/*
 * SlidingTilePuzzle.java
 * A CLUI-based version of the game.
 * To compile: javac -classpath nplayer.jar:. SlidingTilePuzzle.java
 * To run: java -classpath nplayer.jar:. SlidingTilePuzzle
 */
public class SlidingTilePuzzle extends ComputerGame implements CLUIPlayableGame, GUIPlayableGame {
    private char puzzle[] = {'R','R','R',' ','L','L','L'};
    private String solution = "LLL RRR";
    private boolean userQuits = false;
    private int blankAt = 3;

    public SlidingTilePuzzle() {
        super(1);
    }
    public SlidingTilePuzzle (Player p) {   
        super(1);
        addPlayer(p);
    }
    /** Overridden method from TwoPlayerGame */
    public String getRules() {   
        return "\n*** The Rules of SlidingTilePuzzle  ***\n" +
        "The goal is to change the puzzle  into [LLL RRR]\n" +
        "  by sliding tiles L(eft) or R(ight).\n" +
        "Tiles labeled R can only move right.\n" +
        "Tiles labeled L can only move left.\n" +
        "A tile can be moved into the blank space.\n" +
        "A tile can jump over 1 other tile.\n";
    } //getRules()

    public boolean gameOver() {  // Returns true if puzzle solved
        StringBuffer sb = new StringBuffer();
        sb.append(puzzle);
        return sb.toString().equals(solution);    
    } // gameOver()

    public String getWinner() {   
        if (gameOver())
            return "\nYou did it! Very Nice!\n";
        else return "\nGood try. Try again!\n";
    } // getWinner()

    public void play(UserInterface ui) {
        ui.report(getRules());
        ui.report(listPlayers());
        ui.report(reportGameState());

	while(!gameOver() && !userQuits) {  
            ui.prompt(getGamePrompt());
            ui.report(submitUserMove(ui.getUserInput()));
            ui.report("0123456\n" + reportGameState());
        } // while
        ui.report(getWinner());
    }
    /** Implementation of method from CLUIPlayable */
    public String reportGameState() {   
        StringBuffer sb = new StringBuffer();
        sb.append(puzzle);
        return sb.toString();
    } // report()

    /** Implementation of method from CLUIPlayable */
    public String getGamePrompt() {    
        return "\nWhat tile do you want to move, 0..6 or -1 to give up? ";
    } //prompt()

    /** Implementation of method from CLUIPlayable */
    public String submitUserMove(String s) {   
        int tile = Integer.parseInt(s);
        if (tile < -1 || tile > 6)
            return "That is an illegal move.\n";
        else if (tile == -1) {
            userQuits = true;
            return "The user gives up.\n";
	} else if (tile == blankAt) {
            return "That's an illegal move.\n";
	} else {
            char ch = puzzle[tile];
            if (ch == 'L' && (blankAt == tile-1 || blankAt == tile-2))
		swapTiles(tile,blankAt);
            else if (ch == 'R' && (blankAt == tile+1 || blankAt == tile+2))
		swapTiles(tile,blankAt);
            else 
		return "That's an illegal move.\n";
	}
        return "That move is legal.\n";
    } //move()

    private void swapTiles(int ti, int bl) {
        char ch = puzzle[ti];
        puzzle[ti] = puzzle[bl];
        puzzle[bl] = ch;
        blankAt = ti;   // Reset the blank
    }
    public static void main(String args[])  {  
	KeyboardReader kb = new KeyboardReader();
        SlidingTilePuzzle puzzle  = new SlidingTilePuzzle(new SlidingTilePlayer());
        puzzle.play(kb);
    } //main()
    
} //SlidingTilePuzzle