/*
 * This file is part of the MediaWiki extension MultimediaViewer.
 *
 * MultimediaViewer is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * MultimediaViewer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with MultimediaViewer.  If not, see <http://www.gnu.org/licenses/>.
 */

const { EmbedFileFormatter, Utils } = require( 'mmv.ui.ondemandshareddependencies' );
const { UiElement } = require( 'mmv' );

( function () {

	/**
	 * UI component that provides the user html/wikitext snippets needed to share
	 * and/or embed a media asset.
	 */
	class Embed extends UiElement {
		/**
		 * @param {jQuery} $container
		 */
		constructor( $container ) {
			super( $container );

			/**
			 * Formatter converting image data into formats needed for output
			 *
			 * @property {EmbedFileFormatter}
			 */
			this.formatter = new EmbedFileFormatter();

			Utils.createHeader( mw.message( 'multimediaviewer-embed-tab' ).text() )
				.appendTo( $container );

			const $body = $( '<div>' )
				.addClass( 'cdx-dialog__body mw-mmv-pt-0 mw-mmv-pb-150' )
				.appendTo( $container );

			this.createSnippetSelectionButtons( $body );
			this.createSizePulldownMenus( $body );
			this.createSnippetTextAreas( $body );
		}

		/**
		 * Creates text areas for html and wikitext snippets.
		 *
		 * @param {jQuery} $container
		 */
		createSnippetTextAreas( $container ) {
			[ this.$embedTextHtml, this.$embedTextHtmlDiv ] = Utils.createInputWithCopy(
				mw.message( 'multimediaviewer-reuse-copy-embed' ).text(),
				mw.message( 'multimediaviewer-reuse-loading-placeholder' ).text()
			);
			this.$embedTextHtml.attr( 'title', mw.message( 'multimediaviewer-embed-explanation' ).text() );

			[ this.$embedTextWikitext, this.$embedTextWikitextDiv ] = Utils.createInputWithCopy(
				mw.message( 'multimediaviewer-reuse-copy-embed' ).text(),
				mw.message( 'multimediaviewer-reuse-loading-placeholder' ).text()
			);
			this.$embedTextWikitext.attr( 'title', mw.message( 'multimediaviewer-embed-explanation' ).text() );

			$container.append(
				this.$embedTextHtmlDiv,
				this.$embedTextWikitextDiv
			);
		}

		/**
		 * Creates snippet selection buttons.
		 *
		 * @param {jQuery} $container
		 */
		createSnippetSelectionButtons( $container ) {
			const $embedSwitch = $( '<div>' ).addClass( 'cdx-tabs mw-mmv-mb-75' ).appendTo( $container );
			const $embedSwitchHeader = $( '<div>' ).addClass( 'cdx-tabs__header' ).appendTo( $embedSwitch );
			this.$embedSwitchList = $( '<div>' ).addClass( 'cdx-tabs__list' ).attr( 'role', 'tablist' ).appendTo( $embedSwitchHeader );
			[ 'wikitext', 'html' ].forEach( ( name ) => $( '<button>' )
				.addClass( 'cdx-tabs__list__item' )
				.attr( 'role', 'tab' )
				.data( 'name', name )
				.text( mw.message( name === 'wikitext' ? 'multimediaviewer-embed-wt' : 'multimediaviewer-embed-html' ).text() )
				.on( 'click', () => this.handleTypeSwitch( name ) )
				.appendTo( this.$embedSwitchList )
			);
		}

		/**
		 * Creates pulldown menus to select file sizes.
		 *
		 * @param {jQuery} $container
		 */
		createSizePulldownMenus( $container ) {
			// Wikitext sizes pulldown menu
			this.$embedSizeSwitchWikitext = Utils.createSelectMenu(
				[ 'default', 'small', 'medium', 'large' ],
				'default'
			);

			// Html sizes pulldown menu
			this.$embedSizeSwitchHtml = Utils.createSelectMenu(
				[ 'small', 'medium', 'large', 'original' ],
				'original'
			);

			$( '<div>' ).addClass( 'mw-mmv-flex mw-mmv-mb-75' ).append(
				this.$embedSizeSwitchHtml,
				this.$embedSizeSwitchWikitext
			).appendTo( $container );
		}

		/**
		 * Registers listeners.
		 */
		attach() {
			// Logged-out defaults to 'html', logged-in to 'wikitext'
			this.handleTypeSwitch( mw.user.isAnon() ? 'html' : 'wikitext' );

			// Register handlers for switching between file sizes
			this.$embedSizeSwitchHtml.on( 'change', () => this.handleSizeSwitch() );
			this.$embedSizeSwitchWikitext.on( 'change', () => this.handleSizeSwitch() );
		}

		/**
		 * Clears listeners.
		 */
		unattach() {
			super.unattach();

			this.$embedSizeSwitchHtml.off( 'change' );
			this.$embedSizeSwitchWikitext.off( 'change' );
		}

		/**
		 * Handles size menu change events.
		 */
		handleSizeSwitch() {
			// eslint-disable-next-line no-jquery/no-sizzle
			const $html = this.$embedSizeSwitchHtml.find( ':selected' );
			if ( $html.length ) {
				this.updateEmbedHtml( {}, $html.data( 'width' ), $html.data( 'height' ) );
			}
			// eslint-disable-next-line no-jquery/no-sizzle
			const $wikitext = this.$embedSizeSwitchWikitext.find( ':selected' );
			if ( $wikitext.length ) {
				this.updateEmbedWikitext( $wikitext.data( 'width' ) );
			}
		}

		/**
		 * Handles snippet type switch.
		 *
		 * @param {string} value 'html' or 'wikitext'
		 */
		handleTypeSwitch( value ) {
			this.$embedSwitchList.children().each( ( _i, element ) => {
				const $element = $( element );
				$element.attr( 'aria-selected', $element.data( 'name' ) === value );
			} );

			this.$embedTextHtmlDiv.toggle( value === 'html' );
			this.$embedSizeSwitchHtml.toggle( value === 'html' );

			this.$embedTextWikitextDiv.toggle( value === 'wikitext' );
			this.$embedSizeSwitchWikitext.toggle( value === 'wikitext' );
		}

		/**
		 * Reset current menu selection to default item.
		 */
		resetCurrentSizeMenuToDefault() {
			this.$embedSizeSwitchWikitext.val( 'default' );
			this.$embedSizeSwitchHtml.val( 'original' );
			this.handleSizeSwitch();
		}

		/**
		 * Sets the HTML embed text.
		 *
		 * Assumes that the set() method has already been called to update this.embedFileInfo
		 *
		 * @param {Thumbnail} thumbnail (can be just an empty object)
		 * @param {number} width New width to set
		 * @param {number} height New height to set
		 */
		updateEmbedHtml( thumbnail, width, height ) {
			if ( !this.embedFileInfo ) {
				return;
			}

			let src = thumbnail.url || this.embedFileInfo.imageInfo.url;

			// If the image dimension requested are "large", use the current image url
			if ( width > Embed.LARGE_IMAGE_WIDTH_THRESHOLD || height > Embed.LARGE_IMAGE_HEIGHT_THRESHOLD ) {
				src = this.embedFileInfo.imageInfo.url;
			}

			this.$embedTextHtml.val(
				this.formatter.getThumbnailHtml( this.embedFileInfo, src, width, height )
			);
		}

		/**
		 * Updates the wikitext embed text with a new value for width.
		 *
		 * Assumes that the set method has already been called.
		 *
		 * @param {number} width
		 */
		updateEmbedWikitext( width ) {
			if ( !this.embedFileInfo ) {
				return;
			}

			this.$embedTextWikitext.val(
				this.formatter.getThumbnailWikitextFromEmbedFileInfo( this.embedFileInfo, width )
			);
		}

		/**
		 * Gets size options for html and wikitext snippets.
		 *
		 * @param {number} width
		 * @param {number} height
		 * @return {Object}
		 * @return {Object} return.html Collection of possible image sizes for html snippets
		 * @return {Object} return.wikitext Collection of possible image sizes for wikitext snippets
		 */
		getSizeOptions( width, height ) {
			const sizes = {};

			sizes.html = Utils.getPossibleImageSizesForHtml( width, height );
			sizes.wikitext = this.getPossibleImageSizesForWikitext( width, height );

			return sizes;
		}

		/**
		 * Sets the data on the element.
		 *
		 * @param {Image} image
		 * @param {Repo} repo
		 * @param {string} [caption]
		 * @param {string} [alt]
		 */
		set( image, repo, caption, alt ) {
			const sizes = this.getSizeOptions( image.width, image.height );

			this.embedFileInfo = { imageInfo: image, repoInfo: repo };
			if ( caption ) {
				this.embedFileInfo.caption = caption;
			}
			if ( alt ) {
				this.embedFileInfo.alt = alt;
			}

			Utils.updateSelectOptions( sizes.html, this.$embedSizeSwitchHtml.children() );
			Utils.updateSelectOptions( sizes.wikitext, this.$embedSizeSwitchWikitext.children() );

			// Reset defaults
			this.resetCurrentSizeMenuToDefault();

			Utils.getThumbnailUrlPromise( this.LARGE_IMAGE_WIDTH_THRESHOLD )
				.done( ( thumbnail ) => {
					this.updateEmbedHtml( thumbnail );
				} );
		}

		/**
		 * @inheritdoc
		 */
		empty() {
			this.$embedTextHtml.val( '' );
			this.$embedTextWikitext.val( '' );

			this.$embedSizeSwitchHtml.toggle( false );
			this.$embedSizeSwitchWikitext.toggle( false );
		}

		/**
		 * Calculates possible image sizes for wikitext snippets. It returns up to
		 * three possible snippet frame sizes (small, medium, large).
		 *
		 * @param {number} width
		 * @param {number} height
		 * @return {Object}
		 * @return {Object} return.small
		 * @return {Object} return.medium
		 * @return {Object} return.large
		 */
		getPossibleImageSizesForWikitext( width, height ) {
			const buckets = {
				small: 300,
				medium: 400,
				large: 500
			};
			const sizes = {};
			const widthToHeight = height / width;

			for ( const bucketName in buckets ) {
				const bucketWidth = buckets[ bucketName ];

				if ( width > bucketWidth ) {
					sizes[ bucketName ] = {
						width: bucketWidth,
						height: Math.round( bucketWidth * widthToHeight )
					};
				}
			}

			sizes.default = { width: null, height: null };

			return sizes;
		}
	}

	/**
	 * @property {number} Width threshold at which an image is to be considered "large"
	 * @static
	 */
	Embed.LARGE_IMAGE_WIDTH_THRESHOLD = 1200;

	/**
	 * @property {number} Height threshold at which an image is to be considered "large"
	 * @static
	 */
	Embed.LARGE_IMAGE_HEIGHT_THRESHOLD = 900;

	module.exports = Embed;
}() );