/*   Copyright 2011 Robot Media SL (http://www.robotmedia.net)
*
*   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 org.renpy.android.billing.util;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.UUID;

import android.content.Context;

public class Installation {
	private static final String INSTALLATION = "INSTALLATION";
	private static String sID = null;

	public synchronized static String id(Context context) {
		if (sID == null) {
			File installation = new File(context.getFilesDir(), INSTALLATION);
			try {
				if (!installation.exists()) {
					writeInstallationFile(installation);
				}
				sID = readInstallationFile(installation);
			} catch (Exception e) {
				throw new RuntimeException(e);
			}
		}
		return sID;
	}

	private static String readInstallationFile(File installation) throws IOException {
		RandomAccessFile f = new RandomAccessFile(installation, "r");
		byte[] bytes = new byte[(int) f.length()];
		f.readFully(bytes);
		f.close();
		return new String(bytes);
	}

	private static void writeInstallationFile(File installation) throws IOException {
		FileOutputStream out = new FileOutputStream(installation);
		String id = UUID.randomUUID().toString();
		out.write(id.getBytes());
		out.close();
	}
}