// ==UserScript==

// @name           Import Discogs releases to MusicBrainz
// @description    Add a button to import Discogs releases to MusicBrainz and add links to matching MusicBrainz entities for various Discogs entities (artist,release,master,label)
// @version        2021.8.10.1
// @namespace      http://userscripts.org/users/22504
// @downloadURL    https://raw.githubusercontent.com/murdos/musicbrainz-userscripts/master/discogs_importer.user.js
// @updateURL      https://raw.githubusercontent.com/murdos/musicbrainz-userscripts/master/discogs_importer.user.js
// @include        http*://www.discogs.com/*
// @include        http*://*.discogs.com/*release/*
// @exclude        http*://*.discogs.com/*release/*?f=xml*
// @exclude        http*://www.discogs.com/release/add
// @require        https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js
// @require        lib/mbimport.js
// @require        lib/logger.js
// @require        lib/mblinks.js
// @require        lib/mbimportstyle.js
// @icon           https://raw.githubusercontent.com/murdos/musicbrainz-userscripts/master/assets/images/Musicbrainz_import_logo.png
// ==/UserScript==

// prevent JQuery conflicts, see http://wiki.greasespot.net/@grant
this.$ = this.jQuery = jQuery.noConflict(true);

const DEBUG = false;
if (DEBUG) {
    LOGGER.setLevel('debug');
}

////////////////////////////////////////////////////////////////////////////////////////////////////////

/*
 * Test cases:
 * - http://www.discogs.com/release/1566223 : Artist credit of tracks contains an ending ',' join phrase
 */

const mbLinks = new MBLinks('DISCOGS_MBLINKS_CACHE', '1');

$(document).ready(function () {
    MBImportStyle();
    MBSearchItStyle();

    const current_page_key = getDiscogsLinkKey(
        window.location.href.replace(/\?.*$/, '').replace(/#.*$/, '').replace('/master/view/', '/master/')
    );
    if (!current_page_key) return;

    // disable evil pjax (used for artist page navigation)
    // it causes various annoying issues with our code;
    // it should be possible to react to pjax events
    $('div#pjax_container').attr('id', 'pjax_disabled');

    // Display links of equivalent MusicBrainz entities
    insertMBLinks(current_page_key);

    // Add an import button in a new section in sidebar, if we're on a release page
    let current_page_info = link_infos[current_page_key];
    if (current_page_info.type === 'release') {
        // Discogs Webservice URL
        let discogsWsUrl = `https://api.discogs.com/releases/${current_page_info.id}`;

        $.ajax({
            url: discogsWsUrl,
            dataType: 'json',
            crossDomain: true,
            success: data => {
                LOGGER.debug('Discogs JSON Data from API:', data);
                try {
                    let release = parseDiscogsRelease(data);
                    insertMBSection(release, current_page_key);
                } catch (e) {
                    $('div.musicbrainz').remove();
                    let mbUI = $('<div class="section musicbrainz"><h3>MusicBrainz</h3></div>').hide();
                    let mbContentBlock = $('<div class="section_content"></div>');
                    mbUI.append(mbContentBlock);
                    let mbError = $(
                        `<p><small>${e}<br /><b>Please <a href="https://github.com/murdos/musicbrainz-userscripts/issues">report</a> this error, along the current page URL.</b></small></p>`
                    );
                    mbContentBlock.prepend(mbError);
                    insertMbUI(mbUI);
                    mbError.css({ 'background-color': '#fbb', 'margin-top': '4px', 'margin-bottom': '4px' });
                    mbUI.slideDown();
                    throw e;
                }
            },
            error: function (jqXHR, textStatus, errorThrown) {
                LOGGER.error('AJAX Status: ', textStatus);
                LOGGER.error('AJAX error thrown: ', errorThrown);
            },
        });
    }
});

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                              Display links of equivalent MusicBrainz entities                                      //
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

// Insert MusicBrainz links in a section of the page
function insertMBLinks(current_page_key) {
    function searchAndDisplayMbLinkInSection($tr, discogs_type, mb_type, nosearch) {
        if (!mb_type) mb_type = defaultMBtype(discogs_type);
        $tr.find(`a[mlink^="${discogs_type}/"]`).each(function () {
            const $link = $(this);
            if ($link.attr('mlink_stop')) return; // for places
            const mlink = $link.attr('mlink');
            // ensure we do it only once per link
            const done = ($link.attr('mlink_done') || '').split(',');
            for (let i = 0; i < done.length; i++) {
                if (mb_type == done[i]) return;
            }
            done.push(mb_type);
            $link.attr(
                'mlink_done',
                done
                    .filter(function (e) {
                        return e != '';
                    })
                    .join(',')
            );
            if (link_infos[mlink] && link_infos[mlink].type === discogs_type) {
                const discogs_url = link_infos[mlink].clean_url;
                let cachekey = getCacheKeyFromInfo(mlink, mb_type);
                const has_wrapper = $link.closest('span.mb_wrapper').length;
                if (!has_wrapper) {
                    $link.wrap('<span class="mb_wrapper"><span class="mb_valign"></span></span>');
                }
                if (!nosearch) {
                    // add search link for the current link text
                    const entities = {
                        artist: { mark: 'A' },
                        release: { mark: 'R' },
                        'release-group': { mark: 'G' },
                        place: { mark: 'P' },
                        label: { mark: 'L' },
                    };
                    let mark = '';
                    let entity_name = 'entity';
                    if (mb_type in entities) {
                        mark = entities[mb_type].mark;
                        entity_name = mb_type.replace(/[_-]/g, ' ');
                    }
                    $link
                        .closest('span.mb_wrapper')
                        .prepend(
                            `<span class="mb_valign mb_searchit"><a class="mb_search_link" target="_blank" title="Search this ${entity_name} on MusicBrainz (open in a new tab)" href="${MBImport.searchUrlFor(
                                mb_type,
                                $link.text()
                            )}"><small>${mark}</small>?</a></span>`
                        );
                }
                const insert_normal = function (link) {
                    $link.closest('span.mb_valign').before(`<span class="mb_valign">${link}</span>`);
                    $link.closest('span.mb_wrapper').find('.mb_searchit').remove();
                };

                const insert_stop = function (link) {
                    insert_normal(link);
                    $link.attr('mlink_stop', true);
                };

                let insert_func = insert_normal;
                if (mb_type == 'place') {
                    // if a place link was added we stop, we don't want further queries for this 'label'
                    insert_func = insert_stop;
                }
                mbLinks.searchAndDisplayMbLink(discogs_url, mb_type, insert_func, cachekey);
            }
        });
    }

    function debug_color(what, n, id) {
        let colors = [
            '#B3C6FF',
            '#C6B3FF',
            '#ECB3FF',
            '#FFB3EC',
            '#FFB3C6',
            '#FFC6B3',
            '#FFECB3',
            '#ECFFB3',
            '#C6FFB3',
            '#B3FFC6',
            '#B3FFEC',
            '#B3ECFF',
            '#7598FF',
        ];
        if (DEBUG) {
            $(what).css('border', `2px dotted ${colors[n % colors.length]}`);
            let debug_attr = $(what).attr('debug_discogs');
            if (!id) id = '';
            if (debug_attr) {
                $(what).attr('debug_discogs', `${debug_attr} || ${id}(${n})`);
            } else {
                $(what).attr('debug_discogs', `${id}(${n})`);
            }
        }
    }

    let add_mblinks_counter = 0;
    function add_mblinks(_root, selector, types, nosearch) {
        // types can be:
        // 'discogs type 1'
        // ['discogs_type 1', 'discogs_type 2']
        // [['discogs_type 1', 'mb type 1'], 'discogs_type 2']
        // etc.
        if (!$.isArray(types)) {
            // just one string
            types = [types];
        }
        $.each(types, function (idx, val) {
            if (!$.isArray(val)) {
                types[idx] = [val, undefined];
            }
        });

        LOGGER.debug(`add_mblinks: ${selector} / ${JSON.stringify(types)}`);

        _root.find(selector).each(function () {
            const node = $(this).get(0);
            magnifyLinks(node);
            debug_color(this, ++add_mblinks_counter, selector);
            const that = this;
            $.each(types, function (idx, val) {
                const discogs_type = val[0];
                const mb_type = val[1];
                searchAndDisplayMbLinkInSection($(that), discogs_type, mb_type, nosearch);
            });
        });
    }

    // Find MB link for the current page and display it next to page title
    let mbLinkInsert = function (link) {
        const $h1 = $('h1');
        const $titleSpan = $h1.children('span[itemprop="name"]');
        if ($titleSpan.length > 0) {
            $titleSpan.before(link);
        } else {
            $h1.prepend(link);
        }
    };
    const current_page_info = link_infos[current_page_key];
    const mb_type = defaultMBtype(current_page_info.type);
    const cachekey = getCacheKeyFromInfo(current_page_key, mb_type);
    mbLinks.searchAndDisplayMbLink(current_page_info.clean_url, mb_type, mbLinkInsert, cachekey);

    const $root = $('body');
    // artist/label/master pages, release pages (before the 2021-08-09 update)
    add_mblinks($root, 'div.profile', ['artist', 'label']);
    add_mblinks($root, 'tr[data-object-type="release"] td.artist,td.title', 'artist');
    add_mblinks($root, 'tr[data-object-type="release"] td.title', 'release');
    add_mblinks($root, 'tr[data-object-type="release"]', 'label');
    add_mblinks($root, 'tr[data-object-type~="master"]', ['master', 'artist', 'label']);
    // release pages (since the 2021-08-09 update)
    add_mblinks($root, '#release-header', ['artist', 'label']);
    setInterval(() => add_mblinks($root, '#release-other-versions', ['artist', 'release', 'label']), 500); // Discogs loads this dynamically, wait a moment
    add_mblinks($root, '#release-tracklist', 'artist');
    add_mblinks($root, '#release-companies', [['label', 'place'], 'label']);
    add_mblinks($root, '#release-credits', ['label', 'artist']);
    add_mblinks($root, '#release-actions', 'master', true);
    // release pages (before the 2021-08-09 update, TODO: remove after the new layout becomes permanent)
    add_mblinks($root, 'div#tracklist', 'artist');
    add_mblinks($root, 'div#companies', [['label', 'place'], 'label']);
    add_mblinks($root, 'div#credits', ['label', 'artist']);
    add_mblinks($root, 'div#page_aside div.section_content:first', 'master', true);
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                                 Normalize Discogs URLs in a DOM tree                                               //
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
let mlink_processed = 0;

// Normalize Discogs URLs in a DOM tree
function magnifyLinks(rootNode) {
    if (!rootNode) {
        rootNode = document.body;
    }

    // Check if we already added links for this content
    if (rootNode.hasAttribute('mlink_processed')) return;
    rootNode.setAttribute('mlink_processed', ++mlink_processed);

    let elems = rootNode.getElementsByTagName('a');
    for (let i = 0; i < elems.length; i++) {
        let elem = elems[i];

        // Ignore empty links
        if (!elem.href || $.trim(elem.textContent) === '' || elem.textContent.substring(4, 0) === 'http') continue;
        if (!elem.hasAttribute('mlink')) {
            elem.setAttribute('mlink', getDiscogsLinkKey(elem.href));
        }
    }
}

// contains infos for each link key
const link_infos = {};

// Parse discogs url to extract info, returns a key and set link_infos for this key
// the key is in the form discogs_type/discogs_id
function getDiscogsLinkKey(url) {
    const re = /^https?:\/\/(?:www|api)\.discogs\.com\/(?:(?:(?!sell).+|sell.+)\/)?(master|release|artist|label)s?\/(\d+)(?:[^?#]*)(?:\?noanv=1|\?anv=[^=]+)?$/i;
    const m = re.exec(url);
    if (m !== null) {
        const key = `${m[1]}/${m[2]}`;
        if (!link_infos[key]) {
            link_infos[key] = {
                type: m[1],
                id: m[2],
                clean_url: `https://www.discogs.com/${m[1]}/${m[2]}`,
            };
            LOGGER.debug(`getDiscogsLinkKey:${url} --> ${key}`);
        } else {
            LOGGER.debug(`getDiscogsLinkKey:${url} --> ${key} (key exists)`);
        }
        return key;
    }
    LOGGER.debug(`getDiscogsLinkKey:${url} ?`);
    return false;
}

function getCleanUrl(url, discogs_type) {
    try {
        const key = getDiscogsLinkKey(url);
        if (key) {
            if (!discogs_type || link_infos[key].type === discogs_type) {
                LOGGER.debug(`getCleanUrl: ${key}, ${url} --> ${link_infos[key].clean_url}`);
                return link_infos[key].clean_url;
            } else {
                LOGGER.debug(`getCleanUrl: ${key}, ${url} --> unmatched type: ${discogs_type}`);
            }
        }
    } catch (err) {
        LOGGER.error(err);
    }
    LOGGER.debug(`getCleanUrl: ${url} (${discogs_type}) failed`);
    return false;
}

function defaultMBtype(discogs_type) {
    if (discogs_type === 'master') return 'release-group';
    return discogs_type;
}

function getCacheKeyFromInfo(info_key, mb_type) {
    const inf = link_infos[info_key];
    if (inf) {
        if (!mb_type) mb_type = defaultMBtype(inf.type);
        return `${inf.type}/${inf.id}/${mb_type}`;
    }
    return '';
}

function getCacheKeyFromUrl(url, discogs_type, mb_type) {
    try {
        const key = getDiscogsLinkKey(url);
        if (key) {
            if (!discogs_type || link_infos[key].type == discogs_type) {
                const cachekey = getCacheKeyFromInfo(key, mb_type);
                LOGGER.debug(`getCacheKeyFromUrl: ${key}, ${url} --> ${cachekey}`);
                return cachekey;
            } else {
                LOGGER.debug(`getCacheKeyFromUrl: ${key}, ${url} --> unmatched type: ${discogs_type}`);
            }
        }
    } catch (err) {
        LOGGER.error(err);
    }
    LOGGER.debug(`getCacheKeyFromUrl: ${url} (${discogs_type}) failed`);
    return false;
}

function MBIDfromUrl(url, discogs_type, mb_type) {
    const cachekey = getCacheKeyFromUrl(url, discogs_type, mb_type);
    if (!cachekey) return '';
    return mbLinks.resolveMBID(cachekey);
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                             Insert MusicBrainz section into Discogs page                                           //
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

function insertMbUI(mbUI) {
    let e;
    if ((e = $('#release-marketplace')) && e.length) {
        e.before(mbUI);
    }
    // FIXME: the following selectors are broken since the 2021-08-09 release page update, not sure why there are three alternative selectors
    else if ((e = $('div.section.collections')) && e.length) {
        e.after(mbUI);
    } else if ((e = $('#statistics')) && e.length) {
        e.before(mbUI);
    } else if ((e = $('div.section.social')) && e.length) {
        e.before(mbUI);
    }
}

// Insert links in Discogs page
function insertMBSection(release, current_page_key) {
    const current_page_info = link_infos[current_page_key];

    const mbUI = $('<div class="section musicbrainz"><header><h3>MusicBrainz</h3></header></div>').hide();

    if (DEBUG) mbUI.css({ border: '1px dotted red' });

    const mbContentBlock = $('<div class="section_content"></div>');
    mbUI.append(mbContentBlock);

    if (release.maybe_buggy) {
        const warning_buggy = $(
            '<p><small><b>Warning</b>: this release has perhaps a buggy tracklist, please check twice the data you import.</small><p'
        ).css({ color: 'red', 'margin-top': '4px', 'margin-bottom': '4px' });
        mbContentBlock.prepend(warning_buggy);
    }

    // Form parameters
    const edit_note = MBImport.makeEditNote(current_page_info.clean_url, 'Discogs');
    const parameters = MBImport.buildFormParameters(release, edit_note);

    // Build form + search button
    const innerHTML = `<div id="mb_buttons">${MBImport.buildFormHTML(parameters)}${MBImport.buildSearchButton(release)}</div>`;
    mbContentBlock.append(innerHTML);

    insertMbUI(mbUI);

    // FIXME: duplicates some of Discogs' CSS because they seem to use dynamically generated class names since the 2021-08-09 release page update
    $('.musicbrainz header').css({
        // Discogs selector is ".header_W2hzl" (at least now and for me)
        'border-bottom': '1px solid #e5e5e5',
        'padding-left': '5px',
    });
    $('.musicbrainz h3').css({
        // Discogs selector is ".header_W2hzl h3"
        'font-size': '15px',
        'line-height': '20px',
        margin: '0 0 0 -5px',
        padding: '5px',
    });
    $('#mb_buttons').css({
        display: 'inline-block',
        width: '100%',
        'margin-top': '5px', // FIXME: related to the above CSS hacks
    });
    $('form.musicbrainz_import').css({ width: '49%', display: 'inline-block' });
    $('form.musicbrainz_import_search').css({ float: 'right' });
    $('form.musicbrainz_import > button').css({ width: '100%', 'box-sizing': 'border-box' });

    mbUI.slideDown();
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                                               Parsing of Discogs data                                              //
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

function cleanup_discogs_artist_credit(obj) {
    // Fix some odd Discogs release (e.g. http://api.discogs.com/releases/1566223) that have a ',' join phrase after the last artist
    // Discogs set a join phrase even there's only one artist or when extraartists is set (ie. remix)
    const last = obj.artist_credit.length - 1;
    if (last === 0 || obj.artist_credit[last].joinphrase === ', ') {
        obj.artist_credit[last].joinphrase = '';
    }
}

// Returns the name without the numerical suffic Discogs adds as disambiguation
// ie. "ABC (123)" -> "ABC"
function artistNoNum(artist_name) {
    return artist_name.replace(/ \(\d+\)$/, '');
}

// Parse a US date string and set object properties year, month, day
function parse_YYYY_MM_DD(date, obj) {
    if (!date) return;
    const m = date.split(/\D+/, 3).map(function (e) {
        return parseInt(e, 10);
    });
    if (m[0] !== undefined) {
        obj.year = m[0];
        if (m[1] !== undefined) {
            obj.month = m[1];
            if (m[2] !== undefined) {
                obj.day = m[2];
            }
        }
    }
}

// Analyze Discogs data and return a release object
function parseDiscogsRelease(discogsRelease) {
    const release = {
        discs: [],
    };

    //buggy tracklist indicator, used to warn user
    release.maybe_buggy = false;

    // Release artist credit
    release.artist_credit = [];
    $.each(discogsRelease.artists, function (index, artist) {
        let ac = {
            artist_name: artistNoNum(artist.name),
            credited_name: artist.anv != '' ? artist.anv : artistNoNum(artist.name),
            joinphrase: decodeDiscogsJoinphrase(artist.join),
            mbid: MBIDfromUrl(artist.resource_url, 'artist'),
        };
        if (artist.id === 194) {
            // discogs place holder for various
            ac = MBImport.specialArtist('various_artists', ac);
        }
        release.artist_credit.push(ac);
    });
    cleanup_discogs_artist_credit(release);

    // ReleaseGroup
    if (discogsRelease.master_url) {
        release.release_group_mbid = MBIDfromUrl(discogsRelease.master_url, 'master');
    }

    // Release title
    release.title = discogsRelease.title;

    // Release date
    if (discogsRelease.released) {
        parse_YYYY_MM_DD(discogsRelease.released, release);
    }

    // Release country
    if (discogsRelease.country) {
        release.country = Countries[discogsRelease.country];
    }

    // Release labels
    release.labels = [];
    if (discogsRelease.labels) {
        $.each(discogsRelease.labels, function (index, label) {
            const labelInfo = {
                name: label.name,
                catno: label.catno === 'none' ? '[none]' : label.catno,
                mbid: MBIDfromUrl(label.resource_url, 'label'),
            };
            release.labels.push(labelInfo);
        });
    }

    // Release URL
    release.urls = [{ url: getCleanUrl(discogsRelease.uri, 'release'), link_type: MBImport.URL_TYPES.discogs }];

    // Release format
    let release_formats = [];
    release.secondary_types = [];

    if (discogsRelease.formats.length > 0) {
        for (let i = 0; i < discogsRelease.formats.length; i++) {
            // Release format
            const discogs_format = discogsRelease.formats[i].name;
            let mb_format = undefined;
            if (discogs_format in MediaTypes) {
                mb_format = MediaTypes[discogs_format];
            }

            if (discogsRelease.formats[i].descriptions) {
                $.each(discogsRelease.formats[i].descriptions, function (index, desc) {
                    if (!(discogs_format in ['Box Set'])) {
                        // Release format: special handling of Vinyl and Shellac 7", 10" and 12"
                        if (desc.match(/7"|10"|12"/) && discogs_format.concat(desc) in MediaTypes)
                            mb_format = MediaTypes[discogs_format.concat(desc)];
                        // Release format: special handling of specific CD/DVD formats
                        if (desc.match(/^VCD|SVCD|CD\+G|HDCD|DVD-Audio|DVD-Video/) && desc in MediaTypes) mb_format = MediaTypes[desc];
                    }
                    // Release format: special handling of Vinyl, LP == 12" (http://www.discogs.com/help/submission-guidelines-release-format.html#LP)
                    if (discogs_format === 'Vinyl' && desc === 'LP') {
                        mb_format = '12" Vinyl';
                    }
                    // Release format: special handling of CD, Mini == 8cm CD
                    if (discogs_format === 'CD' && desc === 'Mini') {
                        mb_format = '8cm CD';
                    }
                    // Release status
                    if (desc.match(/Promo|Smplr/)) {
                        release.status = 'promotion';
                    }
                    if (desc.match(/Unofficial Release/)) {
                        release.status = 'bootleg';
                    }
                    // Release type
                    if (desc.match(/Compilation/)) {
                        release.secondary_types.push('compilation');
                    }
                    if (desc.match(/^Album/)) {
                        release.type = 'album';
                    }
                    if (desc.match(/Single(?! Sided)/)) {
                        release.type = 'single';
                    }
                    if (desc.match(/EP|Mini-Album/)) {
                        release.type = 'ep';
                    }
                });
            }

            if (mb_format) {
                for (let j = 0; j < discogsRelease.formats[i].qty; j++) {
                    release_formats.push(mb_format);
                }
            }

            // Release packaging
            if (discogsRelease.formats[i].text) {
                const freetext = discogsRelease.formats[i].text.toLowerCase().replace(/[\s-]/g, '');
                if (freetext.match(/cardboard|paper/)) {
                    release.packaging = 'cardboard/paper sleeve';
                } else if (freetext.match(/digi[\s\-‐]?pac?k/)) {
                    release.packaging = 'digipak';
                } else if (freetext.match(/keepcase/)) {
                    release.packaging = 'keep case';
                } else if (freetext.match(/jewel/)) {
                    release.packaging = freetext.match(/slim/) ? 'slim jewel case' : 'jewel case';
                } else if (freetext.match(/gatefold|digisleeve/)) {
                    release.packaging = 'gatefold cover';
                }
            }
        }
    }

    // Barcode
    if (discogsRelease.identifiers) {
        $.each(discogsRelease.identifiers, function (index, identifier) {
            if (identifier.type === 'Barcode') {
                release.barcode = identifier.value.replace(/ /g, '');
                return false;
            }
        });
    }

    // Inspect tracks
    let heading = '';
    let releaseNumber = 1;
    let lastPosition = 0;
    $.each(discogsRelease.tracklist, function (index, discogsTrack) {
        if (discogsTrack.type_ === 'heading') {
            heading = discogsTrack.title;
            return;
        }
        if (discogsTrack.type_ !== 'track' && discogsTrack.type_ !== 'index') {
            return;
        }

        let track = {};

        track.title = discogsTrack.title.replace(/´/g, '’');
        track.duration = MBImport.hmsToMilliSeconds(discogsTrack.duration); // MB in milliseconds

        // Track artist credit
        track.artist_credit = [];
        if (discogsTrack.artists) {
            $.each(discogsTrack.artists, function (index, artist) {
                const ac = {
                    artist_name: artistNoNum(artist.name),
                    credited_name: artist.anv !== '' ? artist.anv : artistNoNum(artist.name),
                    joinphrase: decodeDiscogsJoinphrase(artist.join),
                    mbid: MBIDfromUrl(artist.resource_url, 'artist'),
                };
                track.artist_credit.push(ac);
            });
            cleanup_discogs_artist_credit(track);
        }

        // Track position and release number
        let trackPosition = discogsTrack.position;

        // Handle sub-tracks
        if (trackPosition === '' && discogsTrack.sub_tracks) {
            trackPosition = discogsTrack.sub_tracks[0].position;
            // Append titles of sub-tracks to main track title
            const subtrack_titles = [];
            let subtrack_total_duration = 0;
            $.each(discogsTrack.sub_tracks, function (subtrack_index, subtrack) {
                if (subtrack.type_ !== 'track') {
                    return;
                }
                if (subtrack.duration) {
                    subtrack_total_duration += MBImport.hmsToMilliSeconds(subtrack.duration);
                }
                if (subtrack.title) {
                    subtrack_titles.push(subtrack.title);
                } else {
                    subtrack_titles.push('[unknown]');
                }
            });
            if (subtrack_titles.length) {
                if (track.title) {
                    track.title += ': ';
                }
                track.title += subtrack_titles.join(' / ');
            }
            if (isNaN(track.duration) && !isNaN(subtrack_total_duration)) {
                track.duration = subtrack_total_duration;
            }
        }

        // Skip special tracks
        if (trackPosition.match(/^(?:video|mp3)/i)) {
            trackPosition = '';
        }

        // Possible track position:
        // A1 or A    => Vinyl or Cassette : guess releaseNumber from vinyl side
        // 1-1 or 1.1 => releaseNumber.trackNumber
        // 1          => trackNumber
        let buggyTrackNumber = false;
        const tmp = trackPosition.match(/(\d+|[A-Z])(?:[.-]+(\d+))?/i);
        if (tmp) {
            tmp[1] = parseInt(tmp[1], 10);
            let prevReleaseNumber = releaseNumber;

            if (Number.isInteger(tmp[1])) {
                if (tmp[2]) {
                    // 1-1, 1-2, 2-1, ... - we can get release number and track number from this
                    releaseNumber = tmp[1];
                    lastPosition = parseInt(tmp[2], 10);
                } else if (tmp[1] <= lastPosition) {
                    // 1, 2, 3, ... - We've moved onto a new medium
                    releaseNumber++;
                    lastPosition = tmp[1];
                } else {
                    lastPosition = tmp[1];
                }
            } else {
                if (trackPosition.match(/^[A-Z]\d*$/i)) {
                    // Vinyl or cassette, handle it specially
                    // A,B -> 1; C,D -> 2; E,F -> 3, etc...
                    releaseNumber = (((32 | trackPosition.charCodeAt(0)) - 97) >> 1) + 1;
                    lastPosition++;
                } else if (trackPosition.match(/^[A-Z]+\d*$/i)) {
                    // Vinyl or cassette, handle it specially
                    // something like AA1, exemple : http://www.discogs.com/release/73531
                    // TODO: find a better fix
                    buggyTrackNumber = true;
                }
            }

            if (releaseNumber > release_formats.length) {
                // something went wrong in track position parsing
                buggyTrackNumber = true;
                releaseNumber = prevReleaseNumber;
            }
            if (buggyTrackNumber) {
                // well, it went wrong so ...
                lastPosition++;
            }
        }

        // Create release if needed
        let discindex = releaseNumber - 1;
        if (!release.discs[discindex]) {
            let newdisc = {
                tracks: [],
                format: release_formats[discindex],
            };
            if (heading) {
                newdisc.title = heading;
                heading = '';
            }
            release.discs.push(newdisc);
        }

        // Track number (only for Vinyl and Cassette)
        if (
            buggyTrackNumber ||
            (release.discs[discindex].format.match(/(Vinyl|Cassette)/) && discogsTrack.position.match(/^[A-Z]+[.-]?\d*/i))
        ) {
            track.number = discogsTrack.position;
        }

        // Trackposition is empty e.g. for release title
        if (trackPosition !== '' && trackPosition != null) {
            release.discs[discindex].tracks.push(track);
        }

        if (buggyTrackNumber && !release.maybe_buggy) {
            release.maybe_buggy = true;
        }
    });

    if (release.discs.length === 1 && release.discs[0].title) {
        // remove title if there is only one disc
        // https://github.com/murdos/musicbrainz-userscripts/issues/69
        release.discs[0].title = '';
    }

    LOGGER.info('Parsed release: ', release);
    return release;
}

function decodeDiscogsJoinphrase(join) {
    let joinphrase = '';
    const trimedjoin = join.replace(/^\s*/, '').replace(/\s*$/, '');
    if (trimedjoin === '') {
        return trimedjoin;
    }
    if (trimedjoin !== ',') {
        joinphrase += ' ';
    }
    joinphrase += trimedjoin;
    joinphrase += ' ';
    return joinphrase;
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                                   Discogs -> MusicBrainz mapping                                                   //
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

const MediaTypes = {
    '8-Track Cartridge': 'Cartridge',
    Acetate: 'Vinyl',
    Betamax: 'Betamax',
    'Blu-ray': 'Blu-ray',
    'Blu-ray-R': 'Blu-ray',
    Cassette: 'Cassette',
    CD: 'CD',
    CDr: 'CD-R',
    CDV: 'CDV',
    'CD+G': 'CD+G',
    Cylinder: 'Wax Cylinder',
    DAT: 'DAT',
    Datassette: 'Other',
    DCC: 'DCC',
    DVD: 'DVD',
    DVDr: 'DVD',
    'DVD-Audio': 'DVD-Audio',
    'DVD-Video': 'DVD-Video',
    'Edison Disc': 'Vinyl',
    File: 'Digital Media',
    'Flexi-disc': 'Vinyl',
    'Floppy Disk': 'Other',
    HDCD: 'HDCD',
    'HD DVD': 'HD-DVD',
    'HD DVD-R': 'HD-DVD',
    Hybrid: 'Other',
    Laserdisc: 'LaserDisc',
    'Memory Stick': 'USB Flash Drive',
    Microcassette: 'Other',
    Minidisc: 'MiniDisc',
    MVD: 'Other',
    'Reel-To-Reel': 'Reel-to-reel',
    SACD: 'SACD',
    SelectaVision: 'Other',
    Shellac: 'Shellac',
    'Shellac7"': '7" Shellac',
    'Shellac10"': '10" Shellac',
    'Shellac12"': '12" Shellac',
    SVCD: 'SVCD',
    UMD: 'UMD',
    VCD: 'VCD',
    VHS: 'VHS',
    'Video 2000': 'Other',
    Vinyl: 'Vinyl',
    'Vinyl7"': '7" Vinyl',
    'Vinyl10"': '10" Vinyl',
    'Vinyl12"': '12" Vinyl',
    'Lathe Cut': 'Phonograph record',
};

const Countries = {
    Afghanistan: 'AF',
    Albania: 'AL',
    Algeria: 'DZ',
    'American Samoa': 'AS',
    Andorra: 'AD',
    Angola: 'AO',
    Anguilla: 'AI',
    Antarctica: 'AQ',
    'Antigua and Barbuda': 'AG',
    Argentina: 'AR',
    Armenia: 'AM',
    Aruba: 'AW',
    Australia: 'AU',
    Austria: 'AT',
    Azerbaijan: 'AZ',
    Bahamas: 'BS',
    Bahrain: 'BH',
    Bangladesh: 'BD',
    Barbados: 'BB',
    'Barbados, The': 'BB',
    Belarus: 'BY',
    Belgium: 'BE',
    Belize: 'BZ',
    Benin: 'BJ',
    Bermuda: 'BM',
    Bhutan: 'BT',
    Bolivia: 'BO',
    Croatia: 'HR',
    Botswana: 'BW',
    'Bouvet Island': 'BV',
    Brazil: 'BR',
    'British Indian Ocean Territory': 'IO',
    'Brunei Darussalam': 'BN',
    Bulgaria: 'BG',
    'Burkina Faso': 'BF',
    Burundi: 'BI',
    Cambodia: 'KH',
    Cameroon: 'CM',
    Canada: 'CA',
    'Cape Verde': 'CV',
    'Cayman Islands': 'KY',
    'Central African Republic': 'CF',
    Chad: 'TD',
    Chile: 'CL',
    China: 'CN',
    'Christmas Island': 'CX',
    'Cocos (Keeling) Islands': 'CC',
    Colombia: 'CO',
    Comoros: 'KM',
    Congo: 'CG',
    'Cook Islands': 'CK',
    'Costa Rica': 'CR',
    'Virgin Islands, British': 'VG',
    Cuba: 'CU',
    Cyprus: 'CY',
    'Czech Republic': 'CZ',
    Denmark: 'DK',
    Djibouti: 'DJ',
    Dominica: 'DM',
    'Dominican Republic': 'DO',
    Ecuador: 'EC',
    Egypt: 'EG',
    'El Salvador': 'SV',
    'Equatorial Guinea': 'GQ',
    Eritrea: 'ER',
    Estonia: 'EE',
    Ethiopia: 'ET',
    'Falkland Islands (Malvinas)': 'FK',
    'Faroe Islands': 'FO',
    Fiji: 'FJ',
    Finland: 'FI',
    France: 'FR',
    'French Guiana': 'GF',
    'French Polynesia': 'PF',
    'French Southern Territories': 'TF',
    Gabon: 'GA',
    Gambia: 'GM',
    Georgia: 'GE',
    Germany: 'DE',
    Ghana: 'GH',
    Gibraltar: 'GI',
    Greece: 'GR',
    Greenland: 'GL',
    Grenada: 'GD',
    Guadeloupe: 'GP',
    Guam: 'GU',
    Guatemala: 'GT',
    Guinea: 'GN',
    'Guinea-Bissau': 'GW',
    Guyana: 'GY',
    Haiti: 'HT',
    'Virgin Islands, U.S.': 'VI',
    Honduras: 'HN',
    'Hong Kong': 'HK',
    Hungary: 'HU',
    Iceland: 'IS',
    India: 'IN',
    Indonesia: 'ID',
    'Wallis and Futuna': 'WF',
    Iraq: 'IQ',
    Ireland: 'IE',
    Israel: 'IL',
    Italy: 'IT',
    Jamaica: 'JM',
    Japan: 'JP',
    Jordan: 'JO',
    Kazakhstan: 'KZ',
    Kenya: 'KE',
    Kiribati: 'KI',
    Kuwait: 'KW',
    Kyrgyzstan: 'KG',
    "Lao People's Democratic Republic": 'LA',
    Latvia: 'LV',
    Lebanon: 'LB',
    Lesotho: 'LS',
    Liberia: 'LR',
    'Libyan Arab Jamahiriya': 'LY',
    Liechtenstein: 'LI',
    Lithuania: 'LT',
    Luxembourg: 'LU',
    Montserrat: 'MS',
    Macedonia: 'MK',
    Madagascar: 'MG',
    Malawi: 'MW',
    Malaysia: 'MY',
    Maldives: 'MV',
    Mali: 'ML',
    Malta: 'MT',
    'Marshall Islands': 'MH',
    Martinique: 'MQ',
    Mauritania: 'MR',
    Mauritius: 'MU',
    Mayotte: 'YT',
    Mexico: 'MX',
    'Micronesia, Federated States of': 'FM',
    Morocco: 'MA',
    Monaco: 'MC',
    Mongolia: 'MN',
    Mozambique: 'MZ',
    Myanmar: 'MM',
    Namibia: 'NA',
    Nauru: 'NR',
    Nepal: 'NP',
    Netherlands: 'NL',
    'Netherlands Antilles': 'AN',
    'New Caledonia': 'NC',
    'New Zealand': 'NZ',
    Nicaragua: 'NI',
    Niger: 'NE',
    Nigeria: 'NG',
    Niue: 'NU',
    'Norfolk Island': 'NF',
    'Northern Mariana Islands': 'MP',
    Norway: 'NO',
    Oman: 'OM',
    Pakistan: 'PK',
    Palau: 'PW',
    Panama: 'PA',
    'Papua New Guinea': 'PG',
    Paraguay: 'PY',
    Peru: 'PE',
    Philippines: 'PH',
    Pitcairn: 'PN',
    Poland: 'PL',
    Portugal: 'PT',
    'Puerto Rico': 'PR',
    Qatar: 'QA',
    Reunion: 'RE',
    Romania: 'RO',
    'Russian Federation': 'RU',
    Russia: 'RU',
    Rwanda: 'RW',
    'Saint Kitts and Nevis': 'KN',
    'Saint Lucia': 'LC',
    'Saint Vincent and The Grenadines': 'VC',
    Samoa: 'WS',
    'San Marino': 'SM',
    'Sao Tome and Principe': 'ST',
    'Saudi Arabia': 'SA',
    Senegal: 'SN',
    Seychelles: 'SC',
    'Sierra Leone': 'SL',
    Singapore: 'SG',
    Slovenia: 'SI',
    'Solomon Islands': 'SB',
    Somalia: 'SO',
    'South Africa': 'ZA',
    Spain: 'ES',
    'Sri Lanka': 'LK',
    Sudan: 'SD',
    Suriname: 'SR',
    Swaziland: 'SZ',
    Sweden: 'SE',
    Switzerland: 'CH',
    'Syrian Arab Republic': 'SY',
    Tajikistan: 'TJ',
    'Tanzania, United Republic of': 'TZ',
    Thailand: 'TH',
    Togo: 'TG',
    Tokelau: 'TK',
    Tonga: 'TO',
    'Trinidad & Tobago': 'TT',
    Tunisia: 'TN',
    Turkey: 'TR',
    Turkmenistan: 'TM',
    'Turks and Caicos Islands': 'TC',
    Tuvalu: 'TV',
    Uganda: 'UG',
    Ukraine: 'UA',
    'United Arab Emirates': 'AE',
    UK: 'GB',
    US: 'US',
    'United States Minor Outlying Islands': 'UM',
    Uruguay: 'UY',
    Uzbekistan: 'UZ',
    Vanuatu: 'VU',
    'Vatican City State (Holy See)': 'VA',
    Venezuela: 'VE',
    'Viet Nam': 'VN',
    'Western Sahara': 'EH',
    Yemen: 'YE',
    Zambia: 'ZM',
    Zimbabwe: 'ZW',
    Taiwan: 'TW',
    '[Worldwide]': 'XW',
    Europe: 'XE',
    USSR: 'SU',
    'East Germany (historical, 1949-1990)': 'XG',
    Czechoslovakia: 'XC',
    'Congo, Republic of the': 'CD',
    Slovakia: 'SK',
    'Bosnia & Herzegovina': 'BA',
    "Korea (North), Democratic People's Republic of": 'KP',
    'North Korea': 'KP',
    'Korea (South), Republic of': 'KR',
    'South Korea': 'KR',
    Montenegro: 'ME',
    'South Georgia and the South Sandwich Islands': 'GS',
    'Palestinian Territory': 'PS',
    Macao: 'MO',
    'Timor-Leste': 'TL',
    '<85>land Islands': 'AX',
    Guernsey: 'GG',
    'Isle of Man': 'IM',
    Jersey: 'JE',
    Serbia: 'RS',
    'Saint Barthélemy': 'BL',
    'Saint Martin': 'MF',
    Moldova: 'MD',
    Yugoslavia: 'YU',
    'Serbia and Montenegro': 'CS',
    "Côte d'Ivoire": 'CI',
    'Heard Island and McDonald Islands': 'HM',
    'Iran, Islamic Republic of': 'IR',
    'Saint Pierre and Miquelon': 'PM',
    'Saint Helena': 'SH',
    'Svalbard and Jan Mayen': 'SJ',
};