        },

        reset: function() {
            this.$error.hide();
            this.$loadingTip.hide();
            this.$listContainer.empty();
            if (this.collection.length) {
                this.$emptyTip.hide();
                this.collection.each(this.addOne, this);
                this.$listContainer.removeClass('hide');
                this.$listContainer.show();
            } else {
                this.$emptyTip.show();
                this.$listContainer.hide();
            }
        },

        render: function() {
            this.$listContainer.hide();
            this.$loadingTip.show();

            var _this = this;
            this.collection.setGroupId(this.group_id);
            this.collection.fetch({
                cache: false,
                reset: true,
                success: function(collection, response, opts) {
                },
                error: function(collection, response, opts) {
                    _this.$loadingTip.hide();
                    var err_msg;
                    if (response.responseText) {
                        if (response['status'] == 401 || response['status'] == 403) {
                            err_msg = gettext("Permission error");
                        } else {
                            err_msg = gettext("Error");
                        }
                    } else {
                        err_msg = gettext('Please check the network.');
                    }
                    _this.$error.html(err_msg).show();
                }
            });
        },

        // set max-height for '.popover-con'
        setConMaxHeight: function() {
            this.$('.popover-con').css({'max-height': $(window).height() - this.$el.offset().top - this.$('.popover-hd').outerHeight(true) - 2}); // 2: top, bottom border width of $el
        },

        show: function(options) {
            this.group_id = options.group_id;
            this.$el.show();
            this.setConMaxHeight();
            this.render();
            app.router.navigate('group/' + this.group_id + '/discussions/');
        },

        hide: function() {
            this.$el.hide();
            app.router.navigate('group/' + this.group_id + '/');
        },

        formSubmit: function() {
            var _this = this;
            var content = $.trim(this.$('[name="message"]').val());

            if (!content) {
                return false;
            }

            this.collection.create({ content: content }, {
                wait: true,
                validate: true,
                prepend: true,
                success: function() {
                    _this.$('[name="message"]').val('');
                    if (_this.collection.length == 1) {
                        _this.collection.reset(_this.collection.models);
                    }
                },
                error: function(collection, response, options) {
                    var err_msg;
                    if (response.responseText) {
                        err_msg = response.responseJSON.error_msg;
                    } else {
                        err_msg = gettext('Please check the network.');
                    }
                    _this.$error.html(err_msg).show();
                }
            });

            return false;
        }

    });

    return View;
});