/*
  Tango - Personal Media Center
  Copyright (C) 2021  Ulrich Hilger

  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.

  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 de.uhilger.tango.api;

import com.sun.net.httpserver.Headers;
import com.sun.net.httpserver.HttpExchange;
import de.uhilger.tango.App;
import de.uhilger.tango.Server;
import de.uhilger.tango.entity.Einstellung;
import de.uhilger.tango.entity.Entity;
import de.uhilger.tango.store.FileStorage;
import de.uhilger.tango.store.Storage;
import de.uhilger.tango.store.StorageFile;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.farng.mp3.MP3File;
import org.farng.mp3.TagException;
import org.farng.mp3.id3.AbstractID3v2;
import org.farng.mp3.id3.ID3v1;

/**
 *
 * @author ulrich
 */
public class ListFileHandler extends FileHandler {
  
  public static final String RB_AUDIOEXTS = "audioexts";
  public static final String RB_VIDEOEXTS = "videoexts";
  
  /* Der Logger fuer diesen ListFileHandler */
  private static final Logger logger = Logger.getLogger(ListFileHandler.class.getName());
  
  private static final String[] specialChars = {new String("\u00c4"), new String("\u00d6"), 
      new String("\u00dc"), new String("\u00e4"), new String("\u00f6"), new String("\u00fc"), new String("\u00df")};
  
  public static final String UNWANTED_PATTERN = "[^a-zA-Z_0-9 ]";
  
  Map extMap = new HashMap();
  
  private String conf;
  
  public ListFileHandler(String absoluteDirectoryPathAndName, String conf) {
    super(absoluteDirectoryPathAndName);
    /*
      Ermittlung von Dateifiltern. 
      Sie werden erwartet in den Einstellungen 'audioexts' und 'videoexts'
      jeweils als Dateierweiterungen mit Komma getrennt
      z.B. "mp4,m4v"
    */
    FileStorage fs = new FileStorage(conf);
    initMap(fs, getResString(RB_AUDIOEXTS), StorageFile.TYP_AUDIO);
    initMap(fs, getResString(RB_VIDEOEXTS), StorageFile.TYP_VIDEO);
  }

  private void initMap(Storage s, String key, String typ) {
    Entity e = s.read(Einstellung.class.getSimpleName(), key);
    if(e instanceof Einstellung) {
      String[] exts = ((Einstellung) e).getValue().split(",");
      for(String ext : exts) {
        extMap.put(ext, typ);
      }
    }
  }
  
  @Override
  public void handle(HttpExchange e) throws IOException {
    String path = e.getRequestURI().toString();
    logger.fine(path);
    if(path.endsWith(Server.SLASH)) {
      String fName = getFileName(e);
      logger.fine(fName);
      File dir = new File(fileBase, fName);
      logger.fine(dir.getAbsolutePath());
      File[] files = dir.listFiles(new FileFilter() {
        @Override
        public boolean accept(File pathname) {
          Set keys = extMap.keySet();
          String fname = pathname.getName();
          int pos = fname.lastIndexOf(".");
          String ext = fname.substring(pos+1);          
          return keys.contains(ext) || pathname.isDirectory();
        }
      });
      Arrays.sort(files);      
      ArrayList list = new ArrayList();
      if(files != null) {
        for(File file : files) {
          StorageFile sf = new StorageFile();
          String fname = file.getName();
          sf.setName(fname);
          sf.setTitelAnzName(fname);
          if(file.isDirectory()) {
            sf.setTyp(StorageFile.TYP_FOLDER);
          } else {
            int pos = fname.lastIndexOf(".");
            String ext = fname.substring(pos+1);
            logger.log(Level.FINE, "ext: {0}", ext);
            Object o = extMap.get(ext);
            if(o instanceof String) {
              sf.setTyp(o.toString());
              getMetadata(file, sf);
            } else {
              sf.setTyp(StorageFile.TYP_FILE);
            }
          }
          list.add(sf);
        }
      }
      //Collections.sort(list);
      String rawjson = jsonWithCustomType(list, "Medialiste");
      String json = escapeHtml(rawjson);
      
      logger.fine(json);
      Headers headers = e.getResponseHeaders();
      headers.add("Content-Type", "application/json; charset=UTF-8");
      e.sendResponseHeaders(200, json.length());
      OutputStream os = e.getResponseBody();
      os.write(json.getBytes());
      os.close();        
    } else {
      super.handle(e);
    }
  }
  
  public String escapeHtml(String text) {
    text = text.replace(specialChars[0], "Ae");
    text = text.replace(specialChars[1], "Oe");
    text = text.replace(specialChars[2], "Ue");
    text = text.replace(specialChars[3], "ae");
    text = text.replace(specialChars[4], "oe");
    text = text.replace(specialChars[5], "ue");
    text = text.replace(specialChars[6], "ss");
    
    /*
    text = text.replace(specialChars[0], "&Auml;");
    text = text.replace(specialChars[1], "&Ouml;");
    text = text.replace(specialChars[2], "&Uuml;");
    text = text.replace(specialChars[3], "&auml;");
    text = text.replace(specialChars[4], "&ouml;");
    text = text.replace(specialChars[5], "&uuml;");
    text = text.replace(specialChars[6], "&szlig;");
    */
    return text;
  }
  
  private void getMetadata(File file, StorageFile sf) {
    if(sf.getTyp().equalsIgnoreCase(StorageFile.TYP_AUDIO)) {
      try {
        MP3File mp3 = new MP3File(file);
        ID3v1 tag = mp3.getID3v1Tag();
        if(tag == null) {
          AbstractID3v2 tag2 = mp3.getID3v2Tag();
          sf.setInterpret(tag2.getLeadArtist().replaceAll(UNWANTED_PATTERN, ""));
          String trackTitel = tag2.getSongTitle().replaceAll(UNWANTED_PATTERN, "");
          if(trackTitel != null && trackTitel.length() > 0) {
            sf.setTitelAnzName(trackTitel);
          }
          sf.setAlbum(tag2.getAlbumTitle().replaceAll(UNWANTED_PATTERN, ""));
        } else {
          sf.setInterpret(tag.getArtist().replaceAll(UNWANTED_PATTERN, ""));
          String trackTitel = tag.getTitle().replaceAll(UNWANTED_PATTERN, "");
          if(trackTitel != null && trackTitel.length() > 0) {
            sf.setTitelAnzName(trackTitel);
          }
          sf.setAlbum(tag.getAlbumTitle().replaceAll(UNWANTED_PATTERN, ""));
        }
      } catch (IOException ex) {
        Logger.getLogger(ListFileHandler.class.getName()).log(Level.SEVERE, null, ex);
      } catch (TagException ex) {
        Logger.getLogger(ListFileHandler.class.getName()).log(Level.SEVERE, null, ex);
      }
    }
  }
  
}