/*** Highlight unreferenced passages ***/

(function(){

	// finds passages that lack references and marks them

	function markUnreferencedPassages(){

		// stylesheet to color passages lacking references

		function addStylesheet(){

			const stylesheet = document.createElement('style');

			stylesheet.innerHTML = `

			.has-no-references, .Template-Fact {

				background: LightPink;

			}

			`;

			document.head.appendChild(stylesheet);

		}

		

		// check whether references are relevant to the element 

		function isEligible(element, excludedSections){

			// exclude elements that are part of navboxes, sidebars, and the like

			// references do not matter for them

			if(hasParentClass(element, 'navbox')

				|| hasParentClass(element, 'sidebar')

				|| hasParentClass(element, 'infobox')

				|| hasParentClass(element, 'side-box-flex')

				|| hasParentClass(element, 'noprint')

				|| hasParentClass(element, 'refbegin')

				|| hasParentClass(element, 'gallery')

				|| hasParentClass(element, 'toc')

				|| hasParentClass(element, 'reflist')){

				return false;

			}

			

			// exclude elements that belong to certain sections where references do not matter

			const sectionName = getSectionName(element);

			if(excludedSections.indexOf(sectionName) != -1){

				return false;

			}

			

			return true;

		}

		

		// utility function to check whether the elements parents and grand parents have a certain class

		function hasParentClass(element, className){

			return element.closest('.' + className) != null;

		}

		

		// utility function to get the section name to which an element belongs

		function getSectionName(element){

			var mainContainerChildElement = getGrandchildOfMainContainer(element);

			var sectionName = ''; // default section name, this corresponds to the lead

			var previousElement = mainContainerChildElement.previousElementSibling;

			

			// sections always start with an h2 element

			// the script loops back from an element to the previous element until an h2 element is discovered

			while(previousElement != null){

				// check whether it is an h2 element

				if(previousElement.tagName == 'H2'){

					// extract the section name

					sectionName = previousElement.innerText.split('[edit]').join('');

					break;

				}

				previousElement = previousElement.previousElementSibling;

			}

			

			return sectionName;

		}

		

		// utility function: for any element, return the parent that is a grandchild of the main container

		function getGrandchildOfMainContainer(element){

			const mainContainer = document.getElementById('mw-content-text');

			if(element.parentElement.parentElement == mainContainer){

				return element;

			}

			else{

				return getGrandchildOfMainContainer(element.parentElement);

			}

		}

		

		// utility function to check whether the lead section of the article should be marked

		function shouldMarkLead(){

			// if it is a draft then the lead should be highlighted

			var pageTitleNamespace = document.getElementsByClassName('mw-page-title-namespace')[0];

			if(pageTitleNamespace != null){

				if(pageTitleNamespace.innerText === 'User' || pageTitleNamespace.innerText === 'Draft'){

					return true;

				}

			}

			

			// if it is a stub then the lead should be highlighted

			else if(document.getElementsByClassName('stub').length > 0){

				return true;

			}

			

			// otherwise not

			else {

				return false;

			}

		}

		

		// marks elements that lack references

		function mark(element){

			// mark elements without any reference elements

			if(element.getElementsByClassName('reference').length == 0){

				element.classList.add("has-no-references");

			}

			

			// mark elements with some reference elements

			else{

				// if the last element is not a reference then start marking it

				markUntilPreviousReference(element.lastChild);

				

				// starts from each "citation needed" tag, goes backwards and marks until it reaches a reference 

				var citationNeededTags = element.getElementsByClassName('Template-Fact');

				for(var citationNeededTag of citationNeededTags){

					markUntilPreviousReference(citationNeededTag);

				}

			}

		}

		

		// Function to mark unreferenced passages. It starts with one node and loops back to previous nodes until it hits a reference

		function markUntilPreviousReference(childNode){

			var currentNode = childNode;

			while(currentNode != null){

				// handle nodes that are not HTML elements

				if(currentNode.classList == null){

					// create a span element and classify it

					var span = document.createElement('span');

					span.classList.add("has-no-references");

					

					// copy the node's text into the span element and replace the node with the span element

					span.innerHTML = currentNode.data;

					currentNode.parentElement.replaceChild(span, currentNode);

					currentNode = span;

				}

				

				// handle nodes that are HTML elements

				// if the node is a reference

				else if(currentNode.classList.contains('reference')){

					

					// check whether the node is an actual reference: they contain numbers

					if(currentNode != null && 

						currentNode.innerText != null && 

						/[0-9]/.test(currentNode.innerText) &&

						!currentNode.innerText.toLowerCase().includes('note') &&

						!currentNode.innerText.toLowerCase().includes('nb')){

					

						break;

					}

					// otherwise it is an explanatory footnote and not a reference

					else{

						currentNode.classList.add('has-no-references');

					}

				}

				

				// if the node is an element but not a reference then classify it

				else {

					currentNode.classList.add('has-no-references');

				}

				

				// set the current node to the previous one to continue the loop

				currentNode = currentNode.previousSibling;

			}

		}

		

		// removes the red background from elements that were falsely highlighted

		function excludeFalsePositives(){		

			// exclude references used in nested lists

			var unreferencedElements = document.getElementsByClassName('has-no-references');

			for(let unreferencedElement of unreferencedElements){

				// if the element contains a reference inside then it is not unreferenced, so remove the class

				if(unreferencedElement.getElementsByClassName('reference').length > 0){

					unreferencedElement.classList.remove('has-no-references');

				}

			}

			

			// exclude quoteboxes

			unreferencedElements = document.getElementsByClassName('has-no-references');

			for(let unreferencedElement of unreferencedElements){

				// see if the the element is part of a quotebox that has a citation

				var quoteboxParent = unreferencedElement.closest('.quotebox');

				if(quoteboxParent != null && quoteboxParent.getElementsByTagName('cite').length > 0){

					unreferencedElement.classList.remove('has-no-references');

				}

			}

			

			// do not mark empty elements

			unreferencedElements = document.getElementsByClassName('has-no-references');

			for(let unreferencedElement of unreferencedElements){

					if(unreferencedElement.innerHTML == "\n" || unreferencedElement.innerHTML == " \n"){

						unreferencedElement.classList.remove('has-no-references');

					}

			}

			

			// exclude the template {{rp}}

			var referenceElements = document.getElementsByClassName('reference');

			for(let referenceElement of referenceElements){

				if(referenceElement.classList.contains('has-no-references')){

					referenceElement.classList.remove('has-no-references');

				}

			}

			

			// blockquotes often use a different reference style, so false positives need to be excluded separately

			const unreferencedParagraphsInsideBlockquotes = document.querySelectorAll('blockquote > p.has-no-references');

			for(var unreferencedParagraphInsideBlockquotes of unreferencedParagraphsInsideBlockquotes){

				const parent = unreferencedParagraphInsideBlockquotes.parentElement;

				// check whether the parent blockquote contains a citation element

				if(parent.getElementsByClassName('templatequotecite').length > 0){

					// if it does then the paragraph is not unreferenced

					unreferencedParagraphInsideBlockquotes.classList.remove('has-no-references');

				}

			}

			

			// ignore elements in the template "ombox"

			let unreferencedElementsInOmboxes = document.querySelectorAll(".ombox .has-no-references");

			for (let element of unreferencedElementsInOmboxes) {

			  element.classList.remove("has-no-references");

			}

			

			// for drafts: exclude comments

			var pageTitleNamespace = document.getElementsByClassName('mw-page-title-namespace')[0];

			if(pageTitleNamespace != null){

				if(pageTitleNamespace.innerText === 'User' || pageTitleNamespace.innerText === 'Draft'){

					let unreferencedComments = document.querySelectorAll(".has-no-references:has(.localcomments)");

					for (let unreferencedComment of unreferencedComments) {

					  unreferencedComment.classList.remove("has-no-references");

					}

				}

			}

		}

		

		addStylesheet();

		

		// all paragraphs and list entries should have references

		const paragraphs = document.getElementById('mw-content-text').getElementsByTagName('p');

		const listEntries = document.getElementById('mw-content-text').getElementsByTagName('li');

		const elements = Array.from(paragraphs).concat(Array.from(listEntries));

		

		// these sections are not checked for references

		var excludedSections = 'Plot', 'Plots', 'Plot summary', 'Plot synopsis', 'Synopsis', 'Storylines', 'Further reading', 'See also', 'External links', 'References', 'Bibliography', 'Notes', 'Selected publications', 'Selected works', 'Cited sources', 'Sources', 'Footnotes'];

		

		// dedice whether the lead should be checked for references

		if(!shouldMarkLead()){

			excludedSections.push('');

		}

		

		for(var element of elements){

			// check whether the element should be excluded

			if(isEligible(element, excludedSections)){

				// mark the element if it lacks references

				mark(element);

			}

		}

		

		excludeFalsePositives();

	}

	

	// restrict script to mainspace, userspace, and draftspace

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

	if (namespaceNumber === 0 || namespaceNumber === 2 || namespaceNumber === 118) {

		// add a link to the toolbox

		$.when(mw.loader.using('mediawiki.util'), $.ready).then(function (){

			var portletlink = mw.util.addPortletLink('p-tb', '#', 'Highlight unreferenced passages');

			

			// run the main function when the link is clicked

			portletlink.onclick = function(e) {

				e.preventDefault();

				markUnreferencedPassages();

				const unreferencedElements = document.getElementsByClassName('has-no-references');

				//mw.notify(`${unreferencedElements.length} elements were highlighted`);

				mw.notify('Highlighting finished.');

			};

		});

	}

	if (namespaceNumber === 0 || namespaceNumber === 118) {

		if(typeof highlightUnreferencedPassagesAutomatic != 'undefined' && highlightUnreferencedPassagesAutomatic == true){

			markUnreferencedPassages();

		}

	}

})();