/*

 *   SONEWS News Server

 *   see AUTHORS for the list of contributors

 *

 *   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, or

 *   (at your option) any later version.

 *

 *   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 org.sonews.config;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.util.Properties;

/**

 * Manages the bootstrap configuration. It MUST contain all config values

 * that are needed to establish a database connection.

 * For further configuration values use the Config class instead as that class

 * stores its values within the database.

 * @author Christian Lins

 * @since sonews/0.5.0

 */

class FileConfig extends AbstractConfig

{

	private static final Properties defaultConfig = new Properties();

	private static FileConfig instance = null;

	static {

		// Set some default values

		defaultConfig.setProperty(Config.STORAGE_DATABASE, "jdbc:mysql://localhost/sonews");

		defaultConfig.setProperty(Config.STORAGE_DBMSDRIVER, "com.mysql.jdbc.Driver");

		defaultConfig.setProperty(Config.STORAGE_USER, "sonews_user");

		defaultConfig.setProperty(Config.STORAGE_PASSWORD, "mysecret");

		defaultConfig.setProperty(Config.DEBUG, "false");

	}

	/**

	 * Note: this method is not thread-safe

	 * @return A Config instance

	 */

	public static synchronized FileConfig getInstance()

	{

		if (instance == null) {

			instance = new FileConfig();

		}

		return instance;

	}

	// Every config instance is initialized with the default values.

	private final Properties settings = (Properties) defaultConfig.clone();

	/**

	 * Config is a singelton class with only one instance at time.

	 * So the constructor is private to prevent the creation of more

	 * then one Config instance.

	 * @see Config.getInstance() to retrieve an instance of Config

	 */

	private FileConfig()

	{

		try {

			// Load settings from file

			load();

		} catch (IOException ex) {

			ex.printStackTrace();

		}

	}

	/**

	 * Loads the configuration from the config file. By default this is done

	 * by the (private) constructor but it can be useful to reload the config

	 * by invoking this method.

	 * @throws IOException

	 */

	public void load()

		throws IOException

	{

		FileInputStream in = null;

		try {

			in = new FileInputStream(

				Config.inst().get(Config.LEVEL_CLI, Config.CONFIGFILE, "sonews.conf"));

			settings.load(in);

		} catch (FileNotFoundException e) {

			// MUST NOT use Log otherwise endless loop

			System.err.println(e.getMessage());

			save();

		} finally {

			if (in != null) {

				in.close();

			}

		}

	}

	/**

	 * Saves this Config to the config file. By default this is done

	 * at program end.

	 * @throws FileNotFoundException

	 * @throws IOException

	 */

	public void save() throws FileNotFoundException, IOException

	{

		FileOutputStream out = null;

		try {

			out = new FileOutputStream(

				Config.inst().get(Config.LEVEL_CLI, Config.CONFIGFILE, "sonews.conf"));

			settings.store(out, "SONEWS Config File");

			out.flush();

		} catch (IOException ex) {

			throw ex;

		} finally {

			if (out != null) {

				out.close();

			}

		}

	}

	/**

	 * Returns the value that is stored within this config

	 * identified by the given key. If the key cannot be found

	 * the default value is returned.

	 * @param key Key to identify the value.

	 * @param def The default value that is returned if the key

	 * is not found in this Config.

	 * @return

	 */

	@Override

	public String get(String key, String def)

	{

		return settings.getProperty(key, def);

	}

	/**

	 * Sets the value for a given key.

	 * @param key

	 * @param value

	 */

	@Override

	public void set(final String key, final String value)

	{

		settings.setProperty(key, value);

	}

}