/*
 * Copyright (C) 2000 - 2024 Silverpeas
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * As a special exception to the terms and conditions of version 3.0 of
 * the GPL, you may redistribute this Program in connection with Free/Libre
 * Open Source Software ("FLOSS") applications as described in Silverpeas's
 * FLOSS exception. You should have recieved a copy of the text describing
 * the FLOSS exception, and it is also available here:
 * "https://www.silverpeas.org/legal/floss_exception.html"
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */
package org.silverpeas.components.gallery.media;

import com.drew.imaging.ImageMetadataReader;
import com.drew.imaging.ImageProcessingException;
import com.drew.metadata.Metadata;
import com.drew.metadata.exif.ExifIFD0Descriptor;
import com.drew.metadata.exif.ExifIFD0Directory;
import com.drew.metadata.iptc.IptcDirectory;
import org.silverpeas.components.gallery.model.MetaData;
import org.silverpeas.core.i18n.I18NHelper;
import org.silverpeas.core.util.ArrayUtil;
import org.silverpeas.core.util.Charsets;
import org.silverpeas.core.util.EncodingUtil;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.TimeZone;

import static com.drew.metadata.iptc.IptcDirectory.*;

/**
 * @author ehugonnet
 */
public class DrewMediaMetadataExtractor extends AbstractMediaMetadataExtractor {

  public DrewMediaMetadataExtractor(String instanceId) {
    init(instanceId);
  }

  @Override
  public List<MetaData> extractImageExifMetaData(File image)
      throws MediaMetadataException, IOException {
    return extractImageExifMetaData(image, I18NHelper.DEFAULT_LANGUAGE);
  }

  @Override
  public List<MetaData> extractImageExifMetaData(File image, String lang)
      throws MediaMetadataException, IOException {
    try {
      List<MetaData> result = new ArrayList<>();
      // lire le fichier des properties
      // 1. Traitement des metadata EXIF
      Metadata metadata = ImageMetadataReader.readMetadata(image);
      ExifIFD0Directory exifDirectory = metadata.getFirstDirectoryOfType(ExifIFD0Directory.class);
      ExifIFD0Descriptor descriptor = new ExifIFD0Descriptor(exifDirectory);
      String value;
      if (exifDirectory != null) {
        for (ExifProperty property : imageProperties) {
          value = fetchLabel(exifDirectory, descriptor, property);
          if (value != null) {
            addLabelToMediaMetadata(lang, result, value, property);
          }
        }
      }
      return result;
    } catch (IOException | ImageProcessingException ex) {
      throw new MediaMetadataException(ex);
    }
  }

  private void addLabelToMediaMetadata(final String lang, final List<MetaData> result,
      final String value, final ExifProperty property) {
    // ajout de cette metadata à la photo
    MetaData metaData = new MetaData(value);
    metaData.setLabel(property.getLabel(lang));
    metaData.setProperty(property.getProperty() + "");
    result.add(metaData);
  }

  private String fetchLabel(final ExifIFD0Directory exifDirectory,
      final ExifIFD0Descriptor descriptor, final ExifProperty property) {
    // rechercher la valeur de la metadata "label"
    final String value;
    int currentMetadata = property.getProperty();
    switch (currentMetadata) {
      case ExifIFD0Directory.TAG_WIN_AUTHOR:
        value = descriptor.getWindowsAuthorDescription();
        break;
      case ExifIFD0Directory.TAG_WIN_COMMENT:
        value = descriptor.getWindowsCommentDescription();
        break;

      case ExifIFD0Directory.TAG_WIN_KEYWORDS:
        value = descriptor.getWindowsKeywordsDescription();
        break;

      case ExifIFD0Directory.TAG_WIN_SUBJECT:
        value = descriptor.getWindowsSubjectDescription();
        break;

      case ExifIFD0Directory.TAG_WIN_TITLE:
        value = descriptor.getWindowsTitleDescription();
        break;

      case ExifIFD0Directory.TAG_RESOLUTION_UNIT:
        value = getExifDirectoryValue(exifDirectory, currentMetadata);
        break;

      default:
        value = exifDirectory.getString(currentMetadata);
    }
    return value;
  }

  private String getExifDirectoryValue(final ExifIFD0Directory exifDirectory,
      final int currentMetadata) {
    String value = exifDirectory.getString(currentMetadata);
    if("2".equals(value)) {
      //dots per inch
      value = "DPI";
    } else if ("3".equals(value)) {
      //dots per cm
      value = "DPC";
    }
    return value;
  }

  @Override
  public List<MetaData> extractImageIptcMetaData(File image)
      throws MediaMetadataException, IOException {
    return extractImageIptcMetaData(image, I18NHelper.DEFAULT_LANGUAGE);
  }

  @Override
  public List<MetaData> extractImageIptcMetaData(File image, String lang)
      throws IOException, MediaMetadataException {
    try {
      final int defaultSize = 1024;
      List<MetaData> result = new ArrayList<>();
      Metadata metadata = ImageMetadataReader.readMetadata(image);
      ByteArrayOutputStream forEncodingDetection = new ByteArrayOutputStream(defaultSize);
      IptcDirectory iptcDirectory = metadata.getFirstDirectoryOfType(IptcDirectory.class);
      String iptcCharset = getIptcCharset(iptcDirectory);
      for (IptcProperty iptcProperty : imageIptcProperties) {
        switch (iptcProperty.getProperty()) {
          case TAG_RELEASE_DATE:
          case TAG_DATE_CREATED:
          case TAG_KEYWORDS:
            addStringMetaData(result, iptcDirectory, iptcProperty, lang, forEncodingDetection);
            break;
          default:
            addMetaData(result, iptcDirectory, iptcProperty, lang, forEncodingDetection);
            break;
        }
      }
      String defaultEncoding = Charsets.UTF_8.name();
      if (iptcCharset != null) {
        defaultEncoding = iptcCharset;
      }
      String encoding =
          EncodingUtil.detectStringEncoding(forEncodingDetection.toByteArray(), defaultEncoding);

      for (MetaData metaData : result) {
        metaData.convert(encoding);
      }
      return result;
    } catch (ImageProcessingException ex) {
      throw new MediaMetadataException(ex);
    }
  }

  private void addStringMetaData(List<MetaData> metadata, IptcDirectory iptcDirectory,
      IptcProperty iptcProperty, String lang, ByteArrayOutputStream forEncodingDetection)
      throws IOException {
    String value = getIptcStringValue(iptcDirectory, iptcProperty.getProperty());
    if (value != null) {
      MetaData meta = new MetaData(value.getBytes());
      meta.setLabel(iptcProperty.getLabel(lang));
      meta.setProperty(String.valueOf(iptcProperty.getProperty()));
      if (iptcProperty.isDate()) {
        meta.setDate(true);
        meta.setDateValue(iptcDirectory.getDate(iptcProperty.getProperty(), TimeZone.getDefault()));
      } else {
        forEncodingDetection.write(value.getBytes());
      }
      metadata.add(meta);
    }
  }

  private void addMetaData(List<MetaData> metadata, IptcDirectory iptcDirectory,
      IptcProperty iptcProperty, String lang, ByteArrayOutputStream forEncodingDetection)
      throws IOException {
    byte[] data = getIptcValue(iptcDirectory, iptcProperty.getProperty());
    if (data != null && !ArrayUtil.isEmpty(data)) {
      MetaData meta = new MetaData(data);
      meta.setLabel(iptcProperty.getLabel(lang));
      meta.setProperty(String.valueOf(iptcProperty.getProperty()));
      if (iptcProperty.isDate() && iptcDirectory != null) {
        meta.setDate(true);
        meta.setDateValue(iptcDirectory.getDate(iptcProperty.getProperty(), TimeZone.getDefault()));
      } else {
        forEncodingDetection.write(data);
      }
      metadata.add(meta);
    }
  }

  private byte[] getIptcValue(IptcDirectory iptcDirectory, int iptcTag) {
    if (iptcDirectory != null && iptcDirectory.containsTag(iptcTag)) {
      return iptcDirectory.getByteArray(iptcTag);
    }
    return new byte[0];
  }

  private String getIptcStringValue(IptcDirectory iptcDirectory, int iptcTag) {
    if (iptcDirectory != null && iptcDirectory.containsTag(iptcTag)) {
      return iptcDirectory.getString(iptcTag);
    }
    return null;
  }

  private String getIptcCharset(IptcDirectory iptcDirectory) {
    if (iptcDirectory != null && iptcDirectory.containsTag(TAG_CODED_CHARACTER_SET)) {
      byte[] data = iptcDirectory.getByteArray(TAG_CODED_CHARACTER_SET);
      if (data != null) {
        String escapeCode = new String(data, Charsets.UTF_8);
        if ("%G".equals(escapeCode)) {
          return Charsets.UTF_8.name();
        }
      }
    }
    return null;
  }
}
