//This script uses material from Wikipedia user Ucucha's script "duplinks" ( /info/en/?search=User:Ucucha/duplinks.js ), which is released under the Creative Commons Attribution-Share-Alike License 3.0 ( http://creativecommons.org/licenses/by-sa/3.0/ )

//See also /info/en/?search=User:Ucucha/duplinks for documentation of the original script

$( function($) {

	var namespaceNumber = mw.config.get('wgNamespaceNumber');

	// only check links in mainspace, and userspace (for userspace drafts), and draftspace

	var isCorrectNamespace = namespaceNumber === 0 || namespaceNumber === 2 || namespaceNumber === 118;

	if (!isCorrectNamespace) {

		return;

	}

	mw.loader.using('mediawiki.util').then(function(){

		var portletlink = mw.util.addPortletLink('p-tb', '#', 'Highlight duplicate links', 'ca-findduplicatelinks');

		$(portletlink).click( function(e) {

			e.preventDefault();			

			// Check if VisualEditor is being used - the element surrounding text is different in VE

			var isVisualEditor = window.location.href.search("veaction")>0;

			// Get the element immediately surrounding the article text.

			var $content = isVisualEditor ? $(".ve-ce-documentNode.ve-ce-branchNode") : $($(".mw-parser-output", "#mw-content-text")[0])

			// Create a separate div to conatin the lead

			$lead = $("<div id='lead'>").prependTo($content);

			// Move the elements containing the lead content into this newly-created div

			$lead.nextAll().each( function() {

				if (this.nodeName.toLowerCase() == 'h2') {

					// Reached the first heading after the lead.

					// Returning false breaks out of the jQuery .each() loop early

					return false;

				}

				$lead.append(this);

				return true;

			});



			// Objects to keep track of whether we've seen a link before, and which links are duplicated

			var seen = {};

			var duplicated = {};

			var hasDuplicatedLinks = false;



			// Styles

			mw.util.addCSS(".duplicate-link { border: 1px solid red; }\n.duplicated-link { border: 1px dashed green; }");

			

			// Detect and mark links which are duplicates

			var finddups = function() {

				var href = this.attributes.href && this.attributes.href.value;

				if (href != undefined && href.indexOf('#') != 0) {

					if (seenhref]) {

						this.classList.add("duplicate-link");

						duplicatedhref = true;

						hasDuplicatedLinks = true;

					}

					else {

						seenhref = true;

					  }

				}

				return true;

			};

			// Detect and mark the first occurance of duplicated links

			var markdups = function() {

				var href = this.attributes.href && this.attributes.href.value;

				if(href != undefined && href.indexOf('#') != 0) {

					if(duplicatedhref]) {

						this.classList.add("duplicated-link");

						duplicatedhref = '';

					}

				}

				return true;

			};



			// Process sections after the lead

			mw.util.$content.find('p a').not('#lead *, .infobox *, .navbox *').each(finddups);

			mw.util.$content.find('p a').not('#lead *, .infobox *, .navbox *').each(markdups);

			

			// Reset tracking objects, process lead section

			seen = {};

			duplicated = {};

			mw.util.$content.find('#lead p a').not('.infobox *, .navbox *').each(finddups);

			mw.util.$content.find('#lead p a').not('.infobox *, .navbox *').each(markdups);



			// Show a notice if no duplicates were found

			if (!hasDuplicatedLinks) {

				mw.notify('No duplicated links were detected');

			}

		});

	});

});