/*******************************************************************************
 * This files was developed for CS4233: Object-Oriented Analysis & Design.
 * The course was taken at Worcester Polytechnic Institute.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Copyright ©2020 Gary F. Pollice
 *******************************************************************************/

package escape.initializers;

import java.io.*;
import javax.xml.bind.*;
import javax.xml.transform.stream.StreamSource;

import escape.EscapeGameManagerImpl;
import escape.interfaces.Coordinate;
import escape.EscapeGameManager;
import org.antlr.v4.runtime.CharStreams;
import econfig.EscapeConfigurator;

/**
 * This class builds an instance of an EscapeGameManager from a configuration
 * file (.egc). This uses the EscapeConfigurator for XML to turnthe .egc file
 * into a valid XML string that is then unmarshalled into an EscapeGameInitializer
 * file.
 * 
 * MODIFIABLE: YES
 * MOVEABLE: NO
 * REQUIRED: YES
 * 
 * >>>THIS IS AN EXAMPLE STARTER FILE<<<
 * You must change this class to be able to get the data from the configurtion
 * file and implement the makeGameManager() method. You may not change the signature
 * of that method or the constructor for this class. You can change the file any 
 * other way that you need to.
 * 
 * You do not have to use JAXB to create XML. You might use GSON if you are more
 * familiar with it. You also don't have to use the EscapeGameInitializer object if
 * you have a way that better suits your design and capabilities. Don't go down
 * a rathole, however, in order to use something different. This implementation
 * works and will not take much time to modify the EscapeGameInitializer to create
 * your game instance.
 */
public class EscapeGameBuilder
{
    private final EscapeGameInitializer gameInitializer;
    
    /**
     * The constructor takes a file that points to the Escape game
     * configuration file. It should get the necessary information 
     * to be ready to create the game manager specified by the configuration
     * file and other configuration files that it links to.
     * @param fileName the file for the Escape game configuration file (.egc).
     * @throws Exception on any errors
     */
    public EscapeGameBuilder(String fileName) throws Exception
    {
    	String xmlConfiguration = getXmlConfiguration(fileName);
    	// Uncomment the next instruction if you want to see the XML
    	// System.err.println(xmlConfiguration);
        gameInitializer = unmarshalXml(xmlConfiguration);
    }

	/**
	 * Take the .egc file contents and turn it into XML.
	 * If you want to use JSON, you should change the name of this method and 
	 * initialize the EscapeConfigurator with this code:
	 * 		EscapeConfigurator configurator = new EscapeConfigurator(EscapeConfigurationJsonMaker());
	 * @param fileName
	 * @return the XML data needed to 
	 * @throws IOException
	 */
	private String getXmlConfiguration(String fileName) throws IOException
	{
		EscapeConfigurator configurator = new EscapeConfigurator();
    	return configurator.makeConfiguration(CharStreams.fromFileName(fileName));
	}

	/**
	 * Unmarshal the XML into an EscapeGameInitializer object.
	 * @param xmlConfiguration
	 * @throws JAXBException
	 */
	private EscapeGameInitializer unmarshalXml(String xmlConfiguration) throws JAXBException
	{
		JAXBContext contextObj = JAXBContext.newInstance(EscapeGameInitializer.class);
        Unmarshaller mub = contextObj.createUnmarshaller();
        return (EscapeGameInitializer)mub.unmarshal(
            	new StreamSource(new StringReader(xmlConfiguration)));
	}
	
	/**
	 * Getter for the gameInitializer. Can be used to examine it after the builder
	 * creates it.
	 * @return the gameInitializer
	 */
	/*public EscapeGameInitializer getGameInitializer()
	{
		return gameInitializer;
	}*/
    
    /**
     * Once the builder is constructed, this method creates the
     * EscapeGameManager instance. For this example, you would use the
     * gameInitializer object to get all of the information you need to create
     * your game.
     * @return the game instance
     */
    public EscapeGameManager makeGameManager()
    {
    	// >>> YOU MUST IMPLEMENT THIS METHOD<<<
		EscapeGameManagerImpl manager = new EscapeGameManagerImpl();
		int maxX = gameInitializer.getxMax();
		int maxY = gameInitializer.getyMax();
		Coordinate.CoordinateType type = gameInitializer.getCoordinateType();
		LocationInitializer[] locations = gameInitializer.getLocationInitializers();
		PieceTypeDescriptor[] pieceTypes = gameInitializer.getPieceTypes();
		RuleDescriptor[] rules = gameInitializer.getRules();

		manager.setPieceTypes(pieceTypes);
		manager.setRules(rules);
		manager.setBoard(maxX, maxY, type, locations);
    	return manager;
    }
}