BusDatabase.java

/*******************************************************************************
 * Copyright (c) 2011 Michel DAVID mimah35-at-gmail.com
 * 
 * This program 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.
 * 
 * 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package fr.gotorennes.persistence;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.URL;
import java.util.zip.GZIPInputStream;

import android.app.ProgressDialog;
import android.content.Context;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteQueryBuilder;
import android.util.Log;
import fr.gotorennes.R;

public class BusDatabase {

	private static final String TAG = "GoToRennes.BusDatabase";

	private SQLiteDatabase dataBase;
	
	private final Context context;

	public BusDatabase(Context context) {
		this.context = context;
	}

	public synchronized void initOrUpdate(final ProgressDialog progress, boolean forceUpdate) {
		Log.i(TAG, "Initialisation de la base de données");
		
		if (progress != null) {
		
			if (progress.getOwnerActivity() != null) {
				progress.getOwnerActivity().runOnUiThread(new Runnable() {
					@Override
					public void run() {
						progress.setMessage(context.getString(R.string.checkDatabase));
					}
				});
			}
			
			int version = getCurrentVersion();
	
			if ((version != 0 && needUpdate(version)) || forceUpdate) {
				if (progress.getOwnerActivity() != null) {
					progress.getOwnerActivity().runOnUiThread(new Runnable() {
						@Override
						public void run() {
							progress.setMessage(context.getString(R.string.updateDatabase));
						}
					});
				}	
				close();
				copy();
				open();
				updateVersion(version);
			}
			else {
				open();
			}
		}
		else {
			open();
		}
	}
	
	protected int getCurrentVersion() {
		try {
			String stringVersion = new BufferedReader(new InputStreamReader(new URL("https://raw.githubusercontent.com/mimah/Go2Rennes-utils/master/data/version.txt").openStream())).readLine();
			return Integer.parseInt(stringVersion);
		}
		catch (Exception ex) {
			Log.e(TAG, "Error while checking available version " + ex.getMessage());
		}
		return 0;
	}

	protected boolean needUpdate(int version) {
		return !exists() || dataBase.getVersion() != version;
	}

	protected boolean exists() {
		try {
			open();

		} catch (SQLiteException e) {
			Log.d(TAG, "La base de données n'existe pas");
		}
		return dataBase != null;
	}

	protected void copy() {
		Log.i(TAG, "Copie de la base de données");

		GZIPInputStream myGzipInput = null;
		OutputStream myOutput = null;

		try {
			InputStream myInput = new URL("https://raw.githubusercontent.com/mimah/Go2Rennes-utils/master/data/bus.zip").openStream();
			myGzipInput = new GZIPInputStream(myInput);

			myOutput = context.openFileOutput("bus.db", Context.MODE_PRIVATE);

			byte[] buffer = new byte[1024];
			int length;
			while ((length = myGzipInput.read(buffer)) > 0) {
				myOutput.write(buffer, 0, length);
			}
			
		} catch (IOException e) {
			Log.e(TAG, "Téléchargement de la base de données impossible", e);
			throw new Error("Téléchargement de la base de données impossible.\n" + e.getMessage(), e);
		} finally {
			try {
				if (myOutput != null) {
					myOutput.flush();
					myOutput.close();
				}
				if (myGzipInput != null) {
					myGzipInput.close();
				}
			} catch (IOException e) {

			}
		}
	}

	protected void updateVersion(int version) {
		Log.i(TAG, "Mise à jour de la version de la base de données");
		dataBase.setVersion(version);

		Log.i(TAG, "Création des index");
		dataBase.execSQL("CREATE INDEX IF NOT EXISTS ID1 ON STATION_CIRCUIT (idStation)");
		dataBase.execSQL("CREATE INDEX IF NOT EXISTS ID2 ON ARRET (idStation)");
		dataBase.execSQL("CREATE INDEX IF NOT EXISTS ID3 ON TRAJET (idCircuit)");
		dataBase.execSQL("CREATE INDEX IF NOT EXISTS ID4 ON STATION_CIRCUIT (idCircuit)");
		dataBase.execSQL("CREATE INDEX IF NOT EXISTS ID5 ON ARRET (idTrajet)");
		dataBase.execSQL("CREATE INDEX IF NOT EXISTS ID6 ON ARRET (idStation, idTrajet)");
		
		SharedPreferences prefs = context.getSharedPreferences("fr.gotorennes.Application", 0);
		prefs.edit().putString("gtfs", String.valueOf(version)).commit();
	}

	protected void open() {
		Log.i(TAG, "Ouverture de la base de données");
		dataBase = SQLiteDatabase.openDatabase(context.getFileStreamPath("bus.db").getAbsolutePath(), null, SQLiteDatabase.OPEN_READWRITE);
	}

	public synchronized void close() {
		if (dataBase != null) {
			Log.i(TAG, "Fermeture de la base de données");
			dataBase.close();
		}
	}

	public Cursor query(String tables, String[] projections, String selection, String[] selectionArgs, String sort, String limit) {
		SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
		builder.setTables(tables);

		Cursor cursor = builder.query(dataBase, projections, selection, selectionArgs, null, null, sort, limit);

		if (cursor == null) {
			return null;
		} else if (!cursor.moveToFirst()) {
			cursor.close();
			return null;
		}
		return cursor;
	}

	public Cursor query(String sql, String[] selectionArgs) {
		Cursor cursor = dataBase.rawQuery(sql, selectionArgs);
		if (cursor == null) {
			return null;
		}
		if (!cursor.moveToFirst()) {
			cursor.close();
			return null;
		}
		return cursor;
	}
}