/**
 * AUTOHIT 2003
 * Copyright Erich P Gatejen (c) 1989,1997,2003,2004
 * 
 * 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.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Additional license information can be found in the documentation.
 * @author Erich P Gatejen
 */
package autohit.call;

import java.util.Random;

import autohit.universe.Universe;

/**
 * RANDOM call. Returns a RANDOM integer between 0 and top.
 * 
 * <pre>
 *  REQURIES: logger, core IGNORES: uni PARAMETERS (INPUT): top= highest integer.
 * </pre>
 * 
 * @author Erich P. Gatejen
 * @version 1.0 <i>Version History</i><code>EPG - Initial - 8Jan04</code>
 */
public class Call_RANDOM extends Call {

	// GLOBAL RANDOM
	static Random r;

	/**
	 * Implement this to handle load time initialization. The four main fields
	 * will already be set--vmc, sc, log, and u. You must implement this, but
	 * you don't have to do anything. Remember that calls are cached per VM and
	 * reused as often as possible. There will be no thread-safety issues with
	 * the VMCore or log, but the SystemContecxt and Universe may be shared.
	 * 
	 * @throws CallException
	 */
	public void load_chain() throws CallException {
		// Nothing to do.
	}

	/**
	 * Implement this to return the name of the CALL
	 * 
	 * @return name of the CALL
	 */
	public String name() {
		return "RANDOM";
	}

	/**
	 * Execute it.
	 * 
	 * @return the result or null if there is no result
	 */
	public String call() throws CallException {

		int value = 0;
		String top = null;

		try {

			if (r == null)
				r = new Random();

			try {

				top = this.requiredString("top");
				value = r.nextInt(Integer.parseInt(top + 1));

			} catch (Exception e) {
				throw new CallException(
					this.format("Bad call.  Parameter 'top' is bad.  value=" + top),
					CallException.CODE_CALL_PROGRAM_ERROR);
			}

		} catch (CallException ce) {
			throw ce;
		} catch (Exception e) {
			throw new CallException(
				this.format("General exception.  error=" + e.getMessage()),
				CallException.CODE_CALL_FAULT,
				e);
		}

		this.debug("Random number selected = " + value);

		return Integer.toString(value);
	}

	/**
	 * Execute using the passed universe, rather than the loaded.
	 * 
	 * @param uni
	 *            a universe
	 * @return the result or null if there is no result
	 * @see autohit.universe.Universe
	 */
	public String call(Universe uni) throws CallException {
		return this.call();
	}
}