/* Preview module for wikiEditor */
( function ( $, mw ) {
/*jshint onevar:false */
$.wikiEditor.modules.preview = {

	/**
	 * Compatability map
	 */
	browsers: {
		// Left-to-right languages
		ltr: {
			msie: [ [ '>=', 7 ] ],
			firefox: [ [ '>=', 3 ] ],
			opera: [ [ '>=', 9.6 ] ],
			safari: [ [ '>=', 4 ] ]
		},
		// Right-to-left languages
		rtl: {
			msie: [ [ '>=', 8 ] ],
			firefox: [ [ '>=', 3 ] ],
			opera: [ [ '>=', 9.6 ] ],
			safari: [ [ '>=', 4 ] ]
		}
	},

	/**
	 * Internally used functions
	 */
	fn: {
		/**
		 * Creates a preview module within a wikiEditor
		 *
		 * @param {Object} context Context object of editor to create module in
		 */
		create: function ( context ) {
			var api = new mw.Api();

			if ( 'initialized' in context.modules.preview ) {
				return;
			}
			context.modules.preview = {
				initialized: true,
				previewText: null,
				changesText: null
			};
			context.modules.preview.$preview = context.fn.addView( {
				name: 'preview',
				titleMsg: 'wikieditor-preview-tab',
				init: function ( context ) {
					// Gets the latest copy of the wikitext
					var wikitext = context.$textarea.textSelection( 'getContents' );
					// Aborts when nothing has changed since the last preview
					if ( context.modules.preview.previewText === wikitext ) {
						return;
					}
					context.modules.preview.$preview.find( '.wikiEditor-preview-contents' ).empty();
					context.modules.preview.$preview.find( '.wikiEditor-preview-loading' ).show();
					api.post( {
						action: 'parse',
						title: mw.config.get( 'wgPageName' ),
						text: wikitext,
						prop: 'text|modules',
						pst: ''
					} ).done( function ( data ) {
						if ( !data.parse || !data.parse.text || data.parse.text[ '*' ] === undefined ) {
							return;
						}

						context.modules.preview.previewText = wikitext;
						context.modules.preview.$preview.find( '.wikiEditor-preview-loading' ).hide();
						context.modules.preview.$preview.find( '.wikiEditor-preview-contents' )
							.html( data.parse.text[ '*' ] )
							.append( '<div class="visualClear"></div>' )
							.find( 'a:not([href^=#])' )
								.click( false );

						var loadmodules = data.parse.modules.concat(
							data.parse.modulescripts,
							data.parse.modulestyles
						);
						mw.loader.load( loadmodules );
					} );
				}
			} );

			context.$changesTab = context.fn.addView( {
				name: 'changes',
				titleMsg: 'wikieditor-preview-changes-tab',
				init: function ( context ) {
					// Gets the latest copy of the wikitext
					var wikitext = context.$textarea.textSelection( 'getContents' );
					// Aborts when nothing has changed since the last time
					if ( context.modules.preview.changesText === wikitext ) {
						return;
					}
					context.$changesTab.find( 'table.diff tbody' ).empty();
					context.$changesTab.find( '.wikiEditor-preview-loading' ).show();

					// Call the API. First PST the input, then diff it
					api.post( {
						action: 'parse',
						title: mw.config.get( 'wgPageName' ),
						onlypst: '',
						text: wikitext
					} ).done( function ( data ) {
						try {
							var postdata2 = {
								action: 'query',
								indexpageids: '',
								prop: 'revisions',
								titles: mw.config.get( 'wgPageName' ),
								rvdifftotext: data.parse.text[ '*' ],
								rvprop: ''
							};
							var section = $( '[name="wpSection"]' ).val();
							if ( section !== '' ) {
								postdata2.rvsection = section;
							}

							api.post( postdata2 )
							.done( function ( data ) {
								// Add diff CSS
								mw.loader.load( 'mediawiki.action.history.diff' );
								try {
									var diff = data.query.pages[ data.query.pageids[ 0 ] ]
										.revisions[ 0 ].diff[ '*' ];

									context.$changesTab.find( 'table.diff tbody' )
										.html( diff )
										.append( '<div class="visualClear"></div>' );
									context.modules.preview.changesText = wikitext;
								} catch ( e ) {
									// "data.blah is undefined" error, ignore
								}
								context.$changesTab.find( '.wikiEditor-preview-loading' ).hide();
							} );
						} catch ( e ) {
							// "data.blah is undefined" error, ignore
						}
					} );
				}
			} );

			var loadingMsg = mw.msg( 'wikieditor-preview-loading' );
			context.modules.preview.$preview
				.add( context.$changesTab )
				.append( $( '<div>' )
					.addClass( 'wikiEditor-preview-loading' )
					.append( $( '<img>' )
						.addClass( 'wikiEditor-preview-spinner' )
						.attr( {
							src: $.wikiEditor.imgPath + 'dialogs/loading.gif',
							valign: 'absmiddle',
							alt: loadingMsg,
							title: loadingMsg
						} )
					)
					.append(
						$( '<span>' ).text( loadingMsg )
					)
				)
				.append( $( '<div>' )
					.addClass( 'wikiEditor-preview-contents' )
				);
			context.$changesTab.find( '.wikiEditor-preview-contents' )
				.html( '<table class="diff"><col class="diff-marker"/><col class="diff-content"/>' +
					'<col class="diff-marker"/><col class="diff-content"/><tbody/></table>' );
		}
	}

};

}( jQuery, mediaWiki ) );