// Converse.js
// http://conversejs.org
//
// Copyright (c) 2012-2018, the Converse.js developers
// Licensed under the Mozilla Public License (MPLv2)

import "@converse/headless/converse-chatboxes";
import "backbone.nativeview";
import "backbone.overview";
import converse from "@converse/headless/converse-core";
import tpl_chatboxes from "templates/chatboxes.html";

const { Backbone, _ } = converse.env;

const AvatarMixin = {

    renderAvatar (el) {
        el = el || this.el;
        const canvas_el = el.querySelector('canvas');
        if (_.isNull(canvas_el)) {
            return;
        }
        const image_type = this.model.vcard.get('image_type'),
                image = this.model.vcard.get('image'),
                img_src = "data:" + image_type + ";base64," + image,
                img = new Image();

        return new Promise((resolve, reject) => {
            img.onload = () => {
                const ctx = canvas_el.getContext('2d'),
                        ratio = img.width / img.height;
                ctx.clearRect(0, 0, canvas_el.width, canvas_el.height);
                if (ratio < 1) {
                    const scaled_img_with = canvas_el.width*ratio,
                            x = Math.floor((canvas_el.width-scaled_img_with)/2);
                    ctx.drawImage(img, x, 0, scaled_img_with, canvas_el.height);
                } else {
                    ctx.drawImage(img, 0, 0, canvas_el.width, canvas_el.height*ratio);
                }
                resolve();
            };
            img.src = img_src;
        });
    },
};


converse.plugins.add('converse-chatboxviews', {

    dependencies: ["converse-chatboxes"],

    overrides: {
        // Overrides mentioned here will be picked up by converse.js's
        // plugin architecture they will replace existing methods on the
        // relevant objects or classes.

        initStatus: function (reconnecting) {
            const { _converse } = this.__super__;
            if (!reconnecting) {
                _converse.chatboxviews.closeAllChatBoxes();
            }
            return this.__super__.initStatus.apply(this, arguments);
        }
    },

    initialize () {
        /* The initialize function gets called as soon as the plugin is
         * loaded by converse.js's plugin machinery.
         */
        const { _converse } = this,
              { __ } = _converse;

        _converse.api.promises.add([
            'chatBoxViewsInitialized'
        ]);

        _converse.ViewWithAvatar = Backbone.NativeView.extend(AvatarMixin);
        _converse.VDOMViewWithAvatar = Backbone.VDOMView.extend(AvatarMixin);


        _converse.ChatBoxViews = Backbone.Overview.extend({

            _ensureElement () {
                /* Override method from backbone.js
                 * If the #conversejs element doesn't exist, create it.
                 */
                if (!this.el) {
                    let el = _converse.root.querySelector('#conversejs');
                    if (_.isNull(el)) {
                        el = document.createElement('div');
                        el.setAttribute('id', 'conversejs');
                        const body = _converse.root.querySelector('body');
                        if (body) {
                            body.appendChild(el);
                        } else {
                            // Perhaps inside a web component?
                            _converse.root.appendChild(el);
                        }
                    }
                    el.innerHTML = '';
                    this.setElement(el, false);
                } else {
                    this.setElement(_.result(this, 'el'), false);
                }
            },

            initialize () {
                this.model.on("destroy", this.removeChat, this);
                this.el.classList.add(`converse-${_converse.view_mode}`);
                this.render();
            },

            render () {
                try {
                    this.el.innerHTML = tpl_chatboxes();
                } catch (e) {
                    this._ensureElement();
                    this.el.innerHTML = tpl_chatboxes();
                }
                this.row_el = this.el.querySelector('.row');
            },

            insertRowColumn (el) {
                /* Add a new DOM element (likely a chat box) into the
                 * the row managed by this overview.
                 */
                this.row_el.insertAdjacentElement('afterBegin', el);
            },

            removeChat (item) {
                this.remove(item.get('id'));
            },

            closeAllChatBoxes () {
                /* This method gets overridden in src/converse-controlbox.js if
                 * the controlbox plugin is active.
                 */
                this.each(function (view) { view.close(); });
                return this;
            },

            chatBoxMayBeShown (chatbox) {
                return this.model.chatBoxMayBeShown(chatbox);
            }
        });


        /************************ BEGIN Event Handlers ************************/
        _converse.api.waitUntil('rosterContactsFetched').then(() => {
            _converse.roster.on('add', (contact) => {
                /* When a new contact is added, check if we already have a
                 * chatbox open for it, and if so attach it to the chatbox.
                 */
                const chatbox = _converse.chatboxes.findWhere({'jid': contact.get('jid')});
                if (chatbox) {
                    chatbox.addRelatedContact(contact);
                }
            });
        });


        _converse.api.listen.on('chatBoxesInitialized', () => {
            _converse.chatboxviews = new _converse.ChatBoxViews({
                'model': _converse.chatboxes
            });
            _converse.emit('chatBoxViewsInitialized');
        });

        _converse.api.listen.on('clearSession', () => _converse.chatboxviews.closeAllChatBoxes());
        /************************ END Event Handlers ************************/
    }
});