/*
 This file is part of Subsonic.

 Subsonic 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.

 Subsonic 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 Subsonic.  If not, see <http://www.gnu.org/licenses/>.

 Copyright 2009 (C) Sindre Mehus
 */
package com.thejoshwa.ultrasonic.androidapp.service;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Reader;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.conn.params.ConnManagerParams;
import org.apache.http.conn.params.ConnPerRouteBean;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.scheme.SocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;
import org.xmlpull.v1.XmlPullParser;

import android.content.Context;
import android.content.SharedPreferences;
import android.content.pm.PackageInfo;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;
import android.util.Xml;
import com.thejoshwa.ultrasonic.androidapp.R;
import com.thejoshwa.ultrasonic.androidapp.domain.Genre;
import com.thejoshwa.ultrasonic.androidapp.domain.Indexes;
import com.thejoshwa.ultrasonic.androidapp.domain.JukeboxStatus;
import com.thejoshwa.ultrasonic.androidapp.domain.Lyrics;
import com.thejoshwa.ultrasonic.androidapp.domain.MusicDirectory;
import com.thejoshwa.ultrasonic.androidapp.domain.MusicFolder;
import com.thejoshwa.ultrasonic.androidapp.domain.Playlist;
import com.thejoshwa.ultrasonic.androidapp.domain.SearchCritera;
import com.thejoshwa.ultrasonic.androidapp.domain.SearchResult;
import com.thejoshwa.ultrasonic.androidapp.domain.ServerInfo;
import com.thejoshwa.ultrasonic.androidapp.domain.Version;
import com.thejoshwa.ultrasonic.androidapp.service.parser.AlbumListParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.ErrorParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.GenreParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.IndexesParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.JukeboxStatusParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.LicenseParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.LyricsParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.MusicDirectoryParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.MusicFoldersParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.PlaylistParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.PlaylistsParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.RandomSongsParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.SearchResult2Parser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.SearchResultParser;
import com.thejoshwa.ultrasonic.androidapp.service.parser.VersionParser;
import com.thejoshwa.ultrasonic.androidapp.service.ssl.SSLSocketFactory;
import com.thejoshwa.ultrasonic.androidapp.service.ssl.TrustSelfSignedStrategy;
import com.thejoshwa.ultrasonic.androidapp.util.CancellableTask;
import com.thejoshwa.ultrasonic.androidapp.util.Constants;
import com.thejoshwa.ultrasonic.androidapp.util.FileUtil;
import com.thejoshwa.ultrasonic.androidapp.util.ProgressListener;
import com.thejoshwa.ultrasonic.androidapp.util.Util;

/**
 * @author Sindre Mehus
 */
public class RESTMusicService implements MusicService {

    private static final String TAG = RESTMusicService.class.getSimpleName();

    private static final int SOCKET_CONNECT_TIMEOUT = 10 * 1000;
    private static final int SOCKET_READ_TIMEOUT_DEFAULT = 10 * 1000;
    private static final int SOCKET_READ_TIMEOUT_DOWNLOAD = 30 * 1000;
    private static final int SOCKET_READ_TIMEOUT_GET_RANDOM_SONGS = 60 * 1000;
    private static final int SOCKET_READ_TIMEOUT_GET_PLAYLIST = 60 * 1000;

    // Allow 20 seconds extra timeout per MB offset.
    private static final double TIMEOUT_MILLIS_PER_OFFSET_BYTE = 20000.0 / 1000000.0;

    /**
     * URL from which to fetch latest versions.
     */
    private static final String VERSION_URL = "http://subsonic.org/backend/version.view";

    private static final int HTTP_REQUEST_MAX_ATTEMPTS = 5;
    private static final long REDIRECTION_CHECK_INTERVAL_MILLIS = 60L * 60L * 1000L;

    private final DefaultHttpClient httpClient;
    private long redirectionLastChecked;
    private int redirectionNetworkType = -1;
    private String redirectFrom;
    private String redirectTo;
    private final ThreadSafeClientConnManager connManager;

    public RESTMusicService() {

        // Create and initialize default HTTP parameters
        HttpParams params = new BasicHttpParams();
        ConnManagerParams.setMaxTotalConnections(params, 20);
        ConnManagerParams.setMaxConnectionsPerRoute(params, new ConnPerRouteBean(20));
        HttpConnectionParams.setConnectionTimeout(params, SOCKET_CONNECT_TIMEOUT);
        HttpConnectionParams.setSoTimeout(params, SOCKET_READ_TIMEOUT_DEFAULT);

        // Turn off stale checking.  Our connections break all the time anyway,
        // and it's not worth it to pay the penalty of checking every time.
        HttpConnectionParams.setStaleCheckingEnabled(params, false);

        // Create and initialize scheme registry
        SchemeRegistry schemeRegistry = new SchemeRegistry();
        schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
        schemeRegistry.register(new Scheme("https", createSSLSocketFactory(), 443));

        // Create an HttpClient with the ThreadSafeClientConnManager.
        // This connection manager must be used if more than one thread will
        // be using the HttpClient.
        connManager = new ThreadSafeClientConnManager(params, schemeRegistry);
        httpClient = new DefaultHttpClient(connManager, params);
    }

    private SocketFactory createSSLSocketFactory() {
        try {
            return new SSLSocketFactory(new TrustSelfSignedStrategy(), SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
        } catch (Throwable x) {
            Log.e(TAG, "Failed to create custom SSL socket factory, using default.", x);
            return org.apache.http.conn.ssl.SSLSocketFactory.getSocketFactory();
        }
    }

    @Override
    public void ping(Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "ping", null);
        try {
            new ErrorParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
    }

    @Override
    public boolean isLicenseValid(Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "getLicense", null);
        try {
            ServerInfo serverInfo = new LicenseParser(context).parse(reader);
            return serverInfo.isLicenseValid();
        } finally {
            Util.close(reader);
        }
    }

    public List<MusicFolder> getMusicFolders(boolean refresh, Context context, ProgressListener progressListener) throws Exception {
        List<MusicFolder> cachedMusicFolders = readCachedMusicFolders(context);
        if (cachedMusicFolders != null && !refresh) {
            return cachedMusicFolders;
        }

        Reader reader = getReader(context, progressListener, "getMusicFolders", null);
        try {
            List<MusicFolder> musicFolders = new MusicFoldersParser(context).parse(reader, progressListener);
            writeCachedMusicFolders(context, musicFolders);
            return musicFolders;
        } finally {
            Util.close(reader);
        }
    }
    
    @Override
    public Indexes getIndexes(String musicFolderId, boolean refresh, Context context, ProgressListener progressListener) throws Exception {
        Indexes cachedIndexes = readCachedIndexes(context, musicFolderId);
        if (cachedIndexes != null && !refresh) {
            return cachedIndexes;
        }

        long lastModified = (cachedIndexes == null || refresh) ? 0L : cachedIndexes.getLastModified();

        List<String> parameterNames = new ArrayList<String>();
        List<Object> parameterValues = new ArrayList<Object>();

		if(lastModified != 0L) {
			parameterNames.add("ifModifiedSince");
			parameterValues.add(lastModified);
		}

        if (musicFolderId != null) {
            parameterNames.add("musicFolderId");
            parameterValues.add(musicFolderId);
        }

        Reader reader = getReader(context, progressListener, "getIndexes", null, parameterNames, parameterValues);
        try {
            Indexes indexes = new IndexesParser(context).parse(reader, progressListener);
            if (indexes != null) {
                writeCachedIndexes(context, indexes, musicFolderId);
                return indexes;
            }
			if(cachedIndexes != null) {
				return cachedIndexes;
			} else {
				return new Indexes(0, new ArrayList<com.thejoshwa.ultrasonic.androidapp.domain.Artist>(), new ArrayList<com.thejoshwa.ultrasonic.androidapp.domain.Artist>());
			}
        } finally {
            Util.close(reader);
        }
    }
    
    private Indexes readCachedIndexes(Context context, String musicFolderId) {
        String filename = getCachedIndexesFilename(context, musicFolderId);
        return FileUtil.deserialize(context, filename);
    }

    private void writeCachedIndexes(Context context, Indexes indexes, String musicFolderId) {
        String filename = getCachedIndexesFilename(context, musicFolderId);
        FileUtil.serialize(context, indexes, filename);
    }

    private String getCachedIndexesFilename(Context context, String musicFolderId) {
        String s = Util.getRestUrl(context, null) + musicFolderId;
        return "indexes-" + Math.abs(s.hashCode()) + ".ser";
    }
    
    private ArrayList<MusicFolder> readCachedMusicFolders(Context context) {
        String filename = getCachedMusicFoldersFilename(context);
        return FileUtil.deserialize(context, filename);
    }

    private void writeCachedMusicFolders(Context context, List<MusicFolder> musicFolders) {
        String filename = getCachedMusicFoldersFilename(context);
        FileUtil.serialize(context, new ArrayList<MusicFolder>(musicFolders), filename);
    }

    private String getCachedMusicFoldersFilename(Context context) {
        String s = Util.getRestUrl(context, null);
        return "musicFolders-" + Math.abs(s.hashCode()) + ".ser";
    }
    
    public void star(String id, Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "star", null, "id", id);
        try {
        	new ErrorParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
    }
    
    public void unstar(String id, Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "unstar", null, "id", id);
        try {
        	new ErrorParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
    }

    @Override
    public MusicDirectory getMusicDirectory(String id, String name, boolean refresh, Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "getMusicDirectory", null, "id", id);
        try {
            return new MusicDirectoryParser(context).parse(name, reader, progressListener);
        } finally {
            Util.close(reader);
        }
    }

    @Override
    public SearchResult search(SearchCritera critera, Context context, ProgressListener progressListener) throws Exception {
        try {
            return searchNew(critera, context, progressListener);
        } catch (ServerTooOldException x) {
            // Ensure backward compatibility with REST 1.3.
            return searchOld(critera, context, progressListener);
        }
    }

    /**
     * Search using the "search" REST method.
     */
    private SearchResult searchOld(SearchCritera critera, Context context, ProgressListener progressListener) throws Exception {
        List<String> parameterNames = Arrays.asList("any", "songCount");
        List<Object> parameterValues = Arrays.<Object>asList(critera.getQuery(), critera.getSongCount());
        Reader reader = getReader(context, progressListener, "search", null, parameterNames, parameterValues);
        try {
            return new SearchResultParser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }
    }

    /**
     * Search using the "search2" REST method, available in 1.4.0 and later.
     */
    private SearchResult searchNew(SearchCritera critera, Context context, ProgressListener progressListener) throws Exception {
        checkServerVersion(context, "1.4", null);

        List<String> parameterNames = Arrays.asList("query", "artistCount", "albumCount", "songCount");
        List<Object> parameterValues = Arrays.<Object>asList(critera.getQuery(), critera.getArtistCount(),
                                                             critera.getAlbumCount(), critera.getSongCount());
        Reader reader = getReader(context, progressListener, "search2", null, parameterNames, parameterValues);
        try {
            return new SearchResult2Parser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }
    }

    @Override
    public MusicDirectory getPlaylist(String id, String name, Context context, ProgressListener progressListener) throws Exception {
        HttpParams params = new BasicHttpParams();
        HttpConnectionParams.setSoTimeout(params, SOCKET_READ_TIMEOUT_GET_PLAYLIST);

        Reader reader = getReader(context, progressListener, "getPlaylist", params, "id", id);
        try {
			MusicDirectory playlist = new PlaylistParser(context).parse(reader, progressListener);
			
			File playlistFile = FileUtil.getPlaylistFile(name);
			FileWriter fw = new FileWriter(playlistFile);
			BufferedWriter bw = new BufferedWriter(fw);
			try {
				fw.write("#EXTM3U\n");
				for (MusicDirectory.Entry e : playlist.getChildren()) {
					String filePath = FileUtil.getSongFile(context, e).getAbsolutePath();
					if(! new File(filePath).exists()){
						String ext = FileUtil.getExtension(filePath);
						String base = FileUtil.getBaseName(filePath);
						filePath = base + ".complete." + ext;                
					}
					fw.write(filePath + "\n");
				}
			} catch(Exception e) {
				Log.w(TAG, "Failed to save playlist: " + name);
			} finally {
				bw.close();
				fw.close();
			}
			
			return playlist;
        } finally {
            Util.close(reader);
        }
    }
    
    @Override
    public List<Playlist> getPlaylists(boolean refresh, Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "getPlaylists", null);
        try {
            return new PlaylistsParser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }
    }

    @Override
    public void createPlaylist(String id, String name, List<MusicDirectory.Entry> entries, Context context, ProgressListener progressListener) throws Exception {
        List<String> parameterNames = new LinkedList<String>();
        List<Object> parameterValues = new LinkedList<Object>();

        if (id != null) {
            parameterNames.add("playlistId");
            parameterValues.add(id);
        }
        if (name != null) {
            parameterNames.add("name");
            parameterValues.add(name);
        }
        for (MusicDirectory.Entry entry : entries) {
            parameterNames.add("songId");
            parameterValues.add(entry.getId());
        }

        Reader reader = getReader(context, progressListener, "createPlaylist", null, parameterNames, parameterValues);
        try {
            new ErrorParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
    }
    
	@Override
	public void deletePlaylist(String id, Context context, ProgressListener progressListener) throws Exception {		
		Reader reader = getReader(context, progressListener, "deletePlaylist", null, "id", id);
		try {
            new ErrorParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
	}
	
	@Override
	public void addToPlaylist(String id, List<MusicDirectory.Entry> toAdd, Context context, ProgressListener progressListener) throws Exception {
		checkServerVersion(context, "1.8", "Updating playlists is not supported.");
		List<String> names = new ArrayList<String>();
		List<Object> values = new ArrayList<Object>();
		names.add("playlistId");
		values.add(id);
		for(MusicDirectory.Entry song: toAdd) {
			names.add("songIdToAdd");
			values.add(song.getId());
		}
		Reader reader = getReader(context, progressListener, "updatePlaylist", null, names, values);
    	try {
            new ErrorParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
	}
	
	@Override
	public void removeFromPlaylist(String id, List<Integer> toRemove, Context context, ProgressListener progressListener) throws Exception {
		checkServerVersion(context, "1.8", "Updating playlists is not supported.");
		List<String> names = new ArrayList<String>();
		List<Object> values = new ArrayList<Object>();
		names.add("playlistId");
		values.add(id);
		for(Integer song: toRemove) {
			names.add("songIndexToRemove");
			values.add(song);
		}
		Reader reader = getReader(context, progressListener, "updatePlaylist", null, names, values);
    	try {
            new ErrorParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
	}
	
	@Override
	public void updatePlaylist(String id, String name, String comment, boolean pub, Context context, ProgressListener progressListener) throws Exception {
		checkServerVersion(context, "1.8", "Updating playlists is not supported.");
		Reader reader = getReader(context, progressListener, "updatePlaylist", null, Arrays.asList("playlistId", "name", "comment", "public"), Arrays.<Object>asList(id, name, comment, pub));
		try {
			new ErrorParser(context).parse(reader);
		} finally {
			Util.close(reader);
		}
	}

    @Override
    public Lyrics getLyrics(String artist, String title, Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "getLyrics", null, Arrays.asList("artist", "title"), Arrays.<Object>asList(artist, title));
        try {
            return new LyricsParser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }
    }

    @Override
    public void scrobble(String id, boolean submission, Context context, ProgressListener progressListener) throws Exception {
        checkServerVersion(context, "1.5", "Scrobbling not supported.");
        Reader reader = getReader(context, progressListener, "scrobble", null, Arrays.asList("id", "submission"), Arrays.<Object>asList(id, submission));
        try {
            new ErrorParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
    }

    @Override
    public MusicDirectory getAlbumList(String type, int size, int offset, Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "getAlbumList",
                                  null, Arrays.asList("type", "size", "offset"), Arrays.<Object>asList(type, size, offset));
        try {
            return new AlbumListParser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }
    }

    @Override
    public MusicDirectory getRandomSongs(int size, Context context, ProgressListener progressListener) throws Exception {
        HttpParams params = new BasicHttpParams();
        HttpConnectionParams.setSoTimeout(params, SOCKET_READ_TIMEOUT_GET_RANDOM_SONGS);
		
		List<String> names = new ArrayList<String>();
        List<Object> values = new ArrayList<Object>();

        names.add("size");
        values.add(size);

        Reader reader = getReader(context, progressListener, "getRandomSongs", params, names, values);
        try {
            return new RandomSongsParser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }
    }
    
    @Override
    public SearchResult getStarred(Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReader(context, progressListener, "getStarred", null);
        try {
            return new SearchResult2Parser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }	
    }

    @Override
    public Version getLocalVersion(Context context) throws Exception {
        PackageInfo packageInfo = context.getPackageManager().getPackageInfo("com.thejoshwa.ultrasonic.androidapp", 0);
        return new Version(packageInfo.versionName);
    }

    @Override
    public Version getLatestVersion(Context context, ProgressListener progressListener) throws Exception {
        Reader reader = getReaderForURL(context, VERSION_URL, null, null, null, progressListener);
        try {
            return new VersionParser().parse(reader);
        } finally {
            Util.close(reader);
        }
    }

    private void checkServerVersion(Context context, String version, String text) throws ServerTooOldException {
        Version serverVersion = Util.getServerRestVersion(context);
        Version requiredVersion = new Version(version);
        boolean ok = serverVersion == null || serverVersion.compareTo(requiredVersion) >= 0;

        if (!ok) {
            throw new ServerTooOldException(text, serverVersion, requiredVersion);
        }
    }

    @Override
	public Bitmap getCoverArt(Context context, MusicDirectory.Entry entry, int size, boolean saveToFile, ProgressListener progressListener) throws Exception {
		// Synchronize on the entry so that we don't download concurrently for
		// the same song.
		synchronized (entry) {
			// Use cached file, if existing.
			Bitmap bitmap = FileUtil.getAlbumArtBitmap(context, entry, size);
			boolean serverScaling = Util.isServerScalingEnabled(context);
			
			if (bitmap == null) {
				String url = Util.getRestUrl(context, "getCoverArt");

				InputStream in = null;
				try {
					List<String> parameterNames;
					List<Object> parameterValues;
					
					if (serverScaling) {
						parameterNames = Arrays.asList("id", "size");
						parameterValues = Arrays.<Object>asList(entry.getCoverArt(), size);
					}
					else {
						parameterNames = Arrays.asList("id");
						parameterValues = Arrays.<Object> asList(entry.getCoverArt());	
					}
					
					HttpEntity entity = getEntityForURL(context, url, null, parameterNames, parameterValues, progressListener);
					in = entity.getContent();

					// If content type is XML, an error occurred. Get it.
					String contentType = Util.getContentType(entity);
					if (contentType != null && contentType.startsWith("text/xml")) {
						new ErrorParser(context).parse(new InputStreamReader(in, Constants.UTF_8));
						return null; // Never reached.
					}

					byte[] bytes = Util.toByteArray(in);

					File albumDir = FileUtil.getAlbumDirectory(context, entry);
	                if (albumDir.exists()) {
	                    OutputStream out = null;
	                    try {
	                        out = new FileOutputStream(FileUtil.getAlbumArtFile(albumDir));
	                        out.write(bytes);
	                    } finally {
	                        Util.close(out);
	                    }
	                }
					
					// If we aren't allowing server-side scaling, always save the file to disk because it will be unmodified
					if (!serverScaling || saveToFile) {
						OutputStream out = null;
						try {
							out = new FileOutputStream(FileUtil.getAlbumArtFile(context, entry));
							out.write(bytes);
						} finally {
							Util.close(out);
						}
					}

					bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
				} finally {
					Util.close(in);
				}
			}
			
			// Return scaled bitmap
			return Util.scaleBitmap(bitmap, size);
		}
	}

    @Override
    public HttpResponse getDownloadInputStream(Context context, MusicDirectory.Entry song, long offset, int maxBitrate, CancellableTask task) throws Exception {

        String url = Util.getRestUrl(context, "stream");

        // Set socket read timeout. Note: The timeout increases as the offset gets larger. This is
        // to avoid the thrashing effect seen when offset is combined with transcoding/downsampling on the server.
        // In that case, the server uses a long time before sending any data, causing the client to time out.
        HttpParams params = new BasicHttpParams();
        int timeout = (int) (SOCKET_READ_TIMEOUT_DOWNLOAD + offset * TIMEOUT_MILLIS_PER_OFFSET_BYTE);
        HttpConnectionParams.setSoTimeout(params, timeout);

        // Add "Range" header if offset is given.
        List<Header> headers = new ArrayList<Header>();
        if (offset > 0) {
            headers.add(new BasicHeader("Range", "bytes=" + offset + "-"));
        }
        List<String> parameterNames = Arrays.asList("id", "maxBitRate");
        List<Object> parameterValues = Arrays.<Object>asList(song.getId(), maxBitrate);
        HttpResponse response = getResponseForURL(context, url, params, parameterNames, parameterValues, headers, null, task);

        // If content type is XML, an error occurred.  Get it.
        String contentType = Util.getContentType(response.getEntity());
        if (contentType != null && contentType.startsWith("text/xml")) {
            InputStream in = response.getEntity().getContent();
            try {
                new ErrorParser(context).parse(new InputStreamReader(in, Constants.UTF_8));
            } finally {
                Util.close(in);
            }
        }

        return response;
    }

    @Override
    public String getVideoUrl(int maxBitrate, Context context, String id) {
        StringBuilder builder = new StringBuilder(Util.getRestUrl(context, "videoPlayer"));
        builder.append("&id=").append(id);
        builder.append("&maxBitRate=").append(maxBitrate);
        builder.append("&autoplay=true");

        String url = rewriteUrlWithRedirect(context, builder.toString());
        Log.i(TAG, "Using video URL: " + url);
        return url;
    }
    
	@Override
	public String getVideoStreamUrl(int maxBitrate, Context context, String id) {
		StringBuilder builder = new StringBuilder(Util.getRestUrl(context, "stream"));
        builder.append("&id=").append(id);
        builder.append("&maxBitRate=").append(maxBitrate);

        String url = rewriteUrlWithRedirect(context, builder.toString());
        Log.i(TAG, "Using video URL: " + url);
        return url;
	}

    @Override
    public JukeboxStatus updateJukeboxPlaylist(List<String> ids, Context context, ProgressListener progressListener) throws Exception {
        int n = ids.size();
        List<String> parameterNames = new ArrayList<String>(n + 1);
        parameterNames.add("action");
        for (int i = 0; i < n; i++) {
            parameterNames.add("id");
        }
        List<Object> parameterValues = new ArrayList<Object>();
        parameterValues.add("set");
        parameterValues.addAll(ids);

        return executeJukeboxCommand(context, progressListener, parameterNames, parameterValues);
    }

    @Override
    public JukeboxStatus skipJukebox(int index, int offsetSeconds, Context context, ProgressListener progressListener) throws Exception {
        List<String> parameterNames = Arrays.asList("action", "index", "offset");
        List<Object> parameterValues = Arrays.<Object>asList("skip", index, offsetSeconds);
        return executeJukeboxCommand(context, progressListener, parameterNames, parameterValues);
    }

    @Override
    public JukeboxStatus stopJukebox(Context context, ProgressListener progressListener) throws Exception {
        return executeJukeboxCommand(context, progressListener, Arrays.asList("action"), Arrays.<Object>asList("stop"));
    }

    @Override
    public JukeboxStatus startJukebox(Context context, ProgressListener progressListener) throws Exception {
        return executeJukeboxCommand(context, progressListener, Arrays.asList("action"), Arrays.<Object>asList("start"));
    }

    @Override
    public JukeboxStatus getJukeboxStatus(Context context, ProgressListener progressListener) throws Exception {
        return executeJukeboxCommand(context, progressListener, Arrays.asList("action"), Arrays.<Object>asList("status"));
    }

    @Override
    public JukeboxStatus setJukeboxGain(float gain, Context context, ProgressListener progressListener) throws Exception {
        List<String> parameterNames = Arrays.asList("action", "gain");
        List<Object> parameterValues = Arrays.<Object>asList("setGain", gain);
        return executeJukeboxCommand(context, progressListener, parameterNames, parameterValues);
    }

    private JukeboxStatus executeJukeboxCommand(Context context, ProgressListener progressListener, List<String> parameterNames, List<Object> parameterValues) throws Exception {
        checkServerVersion(context, "1.7", "Jukebox not supported.");
        Reader reader = getReader(context, progressListener, "jukeboxControl", null, parameterNames, parameterValues);
        try {
            return new JukeboxStatusParser(context).parse(reader);
        } finally {
            Util.close(reader);
        }
    }

    private Reader getReader(Context context, ProgressListener progressListener, String method, HttpParams requestParams) throws Exception {
        return getReader(context, progressListener, method, requestParams, Collections.<String>emptyList(), Collections.emptyList());
    }

    private Reader getReader(Context context, ProgressListener progressListener, String method,
                             HttpParams requestParams, String parameterName, Object parameterValue) throws Exception {
        return getReader(context, progressListener, method, requestParams, Arrays.asList(parameterName), Arrays.<Object>asList(parameterValue));
    }

    private Reader getReader(Context context, ProgressListener progressListener, String method,
                             HttpParams requestParams, List<String> parameterNames, List<Object> parameterValues) throws Exception {

        if (progressListener != null) {
            progressListener.updateProgress(R.string.service_connecting);
        }

        String url = Util.getRestUrl(context, method);
        return getReaderForURL(context, url, requestParams, parameterNames, parameterValues, progressListener);
    }

	private Reader getReaderForURL(Context context, String url, HttpParams requestParams, List<String> parameterNames, List<Object> parameterValues, ProgressListener progressListener) throws Exception {
		HttpEntity entity = getEntityForURL(context, url, requestParams, parameterNames, parameterValues, progressListener);
		if (entity == null) {
			throw new RuntimeException("No entity received for URL " + url);
		}

		InputStream in = entity.getContent();
		return new InputStreamReader(in, Constants.UTF_8);
	}

	private HttpEntity getEntityForURL(Context context, String url, HttpParams requestParams, List<String> parameterNames, List<Object> parameterValues, ProgressListener progressListener) throws Exception {
		return getResponseForURL(context, url, requestParams, parameterNames,
				parameterValues, null, progressListener, null).getEntity();
	}

	private HttpResponse getResponseForURL(Context context, String url, HttpParams requestParams, List<String> parameterNames, List<Object> parameterValues, List<Header> headers, ProgressListener progressListener, CancellableTask task) throws Exception {
		Log.d(TAG, "Connections in pool: " + connManager.getConnectionsInPool());

		// If not too many parameters, extract them to the URL rather than
		// relying on the HTTP POST request being
		// received intact. Remember, HTTP POST requests are converted to GET
		// requests during HTTP redirects, thus
		// loosing its entity.
		if (parameterNames != null && parameterNames.size() < 10) {
			StringBuilder builder = new StringBuilder(url);
			for (int i = 0; i < parameterNames.size(); i++) {
				builder.append("&").append(parameterNames.get(i)).append("=");
				builder.append(URLEncoder.encode(String.valueOf(parameterValues.get(i)), "UTF-8"));
			}
			url = builder.toString();
			parameterNames = null;
			parameterValues = null;
		}

		String rewrittenUrl = rewriteUrlWithRedirect(context, url);
		return executeWithRetry(context, rewrittenUrl, url, requestParams, parameterNames, parameterValues, headers, progressListener, task);
	}

	private HttpResponse executeWithRetry(Context context, String url, String originalUrl, HttpParams requestParams, List<String> parameterNames, List<Object> parameterValues, List<Header> headers, ProgressListener progressListener, CancellableTask task) throws IOException {
		Log.i(TAG, "Using URL " + url);

		SharedPreferences prefs = Util.getPreferences(context);
		int networkTimeout = Integer.parseInt(prefs.getString(Constants.PREFERENCES_KEY_NETWORK_TIMEOUT, "15000"));
		HttpParams newParams = httpClient.getParams();
		HttpConnectionParams.setSoTimeout(newParams, networkTimeout);
		httpClient.setParams(newParams);

		final AtomicReference<Boolean> cancelled = new AtomicReference<Boolean>(false);
		int attempts = 0;
		while (true) {
			attempts++;
			HttpContext httpContext = new BasicHttpContext();
			final HttpPost request = new HttpPost(url);

			if (task != null) {
				// Attempt to abort the HTTP request if the task is cancelled.
				task.setOnCancelListener(new CancellableTask.OnCancelListener() {
					@Override
					public void onCancel() {
						new Thread(new Runnable() {
							public void run() {
								try {
									cancelled.set(true);
									request.abort();
								} catch(Exception e) {
									Log.e(TAG, "Failed to stop http task");
								}
							}
						}).start();
					}
				});
			}

			if (parameterNames != null) {
				List<NameValuePair> params = new ArrayList<NameValuePair>();
				for (int i = 0; i < parameterNames.size(); i++) {
					params.add(new BasicNameValuePair(parameterNames.get(i), String.valueOf(parameterValues.get(i))));
				}
				request.setEntity(new UrlEncodedFormEntity(params, Constants.UTF_8));
			}

			if (requestParams != null) {
				request.setParams(requestParams);
				Log.d(TAG, "Socket read timeout: " + HttpConnectionParams.getSoTimeout(requestParams) + " ms.");
			}

			if (headers != null) {
				for (Header header : headers) {
					request.addHeader(header);
				}
			}

			// Set credentials to get through apache proxies that require authentication.
			int instance = prefs.getInt(Constants.PREFERENCES_KEY_SERVER_INSTANCE, 1);
			String username = prefs.getString(Constants.PREFERENCES_KEY_USERNAME + instance, null);
			String password = prefs.getString(Constants.PREFERENCES_KEY_PASSWORD + instance, null);
			httpClient.getCredentialsProvider().setCredentials(new AuthScope(AuthScope.ANY_HOST, AuthScope.ANY_PORT),
					new UsernamePasswordCredentials(username, password));

			try {
				HttpResponse response = httpClient.execute(request, httpContext);
				detectRedirect(originalUrl, context, httpContext);
				return response;
			} catch (IOException x) {
				request.abort();
				if (attempts >= HTTP_REQUEST_MAX_ATTEMPTS || cancelled.get()) {
					throw x;
				}
				if (progressListener != null) {
					String msg = context.getResources().getString(R.string.music_service_retry, attempts, HTTP_REQUEST_MAX_ATTEMPTS - 1);
					progressListener.updateProgress(msg);
				}
				Log.w(TAG, "Got IOException (" + attempts + "), will retry", x);
				increaseTimeouts(requestParams);
				Util.sleepQuietly(2000L);
			}
		}
	}

    private void increaseTimeouts(HttpParams requestParams) {
        if (requestParams != null) {
            int connectTimeout = HttpConnectionParams.getConnectionTimeout(requestParams);
            if (connectTimeout != 0) {
                HttpConnectionParams.setConnectionTimeout(requestParams, (int) (connectTimeout * 1.3F));
            }
            int readTimeout = HttpConnectionParams.getSoTimeout(requestParams);
            if (readTimeout != 0) {
                HttpConnectionParams.setSoTimeout(requestParams, (int) (readTimeout * 1.5F));
            }
        }
    }

    private void detectRedirect(String originalUrl, Context context, HttpContext httpContext) {
        HttpUriRequest request = (HttpUriRequest) httpContext.getAttribute(ExecutionContext.HTTP_REQUEST);
        HttpHost host = (HttpHost) httpContext.getAttribute(ExecutionContext.HTTP_TARGET_HOST);
		
		// Sometimes the request doesn't contain the "http://host" part
		String redirectedUrl;
		if (request.getURI().getScheme() == null) {
			redirectedUrl = host.toURI() + request.getURI();
		} else {
			redirectedUrl = request.getURI().toString();
		}

        redirectFrom = originalUrl.substring(0, originalUrl.indexOf("/rest/"));
        redirectTo = redirectedUrl.substring(0, redirectedUrl.indexOf("/rest/"));

        Log.i(TAG, redirectFrom + " redirects to " + redirectTo);
        redirectionLastChecked = System.currentTimeMillis();
        redirectionNetworkType = getCurrentNetworkType(context);
    }

    private String rewriteUrlWithRedirect(Context context, String url) {

        // Only cache for a certain time.
        if (System.currentTimeMillis() - redirectionLastChecked > REDIRECTION_CHECK_INTERVAL_MILLIS) {
            return url;
        }

        // Ignore cache if network type has changed.
        if (redirectionNetworkType != getCurrentNetworkType(context)) {
            return url;
        }

        if (redirectFrom == null || redirectTo == null) {
            return url;
        }

        return url.replace(redirectFrom, redirectTo);
    }

    private int getCurrentNetworkType(Context context) {
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        return networkInfo == null ? -1 : networkInfo.getType();
    }

	@Override
	public List<Genre> getGenres(Context context, ProgressListener progressListener) throws Exception {
		checkServerVersion(context, "1.9", "Genres not supported.");
        Reader reader = getReader(context, progressListener, "getGenres", null);
        try {
            return new GenreParser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }
	}

	@Override
	public MusicDirectory getSongsByGenre(String genre, int count, int offset, Context context, ProgressListener progressListener) throws Exception {
    	checkServerVersion(context, "1.9", "Genres not supported.");
        HttpParams params = new BasicHttpParams();
        HttpConnectionParams.setSoTimeout(params, SOCKET_READ_TIMEOUT_GET_RANDOM_SONGS);

        List<String> parameterNames = new ArrayList<String>();
        List<Object> parameterValues = new ArrayList<Object>();

        parameterNames.add("genre");
        parameterValues.add(genre);
        parameterNames.add("count");
        parameterValues.add(count);
        parameterNames.add("offset");
        parameterValues.add(offset);
       
        Reader reader = getReader(context, progressListener, "getSongsByGenre", params, parameterNames, parameterValues);
        
        try {
            return new RandomSongsParser(context).parse(reader, progressListener);
        } finally {
            Util.close(reader);
        }
	}
}