package Main;

import com.jcraft.jsch.*;
import java.awt.*;
import javax.swing.*;
import java.io.*;
import java.nio.channels.FileChannel;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.HashMap;

public class Start {

	public static void main(String[] arg) {
		/*
		 * 1-read configuration file and fill hashMap with values
		 * 2-using hashmap start server thread on local machine by change directory to server folder on desktop, compiling and running using make file
		 * send to server number of readers and number of writers
		 * 3-use ssh to log in other hosts as specified in config file, change directory to client folder on desktop, compile and run using make file
		 */

		Process p;
		String command, s, args;
		int rdCount, wrCount;

		//read configuration
		ConfigFileHandler fh = new ConfigFileHandler();
		HashMap<String, String> props = fh.readConfiguration();
		printConfigFile(props);

		//run server
		//cd to server folder on desktop
		makeScript(true); //true server
		//append server args
		try {
			args = "";
			args += " ";
			args += props.get("srvPort");
			args += " ";
			args += props.get("rdCount");
			args += " ";
			args += props.get("wrCount");

		    Files.write(Paths.get("srv_script"), args.getBytes(), StandardOpenOption.APPEND);
		}catch (IOException e) {
		    //exception handling left as an exercise for the reader
		}


		ServerThread srvTh = new ServerThread();
		Thread myThread = new Thread(srvTh);
		myThread.start();
//		try {
//			Runtime.getRuntime().exec("chmod 755 srv_script");
//			p = Runtime.getRuntime().exec("./srv_script");
//			BufferedReader stdInput = new BufferedReader(new
//	                 InputStreamReader(p.getInputStream()));
//
//            BufferedReader stdError = new BufferedReader(new
//                 InputStreamReader(p.getErrorStream()));
//
//            // read the output from the command
//            System.out.println("Here is the standard output of the command:\n");
//            while ((s = stdInput.readLine()) != null) {
//                System.out.println(s);
//            }
//
//            // read any errors from the attempted command
//            System.out.println("Here is the standard error of the command (if any):\n");
//            while ((s = stdError.readLine()) != null) {
//                System.out.println(s);
//            }
//		} catch (IOException e) {
//			e.printStackTrace();
//		}
		System.out.println("Samor");
		//execute clients
		rdCount = Integer.parseInt(props.get("rdCount"));
		wrCount = Integer.parseInt(props.get("wrCount"));

		for(int i=0;i<rdCount;i++) {
			String temp, user, host, password;
			temp = props.get("rd"+i);
			user = temp.substring(0,temp.indexOf('@'));
			host = temp.substring(temp.indexOf('@') + 1);
			password = props.get("rdPass" + i);
			makeScript(false);
			//append args
			try {
				args = "";
				args += " ";
				args += props.get("srvIp");
				args += " ";
				args += props.get("srvPort");
				args += " ";
				args += i; //TODO: fix id
				args += " ";
				args += props.get("acCount");
				args += " ";
				args += "r";

			    Files.write(Paths.get("clt_script"), args.getBytes(), StandardOpenOption.APPEND);
			} catch (IOException e) {
			    //exception handling left as an exercise for the reader
			}

			String commands[] = {"cd $HOME/Desktop/client;pwd; javac *.java;java MyClient"};
			args = commands[0];
			args += " ";
			args += props.get("srvIp");
			args += " ";
			args += props.get("srvPort");
			args += " ";
			args += i; //TODO: fix id
			args += " ";
			args += props.get("acCount");
			args += " ";
			args += "r";
			commands[0] = args;
			/*
			 * transfer client script file to remote in client folder
			 * cd to client folder
			 * execute script file
			 */
			createClient(user, host, password, commands);
		}
		/*
		for(int i=0;i<wrCount;i++) {
			String temp, user, host, password;
			int id = i + rdCount;
			temp = props.get("wr"+i);
			user = temp.substring(0,temp.indexOf('@'));
			host = temp.substring(temp.indexOf('@') + 1);
			password = props.get("wrPass" + i);
			makeScript(false);
			//append args
			try {
				args = "";
				args += " ";
				args += props.get("srvIp");
				args += " ";
				args += props.get("srvPort");
				args += " ";
				args += i; //TODO: fix id
				args += " ";
				args += props.get("acCount");
				args += " ";
				args += "w";

			    Files.write(Paths.get("clt_script"), args.getBytes(), StandardOpenOption.APPEND);
			} catch (IOException e) {
			    //exception handling left as an exercise for the reader
			}

			String commands[] = {"echo magdy", "cd $HOME/workspace/dist1", "pwd", "chmod 755 clt_script", "./clt_script"};
			createClient(user, host, password, commands);
		}
		*/


	}

	private static void createClient(String user, String host, String password, String commands[]) {
		Session session = null;
		try {
			JSch jsch = new JSch();
	        session = jsch.getSession(user, host, 22);
	        session.setPassword(password);
	        java.util.Properties config = new java.util.Properties();
	        config.put("StrictHostKeyChecking", "no");
	        session.setConfig(config);
	        session.connect();
	        for(int it=0;it<commands.length;it++){
	        	Channel channel = session.openChannel("exec");
				((ChannelExec) channel).setCommand(commands[it]);

				channel.setInputStream(null);

				((ChannelExec) channel).setErrStream(System.err);

				InputStream in = channel.getInputStream();

				channel.connect();

				byte[] tmp = new byte[1024];
				while (true) {
					while (in.available() > 0) {
						int i = in.read(tmp, 0, 1024);
						if (i < 0)
							break;
						System.out.print(new String(tmp, 0, i));
					}
					if (channel.isClosed()) {
						if (in.available() > 0)
							continue;
						System.out.println("exit-status: "
								+ channel.getExitStatus());
						break;
					}
					try {
						Thread.sleep(1000);
					} catch (Exception ee) {
					}
				}
				channel.disconnect();
	        }
			session.disconnect();

		} catch (Exception e) {

		}

			}

	private static void makeScript(boolean type){
		String file1,file2;
		if(type) {
			file1="srv_temp";
			file2="srv_script";
		} else {
			file1="clt_temp";
			file2="clt_script";
		}
		try{
			FileChannel src = new FileInputStream(file1).getChannel();
			FileChannel dest = new FileOutputStream(file2).getChannel();
			dest.transferFrom(src, 0, src.size());
			src.close();
			dest.close();
		} catch(Exception e) {
			e.printStackTrace();
		}

	}

	private static void printConfigFile(HashMap<String, String> props) {
		for(String key: props.keySet()) {
			System.out.println(key + " " + props.get(key));
		}
	}

	static class ServerThread implements Runnable {
	   public void run() {
		   String s;
		   Process p;
		   try {
				Runtime.getRuntime().exec("chmod 755 srv_script");
				p = Runtime.getRuntime().exec("./srv_script");
				BufferedReader stdInput = new BufferedReader(new
		                 InputStreamReader(p.getInputStream()));

	            BufferedReader stdError = new BufferedReader(new
	                 InputStreamReader(p.getErrorStream()));

	            // read the output from the command
	            System.out.println("Here is the standard output of the command:\n");
	            while ((s = stdInput.readLine()) != null) {
	                System.out.println(s);
	            }

	            // read any errors from the attempted command
	            System.out.println("Here is the standard error of the command (if any):\n");
	            while ((s = stdError.readLine()) != null) {
	                System.out.println(s);
	            }
			} catch (IOException e) {
				e.printStackTrace();
			}
	   }
	}


	private static class ConfigFileHandler {
		private static final String CONFIG_FILE = "system.properities";

		/**
		 * read configuration file system.properities and sets global variables
		 */
		public HashMap<String, String> readConfiguration() {
			HashMap<String, String> props = new HashMap<String, String>();
			BufferedReader bf = null;

			try {
				bf = new BufferedReader(new FileReader(CONFIG_FILE));
				String sCurrentLine;

				while ((sCurrentLine = bf.readLine()) != null) {
					System.out.println(sCurrentLine);
					int splitIndex = sCurrentLine.indexOf('=');
					String key = sCurrentLine.substring(0, splitIndex);
					String value = sCurrentLine.substring(splitIndex+1);
					key = reformulateKeyString(key);
					props.put(key, value);
				}
				bf.close();
			} catch (Exception e) {
				e.printStackTrace();
			}
			return props;
		}

		private String reformulateKeyString(String key) {
			char num;
			String res;
			boolean hasNum;
			HashMap<String, String> mappingKeys;

			mappingKeys = getMappingKeys();
			hasNum = checkStrHasNo(key);

			if (hasNum) {
				num = key.charAt(key.length() - 1);
				res = mappingKeys.get(key.substring(0, key.length() - 1));
				res += num;
			} else {
				res = mappingKeys.get(key);
			}
			return res;
		}

		private HashMap<String, String> getMappingKeys() {
			HashMap<String, String> mappingKeys = new HashMap<String, String>();
			mappingKeys.put("RW.server", "srvIp");
			mappingKeys.put("RW.server.port", "srvPort");
			mappingKeys.put("RW.numberOfReaders", "rdCount");
			mappingKeys.put("RW.numberOfWriters", "wrCount");
			mappingKeys.put("RW.numberOfAccesses", "acCount");
			mappingKeys.put("RW.reader", "rd");
			mappingKeys.put("RW.writer", "wr");
			mappingKeys.put("RW.password.reader", "rdPass");
			mappingKeys.put("RW.password.writer", "wrPass");
			return mappingKeys;
		}

		private boolean checkStrHasNo(String txt) {
			return txt.matches(".*\\d+.*");
		}
	}


}