PacMan/src/main/java/se/urmo/game/entities/Ghost.java

package se.urmo.game.entities;

import se.urmo.game.collision.GhostCollisionChecker;
import se.urmo.game.main.Game;
import se.urmo.game.map.GameMap;
import se.urmo.game.util.Direction;
import se.urmo.game.util.LoadSave;
import se.urmo.game.util.MiscUtil;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.image.BufferedImage;
import java.util.List;

public class Ghost {
    private static final int COLLISION_BOX_SIZE = 16;
    private static final int GHOST_SPEED = 1;
    private static final int GHOST_MOVEMENT_UPDATE_FREQUENCY = 2;

    private static int GHOST_SIZE = 32;
    private static final int ANIMATION_UPDATE_FREQUENCY = 25;
    private static final int COLLISION_BOX_OFFSET = (GHOST_SIZE - COLLISION_BOX_SIZE) / 2;
    private static final BufferedImage COLLISION_BOX = MiscUtil.createOutlinedBox(COLLISION_BOX_SIZE, COLLISION_BOX_SIZE, Color.black, 2);

    private final Game game;
    private final GhostCollisionChecker collisionChecker;
    private Point position;

    private boolean moving = true;
    private int aniTick = 0;
    private int aniIndex = 0;
    private BufferedImage[] animation;
    private Direction direction = Direction.LEFT;
    private int movementTick = 0;


    public Ghost(Game game, GhostCollisionChecker collisionChecker, GhostStrategy strategy) {
        this.game = game;
        this.collisionChecker = collisionChecker;
        position = new Point(13 * 16 + 8 + GameMap.OFFSET_X, 4 * 16 + GameMap.OFFSET_Y);
        loadAnimation();
    }

    private void loadAnimation() {
        BufferedImage[][] image = new BufferedImage[10][4];

        BufferedImage img = LoadSave.GetSpriteAtlas("sprites/PacManAssets-Ghosts.png");
        for (int row = 0; row < 3; row++) {
            for (int col = 0; col < 4; col++) {
                image[row][col] = img.getSubimage(32 * col, 32 * row, GHOST_SIZE, GHOST_SIZE);
            }
        }
        animation = image[0];
    }

    public void draw(Graphics g) {
        g.drawImage(
                animation[aniIndex],
                position.x - COLLISION_BOX_OFFSET,
                position.y - COLLISION_BOX_OFFSET,
                GHOST_SIZE,
                GHOST_SIZE, null);
        g.drawImage(COLLISION_BOX, position.x, position.y, COLLISION_BOX_SIZE, COLLISION_BOX_SIZE, null);
    }

    public void update() {
        updateAnimationTick();
        if(movementTick >= GHOST_MOVEMENT_UPDATE_FREQUENCY) {
            // if intersection - decide direction
            // else if direction isPassible
            List<Direction> i = collisionChecker.isIntersection(position);
            if(!i.isEmpty()){
                // Change direction
                if(i.contains(Direction.DOWN)) direction = Direction.DOWN;
                else if(i.contains(Direction.RIGHT)) direction = Direction.RIGHT;
                else if(i.contains(Direction.UP)) direction = Direction.UP;
                else direction = Direction.LEFT;

            }

            //Point target = strategy.chooseTarget(pacman, this, blinky);

            Point newPosition =  switch (direction){
                    case RIGHT -> new Point(position.x += GHOST_SPEED, position.y);
                    case LEFT -> new Point(position.x -= GHOST_SPEED, position.y);
                    case DOWN -> new Point(position.x, position.y += GHOST_SPEED);
                    case UP -> new Point(position.x, position.y -= GHOST_SPEED);
                    default -> throw new IllegalStateException("Illegal direction");
                };

            Point destination = collisionChecker.getValidDestination(direction, newPosition, GHOST_SIZE, GHOST_SIZE);

//            if (position.x + direction.dx * GHOST_SPEED < GameMap.OFFSET_X) direction = direction.opposite();
//            if (position.x + GHOST_SIZE + (direction.dx * GHOST_SPEED) > GamePanel.SCREEN_WIDTH - GameMap.OFFSET_X)
//                direction = direction.opposite();

            if(destination != null) {
                position = destination;
            }
            movementTick = 0;
        } else movementTick++;
    }

    private Direction chooseDirection(List<Direction> options, Point target) {
        Direction best = options.get(0);
        double bestDist = Double.MAX_VALUE;

        for (Direction d : options) {
            int nx = position.x + d.dx * GameMap.MAP_TILESIZE;
            int ny = position.y + d.dy * GameMap.MAP_TILESIZE;
            double dist = target.distance(nx, ny);
            if (dist < bestDist) {
                bestDist = dist;
                best = d;
            }
        }
        return best;
    }

    private void updateAnimationTick() {
        if (moving) {
            aniTick++;
            if (aniTick >= ANIMATION_UPDATE_FREQUENCY) {
                aniTick = 0;
                aniIndex++;
                if (aniIndex >= 3) {
                    aniIndex = 0;
                }

            }
        }
    }

}