/*
 * Copyright 2002-2008 The Jamocha Team
 * 
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.jamocha.org/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

package org.jamocha.engine.functions.ruleengine;

import java.util.Collection;
import java.util.Iterator;

import org.jamocha.Constants;
import org.jamocha.engine.Engine;
import org.jamocha.engine.Parameter;
import org.jamocha.engine.functions.AbstractFunction;
import org.jamocha.engine.functions.FunctionDescription;
import org.jamocha.engine.modules.Module;
import org.jamocha.parser.EvaluationException;
import org.jamocha.parser.JamochaType;
import org.jamocha.parser.JamochaValue;

/**
 * @author Sebastian Reinartz
 * 
 * Modules will print out all the modules currently in the rule engine.
 */
public class Modules extends AbstractFunction {

	private static final class Description implements FunctionDescription {

		public String getDescription() {
			return "Prints out all the modules which are currently defined in the rule engine.";
		}

		public int getParameterCount() {
			return 0;
		}

		public String getParameterDescription(int parameter) {
			return "";
		}

		public String getParameterName(int parameter) {
			return "";
		}

		public JamochaType[] getParameterTypes(int parameter) {
			return JamochaType.NONE;
		}

		public JamochaType[] getReturnType() {
			return JamochaType.NONE;
		}

		public boolean isParameterCountFixed() {
			return true;
		}

		public boolean isParameterOptional(int parameter) {
			return false;
		}

		public String getExample() {
			return "(defmodule TESTMODUL)\n" + "(modules)";
		}

		public boolean isResultAutoGeneratable() {
			return true;
		}

		public Object getExpectedResult() {
			return "TESTMODUL\nMAIN\nfor a total of 2\n";
		}
	}

	public static final FunctionDescription DESCRIPTION = new Description();

	private static final long serialVersionUID = 1L;

	public static final String NAME = "modules";

	@Override
	public FunctionDescription getDescription() {
		return DESCRIPTION;
	}

	@Override
	public String getName() {
		return NAME;
	}

	@Override
	public JamochaValue executeFunction(Engine engine, Parameter[] params)
			throws EvaluationException {
		Collection<Module> modules = engine.getModules().getModuleList();
		int count = modules.size();
		Iterator<Module> itr = modules.iterator();
		StringBuilder sb = new StringBuilder();
		while (itr.hasNext()) {
			Module r = itr.next();
			sb.append(r.getName()).append(Constants.LINEBREAK);
		}
		sb.append("for a total of ").append(count).append(Constants.LINEBREAK);
		return JamochaValue.newString(sb.toString());
	}
}