/**
 * [[ВП:Гаджеты/Упрощение ссылок]]
 */

mw.loader.using( 'ext.gadget.registerTool' ).done( function () {
	window.urlDecoderRun = function ( input ) { // main function

		// 2nd-lvl WMF domains; old secure link: .../wikipedia/mediawiki,
		// .../wikipedia/foundation
		var wmDomain = {
			mediawiki: 'mw',
			wikidata: 'd',
			wikisource: 's:mul',
			wikimediafoundation: 'foundation'
		};

		/*
		 * 2nd-lvl WMF domains with multiple languages; old secure link:
		 * wikinews/en
		 */
		var wmDomainM = {
			wikipedia: 'w',
			wikibooks: 'b',
			wikinews: 'n',
			wikiquote: 'q',
			wikisource: 's',
			wikiversity: 'v',
			wikivoyage: 'voy',
			wiktionary: 'wikt'
		};

		/*
		 * 3rd-lvl WMF domains on .wikimedia.org; for some reason old secure
		 * link is wikipedia
		 */
		var wmSubDomains = /^(meta|commons|incubator|species|strategy|wikitech)$/;

		var newText, oldText, rx, isBeforeCursor = false, colonNS, selectionRange,
			// any chars except []<>" and \n and spaces
			httpRegExp = '(https?:\\/\\/[^\\]\\[\\n\\r<>" ]+)',
			localPrefix = WMPrefixes( unSecure( mw.config.get( 'wgServer' ).replace( /^\/\//, 'http://' ) + mw.config.get( 'wgScript' ) ) ),
			tbox = $( input || '#wpTextbox1' ).focus(),
			caretPos = tbox.textSelection( 'getCaretPosition', {
				startAndEnd: true
			} ),
			selectionStartPos = caretPos[0],
			selectionEndPos = caretPos[1];
			
		if (selectionStartPos !== selectionEndPos) { // there was selection
			oldText = tbox.textSelection( 'getSelection' ); 
			rx = RegExp( '(\\[{0,2})' + httpRegExp + '([^\\]\\[\\n\\r]*?\\]\\]?)?', 'ig' );
			newText = oldText.replace( rx, simplifyMatched );

			if ( window.urlDecoderIntLinks ) {
				var ut = '(' + mw.config.get( 'wgFormattedNamespaces' )[3].replace( / /g, '_' ) + '|user_talk)'; // both
				/* localized and canonical 'user_talk' */
				ut = RegExp( '\\[\\[' + ut.toLowerCase() + ':[^#]+$', 'i' );
				newText = newText.replace( /\[\[[^\]\|\n]+/g, function( lnk ) {
					return ut.test( lnk ) ? lnk : decodeAnchor( lnk ); // skip
					// user_talk,
					// usually
					// found in
					// signatures
				} );
			}
			if ( newText == oldText ) {
				return;
			}
			
		} else { // process all text
				
			var content = tbox.textSelection( 'getContents');
			isBeforeCursor = true;

			// search for http string containing cursor
			rx = new RegExp( '(\\[{0,2})' + httpRegExp + '([^\\]\\[\\n\\r]*?\\]\\]?)?', 'ig' );
			while ((ma = rx.exec( content )) !== null) {
				if ((ma.index <= selectionStartPos) && (selectionStartPos <= (ma.index + ma[0].length))) {
					break;
				}
			}
			
			// (whole
			// string)'
			// '[',
			// 'http:...',
			// '
			// name]'
			if ( !ma ) {
				return;
			}
			oldText = ma[0];
			if ( ma[3] ) { // link with name: automatically add brackets
				newText = simplifyMatched( ma[0], '[', ma[2], ma[3] + ']' );
			} else { // just url: add closing bracket only if there is leading bracket
				newText = simplifyMatched( ma[0], ma[1], ma[2], ma[1] ? ']' : '' );
			}

			if ( oldText == newText ) {
				return;
			}
			selectionStartPos = ma.index;
			selectionEndPos = selectionStartPos + oldText.length;
		}
		
		tbox.textSelection( 'setSelection', {
			start: selectionStartPos,
			end: selectionEndPos
		} );
		// replace text
		tbox.textSelection( 'encapsulateSelection', {
			replace: true,
			peri: newText
		} );
		
		// FIXME: restructure
		if ( selectionRange ) {
			tbox.textSelection( 'setSelection', {
				start: selectionEndPos - oldText.length + selectionRange[0],
				end: selectionEndPos - oldText.length + selectionRange[1]
			} );
		}

		// end of main code
		return;

		// ---FUNCTIONS

		function simplifyMatched( str, bracket, url, rest ) { // arguments:
			// (whole
			// string), '[',
			// url, ' name]'
			if ( !bracket ) {// no brackets, just url
				var trail = RegExp( '[' + ',;\\\\\.:!\\?' + // trailing
				// punctuation,
				// per Parser.php
				( /\(/.test( url ) ? '' : '\\)' ) + // also closing bracket
				// without
				// opening bracket
				']+$' + "|''+$" // or possible bold/italic at the end of url
				).exec( url );
				if ( trail ) {
					url = url.substring( 0, url.length - trail[0].length ); // move
					// these
					// out
					// of
					// url
				}
				return decodeUrl( url ) + str.substring( url.length );

			} else if ( rest ) { // both brackets and possibly name
				return decodeUrl( url, rest.replace( /\]+$|^ +| +$/g, '' ) ); // trim
				// ending
				// brackets
				// and
				// spaces
				// in
				// 'name]'
			} else {
				return str; // probably broken wikicode in selected text
			}
		}

		function decodeUrl( url, name ) { // url -> %-decoded -> [[link|name]]
			// (if
			// possible); name is optional

			var decodingFailed; // need to skip some strange percent-encoded
			// URIs
			url = unSecure( url );

			// percent-decoding
			if ( url.indexOf( '%' ) !== -1 ) {
				try {
					url = decodeURI( url );
					url = url.replace( /%(3B|2F|2C|3A)/g, decodeURIComponent ); // decode
					// ;/,:
					url = url.replace( /[ <>"\[\]\n\r]/g, encodeURIComponent ); // "
					/*
					 * some disallowed chars can screw template params
					 */
				} catch ( e ) {
					decodingFailed = true;
				}
			}

			if ( isBeforeCursor ) { // user-defined conversion to eng keywords
				for ( var n in window.urlDecoderEngNames ) {
					url = url.replace( RegExp( '(title=|wiki\/)(' + window.urlDecoderEngNames[n] + ':)' ), '$1' + n + ':' );
				}
			}

			// try converting to internal link
			var linkOrArr, link, isIwTemplate;
			// trailing | or }} could mean a part of a template, skip to be safe
			if ( !decodingFailed && !/(\}\}|\|)$/.test( url ) ) {
				// FIXME: restructure
				linkOrArr = toWikilink( url );
				if ( linkOrArr !== null && typeof linkOrArr === 'object' ) {
					isIwTemplate = linkOrArr[0];
					link = linkOrArr[1];
				} else {
					link = linkOrArr;
				}
			}

			if ( isIwTemplate ) {
				return link.replace( '||', '|' + ( name ? name : '' ) + '|' );
			}

			// user-defined function
			if ( window.urlDecoderCustom ) {
				url = urlDecoderCustom( url );
				if ( !/^(https?:\/\/|\{\{)/.test( url ) ) {
					link = url; // was converted to internal link
					isIwTemplate = false;
				}
			}

			// return internal link
			if ( link ) {
				link = link.replace( /%(3f|26|22)/ig, decodeURIComponent ); // decode ?&"
				if ( ( mw.config.get( 'wgNamespaceNumber' ) === 0 || mw.config.get( 'wgNamespaceNumber' ) == 14 ) && isBeforeCursor ) {
					link = link.replace( /^:/, '' ); // probably user adding
					// interwiki
				}
				return '[[' + link + ( name ? '|' + name : '' ) + ']]';
			}

			// or return external link
			if ( typeof name == 'string' ) {
				if ( isBeforeCursor ) {
					url = url.replace( /''/g, '%27%27' ); // techically ''
					// should
					// stop URL, but more
					// likely it's part of
					// it
				}
				return '[' + url + ( name ? ' ' + name : '' ) + ']'; // empty
				// name
			} else {
				return url;
			}

		}

		function toWikilink( url ) { // 'http://xx.wikipedia.org/wiki/YY' ->
			// xx:YY

			// add bugzilla to user-defined prefixes
			var urlDecoderPrefixes = $.extend( window.urlDecoderPrefixes, {
				'https://bugzilla.wikimedia.org/show_bug.cgi?id=': 'mediazilla',
				'wikidata.org/wiki/': 'd',
				'phabricator.wikimedia.org/': 'phab',
				'translatewiki.net/wiki/': 'translatewiki',
				'ru.wikimedia.org/wiki/': 'wmru'
			} );

			// apply user-defined prefixes
			for ( var key in urlDecoderPrefixes ) {
				if ( url.toLowerCase().indexOf( key ) !== -1 ) {
					return urlDecoderPrefixes[key] + ':' + url.substring( url.indexOf( key ) + key.length );
				}
			}

			// check if we can convert to internal link with WM prefixes
			var ma = /^(https?:\/\/[^\/]+)\/wiki\/([^?]+)$/.exec( url ); // 1:'http://domain.org'
			// 2:part
			// after
			// /wiki/
			if ( !ma ) {
				return null;
			}
			var linkPrefix = WMPrefixes( ma[1] );
			if ( !linkPrefix ) {
				return null;
			}

			var title = decodeAnchor( ma[2] );
			if ( mw.config.get( 'wgServerName' ) === 'ru.wikipedia.org' &&
				// namespaces: main, "Portal", "Incubator"
				[ 0, 100, 102 ].indexOf( mw.config.get( 'wgNamespaceNumber' ) ) !== -1 &&
				linkPrefix[0] === 'w' &&
				linkPrefix[1] !== 'ru'
			) {
				title = title.replace( /%(3f|26|22)/ig, decodeURIComponent ); // decode ?&"
				selectionRange = [ 5, 5 + title.length ];
				return [ true, '{{iw|' + title + '||' + linkPrefix[1] + '|' + title + '}}' ];
			} else {
				// convert to internal
				var prefixes = '';
				if ( linkPrefix[0] && ( linkPrefix[0] !== localPrefix[0] ) ) {
					prefixes = linkPrefix[0];
				}
				if ( linkPrefix[1] && ( linkPrefix[1] !== localPrefix[1] ) ) {
					prefixes += ':' + linkPrefix[1];
				}
				if ( prefixes || isColonNeeded( title ) ) {
					prefixes += ':'; // colon after prefix or leading colon on
					// cat/file link
				}
				return prefixes + title;
			}

		}

		function decodeAnchor( link ) { // simplify internal link: replace %20
			// and _
			// then decode anchor
			link = link.replace( /(_|%20)/g, ' ' ).replace( /^ +| +$/g, '' );
			var parts = link.split( '#' );
			if ( parts.length !== 2 ) {
				return link; // no anchor
			}
			var anchor = parts[1], hidIdx = -1, hidden = [];
			// decode 4, 3 and 2-byte: http://en.wikipedia.org/wiki/UTF-8
			anchor = anchor.replace( /\.F[0-4]\.[89AB][\dA-F]\.[89AB][\dA-F]\.[89AB][\dA-F]/g, deChar );
			anchor = anchor.replace( /\.E[\dA-F]\.[89AB][\dA-F]\.[89AB][\dA-F]/g, deChar );
			anchor = anchor.replace( /\.[CD][\dA-F]\.[89AB][\dA-F]/g, deChar );
			anchor = anchor
					.replace(
							// hide IPs
							/(?:^|[^0-9A-F\.])(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)/,
							function( s ) {
								hidden[++hidIdx] = s;
								return '\x01' + hidIdx + '\x02';
							} );
			// decode 1-byte chars: all symbols except -.:_ and []{} prohibited
			// in
			// links
			anchor = anchor.replace( /\.[2-7][0-9A-F]/g, function( hhh ) {
				var ch = deChar( hhh );
				if ( '!"#$%&\'()*+,/;<=>?@\\^`~'.indexOf( ch ) >= 0 ) {
					return ch;
				} else {
					return hhh;
				}
			} );
			// unhide IPs and return
			for ( var i = hidIdx; i >= 0; i-- ) {
				anchor = anchor.replace( '\x01' + i + '\x02', hidden[i] );
			}
			if ( anchor.indexOf( "''" ) !== -1 ) {
				return link; // cannot have double '' in link
			} else {
				return parts[0] + '#' + anchor;
			}

			function deChar( ss ) {
				try {
					ss = decodeURIComponent( ss.replace( /\.([0-9A-F][0-9A-F])/g, '%$1' ) );
				} catch ( e ) {
				}
				return ss;
			}
		}

		function WMPrefixes( url ) { // http: //en.wikipedia.org/wiki/... ->
			// [
			// 'w', 'en']
			var dd = /^https?:\/\/([a-z\.]+)\.org/.exec( url.toLowerCase() );
			if ( !dd ) {
				return null;
			}
			dd = dd[1].split( '.' ); // domains, e.g. ['en','wikipedia']
			if ( dd.length > 3 ) {
				return null; // too many subdomains
			}

			var lang = '', proj = '', domain = dd.pop(), subdomain = dd.pop();
			
			if ( subdomain === 'm' ) {
				subdomain = dd.pop();
			} else if ( subdomain === 'www' ) {
				subdomain = '';
			}

			if ( domain == 'wikimedia' ) { // *.wikimedia.org
				if ( !subdomain ) {
					proj = 'foundation';
				} else if ( wmSubDomains.test( subdomain ) ) {
					proj = subdomain;
				} else {
					return null;
				}

			} else if ( ( proj = wmDomain[domain] ) && !subdomain ) { // mediawiki.org
				// &
				// wikimediafoundation.org
				// done: proj is set

			} else if ( proj = wmDomainM[domain] ) { // multi-lang domains
				if ( !subdomain ) {
					// done: e.g. 'wikisource.org'
				} else if ( proj == 'w' && subdomain == 'test' ) {
					proj = 'testwiki';
				} else if ( subdomain.length >= 2 ) {
					lang = subdomain;
				} else {
					return null;
				}

			} else {
				return null; // unrecognized domain
			}

			return [ proj, lang ];
		}

		function unSecure( url ) {
			var mm = /https:\/\/secure\.wikimedia\.org\/(\w+)\/(\w+)\/([^\]\|\n\r ]+)/i.exec( url );
			if ( !mm ) {
				return url;
			}
			var domain = mm[1].toLowerCase(), sub = mm[2].toLowerCase();

			if ( !wmDomainM[domain] ) {
				return url; // domain not recognized
			}

			if ( domain == 'wikipedia' ) { // handle some special cases
				switch ( sub ) {
				case 'mediawiki':
					sub = 'www';
					domain = 'mediawiki';
					break;
				case 'foundation':
					sub = '';
					domain = 'wikimediafoundation';
					break;
				case 'sources':
					sub = '';
					domain = 'wikisource';
					break;
				default:
					if ( wmSubDomains.test( sub ) ) {
						domain = 'wikimedia'; // .../wikipedia/meta ->
						// meta.wikimedia.org
					}
					// otherwise: consider it language: .../wikipedia/en
				}
			}

			return 'http://' + ( sub ? sub + '.' : '' ) + domain + '.org/' + mm[3];
		}

		function isColonNeeded( pg ) {
			if ( !/:/.test( pg ) ) {
				return false;
			}
			if ( !colonNS ) { // define list of all possible category and file
				// namespaces
				var list = [ 'file', 'category' ]; // canonical aliases
				for ( var name in mw.config.get( 'wgNamespaceIds' ) ) {
					if ( ( mw.config.get( 'wgNamespaceIds' )[name] == 6 || mw.config.get( 'wgNamespaceIds' )[name] == 14 ) && $.inArray( name, list ) == -1 ) {
						list.push( name );
					}
				}
				colonNS = RegExp( '^(' + list.join( '|' ) + ') *:', 'i' );
			}
			return colonNS.test( $.trim( pg ) );
		}

	};

	registerTool( {
		name: 'urldecoder',
		position: 200,
		title: 'Раскодировать URL',
		label: 'Раскодировать URL перед курсором или все URL в выделенном тексте',
		callback: urlDecoderRun,
		classic: {
			icon: '//upload.wikimedia.org/wikipedia/commons/0/01/Link_go_remake.png',
		},
		visual: {
			icon: '//upload.wikimedia.org/wikipedia/commons/thumb/3/3d/URL_decoder_VE_icon.svg/20px-URL_decoder_VE_icon.svg.png',
			modes: [ 'source' ],
		},
	} );
} );