/*****************************************************/
/*          This java file is a part of the          */
/*                                                   */
/*           -  Plouf's Java IRC Client  -           */
/*                                                   */
/*   Copyright (C)  2002 - 2004 Philippe Detournay   */
/*                                                   */
/*         All contacts : theplouf@yahoo.com         */
/*                                                   */
/*  PJIRC 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; version 2 or later of  */
/*  the License.                                     */
/*                                                   */
/*  PJIRC 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 PJIRC; if      */
/*  not, write to the Free Software Foundation,      */
/*  Inc., 59 Temple Place, Suite 330, Boston,        */
/*  MA  02111-1307  USA                              */
/*                                                   */
/*****************************************************/

package irc;

import java.util.Vector;

/**
 * IRC mode handler.
 */
public class ModeHandler {
	private String _mode;
	private Vector _parameters;
	private char[][] _modes;
	private char[] _prefix;

	/**
	 * Create a new ModeHandler with empty mode.
	 * 
	 * @param modes
	 *          A,B,C,D known modes. This is an array of four arrays of chars.
	 * @param prefix
	 *          prefix modes.
	 */
	public ModeHandler(char[][] modes, char[] prefix) {
		this("", modes, prefix);
	}

	/**
	 * Create a new ModeHandler with given mode.
	 * 
	 * @param mode
	 *          initial mode.
	 * @param modes
	 *          A,B,C,D know modes.
	 * @param prefix
	 *          prefix modes.
	 */
	public ModeHandler(String mode, char[][] modes, char[] prefix) {
		_modes = modes;
		_prefix = prefix;
		_mode = "";
		_parameters = new Vector();
		if (mode.startsWith("+"))
			mode = mode.substring(1);
		apply("+" + mode);
	}

	/**
	 * Reset current mode.
	 */
	public void reset() {
		_mode = "";
	}

	/**
	 * Get password (+k), if defined.
	 * 
	 * @return password.
	 */
	public String getPassword() {
		if (hasMode('k'))
			return findParameter('k');
		return "";
	}

	/**
	 * Get user limit (+l), if defined.
	 * 
	 * @return the user limit.
	 */
	public int getLimit() {
		if (hasMode('l'))
			return new Integer(findParameter('l')).intValue();
		return 0;
	}

	private boolean inside(char[] list, char c) {
		for (int i = 0; i < list.length; i++)
			if (list[i] == c)
				return true;
		return false;
	}

	private String findParameter(char k) {
		int index = getParameterIndex(k);
		if (index >= 0)
			return (String) _parameters.elementAt(index);
		return "";
	}

	private boolean hasParameter(boolean positive, char c) {
		if (inside(_prefix, c))
			return false;
		else if (inside(_modes[0], c))
			return true;
		else if (inside(_modes[1], c))
			return true;
		else if (inside(_modes[2], c))
			return positive;
		else
			return false;
	}

	private int getParameterIndex(char k) {
		if (_parameters.size() == 0)
			return -1;
		int index = 0;
		for (int i = 0; i < _mode.length(); i++) {
			char c = _mode.charAt(i);
			if (hasParameter(true, c)) {
				if (c == k)
					return index;
				index++;
				if (index >= _parameters.size())
					return -1;
			} else {
				if (c == k)
					return -1;
			}
		}
		return -1;
	}

	private void addMode(char mode, String param) {
		if (hasMode(mode))
			removeMode(mode, param);
		_mode += mode;
		if (hasParameter(true, mode))
			_parameters.insertElementAt(param, _parameters.size());
	}

	private void removeMode(char mode, String param) {
		if (!hasMode(mode))
			return;
		if (hasParameter(true, mode))
			_parameters.removeElementAt(getParameterIndex(mode));
		int pos = _mode.indexOf(mode);
		_mode = _mode.substring(0, pos) + _mode.substring(pos + 1);
	}

	private void applyOne(boolean positive, char mode, String param) {
		if (positive)
			addMode(mode, param);
		else
			removeMode(mode, param);
	}

	/**
	 * Apply a new mode on the current mode.
	 * 
	 * @param mode
	 *          new mode to apply.
	 */
	public void apply(String mode) {
		String[] params = (new StringParser()).parseString(mode);
		boolean positive = true;
		int index = 0;

		for (int i = 0; i < params[0].length(); i++) {
			char c = params[0].charAt(i);
			if (c == '+') {
				positive = true;
			} else if (c == '-') {
				positive = false;
			} else {
				String param = "";
				if (hasParameter(positive, c)) {
					index++;
					if (index >= params.length)
						return;
					param = params[index];
				}
				applyOne(positive, c, param);
			}
		}
	}

	/**
	 * Test wether the given mode is set.
	 * 
	 * @param mode
	 *          mode to test.
	 * @return true if mode is set, false otherwise.
	 */
	public boolean hasMode(char mode) {
		return _mode.indexOf(mode) != -1;
	}

	/**
	 * Get a string representation of the current mode.
	 * 
	 * @return string representation of current mode.
	 */
	public String getMode() {
		String ans = _mode;
		for (int i = 0; i < _parameters.size(); i++)
			ans += " " + _parameters.elementAt(i);
		return ans;
	}
}