// CSE 143, Winter 2012

public class Maze {
    private char[][] squares;
    private boolean[][] explored;
    private boolean animated;
    private int lastIsRow, lastIsCol;   // last location on which an 'is' method
                                        // was called; used for toString '?'
    
    public Maze(String text) {
        if (text == null || (text = text.trim()).length() == 0) {
            throw new IllegalArgumentException("empty lines data");
        }
        
    	String[] lines = text.split("[\r]?\n");
        squares = new char[lines.length][lines[0].length()];
        explored = new boolean[lines.length][lines[0].length()];
        
        for (int row = 0; row < getHeight(); row++) {
            if (lines[row].length() != getWidth()) {
                throw new IllegalArgumentException("line " + (row + 1) + " wrong length (was "
                		+ lines[row].length() + " but should be " + getWidth() + ")");
            }
            
            for (int col = 0; col < getWidth(); col++) {
                squares[row][col] = lines[row].charAt(col);
            }
        }
        
        lastIsRow = -1;
        lastIsCol = -1;
        animated = false;
    }
    
    public int getHeight() {
        return squares.length;
    }
    
    public char getSquare(int row, int col) {
        checkIndexes(row, col);
        return squares[row][col];
    }
    
    public int getWidth() {
        return squares[0].length;
    }
    
    public boolean isEscaped() {
        // check left/right edges
        for (int row = 0; row < getHeight(); row++) {
            if (explored[row][0] || explored[row][getWidth() - 1]) {
                return true;
            }
        }

        // check top/bottom edges
        for (int col = 0; col < getWidth(); col++) {
            if (explored[0][col] || explored[getHeight() - 1][col]) {
                return true;
            }
        }
        
        return false;
    }
    
    public boolean isExplored(int row, int col) {
        checkIndexes(row, col);
    	lastIsRow = row;
    	lastIsCol = col;
        return explored[row][col];
    }
    
    public boolean isMarked(int row, int col) {
    	checkIndexes(row, col);
    	lastIsRow = row;
    	lastIsCol = col;
    	return squares[row][col] == '.';
    }
    
    public boolean isWall(int row, int col) {
    	checkIndexes(row, col);
    	lastIsRow = row;
    	lastIsCol = col;
    	return squares[row][col] == '#';
    }
    
    public void mark(int row, int col) {
        checkIndexes(row, col);
        maybePause();
        squares[row][col] = 'x';
    }
    
    public void setAnimated(boolean value) {
    	animated = value;
    }
    
    public void setExplored(int row, int col, boolean value) {
        checkIndexes(row, col);
        explored[row][col] = value;
    }
    
    public String toString() {
        StringBuilder result = new StringBuilder(getWidth() * (getHeight() + 1));
    	for (int row = 0; row < getHeight(); row++) {
    		for (int col = 0; col < getWidth(); col++) {
    			if (row == lastIsRow && col == lastIsCol) {
    				result.append('?');
    			} else if (squares[row][col] == '#') {
    				result.append('#');
    			} else if (squares[row][col] == 'x') {
    				result.append('x');
    			} else if (explored[row][col]) {
    				result.append('.');
    			} else {
    				result.append(' ');
    			}
    		}
    		result.append('\n');
    	}
        maybePause();
        return result.toString();
    }
    
    private void checkIndexes(int row, int col) {
        if (row < 0 || row >= getHeight() || col < 0 || col >= getWidth()) {
            throw new IllegalArgumentException("illegal indexes: (" + 
                                               row + ", " + col + ")");
        }
    }
    
    private void maybePause() {
    	if (animated) {
    		sleep(100);
    	}
    }
    
    private void sleep(int ms) {
    	try {
    		Thread.sleep(ms);
    	} catch (InterruptedException ie) {}
    }
}