/*
 * Created on Feb 29, 2004 @author kim
 * 
 * Two dimensional color grid with cells that can be updated.
 */
import java.awt.*;
import objectdraw.*;

public class MazeGrid {
	// constants
	// maze colors corresponding to:
	public static final Color FAILED_COLOR = Color.yellow;// Visited, but failed
	public static final Color VISITED_COLOR = Color.blue; // On current path
	public static final Color WALL_COLOR = Color.black; 	// Wall
	public static final Color OPEN_COLOR = Color.white; 	// Unvisited cell
	public static final Color START_COLOR = Color.green;  // Start position
	public static final Color FINISH_COLOR = Color.red;	// Finish position

	protected int numRows, numCols; // num rows and cols in grid
	protected double rwidth, rheight; // width and ht of each square
	protected double gleft, gtop;	// coords of upper left hand corner of grid
	
	protected FilledRect[][] colorRect; // rectangles of grid

	// post: two dim'l grid drawn at (left,top) with "rows" rows and "cols"
	// columns. Each square is width x height and initially colored "WALL_COLOR".
	public MazeGrid(double left, double top, int rows, int cols,
						 double width, double height, DrawingCanvas canvas) {
		canvas.clear();		// erase canvas
		
		rwidth = width;		// save parameters needed later
		rheight = height;
		gleft = left;
		gtop = top;
		numRows = rows;
		numCols = cols;
		
		// create grid as numRows x numCols table of colored rectangles
		colorRect = new FilledRect[numRows][numCols];
		for (int rowNum = 0; rowNum < numRows; rowNum++) {
			for (int colNum = 0; colNum < numCols; colNum++) {
				colorRect[rowNum][colNum] =
					new FilledRect(left + colNum * width, top + rowNum * height,
										width, height, canvas);
				colorRect[rowNum][colNum].setColor(WALL_COLOR);
				new FramedRect(left + colNum * width, top + rowNum * height,
									width, height, canvas);
			}
		}
	}

	// pre: pos is legal position in grid
	// post: rectangle at pos is made into start cell
	public void setStart(Position pos) {
		colorRect[pos.getRow()][pos.getCol()].setColor(START_COLOR);
	}

	// pre: pos is legal position in grid
	// post: rectangle at pos is made into finish cell
	public void setFinish(Position pos) {
		colorRect[pos.getRow()][pos.getCol()].setColor(FINISH_COLOR);
	}

	// pre: pos is legal position in grid
	// post: rectangle at pos is made into open cell
	public void setOpen(Position pos) {
		colorRect[pos.getRow()][pos.getCol()].setColor(OPEN_COLOR);
	}

	// pre: pos is legal position in grid
	// post: rectangle at pos is made into visited cell
	public void visit(Position pos) {
		colorRect[pos.getRow()][pos.getCol()].setColor(VISITED_COLOR);
	}

	// pre: pos is legal position in grid
	// post: rectangle at pos is made into "failed" cell
	public void fail(Position pos) {
		colorRect[pos.getRow()][pos.getCol()].setColor(FAILED_COLOR);
	}
	
	// pre: pos is legal position in grid
	// post: returns true iff pos is start cell
	public boolean isStart(Position pos) {
		return colorRect[pos.getRow()][pos.getCol()].getColor().equals(
				START_COLOR);
	}

	// pre: pos is legal position in grid
	// post: returns true iff pos is wall cell
	public boolean isWall(Position pos) {
		return colorRect[pos.getRow()][pos.getCol()].getColor().equals(
				WALL_COLOR);
	}

	// pre: pos is legal position in grid
	// post: returns true iff pos is open cell
	public boolean isOpen(Position pos) {
		return colorRect[pos.getRow()][pos.getCol()].getColor().equals(
				OPEN_COLOR);
	}

	// pre: pos is legal position in grid
	// post: returns true iff pos is currently on path from start cell
	public boolean isOnPath(Position pos) {
		return colorRect[pos.getRow()][pos.getCol()].getColor().equals(
				VISITED_COLOR);
	}

	// pre: pos is legal position in grid
	// post: returns true iff pos was tried but can't get to finish
	// 	from there.
	public boolean isFailed(Position pos) {
		return colorRect[pos.getRow()][pos.getCol()].getColor().equals(
				FAILED_COLOR);
	}
	
	// pre: pos is legal position in grid
	// post: returns true iff pos is finish cell
	public boolean isFinish(Position pos) {
		return colorRect[pos.getRow()][pos.getCol()].getColor().equals(
				FINISH_COLOR);
	}
	
	// returns true iff in Maze and either open or finish cell
	public boolean canVisit(Position pos) {
		int rowNum = pos.getRow();
		int colNum = pos.getCol();
		return ((rowNum > 0 && rowNum < numRows && colNum > 0 && colNum < numCols)
			&& (isOpen(pos) || isFinish(pos)));
	}

}