/**
 * EGroupware eTemplate2 - JS Template base class
 *
 * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
 * @package etemplate
 * @subpackage api
 * @link http://www.egroupware.org
 * @author Andreas Stöckel
 */

/*egw:uses
	et2_core_xml;
	et2_core_DOMWidget;
*/

import './et2_core_interfaces';
import './et2_core_common';
import {et2_DOMWidget} from './et2_core_DOMWidget';
import {ClassWithAttributes} from "./et2_core_inheritance";
import {et2_register_widget, WidgetConfig} from "./et2_core_widget";
import './et2_types';

/**
 * Class which implements the "template" XET-Tag. When the id parameter is set,
 * the template class checks whether another template with this id already
 * exists. If yes, this template is removed from the DOM tree, copied and
 * inserted in place of this template.
 */
export class et2_template extends et2_DOMWidget
{
	static readonly _attributes : any = {
		"template": {
			"name": "Template",
			"type": "string",
			"description": "Name / ID of template with optional cache-buster ('?'+filemtime of template on server)",
			"default": et2_no_init
		},
		"group": {
			// TODO: Not implemented
			"name": "Group",
			"description":"Not implemented",
			//"default": 0
			"default": et2_no_init
		},
		"version": {
			"name": "Version",
			"type": "string",
			"description": "Version of the template"
		},
		"lang": {
			"name": "Language",
			"type": "string",
			"description": "Language the template is written in"
		},
		"content": {
			"name": "Content index",
			"default": et2_no_init,
			"description": "Used for passing in specific content to the template other than what it would get by ID."
		},
		url: {
			name: "URL of template",
			type: "string",
			description: "full URL to load template incl. cache-buster"
		},
		"onload": {
			"name": "onload",
			"type": "js",
			"default": et2_no_init,
			"description": "JS code which is executed after the template is loaded."
		}
	};

	content: string;
	div: HTMLDivElement;
	loading: JQueryDeferred<unknown>;

	/**
	 * Constructor
	 */
	constructor(_parent, _attrs? : WidgetConfig, _child? : object)
	{
		// Call the inherited constructor
		super(_parent, _attrs, ClassWithAttributes.extendAttributes(et2_template._attributes, _child || {}));

		// Set this early, so it's available for creating namespace
		if(_attrs.content)
		{
			this.content = _attrs.content;
		}
		// constructor was called here before!

		this.div = document.createElement("div");

		// Deferred object so we can load via AJAX
		this.loading = jQuery.Deferred();

		// run transformAttributes now, to get server-side modifications (url!)
		if (_attrs.template)
		{
			this.id = _attrs.template;
			this.transformAttributes(_attrs);
			this.options = et2_cloneObject(_attrs);
			_attrs = {};
		}
		if (this.id != "" || this.options.template)
		{
			var parts = (this.options.template || this.id).split('?');
			var cache_buster = parts.length > 1 ? parts.pop() : null;
			var template_name = parts.pop();

			// Check to see if XML is known
			var xml = null;
			var templates = etemplate2.templates;	// use global eTemplate cache
			if(!(xml = templates[template_name]))
			{
				// Check to see if ID is short form --> prepend parent/top-level name
				if(template_name.indexOf('.') < 0)
				{
					var root = _parent ? _parent.getRoot() : null;
					var top_name = root && root._inst ? root._inst.name : null;
					if (top_name && template_name.indexOf('.') < 0) template_name = top_name+'.'+template_name;
				}
				xml = templates[template_name];
				if(!xml)
				{
					// Ask server
					var url = this.options.url;
					if (!this.options.url)
					{
						var splitted = template_name.split('.');
						var app = splitted.shift();
						// use template base url from initial template, to continue using webdav, if that was loaded via webdav
						url = this.getRoot()._inst.template_base_url + app + "/templates/default/" +
							splitted.join('.')+ ".xet" + (cache_buster ? '?download='+cache_buster : '');
					}
					// if server did not give a cache-buster, fall back to current time
					if (url.indexOf('?') == -1) url += '?download='+(new Date).valueOf();

					if(this.options.url || splitted.length)
					{
						var fetch_url_callback = function(_xmldoc) {
							// Scan for templates and store them
							for(var i = 0; i < _xmldoc.childNodes.length; i++) {
								var template = _xmldoc.childNodes[i];
								if(template.nodeName.toLowerCase() != "template") continue;
								templates[template.getAttribute("id")] = template;
							}

							// Read the XML structure of the requested template
							if (typeof templates[template_name] != 'undefined') this.loadFromXML(templates[template_name]);

							// Update flag
							this.loading.resolve();
						};

						et2_loadXMLFromURL(url, fetch_url_callback, this, function( error) {
							url = egw.link('/'+ app + "/templates/default/" +
								splitted.join('.')+ ".xet", {download:cache_buster? cache_buster :(new Date).valueOf()});

							et2_loadXMLFromURL(url, fetch_url_callback, this);
						});
					}
					return;
				}
			}
			if(xml !== null && typeof xml !== "undefined")
			{
				this.egw().debug("log", "Loading template from XML: ", template_name);
				this.loadFromXML(xml);
				// Don't call this here - done by caller, or on whole widget tree
				//this.loadingFinished();

				// But resolve the promise
				this.loading.resolve();
			}
			else
			{
				this.egw().debug("warn", "Unable to find XML for ", template_name);
				this.loading.reject();
			}
		}
		else
		{
			// No actual template
			this.loading.resolve();
		}
	}

	/**
	 * Override parent to support content attribute
	 * Templates always have ID set, but seldom do we want them to
	 * create a namespace based on their ID.
	 */
	checkCreateNamespace(_attrs)
	{
		if(_attrs.content)
		{
			var old_id = _attrs.id;
			this.id = _attrs.content;
			super.checkCreateNamespace.apply(this, arguments);
			this.id = old_id;
		}
	}

	_createNamespace() : boolean
	{
		return true;
	}

	getDOMNode()
	{
		return this.div;
	}

	attachToDOM()
	{
		if (this.div)
		{
			jQuery(this.div)
				.off('.et2_template')
				.bind("load.et2_template", this, function(e) {
					e.data.load.call(e.data, this);
				});
		}

		return super.attachToDOM();
	}

	/**
	 * Called after the template is fully loaded to handle any onload handlers
	 */
	load()
	{
		if(typeof this.options.onload == 'function')
		{
			// Make sure function gets a reference to the widget
			var args = Array.prototype.slice.call(arguments);
			if(args.indexOf(this) == -1) args.push(this);

			return this.options.onload.apply(this, args);
		}
	}

	/**
	 * Override to return the promise for deferred loading
	 */
	doLoadingFinished()
	{
		// Apply parent now, which actually puts into the DOM
		super.doLoadingFinished();

		// Fire load event when done loading
		this.loading.done(jQuery.proxy(function() {jQuery(this).trigger("load");},this.div));

		// Not done yet, but widget will let you know
		return this.loading.promise();
	}
}
et2_register_widget(et2_template, ["template"]);