/*
 *    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 2 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, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
/*
 * Created on 2006/8/25
 *
 * @Author: Xiaojun Chen
 * $Revision$ 1.0
 *
 */
package eti.bi.common.System;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.Enumeration;
import java.util.Properties;
import eti.bi.common.MLPropertyResourceBundle;

public class SystemVariable {
	private static String HOME;
	private static MLPropertyResourceBundle property;
	private static String[] fields = new String[0];
	private static boolean[] register = new boolean[0];
	
	public static void initialize() {
		HOME = SysConfig.getProperty("SYSTEM_VARIABLE_HOME");
		File homedir = new File(HOME);
		if (!homedir.exists()) {
			if (!homedir.mkdirs()) {
				System.err.println("Can't create system variable dir: " + HOME);
				SysLog.warn("Can't create system variable dir: " + HOME);
				return;
			}
		}
		// load system variable
		String filepath = HOME + File.separator + "system.properties";
		File file = new File(filepath);
		if (!file.exists()) {
			System.err.println("SysTem property file: " + filepath + " dosen't exist!");
			SysLog.warn("SysTem property file: " + filepath + " dosen't exist!");
			return;
		}
		try {
			FileInputStream is = new FileInputStream(file);
			property = new MLPropertyResourceBundle();
			property.addResource(is);
			is.close();
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			SysLog.warn("Registering the system variable fail!", e);
		}
		// load other variable
		File[] files = homedir.listFiles();
		if (files == null) {
			SysLog.info("No other fields of system variable!");
			return;
		}
		String temp;
		String[] temp_fileds = new String[files.length];
		int i,index = 0;
		for (i = 0; i < files.length; i++) {
			temp = files[i].getName();
			if ((!temp.endsWith("system.properties") && temp.endsWith(".properties"))) {
				temp_fileds[index] = temp.replaceAll(".properties", "");
				
				try {
					InputStream in = new FileInputStream(files[i]);
					Properties properties = new Properties();
					properties.load(in);
					in.close();
					Enumeration enu = properties.keys();
					String key;
					while (enu.hasMoreElements()) {
						key = (String) enu.nextElement();
						try {
							property.addProperty(temp_fileds[index] + "_" + key, properties.getProperty(key));
						} catch (Exception e) {
							e.printStackTrace();
							SysLog.warn("Registering the key: " + key + " of " + temp_fileds[index] + "from file: "
									+ files[i].getAbsolutePath() + " fail!");
						}
					}
				} catch (Exception e) {
					e.printStackTrace();
					SysLog.warn("Registering the property file: "+files[i].getAbsolutePath()+" fail!",e);
				}
				index++;
			}
		}
		
		fields = new String[index];
		register = new boolean[index];
		for(i=0;i<index;i++) {
			fields[i] = temp_fileds[i];
			register[i] = false;
		}
	}

	private static void registerFileProperty(Properties properties, String field) {
		Enumeration enu = properties.keys();
		String key;
		while (enu.hasMoreElements()) {
			key = (String) enu.nextElement();
			try {
				property.addProperty( field + "_" + key, properties.getProperty(key));
			} catch (Exception e) {
				e.printStackTrace();
				SysLog.warn("Registering the key: " + key + " of " + field + " fail!");
			}
		}
		
		String[] temp_fields = new String[fields.length+1];
		boolean[] temp_register = new boolean[fields.length+1];
		for(int i=0;i<fields.length;i++) {
			temp_fields[i] = fields[i];
			temp_register[i]= register[i];
		}
		temp_fields[fields.length] = field;
		temp_register[fields.length] = true;
		fields = temp_fields;
		register = temp_register;
	}
	
	private static boolean registerField(String field) {
		int len = fields.length;
		for(int i=0;i<len;i++) {
			if(fields[i].equals(field)) {
				register[i] = true;
				return true;
			}
		}
		return false;
	}
	
	/**
	 * add a system variable properties to root system viariable property file
	 * 
	 * @param afile
	 *            the Properties file added
	 * @param field
	 *            the field of system viariable Property, null for the system
	 *            variable. If this file is in a plug-in, the name should be the
	 *            file name of the plug-in.
	 * @throws Exception 
	 */
	public static void addViariableProperty(String afile, String field) throws Exception {
		
		if(hasField(field)) {
			registerField(field);
			return;
		}
		
		if (field != null) {
			File file = new File(afile);
			if (!file.exists()) {
				throw new FileNotFoundException("File propertyfile not found!");
			}
			if (!file.isFile()) {
				throw new FileNotFoundException(afile + " should be a file!");
			}

			File newFile = copyFile(file, field);
			Properties properties = openProperty(newFile);
			registerFileProperty(properties, field);
			
		} else {
			property.addResource(afile);
		}
	}
	
	

	/**
	 * add a system variable property file to root system viariable property
	 * file
	 * 
	 * @param in
	 *            input stream of property file to add
	 * @param field
	 *            the field of system viariable Property, null for the system
	 *            variable. If this input stream in is from a plug-in, the name
	 *            should be the file name of the plug-in.
	 * @throws Exception 
	 */
	public static void addViariableProperty(InputStream in, String field) throws Exception {
		
		if(hasField(field)) {
			registerField(field);
			return;
		}
		
		if (field != null) {
			
			File newFile = copyInputStream(in, field);
			Properties properties = openProperty(newFile);
			registerFileProperty(properties, field);
			
		} else {
			property.addResource(in);
		}
	}
	
	/**
	 * add a system variable properties to root system viariable property file
	 * 
	 * @param properties
	 *            the Properties added
	 * @param field
	 *            the field of system viariable Property, null for the system
	 *            variable. If the properties is form a plug-in, the name should
	 *            be the file name of the plug-in.
	 * @throws Exception
	 */
	public static void addVariableProperty(Properties properties, String field) throws Exception {
		if(hasField(field)) {
			registerField(field);
			return;
		}
		
		if (field != null) {
			File newFile = copyProperty(properties, field);
			Properties propert = openProperty(newFile);
			registerFileProperty(propert, field);
		} else {
			property.addResource(properties);
		}
	}

	/**
	 * add a system variable properties to root system viariable property file
	 * 
	 * @param url
	 *            the Properties URL added.
	 * @param field
	 *            the field of system viariable Property, null for the system
	 *            variable. If the url is from a plug-in, the name should be the
	 *            file name of the plug-in.
	 * @throws Exception
	 */
	public static void addVariableProperty(URL url, String field) throws Exception {
		if(hasField(field)) {
			registerField(field);
			return;
		}
		
		if (field != null) {
			File newFile = copyURL(url, field);
			Properties properties = openProperty(newFile);
			registerFileProperty(properties, field);
		} else {
			property.addResource(url);
		}
	}

	public static File copyFile(File file, String field) throws Exception{
		File newFile = new File(HOME+File.separator+field+".properties");
		if(newFile.exists()) {
			throw new IOException("The variable file of field "+field+" already exists!");
		}
		
		InputStream in = null;
		OutputStream ou = null;
		try {
			in = new FileInputStream(file);
			
			ou = new FileOutputStream(newFile);
			byte[] bytes = new byte[5000];
			int read = 0;
			int size = in.available();
			int hasread = 0;
			int step = 0;
			
			while(hasread<size) {
				read=0;
				step = 5000>(size-hasread)?(size-hasread):5000;
				while(read<step) {
					read += in.read(bytes, read, step-read);
				}
				hasread += read;
				ou.write(bytes, 0, read);
			}
		}
		catch(Exception e) {
			e.printStackTrace();
			return null;
		}
		finally {
			try{
				if(in!=null) {
					in.close();
				}
				if(ou!=null) {
					ou.close();
				}
			}
			catch(Exception e) {
				e.printStackTrace();
			}
		}
		
		return newFile;
	}
	
	public static File copyInputStream(InputStream in, String field) throws Exception{
		File newFile = new File(HOME+File.separator+field+".properties");
		if(newFile.exists()) {
			throw new IOException("The variable file of field "+field+" already exists!");
		}
		
		OutputStream ou = new FileOutputStream(newFile);
		
		try {
			
			ou = new FileOutputStream(newFile);
			byte[] bytes = new byte[5000];
			int read = 0;
			int size = in.available();
			int hasread = 0;
			int step = 0;
			
			while(hasread<size) {
				read=0;
				step = 5000>(size-hasread)?(size-hasread):5000;
				while(read<step) {
					read += in.read(bytes, read, step-read);
				}
				hasread += read;
				ou.write(bytes, 0, read);
			}
		}
		catch(Exception e) {
			e.printStackTrace();
			return null;
		}
		finally {
			try{
				if(ou!=null) {
					ou.close();
				}
			}
			catch(Exception e) {
				e.printStackTrace();
			}
		}
		
		return newFile;
	}
	
	public static File copyProperty(Properties properties, String field) throws Exception{
		File newFile = new File(HOME+File.separator+field+".properties");
		if(newFile.exists()) {
			throw new IOException("The variable file of field "+field+" already exists!");
		}
		
		OutputStream ou = new FileOutputStream(newFile);
		properties.store(ou, null);
		ou.close();
		
		return newFile;
	}
	
	private static File copyURL(URL url, String field) throws Exception{
		File newFile = new File(HOME+File.separator+field+".properties");
		if(newFile.exists()) {
			throw new IOException("The variable file of field "+field+" already exists!");
		}
		
		InputStream in = null;
		OutputStream ou = new FileOutputStream(newFile);
		
		try {
			in = url.openStream();
			ou = new FileOutputStream(newFile);
			byte[] bytes = new byte[5000];
			int read = 0;
			int size = in.available();
			int hasread = 0;
			int step = 0;
			
			while(hasread<size) {
				read=0;
				step = 5000>(size-hasread)?(size-hasread):5000;
				while(read<step) {
					read += in.read(bytes, read, step-read);
				}
				hasread += read;
				ou.write(bytes, 0, read);
			}
		}
		catch(Exception e) {
			e.printStackTrace();
			return null;
		}
		finally {
			try{
				if(in!=null) {
					in.close();
				}
				if(ou!=null) {
					ou.close();
				}
			}
			catch(Exception e) {
				e.printStackTrace();
			}
		}
		
		return newFile;
	}
	
	private static Properties openProperty(File file) throws Exception{
		InputStream in = new FileInputStream(file);
		Properties properties = new Properties();
		properties.load(in);
		in.close();
		return properties;
	}
	
	/**
	 * Get the system property for a give key.
	 * 
	 * @param key
	 *            the key for the desired string
	 * @param field
	 *            the field of system viariable Property, null for the system
	 *            variable.
	 * @return the system property for a give key.
	 */
	public static String getSystemProperty(String key ) {
		if (property == null) {
			return null;
		} else {
			try {
				return property.getString(key);
			} catch (Exception e) {
				e.printStackTrace();
				return null;
			}
		}
	}
	
	/**
	 * Get the field property for a give key.
	 * 
	 * @param key
	 *            the key for the desired string
	 * @param field
	 *            the field of system viariable Property, null for the system
	 *            variable.
	 * @return the system property for a give key.
	 */
	public static String getFieldProperty(String key, String field) {
		if (property == null) {
			return null;
		} else {
			try {
				if (field != null) {
					return property.getString(field + "_" + key);
				}
				return property.getString(key);
			} catch (Exception e) {
				e.printStackTrace();
				return null;
			}
		}
	}
	
	public static String getAllProperty(String key) {
		String value = property.getString(key);
		if(value!=null) {
			return value;
		}
		for(int i=0;i<fields.length;i++) {
			value = property.getString(fields[i] + "_" + key);
			if(value!=null) {
				return value;
			}
		}
		return null;
	}
	
	public static Properties getAllProperties() {
		return property.getProperties();
	}
	
	/**
	 * get the property of the specific field
	 * @param field 
	 *				the field of system viariable Property, null for the system
	 *           	variable. If the url is from a plug-in, the name should be the
	 *            	file name of the plug-in.
	 * @return the properties of the specific field, null if no properties of this field
	 * */
	public static Properties getFieldProperties(String field) {
		if(!hasField(field)) {
			return null;
		}
		Properties prop = new Properties();
		String file = HOME+File.separator+field+".properties";
		InputStream in = null;
		try {
			File temp = new File(file);
			in = new FileInputStream(temp);
			prop.load(in);
		}
		catch(Exception e) {
			e.printStackTrace();
		}
		finally {
			if(in!=null){
				try {
					in.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}
		return prop;
	}
	
	public static boolean hasField(String field) {
		int len = fields.length;
		for(int i=0;i<len;i++) {
			if(fields[i].equals(field)) {
				return true;
			}
		}
		return false;
	}
	
	public static void Clean() {
		if(fields==null) {
			return;
		}
		int len = register.length;
		for(int i=0;i<len;i++) {
			if(!register[i]) {
				String file = HOME+File.separator+fields[i]+".properties";
				File deleteFile = new File(file);
				deleteFile.delete();
			}
		}
	}
}