package com.e4net.authentibot;
import gnu.getopt.Getopt;
import gnu.getopt.LongOpt;

public class Test {
	private static void usage() {

		System.out.println("Usage: myapp [-x filename] [--command] [args...]");
		System.out.println("\twhere commands is one of:");
		System.out.println("\tfroboz param1 param2 param3");
		System.out.println("\tbazznot param1 param2");
		System.exit(1);
	}

	// The various supported command line commands
	// code is the short form command argument
	// size is the number of arguments needed for this command
	private enum Commands {
		froboz('f', 3) {
			boolean doit(int off, String [] argv){
				// do whatever froboz does with three arguments
				System.out.println("In froboz with: " + argv[off] + ", " + argv[off+1] + ", " + argv[off+2]);
				return true;
			}
		},

		bazznot('b', 2) {
			boolean doit(int off, String [] argv){
				// do whatever bazznot does with two arguments
				System.out.println("In bazznot with: " + argv[off] + ", " + argv[off+1]);
				return true;
			}
		};

		private final int code, size;
		Commands(int code, int size){
			this.code= code;
			this.size= size;
		}
		public int code() { return code; }
		public int size() { return size; }

		// Do the command, off is the offset within argv the commands
		// parameters start
		abstract boolean doit(int off, String [] argv);

	};

	public static void main(String[] args) {

		// build the long commands from the enum
		LongOpt[] longopts = new LongOpt[Commands.values().length+1];
		longopts[0] = new LongOpt("help", LongOpt.NO_ARGUMENT, null, 'h');

		// loops through each enum and generates the long command
		// based on the enums value, the code() is the short form of
		// the command so either --froboz can be used or -f
		int off= 1;
		for(Commands c : Commands.values()){
			longopts[off++] = new LongOpt(c.toString(), LongOpt.NO_ARGUMENT, null, c.code());
		}

		Getopt g = new Getopt("myprog", args, "x:", longopts);
		String file= "default.file";
		int c;
		boolean found= false;
		while ((c = g.getopt()) != -1 && !found) {
			int i= g.getOptind();
			switch (c) {
				case 'x': // get some file name with the -x
					// option
					file = g.getOptarg();
					break;

					// this is the help which runs with --help or -h
				case '?':
				case 'h':
					usage();
					break;

				// this will lookup the command and execute it
				default:
					// see if in commands
					String cmd= longopts[g.getLongind()].getName();
					Commands cm= null;
					try {
						// lookup the text command in the enum
						cm= Commands.valueOf(cmd);						
					} catch (IllegalArgumentException e) {
						usage();
					}
					
					// check we have enough arguments for this command
					if(args.length - i == cm.size){
						// do the command
						cm.doit(g.getOptind(), args);
						found= true;
					}else {
						// not enough arguments so show usage
						System.err.println("Not enough arguments for: " + cmd);
						usage();
					}
			}
		}
		
		Test t= new Test();
		t.handle("froboz", new String[]{"arg1", "arg2", "arg3"});
	}
	
	// another way to do it
	private Commands getCommand(String command) {
		Commands cmd;
		try {
			cmd= Commands.valueOf(command.toLowerCase());
		} catch (IllegalArgumentException e) {
			cmd= null;			
		}
		return cmd;
	}

	public boolean handle(String command, String [] args) {		
		// lookup and execute the command
		Commands cmd= getCommand(command);
		if(cmd != null) {
			return cmd.doit(0, args);
		}else{
			System.err.println("handle() - Unknown command: " + command);
			return false;
		}		
	}
}