/*
 This file is part of Airsonic.

 Airsonic is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 Airsonic is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with Airsonic.  If not, see <http://www.gnu.org/licenses/>.

 Copyright 2016 (C) Airsonic Authors
 Based upon Subsonic, Copyright 2009 (C) Sindre Mehus
 */
package org.airsonic.player.service.metadata;

import org.airsonic.player.domain.MediaFile;
import org.airsonic.player.service.SettingsService;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.lang.StringUtils;
import org.jaudiotagger.audio.AudioFile;
import org.jaudiotagger.audio.AudioFileIO;
import org.jaudiotagger.audio.AudioHeader;
import org.jaudiotagger.tag.FieldKey;
import org.jaudiotagger.tag.Tag;
import org.jaudiotagger.tag.id3.AbstractID3Tag;
import org.jaudiotagger.tag.id3.ID3v24Frames;
import org.jaudiotagger.tag.id3.ID3v24Tag;
import org.jaudiotagger.tag.images.Artwork;
import org.jaudiotagger.tag.reference.GenreTypes;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.ObjectUtils;

import java.io.File;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.logging.LogManager;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Parses meta data from audio files using the Jaudiotagger library
 * (http://www.jthink.net/jaudiotagger/)
 *
 * @author Sindre Mehus
 */
@Service
public class JaudiotaggerParser extends MetaDataParser {

    private static final Logger LOG = LoggerFactory.getLogger(JaudiotaggerParser.class);
    private static final Pattern GENRE_PATTERN = Pattern.compile("\\((\\d+)\\).*");
    private static final Pattern TRACK_NUMBER_PATTERN = Pattern.compile("(\\d+)/\\d+");
    private static final Pattern YEAR_NUMBER_PATTERN = Pattern.compile("(\\d{4}).*");
    @Autowired
    private final SettingsService settingsService;

    public JaudiotaggerParser(SettingsService settingsService) {
        this.settingsService = settingsService;
    }

    static {
        try {
            LogManager.getLogManager().reset();
        } catch (Throwable x) {
            LOG.warn("Failed to turn off logging from Jaudiotagger.", x);
        }
    }

    /**
     * Parses meta data for the given music file. No guessing or reformatting is done.
     *
     *
     * @param file The music file to parse.
     * @return Meta data for the file.
     */
    @Override
    public MetaData getRawMetaData(File file) {

        MetaData metaData = new MetaData();

        try {
            AudioFile audioFile = AudioFileIO.read(file);
            Tag tag = audioFile.getTag();
            if (tag != null) {
                metaData.setAlbumName(getTagField(tag, FieldKey.ALBUM));
                metaData.setTitle(getTagField(tag, FieldKey.TITLE));
                metaData.setYear(parseYear(getTagField(tag, FieldKey.YEAR)));
                metaData.setGenre(mapGenre(getTagField(tag, FieldKey.GENRE)));
                metaData.setDiscNumber(parseInteger(getTagField(tag, FieldKey.DISC_NO)));
                metaData.setTrackNumber(parseTrackNumber(getTagField(tag, FieldKey.TRACK)));
                metaData.setMusicBrainzReleaseId(getTagField(tag, FieldKey.MUSICBRAINZ_RELEASEID));

                metaData.setArtist(getTagField(tag, FieldKey.ARTIST));
                metaData.setAlbumArtist(getTagField(tag, FieldKey.ALBUM_ARTIST));

                if (tag instanceof AbstractID3Tag && 0 < audioFile.getTag().getFieldCount()) {

                    AbstractID3Tag id3Tag = (AbstractID3Tag)tag;
                    if (ID3v24Tag.RELEASE == id3Tag.getRelease()
                            && ID3v24Tag.MAJOR_VERSION == id3Tag.getMajorVersion()
                            && ID3v24Tag.REVISION == id3Tag.getRevision()) {

                        audioFile.getTag().getFields().forEachRemaining(f -> {
                            switch (f.getId()) {
                                case ID3v24Frames.FRAME_ID_ALBUM:
                                    if (StringUtils.isBlank(metaData.getAlbumName())) {
                                        metaData.setAlbumName(f.toString());
                                    }
                                    break;
                                case ID3v24Frames.FRAME_ID_TITLE:
                                    if (StringUtils.isBlank(metaData.getTitle())) {
                                        metaData.setTitle(f.toString());
                                    }
                                    break;
                                case ID3v24Frames.FRAME_ID_YEAR:
                                    if (ObjectUtils.isEmpty(metaData.getYear())) {
                                        metaData.setYear(parseYear(f.toString()));
                                    }
                                    break;
                                case ID3v24Frames.FRAME_ID_GENRE:
                                    if (StringUtils.isBlank(metaData.getGenre())) {
                                        metaData.setGenre(mapGenre(f.toString()));
                                    }
                                    break;
                                case ID3v24Frames.FRAME_ID_SET:
                                    if (ObjectUtils.isEmpty(metaData.getDiscNumber())) {
                                        metaData.setDiscNumber(parseInteger(f.toString()));
                                    }
                                    break;
                                case ID3v24Frames.FRAME_ID_TRACK:
                                    if (ObjectUtils.isEmpty(metaData.getTrackNumber())) {
                                        metaData.setTrackNumber(parseTrackNumber(f.toString()));
                                    }
                                    break;
                                case ID3v24Frames.FRAME_ID_ARTIST:
                                    if (StringUtils.isBlank(metaData.getArtist())) {
                                        metaData.setArtist(f.toString());
                                    }
                                    break;
                                case ID3v24Frames.FRAME_ID_ACCOMPANIMENT:
                                    if (StringUtils.isBlank(metaData.getAlbumArtist())) {
                                        metaData.setAlbumArtist(f.toString());
                                    }
                                    break;
                                default:
                                    break;
                            }
                        });
                    }
                }
                if (StringUtils.isBlank(metaData.getArtist())) {
                    metaData.setArtist(metaData.getAlbumArtist());
                }
                if (StringUtils.isBlank(metaData.getAlbumArtist())) {
                    metaData.setAlbumArtist(metaData.getArtist());
                }

            }

            AudioHeader audioHeader = audioFile.getAudioHeader();
            if (audioHeader != null) {
                metaData.setVariableBitRate(audioHeader.isVariableBitRate());
                metaData.setBitRate((int) audioHeader.getBitRateAsNumber());
                metaData.setDurationSeconds(audioHeader.getTrackLength());
            }


        } catch (Throwable x) {
            LOG.warn("Error when parsing tags in " + file, x);
        }

        return metaData;
    }

    private String getTagField(Tag tag, FieldKey fieldKey) {
        try {
            return StringUtils.trimToNull(tag.getFirst(fieldKey));
        } catch (Exception x) {
            // Ignored.
            return null;
        }
    }

    /**
     * Returns all tags supported by id3v1.
     */
    public static SortedSet<String> getID3V1Genres() {
        return new TreeSet<String>(GenreTypes.getInstanceOf().getAlphabeticalValueList());
    }

    /**
     * Sometimes the genre is returned as "(17)" or "(17)Rock", instead of "Rock".  This method
     * maps the genre ID to the corresponding text.
     */
    private String mapGenre(String genre) {
        if (genre == null) {
            return null;
        }
        Matcher matcher = GENRE_PATTERN.matcher(genre);
        if (matcher.matches()) {
            int genreId = Integer.parseInt(matcher.group(1));
            if (genreId >= 0 && genreId < GenreTypes.getInstanceOf().getSize()) {
                return GenreTypes.getInstanceOf().getValueForId(genreId);
            }
        }
        return genre;
    }

    /**
     * Parses the track number from the given string.  Also supports
     * track numbers on the form "4/12".
     */
    private Integer parseTrackNumber(String trackNumber) {
        if (trackNumber == null) {
            return null;
        }

        Integer result = null;

        try {
            result = Integer.valueOf(trackNumber);
        } catch (NumberFormatException x) {
            Matcher matcher = TRACK_NUMBER_PATTERN.matcher(trackNumber);
            if (matcher.matches()) {
                try {
                    result = Integer.valueOf(matcher.group(1));
                } catch (NumberFormatException e) {
                    return null;
                }
            }
        }

        if (Integer.valueOf(0).equals(result)) {
            return null;
        }
        return result;
    }

    private Integer parseYear(String year) {
        if (year == null) {
            return null;
        }

        Integer result = null;

        try {
            result = Integer.valueOf(year);
        } catch (NumberFormatException x) {
            Matcher matcher = YEAR_NUMBER_PATTERN.matcher(year);
            if (matcher.matches()) {
                try {
                    result = Integer.valueOf(matcher.group(1));
                } catch (NumberFormatException e) {
                    return null;
                }
            }
        }

        if (Integer.valueOf(0).equals(result)) {
            return null;
        }
        return result;
    }

    private Integer parseInteger(String s) {
        s = StringUtils.trimToNull(s);
        if (s == null) {
            return null;
        }
        try {
            Integer result = Integer.valueOf(s);
            if (Integer.valueOf(0).equals(result)) {
                return null;
            }
            return result;
        } catch (NumberFormatException x) {
            return null;
        }
    }

    /**
     * Updates the given file with the given meta data.
     *
     * @param file     The music file to update.
     * @param metaData The new meta data.
     */
    @Override
    public void setMetaData(MediaFile file, MetaData metaData) {

        try {
            AudioFile audioFile = AudioFileIO.read(file.getFile());
            Tag tag = audioFile.getTagOrCreateAndSetDefault();

            tag.setField(FieldKey.ARTIST, StringUtils.trimToEmpty(metaData.getArtist()));
            tag.setField(FieldKey.ALBUM, StringUtils.trimToEmpty(metaData.getAlbumName()));
            tag.setField(FieldKey.TITLE, StringUtils.trimToEmpty(metaData.getTitle()));
            tag.setField(FieldKey.GENRE, StringUtils.trimToEmpty(metaData.getGenre()));
            try {
                tag.setField(FieldKey.ALBUM_ARTIST, StringUtils.trimToEmpty(metaData.getAlbumArtist()));
            } catch (Exception x) {
                // Silently ignored. ID3v1 doesn't support album artist.
            }

            Integer track = metaData.getTrackNumber();
            if (track == null) {
                tag.deleteField(FieldKey.TRACK);
            } else {
                tag.setField(FieldKey.TRACK, String.valueOf(track));
            }

            Integer year = metaData.getYear();
            if (year == null) {
                tag.deleteField(FieldKey.YEAR);
            } else {
                tag.setField(FieldKey.YEAR, String.valueOf(year));
            }

            audioFile.commit();

        } catch (Throwable x) {
            LOG.warn("Failed to update tags for file " + file, x);
            throw new RuntimeException("Failed to update tags for file " + file + ". " + x.getMessage(), x);
        }
    }

    /**
     * Returns whether this parser supports tag editing (using the {@link #setMetaData} method).
     *
     * @return Always true.
     */
    @Override
    public boolean isEditingSupported() {
        return true;
    }

    @Override
    SettingsService getSettingsService() {
        return settingsService;
    }

    /**
     * Returns whether this parser is applicable to the given file.
     *
     * @param file The music file in question.
     * @return Whether this parser is applicable to the given file.
     */
    @Override
    public boolean isApplicable(File file) {
        if (!file.isFile()) {
            return false;
        }

        String format = FilenameUtils.getExtension(file.getName()).toLowerCase();

        return "mp3".equals(format) ||
               "m4a".equals(format) ||
               "m4b".equals(format) ||
               "aac".equals(format) ||
               "ogg".equals(format) ||
               "flac".equals(format) ||
               "wav".equals(format) ||
               "mpc".equals(format) ||
               "mp+".equals(format) ||
               "ape".equals(format) ||
               "wma".equals(format);
    }

    /**
     * Returns whether cover art image data is available in the given file.
     *
     * @param file The music file.
     * @return Whether cover art image data is available.
     */
    public boolean isImageAvailable(MediaFile file) {
        try {
            return getArtwork(file) != null;
        } catch (Throwable x) {
            LOG.warn("Failed to find cover art tag in " + file, x);
            return false;
        }
    }

    public Artwork getArtwork(MediaFile file) throws Exception {
        AudioFile audioFile = AudioFileIO.read(file.getFile());
        Tag tag = audioFile.getTag();
        return tag == null ? null : tag.getFirstArtwork();
    }
}