/**
 * EGroupware Custom Html Elements - pdf player Web Components
 *
 * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
 * @package etemplate
 * @subpackage api
 * @link https://www.egroupware.org
 * @author Hadi Nategh <hn[at]egroupware.org>
 * @copyright EGroupware GmbH
 */
// Unfortunately compiled version of module:ES2015 TS would break webcomponent constructor.
// Since we don't have ES2020 available on 21.1 we have to use dynamic import.

import(egw.webserverUrl+"/node_modules/@bundled-es-modules/pdfjs-dist/build/pdf.js").then((_module)=>{
	const pdfjs = _module.default;
	pdfjs.GlobalWorkerOptions.workerSrc = egw.webserverUrl+'/node_modules/@bundled-es-modules/pdfjs-dist/build/pdf.worker.js';

	/*
	This web component allows to display and play pdf file like a video player widget/element. Its attributes and
	methodes are mostley identical as video html. No controls attribute supported yet.
	*/
	class pdf_player extends HTMLElement {

		constructor() {
			super(); // Create a shadow root

			/**
			 * keeps duration time internally
			 * @private
			 */
			this._duration = 0;
			/**
			 * keeps currentTime internally
			 * @private
			 */

			this._currentTime = 0;
			/**
			 * Keeps playing state internally
			 * @private
			 */

			this.__playing = false;
			/**
			 * keeps playing interval id
			 * @private
			 */

			this.__playingInterval = 0;
			/**
			 * keeps play back rate
			 * @private
			 */

			this._playBackRate = 1000;
			/**
			 * keeps ended state of playing pdf
			 * @private
			 */

			this._ended = false;
			/**
			 * keep paused state
			 * @private
			 */

			this._paused = false;
			/**
			 * keeps pdf doc states
			 * @private
			 */

			this.__pdfViewState = {
				pdf: null,
				currentPage: 1,
				zoom: 1
			};

			/**
			 * shadow dom container
			 * @private
			 */
			this._shadow = this.attachShadow({
				mode: 'open'
			}); // Create wrapper

			/**
			 * wrapper container holds canvas
			 * @private
			 */
			this._wrapper = document.createElement('div');

			this._wrapper.setAttribute('class', 'wrapper'); // Create some CSS to apply to the shadow dom


			this._style = document.createElement('style');
			this._style.textContent = '.wrapper {' + 'width: 100%;' + 'height: auto;' + 'display: block;' + '}' + '.wrapper canvas {' + 'width: 100%;' + 'height: auto;' + '}'; // attach to the shadow dom

			this._shadow.appendChild(this._style);

			this._shadow.appendChild(this._wrapper);
		}
		/**
		 * set observable attributes
		 * @return {string[]}
		 */


		static get observedAttributes() {
			return ['src', 'type'];
		}
		/**
		 * Gets called on observable attributes changes
		 * @param name attribute name
		 * @param _
		 * @param newVal new value
		 */


		attributeChangedCallback(name, _, newVal) {
			switch (name) {
				case 'src':
					this.__buildPDFView(newVal);

					break;

				case 'type':
					// do nothing
					break;
			}
		}
		/**
		 * init/update pdf tag
		 * @param _value
		 * @private
		 */


		__buildPDFView(_value) {
			this._canvas = document.createElement('canvas');

			this._wrapper.appendChild(this._canvas);

			let longTask = pdfjs.getDocument(_value);
			longTask.promise.then(pdf => {
				this.__pdfViewState.pdf = pdf;
				this._duration = this.__pdfViewState.pdf._pdfInfo.numPages; // initiate the pdf file viewer for the first time after loading

				this.__render(1).then(_ => {
					this.__pushEvent('loadedmetadata');
				});
			});
		}
		/**
		 * Render given page from pdf into the canvas container
		 *
		 * @param _page
		 * @private
		 */


		__render(_page) {
			if (!this.__pdfViewState.pdf) return;
			let p = _page || this.__pdfViewState.currentPage;
			let self = this;
			return this.__pdfViewState.pdf.getPage(p).then(page => {
				let canvasContext = self._canvas.getContext('2d');

				let viewport = page.getViewport({
					scale: self.__pdfViewState.zoom
				});
				self._canvas.width = viewport.width;
				self._canvas.height = viewport.height;
				page.render({
					canvasContext: canvasContext,
					viewport: viewport
				});
			});
		}
		/**
		 * Creates event and dispatches it
		 * @param _name
		 */


		__pushEvent(_name) {
			let event = document.createEvent("Event");
			event.initEvent(_name, true, true);
			this.dispatchEvent(event);
		}
		/**************************** PUBLIC ATTRIBUTES & METHODES *************************************************/

		/****************************** ATTRIBUTES **************************************/

		/**
		 * set src
		 * @param _value
		 */


		set src(_value) {
			Array.from(this._wrapper.children).forEach(_ch => {
				_ch.remove();
			});

			this.__buildPDFView(_value);
		}
		/**
		 * get src
		 * @return string returns comma separated sources
		 */


		get src() {
			return this.src;
		}
		/**
		 * currentTime
		 * @param _time
		 */


		set currentTime(_time) {
			let time = Math.floor(_time < 1 ? 1 : _time);

			if (time > this._duration) {
				// set ended state to true as it's the last page of pdf
				this._ended = true; // don't go further because it's litterally the last page

				return;
			} // set ended state to false as it's not the end of the pdf


			this._ended = false;
			this._currentTime = time;
			this.__pdfViewState.currentPage = time;

			this.__render(time);
		}
		/**
		 * get currentTime
		 * @return {number}
		 */


		get currentTime() {
			return this._currentTime;
		}
		/**
		 * get duration time
		 */


		get duration() {
			return this._duration;
		}
		/**
		 * get paused attribute
		 */


		get paused() {
			return this._paused;
		}
		/**
		 * set muted attribute
		 * @param _value
		 */


		set muted(_value) {
			return;
		}
		/**
		 * get muted attribute
		 */


		get muted() {
			return true;
		}

		set ended(_value) {
			this._ended = _value;
		}
		/**
		 * get ended attribute
		 */


		get ended() {
			return this._ended;
		}
		/**
		 * set playbackRate
		 * @param _value
		 */


		set playbackRate(_value) {
			this._playBackRate = _value * 1000;
		}
		/**
		 * get playbackRate
		 */


		get playbackRate() {
			return this._playBackRate;
		}
		/**
		 * set volume
		 */


		set volume(_value) {
			return;
		}
		/**
		 * get volume
		 */


		get volume() {
			return 0;
		}
		/************************************************* METHODES ******************************************/

		/**
		 * Play
		 */


		play() {
			this.__playing = true;
			let self = this;
			return new Promise(function (_resolve, _reject) {
				self.__playingInterval = window.setInterval(_ => {
					if (self.currentTime >= self._duration) {
						self.ended = true;
						self.pause();
					}

					self.currentTime += 1;

					self.__pushEvent('timeupdate');
				}, self._playBackRate);

				_resolve();
			});
		}
		/**
		 * pause
		 */


		pause() {
			this.__playing = false;
			this._paused = true;
			window.clearInterval(this.__playingInterval);
		}
		/**
		 * seek previous page
		 */


		prevPage() {
			this.currentTime -= 1;
		}
		/**
		 * seek next page
		 */


		nextPage() {
			this.currentTime += 1;
		}

	} // Define pdf-player element


	customElements.define('pdf-player', pdf_player);
});