///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                                          MusicBrainz Import helper functions
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////

/*

- First build a 'release' object that you'll fill in with your source of data

- Call as follows, e.g.:

    var parameters = MBReleaseImportHelper.buildFormParameters( theParsedRelease, optionalEditNote );

- Then build the HTML that you'll inject into source site page:

    var formHtml = MBReleaseImportHelper.buildFormHTML( parameters );

- Addinionally, you can inject a search link to verify that the release is not already known by MusicBrainz:

    var linkHtml = MBReleaseImportHelper.buildSearchLink( theParsedRelease );

--- 'release' object format : ---

    release = {
         title,
         artist_credit = [ { name: '',
         type,
         status,
         language,
         script,
         packaging,
         country,
         year,
         month,
         day,
         labels = [ { name, mbid, catno }, ... ],
         barcode,
         discs = [
             {
                 title,
                 format,
                 position,
                 tracks = [
                     { number, title, duration, artist_credit },
                     ...
                 ]
             },
             ...
         ],
     }

    where 'artist_credit' has the following format:

    artist_credit = [
         {
             credited_name,
             artist_name,
             artist_mbid,
             joinphrase
         },
         ...
     ]

*/

var MBReleaseImportHelper = (function() {

    // --------------------------------------- publics ----------------------------------------- //

    // compute HTML of search link
    function fnBuildSearchLink(release) {

        var totaltracks = 0;
        for (var i=0; i < release.discs.length; i++) {
            totaltracks += release.discs[i].tracks.length;
        }
        var release_artist = "";
        for (var i=0; i < release.artist_credit.length; i++) {
            var ac = release.artist_credit[i];
            release_artist += ac.artist_name;
            if (typeof ac.joinphrase != 'undefined' && ac.joinphrase != "") {
                release_artist += ac.joinphrase;
            } else {
                if (i != release.artist_credit.length-1) release_artist += ", ";
            }
        }

        var innerHTML = '<a href="http://musicbrainz.org/search?query=artist%3A(' + luceneEscape(release_artist) + ')%20release%3A(' + luceneEscape(release.title) + ')%20tracks%3A(' + totaltracks + ')';
        if(release.country) innerHTML += '%20country:'+release.country;
        innerHTML += '&type=release&advanced=1">Search in MusicBrainz</a>';

        return innerHTML;
    }

    // compute HTML of import form
    function fnBuildFormHTML(parameters) {

        // Build form
        var innerHTML = '<form action="http://musicbrainz.org/release/add" method="post" target="_blank" accept-charset="UTF-8" charset="' + document.characterSet + '">';
        parameters.forEach(function(parameter) {
            var value = parameter.value + "";
            innerHTML += "<input type='hidden' value='" + value.replace(/'/g,"&apos;") + "' name='" + parameter.name + "'/>";
        });

        innerHTML += '<input type="submit" value="Import into MB">';
        innerHTML += '</form>';

        return innerHTML;
    }

    // build form POST parameters that MB is waiting
    function fnBuildFormParameters(release, edit_note) {
        // Form parameters
        var parameters = new Array();
        appendParameter(parameters, 'name', release.title);

        // Release Artist credits
        buildArtistCreditsFormParameters(parameters, "", release.artist_credit);

        appendParameter(parameters, 'type', release.type);
        appendParameter(parameters, 'status', release.status);
        appendParameter(parameters, 'language', release.language);
        appendParameter(parameters, 'script', release.script);
        appendParameter(parameters, 'packaging', release.packaging);

        // Date + country
        appendParameter(parameters, 'country', release.country);
        if (!isNaN(release.year) && release.year != 0) { appendParameter(parameters, 'date.year', release.year); };
        if (!isNaN(release.month) && release.month != 0) { appendParameter(parameters, 'date.month', release.month); };
        if (!isNaN(release.day) && release.day != 0) { appendParameter(parameters, 'date.day', release.day); };

        // Barcode
           appendParameter(parameters, 'barcode', release.barcode);

        // Label + catnos
        for (var i=0; i < release.labels.length; i++) {
            var label = release.labels[i];
            appendParameter(parameters, 'labels.'+i+'.name', label.name);
            appendParameter(parameters, 'labels.'+i+'.mbid', label.mbid);
            if (label.catno != "none") {
                appendParameter(parameters, 'labels.'+i+'.catalog_number', label.catno);
            }
        }

        // Mediums
        for (var i=0; i < release.discs.length; i++) {
            var disc = release.discs[i];
            appendParameter(parameters, 'mediums.'+i+'.format', disc.format);
            appendParameter(parameters, 'mediums.'+i+'.position', i);
            appendParameter(parameters, 'mediums.'+i+'.name', disc.title);

            // Tracks
            for (var j=0; j < disc.tracks.length; j++) {
                var track = disc.tracks[j];
                appendParameter(parameters, 'mediums.'+i+'.track.'+j+'.number', track.number);
                appendParameter(parameters, 'mediums.'+i+'.track.'+j+'.name', track.title);
                var tracklength = (typeof track.duration != 'undefined' && track.duration != '') ? track.duration : "?:??";
                appendParameter(parameters, 'mediums.'+i+'.track.'+j+'.length', tracklength);

                buildArtistCreditsFormParameters(parameters, 'mediums.'+i+'.track.'+j+'.', track.artist_credit);
            }
        }

        // Add Edit note parameter
        appendParameter(parameters, 'edit_note', edit_note);

        // Set auto-editor flag, http://tickets.musicbrainz.org/browse/MBS-4315
        appendParameter(parameters, 'as_auto_editor', "1");

        return parameters;
    }

    // --------------------------------------- privates ----------------------------------------- //

    function appendParameter(parameters, paramName, paramValue) {
        if(!paramValue) return;
        parameters.push( { name: paramName, value: paramValue } );
    }

    function luceneEscape(text) {
        var newtext = text.replace(/[-[\]{}()*+?~:\\^!"]/g, "\\$&");
        return newtext.replace("&&", "\&&").replace("||", "\||");
    }

    function buildArtistCreditsFormParameters(parameters, paramPrefix, artist_credit) {
        if(!artist_credit) return;
        for (var i=0; i < artist_credit.length; i++) {
            var ac = artist_credit[i];
            appendParameter(parameters, paramPrefix+'artist_credit.names.'+i+'.name', ac.credited_name);
            appendParameter(parameters, paramPrefix+'artist_credit.names.'+i+'.artist.name', ac.artist_name);
            appendParameter(parameters, paramPrefix+'artist_credit.names.'+i+'.artist.mbid', ac.artist_mbid);
            if (typeof ac.joinphrase != 'undefined' && ac.joinphrase != "") {
                appendParameter(parameters, paramPrefix+'artist_credit.names.'+i+'.join_phrase', ac.joinphrase);
            }
        }
    }

    // ---------------------------------- expose publics here ------------------------------------ //

    return {
                buildSearchLink: fnBuildSearchLink,
                buildFormHTML: fnBuildFormHTML,
                buildFormParameters: fnBuildFormParameters
            };
})();