package com.annimon.playlisteditor;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import com.annimon.playlisteditor.data.Playlist;
import com.annimon.playlisteditor.data.Track;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.provider.MediaStore;
import android.text.TextUtils;


public class PlaylistDatabase {
    
    public static void createPlaylist(Context context, String name, int[] trackIds) {
        if (TextUtils.isEmpty(name)) return;
        
        ContentValues cv = new ContentValues();
        cv.put(MediaStore.Audio.Playlists.NAME, name);
        
        ContentResolver resolver = context.getContentResolver();
        Uri uri = resolver.insert(MediaStore.Audio.Playlists.getContentUri("external"), cv);
        
        int size = trackIds.length;
        ContentValues[] values = new ContentValues[size];
        for (int i = 0; i < size; i++) {
            values[i] = new ContentValues();
            values[i].put(MediaStore.Audio.Playlists.Members.PLAY_ORDER, i);
            values[i].put(MediaStore.Audio.Playlists.Members.AUDIO_ID, trackIds[i]);
        }
        
        resolver.bulkInsert(uri, values);
    }

    public static Playlist[] getPlaylists(Context context) {
        String[] projection = {
                MediaStore.Audio.Playlists._ID,
                MediaStore.Audio.Playlists.NAME
        };
        
        Cursor playlistSDCardCursor = query(context,
              MediaStore.Audio.Playlists.EXTERNAL_CONTENT_URI,
              projection, projection[1]);
        
        int size = playlistSDCardCursor.getCount();
        Playlist[] playlists = new Playlist[size];
        
        playlistSDCardCursor.moveToFirst();
        for (int i = 0; i < size; i++) {
            int id = playlistSDCardCursor.getInt(0);
            String name = playlistSDCardCursor.getString(1);
            playlists[i] = new Playlist(id, name);
            
            playlistSDCardCursor.moveToNext();
        }
        
        return playlists;
    }
    
    /**
     * Get tracks of playlist. If playlistId equals -1 - return all tracks in system.
     * @param context
     * @param playlistId id of playlist, or -1.
     * @return tracks array.
     */
    public static Track[] getTracks(Context context, long playlistId) {
        String[] projection = {
                (playlistId == -1) ?
                        MediaStore.Audio.Media._ID :
                        MediaStore.Audio.Playlists.Members.AUDIO_ID,
                        
                        MediaStore.Audio.Media.ARTIST,
                        MediaStore.Audio.Media.TITLE
        };
        
        Cursor tracksCursor;
        if (playlistId == -1) {
            // Get all tracks.
            String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0 ";
            tracksCursor = query(context,
                    MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                    projection, selection, null, null, 0);
        } else {
            // Get tracks of playlist.
            tracksCursor = query(context,
                  MediaStore.Audio.Playlists.Members.getContentUri("external", playlistId),
                  projection, null);
        }
        
        int size = tracksCursor.getCount();
        Track[] tracks = new Track[size];
        
        tracksCursor.moveToFirst();
        for (int i = 0; i < size; i++) {
            int audioId = tracksCursor.getInt(0);
            String artist = tracksCursor.getString(1);
            String title = tracksCursor.getString(2);
            tracks[i] = new Track(audioId, artist, title);
            
            tracksCursor.moveToNext();
        }
        
        return tracks;
    }
    
    private static Cursor query(Context context,
            Uri uri, String[] projection, String sortOrder) {
        return query(context, uri, projection, null, null, sortOrder, 0);
    }
    
    private static Cursor query(Context context, Uri uri, String[] projection,
             String selection, String[] selectionArgs, String sortOrder, int limit) {
        try {
            ContentResolver resolver = context.getContentResolver();
            if (resolver == null) {
                return null;
            }
            if (limit > 0) {
                uri = uri.buildUpon().appendQueryParameter("limit", String.valueOf(limit)).build();
            }
            return resolver.query(uri, projection, selection, selectionArgs, sortOrder);
        } catch (UnsupportedOperationException ex) {
            ExceptionHandler.log(ex);
            return null;
        }
    }
}