// import statements

public class PuzzleSkeleton
{
    public static void main(String[] args)
    {
    	// starting grid
        char[] grid={'1', '4', '3', '-', '6', '5', '2', '7', '8'};
		// goal grid
        char[] goal={'1', '2', '3', '4', '5', '-', '6', '7', '8'};
        
        char move;
        int turn=0;
     	Scanner in = new Scanner(System.in);   
        // play the game while the grid does not match the goal
        while(!isGoal(grid,goal)) {
            turn++;
            move=getMove(grid,in);	 // get the user's move (which tile will be moved)
            update(move,grid);   // update the grid based on the move
        }
        JOptionPane.showMessageDialog(null,"It took you " + turn + " turns to get " + getGridForOutput(grid));  // output result
        System.exit(0);
    }
    

// this method will compare each array value of grid with goal and if there are any mismatches, return false, otherwise return true.
// That is, if g1[i]==g2[i] for all i, return true, else return false.

    public static boolean isGoal(char[] g1, char[] g2)
    {
    	// fill in the code here
    }
    
// this method will update the grid by swapping the tile, move, with the blank

    public static void update(char move, char[] grid)
    {
        char temp;
        int blank=getLocationOfBlank(grid);				// you have to implement getLocationOfBlank
        int tile=getLocationOfTile(move, grid);			// you have to implement getLocationOfTile
        temp=grid[blank];
        grid[blank]=grid[tile];
        grid[tile]=temp;
    }

// this method will display the current grid and ask the user which tile he/she wishes to move.  The tile can only be
// moved to the location of the blank, so the choice will only be a tile adjacent to the blank.  You SHOULD verify that the
// choice is correct which means it cannot be < '1' or > '8' and that it is adjacent to the blank.  This last part is 
// challenging and will be explained in the lecture.

    public static char getMove(char[] grid, Scanner in)
    {
        char move;
        do {		// you will need to implement printGrid
        	printGrid(grid);
            System.out.print("Enter the tile you wish to move (1-8):  ");
            move=in.next().charAt(0);
        }while(/*place data verification conditions here*/);
        return move;
    }

// this method returns the index of the blank (which is denoted as '-')
    public static int getLocationOfBlank(char[] g)
    {
        int location=-1;
        // place code here to search for the blank
        return location;
    }

// this method will receive the tile we want to move, which is a character like '5', and will find its index in the grid
    public static int getLocationOfTile(char t, char[] g)
    {
        int location=-1;
        // place code here to search for the tile t
        return location;
    }
   
/*  this method can be used to make sure that the move input is a legal one in that we need to make sure that the tile is adjacent to
 *  the blank -- this is optional, only implement this once you have the rest of the game working but without this method, the user
 *  will be able to cheat!
    public static boolean moveLegal(char m, char[] g)
    {
        int location=getLocationOfTile(m, g);
        int blank=getLocationOfBlank(g);
        switch(location)
        {
        	// the switch statement will have for each possible location of the tile to be moved an entry like:
        	//	Case 0: if(blank==1||blank==3) return true; break;
        	// the above statement says that if the user wants to move the tile at array location 0, then the blank must
        	//  either be to its right or below it
        }
        return false;  // if none of the cases match or if a case matches but the blank is not where expected, return false, not a legal move
    }
*/

    public static void printGrid(char[] grid)
    {
    	// output the grid using a format like this:
    	// 1 2 3
    	// 4 b 5
    	// 6 7 8
    	// you can use ' ' to output the blank or a character like 'b' or '_' or '-'
    }
    
}