// ==UserScript==
// @name         MB Auto Track Lengths
// @version      1.04
// @match        https://musicbrainz.org/release/*
// @match        https://beta.musicbrainz.org/release/*
// @match        https://musicbrainz.org/cdtoc/*
// @match        https://beta.musicbrainz.org/cdtoc/*
// @run-at       document-end
// @author       Anakunda
// @namespace    https://greasyfork.org/users/321857
// @copyright    2024, Anakunda (https://greasyfork.org/users/321857)
// @license      GPL-3.0-or-later
// @description  Autoset track lengths for media from unique CD-TOC when attached.
// @grant        GM_getValue
// @require      https://openuserjs.org/src/libs/Anakunda/xhrLib.min.js
// @downloadURL none
// ==/UserScript==

'use strict';

const flashElement = elem => elem instanceof HTMLElement ? elem.animate([
	{ offset: 0.0, opacity: 1 },
	{ offset: 0.4, opacity: 1 },
	{ offset: 0.5, opacity: 0.1 },
	{ offset: 0.9, opacity: 0.1 },
], { duration: 600, iterations: Infinity }) : null;
const getTime = str => str ? str.split(':').reverse().reduce((t, v, n) => t + parseInt(v) * Math.pow(60, n), 0) : NaN;

function processDocument(document, mode = 2) {
	function getRequestparams(link) {
		console.assert(link instanceof HTMLAnchorElement);
		if (!(link instanceof HTMLAnchorElement)) throw 'Invalid argument';
		const params = { discId: /^\/cdtoc\/([\w\_\.\-]+)\/set-durations$/i.exec(link.pathname) };
		if (params.discId != null) params.discId = params.discId[1]; else return null;
		const query = new URLSearchParams(link.search);
		if (!query.has('medium')) return null;
		console.assert(link.textContent.trim() == 'Set track lengths', link);
		params.mediumId = parseInt(query.get('medium'));
		console.assert(params.mediumId > 0, link.href);
		return params.mediumId >= 0 ? params : null;
	}

	const isDiscIdRow = row => row instanceof HTMLElement && ['odd', 'even'].some(cls => row.classList.contains(cls));
	const getSetLink = row => Array.prototype.find.call(row.querySelectorAll('td a'), a => getRequestparams(a) != null) || null;
	let rows = document.body.querySelectorAll('table.tbl > tbody > tr.subh'), groups = [ ];
	if (rows.length > 0) rows.forEach(function(row) {
		const discIds = [ ];
		while (isDiscIdRow(row = row.nextElementSibling)) discIds.push(getSetLink(row));
		groups.push(discIds);
	}); else {
		rows = document.body.querySelectorAll('table.tbl > tbody > tr');
		groups = Array.prototype.filter.call(rows, isDiscIdRow).map(getSetLink);
	}
	return groups.length > 0 ? Promise.all(groups.map(function(group) {
		function setTrackLengths(link, makeVotable = false) {
			console.assert(link instanceof HTMLAnchorElement);
			if (!(link instanceof HTMLAnchorElement)) throw 'Invalid argument';
			if (link.disabled) return Promise.resolve(undefined); else link.disabled = true;
			const animation = flashElement(link);
			return localXHR(link).then(function(document) {
				const deltas = Array.from(document.body.querySelectorAll('div#page > table.wrap-block.details'), function(track) {
					const times = ['old', 'new'].map(function(cls) {
						if ((cls = track.querySelector('td.' + cls)) != null) cls = cls.textContent; else return NaN;
						return getTime(cls);
					});
					return Math.abs(times[1] - times[0]);
				});
				return Promise[deltas.some(delta => delta > 5) ? 'reject' : 'resolve'](deltas);
			}).then(function(deltas) {
				if (mode == 1) return 10;
				const postData = new URLSearchParams({ 'confirm.edit_note': '' });
				if (makeVotable) postData.set('confirm.make_votable', 1);
				return localXHR(link, { responseType: null }, postData).then(function(statusCode) {
					let title = 'Status code: ' + statusCode;
					if (deltas.length > 0) title = 'Deltas: ' + deltas + '\n' + title;
					link.replaceWith(Object.assign(document.createElement('span'), {
						textContent: 'Track lengths successfully set',
						style: 'color: green;',
						title: title,
					}));
					return 20;
				});
			}).catch(function(reason) {
				if (animation != null) animation.cancel();
				link.style.color = 'red';
				link.title = reason;
				link.disabled = false;
				return Array.isArray(reason) ? reason.some(delta => delta > 30) ? -20 : -10 : -100;
			});
		}

		if (!(mode > 0) || group.length > 1) {
			for (let link of group.filter(Boolean)) link.onclick = function(evt) {
				setTrackLengths(link = evt.currentTarget)
					.then(status => { if (status <= -10) document.location.assign(link) });
				return false;
			};
			return 1;
		} else if (group.length > 0) group = group.filter(Boolean);
		return group.length == 1 ? setTrackLengths(group[0]) : 0;
	})) : Promise.reject('No disc ids found');
}

if (document.location.pathname.startsWith('/release/')) {
	function releaseScanned() {
		if (entity == null || scannedReleaseIds.includes(entity[2])) return;
		scannedReleaseIds.push(entity[2]);
		sessionStorage.setItem('scanned_discids', JSON.stringify(scannedReleaseIds));
	}

	let scannedReleaseIds = [ ];
	if ('scanned_discids' in sessionStorage) try {
		scannedReleaseIds = JSON.parse(sessionStorage.getItem('scanned_discids'));
	} catch(e) { console.warn(e) }
	const entity = /^\/(\w+)\/([\da-f]{8}-[\da-f]{4}-[\da-f]{4}-[\da-f]{4}-[\da-f]{12})(?=[\/\?]|$)/i.exec(document.location.pathname);
	console.assert(entity != null && entity[1] == 'release', document.location.pathname);
	let tabLinks = document.body.querySelectorAll('div#page ul.tabs > li a');
	tabLinks = Array.prototype.filter.call(tabLinks, a => a.href.endsWith('/discids'));
	console.assert(tabLinks.length == 1, tabLinks);
	if (document.location.pathname.endsWith('/discids')) processDocument(document);
	if (tabLinks.length == 1 && (entity == null || !scannedReleaseIds.includes(entity[2]))) (function(tabLink) {
		const li = tabLink.closest('li');
		console.assert(li != null);
		if (li.classList.contains('disabled')) {
			releaseScanned();
			return Promise.reject('Release has no disc ids attached');
		} else if (li.classList.contains('sel')) {
			releaseScanned();
			return Promise.reject('Disc ids is current tab');
		}
		const autoSet = GM_getValue('auto_set', true), animation = flashElement(tabLink);
		const processUrl = url => localXHR(url).then(document => processDocument(document, autoSet ? 2 : 1));
		const requestParams = new URLSearchParams({ inc: 'recordings+discids', fmt: 'json' })
		return localXHR(`/ws/2/${entity[1]}/${entity[2]}?${requestParams}`, { responseType: 'json' }).then(function(release) {
			const statuses = release.media.map(function(medium) {
				if (!medium.discs || medium.discs.length <= 0) return -2;
				const discIds = medium.discs.map(function(discId) {
					if (medium.tracks.every(function lengthsEqual(track, index, tracks) {
						if (typeof track.length != 'number') return false;
						const hiOffset = (index + 1) in discId.offsets ? discId.offsets[index + 1] : discId.sectors;
						const tocLength = Math.floor((hiOffset - discId.offsets[index]) * 1000 / 75);
						//console.debug('Track %d length: %d, TOC length: %d', (index + 1), track.length, tocLength);
						return track.length == tocLength;
					})) return 0;
					const deltas = medium.tracks.map(function lengthsEqual(track, index, tracks) {
						const length = 'length' in track ? typeof track.length == 'number' ? track.length / 1000
							: typeof track.length == 'string' ? getTime(track.length) : NaN : NaN;
						const hiOffset = (index + 1) in discId.offsets ? discId.offsets[index + 1] : discId.sectors;
						return Math.abs(((hiOffset - discId.offsets[index]) / 75) - length);
					});
					return deltas.some(delta => delta > 30) ? -20 : deltas.some(delta => delta > 5) ? -10 : autoSet ? 20 : 10;
				});
				return discIds.length > 1 ? 1 : discIds[0];
			});
			return statuses.some(status => status >= 20) ? processUrl(tabLink) : Promise.resolve(statuses);
		}).catch(function(reason) {
			console.warn('MB API request failed:', reason, ', falling back to scraping HTML');
			return processUrl(tabLink);
		}).then(function(statuses) {
			if (animation != null) animation.cancel();
			const tooltips = [ ];
			if (statuses.some(status => status == 20)) {
				li.style.backgroundColor = '#0f02';
				tooltips.push('TOC lengths successfully applied to tracks');
			}
			if (statuses.some(status => status <= -100)) {
				li.style.backgroundColor = '#f006';
				tooltips.push('Network error occured');
			} else if (statuses.some(status => status <= -10)) li.style.backgroundColor = '#f002';
			if (statuses.some(status => status == -20))
				tooltips.push('Potentially wrong TOC assigned (severe timing differences)');
			else if (statuses.some(status => status == -10))
				tooltips.push('Potentially wrong TOC assigned (considerable timing differences)');
			if (statuses.some(status => status == -2)) tooltips.push('Some media have no disc ids attached');
			if (statuses.some(status => status == 10)) {
				li.style.fontWeight = 'bold';
				tooltips.push('CD TOC available to apply');
			}
			if (statuses.some(status => status == 1))
				tooltips.push('Ambiguity: multiple TOCs attached to medium');
			if (statuses.some(status => status == 0))
				tooltips.push('TOC already applied');
			if (tooltips.length <= 0) tooltips.push('Status codes: ' + statuses);
			li.title = tooltips.join('\n');
			if (statuses.every(status => status > -10)) releaseScanned();
			return statuses;
		}, function(reason) {
			if (animation != null) animation.cancel();
			[li.style.color, li.style.backgroundColor] = ['white', 'red'];
			li.title = `Failed to scan disc ids (${reason})`;
			return Promise.reject(reason);
		});
	})(tabLinks[0]); else releaseScanned();
} else if (document.location.pathname.startsWith('/cdtoc/')) processDocument(document);