/**
    *    Copyright 2009 Webster Smalley
    *
    *   Licensed under the Apache License, Version 2.0 (the "License");
    *   you may not use this file except in compliance with the License.
    *   You may obtain a copy of the License at
    *
    *       http://www.apache.org/licenses/LICENSE-2.0
    *
   *   Unless required by applicable law or agreed to in writing, software
   *   distributed under the License is distributed on an "AS IS" BASIS,
   *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *   See the License for the specific language governing permissions and
   *   limitations under the License.
   *
   */
  package com.webstersmalley.iplayer.mp3;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.util.Set;
  
  import org.apache.log4j.Logger;
  import org.blinkenlights.jid3.ID3Exception;
  import org.blinkenlights.jid3.ID3Tag;
  import org.blinkenlights.jid3.MP3File;
  import org.blinkenlights.jid3.MediaFile;
  import org.blinkenlights.jid3.v2.ID3V2Tag;
  import org.blinkenlights.jid3.v2.ID3V2_3_0Tag;
  
  import com.webstersmalley.iplayer.informer.ProgramInformation;
  import com.webstersmalley.iplayer.organiser.RadioProgramBean;
  import com.webstersmalley.musiclibrary.model.FileSystemMusicFileFactory;
  import com.webstersmalley.musiclibrary.model.MusicFile;
  
  /**
   * @author Matthew Smalley
   * 
   */
  public class MP3Utils {
  	private static final String COMMAND_LINE_TEMPLATE = "%1$s --nohist --preset \"%2$s\" \"%3$s\" \"%4$s\"";
  	private String mp3Encoder;
  	private FileSystemMusicFileFactory musicFileFactory = new FileSystemMusicFileFactory();
  	private FileSystemUtils fileSystemUtils = new FileSystemUtils();
  
  	private Logger logger = Logger.getLogger(getClass());
  
  	public void setMp3Encoder(String mp3Encoder) {
  		this.mp3Encoder = mp3Encoder;
  	}
  
  	public ID3V2Tag getID3V2Tags(String filename) {
  		try {
  			MediaFile mediaFile = new MP3File(new File(filename));
  			ID3Tag[] tags = mediaFile.getTags();
  			for (ID3Tag tag : tags) {
  				if (tag instanceof ID3V2Tag) {
  					return (ID3V2Tag) tag;
  				}
  			}
  		} catch (ID3Exception e) {
  			throw new RuntimeException("Error reading tags", e);
  		}
  		return null;
  	}
  
  	public String dumpAllTags(String filename) {
  		StringBuffer sb = new StringBuffer();
  		try {
  			MediaFile mediaFile = new MP3File(new File(filename));
  
  			ID3Tag[] tags = mediaFile.getTags();
  
  			for (ID3Tag tag : tags) {
  				sb.append(tag.getClass());
  				sb.append("\n");
  				sb.append(tag);
  
  				sb.append("\n");
  			}
  
  		} catch (ID3Exception e) {
  			throw new RuntimeException("Error reading tags", e);
  		}
  
  		return sb.toString();
  	}
  
  	public void reencodeFolder(String inputFolder, String outputFolder, String preset) {
  		logger.info("Re-encoding folder: " + inputFolder + " into " + outputFolder + ", using preset " + preset);
  		if (inputFolder == null || outputFolder == null || preset == null) {
  			throw new RuntimeException("Null parameters not allowed");
  		}
  		if (!inputFolder.endsWith(File.separator)) {
  			inputFolder += File.separator;
  		}
 		if (!outputFolder.endsWith(File.separator)) {
 			outputFolder += File.separator;
 		}
 
 		Set<MusicFile> inputFiles = musicFileFactory.getMusicFiles(inputFolder);
 		for (MusicFile musicFile : inputFiles) {
 			String inputFilename = inputFolder + musicFile.getFilename();
 			String outputFilename = outputFolder + musicFile.getFilename();
 			logger.info("Processing file: " + inputFilename);
 			fileSystemUtils.checkFolder(new File(outputFilename).getParentFile().getAbsolutePath());
 			if (fileSystemUtils.destinationFileNewer(inputFilename, outputFilename)) {
 				logger.info("Destination file exists + is newer, skipping");
 			} else {
 				logger.info("Running: " + inputFilename + ", " + outputFilename);
 				reencodeMP3(inputFilename, outputFilename, preset);
 			}
 		}
 	}
 
 	public void reencodeMP3(String inputFilename, String outputFilename, String preset) {
 		reencodeMP3(inputFilename, outputFilename, preset, true);
 	}
 
 	public void reencodeMP3(String inputFilename, String outputFilename, String preset, boolean retag) {
 
 		try {
 			File outputFolder = new File(outputFilename).getParentFile();
 			if (!outputFolder.exists()) {
 				if (!outputFolder.mkdirs()) {
 					throw new RuntimeException("Error creating output folder");
 				}
 			}
 			String commandLine = String.format(COMMAND_LINE_TEMPLATE, mp3Encoder, preset, inputFilename, outputFilename).replaceAll("\\\\", "/");
 
 			logger.debug("Running command: " + commandLine);
 
 			Process p = Runtime.getRuntime().exec(commandLine);
 
 			StreamConsumer stdout = new StreamConsumer(p.getInputStream(), true);
 			StreamConsumer error = new StreamConsumer(p.getErrorStream(), false);
 
 			new Thread(stdout, "stdout reader").start();
 			new Thread(error, "error reader").start();
 
 			p.waitFor();
 			int exitValue = p.exitValue();
 			if (exitValue != 0) {
 				throw new RuntimeException("MP3 Encoder exited with code: " + exitValue);
 			}
 			if (retag) {
 				copyTags(inputFilename, outputFilename);
 			}
 		} catch (Exception e) {
 			logger.error("Error running mp3 encoder", e);
 			throw new RuntimeException("Error running mp3 encoder", e);
 		}
 	}
 
 	private void copyTags(String inputFilename, String outputFilename) {
 		ID3V2Tag inputTags = getID3V2Tags(inputFilename);
 		MediaFile mediaFile = new MP3File(new File(outputFilename));
 		mediaFile.setID3Tag(inputTags);
 		try {
 			mediaFile.sync();
 		} catch (ID3Exception e) {
 			throw new RuntimeException("Error writing tags to: " + outputFilename, e);
 		}
 	}
 
 	private class StreamConsumer implements Runnable {
 		private Logger logger = Logger.getLogger(getClass());
 		private InputStream stream;
 		private boolean log;
 
 		public StreamConsumer(InputStream stream, boolean log) {
 			this.stream = stream;
 			this.log = log;
 		}
 
 		public void run() {
 			BufferedReader br = new BufferedReader(new InputStreamReader(stream));
 			try {
 				for (String line; (line = br.readLine()) != null;) {
 					if (log) {
 						logger.info(line);
 					}
 				}
 			} catch (IOException e) {
 				logger.error("Error reading stream", e);
 			}
 		}
 	}
 
 	public void retagMP3(String filename, RadioProgramBean program) {
 		try {
 			ID3V2_3_0Tag tag = new ID3V2_3_0Tag();
 			tag.setTitle(program.getEpisodeTitle());
 			tag.setAlbum(program.getSeriesTitle());
 			tag.setArtist(program.getArtist());
 
 			MediaFile mediaFile = new MP3File(new File(filename));
 			mediaFile.setID3Tag(tag);
 			mediaFile.sync();
 		} catch (Exception e) {
 			logger.error("Error writing mp3 tags", e);
 			throw new RuntimeException("Error writing mp3 tags", e);
 		}
 	}
 
 	public void retagMP3(String filename, ProgramInformation prog) {
 		try {
 			ID3V2_3_0Tag tag = new ID3V2_3_0Tag();
 			tag.setTitle(prog.getProgramName());
 			tag.setAlbum(prog.getProgramSetName());
 			tag.setArtist(prog.getAuthor());
 
 			MediaFile mediaFile = new MP3File(new File(filename));
 			mediaFile.setID3Tag(tag);
 			mediaFile.sync();
 		} catch (Exception e) {
 			logger.error("Error writing mp3 tags", e);
 			throw new RuntimeException("Error writing mp3 tags", e);
 		}
 	}
 
 }