'use strict';

// based on [[User:RoySmith/tag-check.js]]
mw.loader.using(['mediawiki.api', 'mediawiki.storage', 'mediawiki.util']).then(function () {
	const title = mw.config.get('wgPageName');

	if (!/^Wikipedia:Sockpuppet_investigations\/[^\/]+/.test(title)) {
		return;
	}

	const IPV4REGEX = /^((?:1?\d\d?|2[0-4]\d|25[0-5])\b(?:\.(?:1?\d\d?|2[0-4]\d|25[0-5])){3})(?:\/(?:[12]?\d|3[0-2]))?$/;
	const IPV6REGEX = /^((?:[\dA-Fa-f]{1,4}:){7}[\dA-Fa-f]{1,4}|(?:[\dA-Fa-f]{1,4}:){1,7}:|(?:[\dA-Fa-f]{1,4}:){1,6}:[\dA-Fa-f]{1,4}|(?:[\dA-Fa-f]{1,4}:){1,5}(?:\:[\dA-Fa-f]{1,4}){1,2}|(?:[\dA-Fa-f]{1,4}:){1,4}(?:\:[\dA-Fa-f]{1,4}){1,3}|(?:[\dA-Fa-f]{1,4}:){1,3}(?:\:[\dA-Fa-f]{1,4}){1,4}|(?:[\dA-Fa-f]{1,4}:){1,2}(?:\:[\dA-Fa-f]{1,4}){1,5}|[\dA-Fa-f]{1,4}:(?:(?:\:[\dA-Fa-f]{1,4}){1,6}))(?:\/(1[6-9]|[2-9]\d|1[01]\d|12[0-8]))?$/; // based on https://stackoverflow.com/a/17871737
	const api = new mw.Api();
	const redirectMap = {
		sockmaster: 'sockpuppeteer',
		sock: 'sockpuppet',
		sockpuppetcheckuser: 'checked sockpuppet',
		checkedsockpuppet: 'checked sockpuppet',
		...(mw.storage.getObject('socktags-redirect-map') || {})
	};

	addCSS();
	processContent(document.getElementById('mw-content-text'));
	refreshRedirectMap();

	function addCSS() {
		mw.util.addCSS(`
			span[class^="socktag-"] {
				display: inline-block;
				width: 1.4em;
				height: 1.4em;
				line-height: 1.4em;
				text-align: center;
				font-size: 1em;
				font-weight: bold;
				font-family: monospace;
				border-radius: 2px;
				margin-right: 4px;
				vertical-align: middle;
				border: 1px solid darkgrey;
				color: #000;
			}
			.socktag-type-master::before { content: "M"; }
			.socktag-type-puppet::before { content: "P"; }
			.socktag-status-banned { background-color: #b080ff; }
			.socktag-status-blocked { background-color: #ffff66; }
			.socktag-status-confirmed { background-color: #ff3300; }
			.socktag-status-proven { background-color: #ffcc99; }
			.socktag-status-suspected { background-color: #ffffff; }
			.socktag-status-unknown { background-color: #ffffff; }
		`);
	}

	async function processContent(content) {
		const userMap = new Map();
		// collect all usernames and elements
		const entries = content.querySelectorAll('span.cuEntry');
		for (const entry of entries) {
			const userLinks = entry.querySelectorAll('a[href*="/User:"]');
			for (const userNode of userLinks) {
				const username = userNode.textContent.trim();
				if (!username || ipAddress(username)) continue;

				if (!userMap.has(username)) {
					userMap.set(username, []);
				}
				userMap.get(username).push(userNode);
			}
		}
		// for each unique user, fetch parse tree and decorate all their nodes
		await Promise.all(
			Array.from(userMap.entries()).map(async ([username, nodes]) => {
				const parseTree = await getParseTree('User:' + username);
				if (!parseTree) return;
				const tags = getTags(parseTree);
				if (!tags.length) return;
				for (const userNode of nodes) {
					for (const tag of tags) {
						userNode.parentNode.insertBefore(createTagSpan(tag), userNode);
					}
				}
			})
		);
	}

	function ipAddress(input) {
		return IPV4REGEX.test(input) || IPV6REGEX.test(input);
	}

	async function getParseTree(pageTitle) {
		try {
			const response = await api.get({
				action: 'parse',
				page: pageTitle,
				prop: 'parsetree',
				formatversion: 2
			});
			if (!response || !response.parse || typeof response.parse.parsetree !== 'string') {
				console.debug('No parse tree found in response for', pageTitle);
				return null;
			}
			const parseTreeXml = response.parse.parsetree;
			const parser = new DOMParser();
			const xmlDoc = parser.parseFromString(parseTreeXml, 'application/xml');
			if (xmlDoc.getElementsByTagName('parsererror').length) {
				console.warn('XML parse error in getParseTree for', pageTitle);
				return null;
			}
			return xmlDoc;
		} catch (error) {
			if (error !== 'missingtitle') {
				console.warn('Failed to get parse tree for', pageTitle, error);
			}
			return null;
		}
	}

	function getTags(parseTree) {
		const templates = parseTree.getElementsByTagName('template');
		const tags = [];
		let unmatched = 0;
		for (const template of templates) {
			const rawTemplateName = template.getElementsByTagName('title')[0]?.textContent;
			if (!rawTemplateName) continue;
			const templateName = resolveRedirect(rawTemplateName.trim().toLowerCase());
			switch (templateName) {
				case 'sockpuppeteer':
					tags.unshift({
						type: 'master',
						status: extractParam(template, '1', true) || 'suspected'
					});
					break;
				case 'sockpuppet':
					const altmaster = extractParam(template, 'altmaster');
					tags.push({
						type: 'puppet',
						master: extractParam(template, '1'),
						status: extractParam(template, '2', true) || 'unknown',
						altmaster,
						altstatus: extractParam(template, 'altmaster-status', true) || (altmaster ? 'unknown' : null)
					});
					break;
				case 'checked sockpuppet':
					tags.push({
						type: 'puppet',
						status: 'confirmed',
						master: extractParam(template, '1')
					});
					break;
				default:
					if (++unmatched >= 5) return tags;
					continue;
			}
			if (tags.length >= 2) return tags;
			unmatched = 0;
		}
		return tags;
	}

	function extractParam(template, target, lowercase = false) {
		const parts = template.getElementsByTagName('part');
		for (const part of parts) {
			const nameNode = part.getElementsByTagName('name')[0];
			const name = nameNode?.getAttribute('index') ?? nameNode?.textContent.trim();
			if (name === target) {
				const value = part.getElementsByTagName('value')[0]?.textContent.trim();
				return lowercase ? value?.toLowerCase() : value;
			}
		}
		return null;
	}

	function resolveRedirect(templateName) {
		return redirectMap[templateName] || templateName;
	}

	function createTagSpan(tag) {
		const span = document.createElement('span');
		span.classList.add('socktag-type-' + tag.type);
		span.classList.add('socktag-status-' + tag.status);
		let title = tag.status;
		if (tag.master) {
			title += ' (' + tag.master + ')';
		}
		if (tag.altmaster) {
			title += ' / ' + tag.altstatus + ' (' + tag.altmaster + ')';
		}
		span.title = title;
		return span;
	}

	async function refreshRedirectMap() {
		if (Math.abs(Date.now() - (redirectMap?.__timestamp || 0)) < 2592000000) {
			return;
		}
		const templates = ['Sockpuppeteer', 'Sockpuppet', 'Checked sockpuppet'];
		const map = {};
		for (const base of templates) {
			const baseKey = base.toLowerCase();
			for (const redirect of await getRedirects(base)) {
				const redirectKey = redirect.toLowerCase();
				if (redirectKey !== baseKey && await isUsedOnUserPage(redirect)) {
					map[redirectKey] = baseKey;
				}
			}
		}
		map.__timestamp = Date.now();
		mw.storage.setObject('socktags-redirect-map', map, 15552000);
	}

	async function getRedirects(template) {
		const res = await api.get({
			action: 'query',
			list: 'backlinks',
			bltitle: 'Template:' + template,
			blnamespace: 10,
			blfilterredir: 'redirects',
			bllimit: 'max'
		});
		return res.query.backlinks.map(b => b.title.replace(/^Template:/, ''));
	}

	async function isUsedOnUserPage(template) {
		const res = await api.get({
			action: 'query',
			list: 'embeddedin',
			eititle: 'Template:' + template,
			einamespace: 2,
			eilimit: 1
		});
		return res.query.embeddedin.length > 0;
	}
});