// CSE 373 Homework 3: The Amazing Deque 
// YOU DO NOT NEED TO MODIFY THIS INSTRUCTOR-PROVIDED FILE.
// Your code should work properly with an unmodified version of this file.

import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;

/**
 * A graphical extension of the Maze class that allows the client to view the
 * maze as it is being searched.  As the client calls the various 'is' methods
 * on the maze (isWall, isVisited, etc.) or marks squares as visited, the board
 * pauses and animates the action on screen to show the algorithm's progress.
 * Parts of this code are based on graphical 8 Queens by Stuart Reges.
 */
public class GraphicalMaze extends Maze {
	private static final Color VISITED_COLOR = new Color(192, 228, 255);
	private static final Font LABEL_FONT = new Font("SansSerif", Font.BOLD, 20);
	private static final int MAX_PAUSE = 1000;  // milliseconds
	private JLabel[][] labels;
	private int delayMS;

	/**
	 * Constructs a new graphical maze using the given text string of lines.
	 * @param text the string of lines to pass; the complete contents of a maze input file
	 * @throws IllegalArgumentException if the file is in an invalid format
	 */
	public GraphicalMaze(String text) {
		super(text);
		this.delayMS = MAX_PAUSE / 2;
		try {
			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
		} catch (ClassNotFoundException e) {
			e.printStackTrace();  // will not happen
		} catch (InstantiationException e) {
			e.printStackTrace();  // will not happen
		} catch (IllegalAccessException e) {
			e.printStackTrace();  // will not happen
		} catch (UnsupportedLookAndFeelException e) {
			e.printStackTrace();  // will not happen
		}
	
		// add buttons in the middle for the maze squares
		Container center = createLabels();

		// initialize delay and add slider to control it at bottom
		JSlider slider = new JSlider(0, MAX_PAUSE - 10);
		delayMS = slider.getValue();
		slider.addChangeListener(new MazeSliderChangeListener());
		
		Container south = new JPanel();
		south.add(new JLabel("slow"));
		south.add(slider);
		south.add(new JLabel("fast"));
		
		JFrame frame = new JFrame("CSE 373 Maze Solver");
		frame.add(center);
		frame.add(south, BorderLayout.SOUTH);
		frame.pack();
		frame.setResizable(false);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setAlwaysOnTop(true);
		frame.setVisible(true);
		frame.toFront();
	}

	/**
	 * Sets all squares in the maze as not visited.
	 */
	public void clearVisited() {
		super.clearVisited();
		for (int y = 0; y < height(); y++) {
			for (int x = 0; x < width(); x++) {
				updateLabel(x, y);
			}
		}
	}
	
	/**
	 * Returns whether or not the given x/y position is marked as visited (via setVisited).
	 * Also temporarily draws a colored '?' mark on that square to show the algorithm's progress.
	 * @param x x-position to check
	 * @param y y-position to check
	 * @return true if x/y is marked as visited, false if not
	 * @throws IllegalArgumentException if the x/y location is out of the bounds of the maze
	 */
	public boolean isVisited(int x, int y) {
		return isHelper(x, y, super.isVisited(x, y));
	}
	
	/**
	 * Returns whether or not the given x/y position is a wall of the maze ('#').
	 * Also temporarily draws a colored '?' mark on that square to show the algorithm's progress.
	 * @param x x-position to check
	 * @param y y-position to check
	 * @return true if x/y is a wall, false if not
	 * @throws IllegalArgumentException if the x/y location is out of the bounds of the maze
	 */
	public boolean isWall(int x, int y) {
		return isHelper(x, y, super.isWall(x, y));
	}
	
	/**
	 * Marks the given x/y position as having been visited (.).
	 * Also draws a colored '.' mark on that square to show the algorithm's progress.
	 * @param x x-position to mark
	 * @param y y-position to mark
	 * @throws IllegalArgumentException if the x/y location is out of the bounds of the maze
	 */
	public void setVisited(int x, int y) {
	   	super.setVisited(x, y);
		updateLabel(x, y);
	   	pause();
	}
	
	// sets up the button labels for each square in the maze
	private Container createLabels() {
		JPanel center = new JPanel(new GridLayout(height(), width(), 1, 1));
		center.setBackground(Color.BLACK);
		labels = new JLabel[height()][width()];
		Dimension labelSize = new Dimension(LABEL_FONT.getSize() + 10, LABEL_FONT.getSize() + 10);
		for (int y = 0; y < height(); y++) {
			for (int x = 0; x < width(); x++) {
				JLabel label = new JLabel();
				label.setHorizontalAlignment(JLabel.CENTER);
				label.setOpaque(true);
				label.setBackground(Color.WHITE);
				label.setForeground(Color.BLACK);
				label.setFont(LABEL_FONT);
				label.setPreferredSize(labelSize);
				labels[y][x] = label;
				updateLabel(x, y);
				center.add(label);
			}
		}
		return center;
	}
	
	// helper to call one of the maze's 'is' methods and temporarily show a '?' mark
	private boolean isHelper(int x, int y, boolean value) {
		labels[y][x].setText("?");
		labels[y][x].setBackground(Color.YELLOW);
		pause();
		updateLabel(x, y);
		return value;
	}
	
	// causes the board to pause for a given amount of time for animation
	private void pause() {
		try {
			Thread.sleep(delayMS);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
	
	// helper to set the graphical text label at the given x/y position to its current maze state
	private void updateLabel(int x, int y) {
	   	char square = getSquare(x, y);
		labels[y][x].setText(String.valueOf(square));
		if (square == START) {
			labels[y][x].setBackground(Color.GREEN);
		} else if (square == END) {
			labels[y][x].setBackground(Color.PINK);
		} else if (square == WALL) {
			labels[y][x].setBackground(Color.LIGHT_GRAY);
		} else if (square == VISITED) {
			labels[y][x].setBackground(VISITED_COLOR);
		} else {
			labels[y][x].setBackground(Color.WHITE);
		}
	}
	
	/**
	 * A helper class to listen to change events on the speed slider.
	 */
	private class MazeSliderChangeListener implements ChangeListener {
		/**
		 * Called when the slider's value changes during a slide action.
		 */
		public void stateChanged(ChangeEvent e) {
			JSlider slider = (JSlider) e.getSource();
			delayMS = MAX_PAUSE - slider.getValue();
		}
	}
}