package shared;

import java.util.*;
import java.net.*;
import java.io.*;

/**
 * This class makes all the configuration options available to all the other classes and objects
 * of this program. Its reading and writing back the values from and to the config.txt file.  
 * @author buetow
 *
 */
public final class Config {
	public static final String VERSION = "NetCalendar 1.0";
	private static final String CONFIG_FILE = "config.txt";
	private static HashMap mapConfigVals;

	/**
	 * Initializes all the config values.
	 * @param args The start parameters.
	 */
	public static void initialize(String[] args) {
		if (args.length > 0) {
			if (args[0].equals("--help")) {
				System.out.println(Config.VERSION + " help");
				System.out.println("(c) 2006, 2009 by Dipl.-Inform. (FH) Paul C. Buetow [netcalendar@dev.buetow.org]");
				System.out.println("This is free software, see the LICENSE.txt for copying conditions. There is NO");
				System.out.println("warranty; not even for MERCHANTABILITY of FITNESS FOR A PARTICULAR PURPOSE.");
				System.out.println();
				System.out.println("Possible start parameters are:");
				System.out.println("\t--help Shows this help and exists");
				System.out.println("\t--client-only Runs the NetCalendar client only");
				System.out.println("\t--server-address=host Specifies the server host to connect to");
				System.out.println("\t--server-only Runs the NetCalendar server only");
				System.out.println("\t--client-and-server Runs the NetCalendar server and client");
				System.out.println("\t  within the same process!");
				System.out.println();
				System.exit(0);
			}
		}
		
		mapConfigVals = new HashMap();
		readConfig(CONFIG_FILE);
		
		for (int i = 0; i < args.length; ++i) {
			if (args[i].equals("--server-only")) {
				mapConfigVals.put("server_run", "true");
				mapConfigVals.put("client_run", "false");
				
			} else if(args[i].equals("--client-only")) {
				mapConfigVals.put("server_run", "false");
				mapConfigVals.put("client_run", "true");
				
			} else if(args[i].equals("--client-and-server")) {
				mapConfigVals.put("server_run", "true");
				mapConfigVals.put("client_run", "true");
				mapConfigVals.put("server_address", "localhost");
				
			} else if(args[i].startsWith("--server-address=")) {
				mapConfigVals.put("server_address", args[i].substring(17));
			}
		}
		
		if (args.length > 0)
			writeConfigToFile();
	}
	
	/**
	 * This methods reads the options from the calendar config file 'config.txt'.
	 * @param sConfigFile Specifies the relative or absolute path to the config file.
	 */
	public static void readConfig(String sConfigFile) {
		Main.infoMessage("Config: Using config file " + sConfigFile);
		File file = new File(sConfigFile);
		
		if (!file.isFile()) {
			Main.infoMessage("Config: " + sConfigFile + " is not a file!");
			System.exit(1);
		}
		
		try {
			BufferedReader in = new BufferedReader(new FileReader(file));
			String sLine;

			while ((sLine = in.readLine()) != null) {
				int iSeperator = sLine.indexOf('=');
				
				if (iSeperator > -1) {
					int iEnd = sLine.indexOf(';');
										
					if (iEnd > -1) {
						String sKey = sLine.substring(0, iSeperator).trim();
						String sVal = sLine.substring(iSeperator+1, iEnd).trim();
						mapConfigVals.put(sKey, sVal);
					}
				}
			}

		} catch (Exception e) {
			Main.infoMessage("Config: " + e.getMessage());
			System.exit(1);
		}
	}

	/**
	 * This method returns the inet address of the calendar server.
	 * @return Returns the calendar server's address .
	 */
	public static InetAddress getServerAddress() {
		InetAddress serverAddress = null;
		
		try {
			serverAddress = InetAddress.getByName(Config.getStringValue("server_address"));
		} catch(Exception e) {
			Main.infoMessage("Server address error: " + e.getMessage());
		}
		
		return serverAddress;
	}
	
	/**
	 * This method returns a specific string config value.
	 * @param sKey Specifies the key of the config value to return.
	 * @return Returns the requested config value.
	 */
	public static String getStringValue(String sKey) {
		return getStringValue(sKey, true);
	}
	
	/**
	 * This method returns a specific string config value.
	 * @param sKey Specifies the key of the config value to return.
	 * @param bLogMessages Specifies if this action should be logged or not.
	 * @return Returns the requested config value.
	 */
	public static String getStringValue(String sKey, boolean bLogMessage) {
		String sRet = (String) mapConfigVals.get(sKey);
		
		if (sRet != null)
			sRet = sRet.trim();

		return sRet;
	}
	
	/**
	 * This method returns a specific integer config value.
	 * @param sKey Specifies the key of the config value to return.
	 * @return Returns the requested config value.
	 */
	public static int getIntValue(String sKey) {
		String sVal = (String) mapConfigVals.get(sKey);
		
		if (sVal != null)
			sVal = sVal.trim();
		
		return Integer.parseInt(sVal);
	}
	
	/**
	 * This method returns a specific boolean config value.
	 * @param sKey Specifies the key of the config value to return.
	 * @return Returns the requested config value.
	 */
	public static boolean getBooleanValue(String sKey) {
		String sVal = (String) mapConfigVals.get(sKey);
		
		if (sVal != null)
			sVal = sVal.trim();
		
		boolean bRet = false;
		
		if (sVal != null)
			bRet = sVal.equals("true");
		
		return bRet;
	}
	
	/**
	 * This method returns a set of keys of the config hash map.
	 * @return Returns a Set object containing all keys of the Config's hash map.
	 */
	public static Set getKeySet() {
		return mapConfigVals.keySet();
	}
	
	/**
	 * This method changes or adds a specific config value.
	 * @param sKey Specifies the config key to set or update.
	 * @param sVal Specifies the value of the key to set or update.
	 */
	public static void setValue(String sKey, String sVal) {
		mapConfigVals.put(sKey, sVal);
	}
	
	/**
	 * This method returns a sorted String array of all available config keys. 
	 * @return Returns a sorted String array of all available config keys.
	 */
	public static String [] getSortedKeyArray() {
        Set keySet = getKeySet();
        Object [] keys = keySet.toArray();
        int iNumPairs = keys.length;
        String [] sKeys = new String[iNumPairs];
        
        for (int i = 0; i < iNumPairs; ++i)
        		sKeys[i] = (String) keys[i];
        
        Arrays.sort(sKeys);
        
        return sKeys;
	}
	
	/**
	 * This method writes the current configuration to the config file "config.txt".
	 */
	public static void writeConfigToFile() {
		String [] sKeys = getSortedKeyArray();
		int iNumKeys = sKeys.length;
	
		try {
			FileWriter fileWriter = new FileWriter(CONFIG_FILE);
			BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
		
			for (int i = 0; i < iNumKeys; ++i) {
				String sKey = sKeys[i];
				String sVal = getStringValue(sKey);
				bufferedWriter.write(sKey + "=" + sVal + ";\n");
			}
			
			bufferedWriter.close();
			
		} catch(IOException e) {
			Main.infoMessage("Error: " + e.toString());
		}
	}
}