package boat;

import javax.microedition.lcdui.*;

/**
 * 游戲界面
 */
public class BoatGameCanvas extends Canvas implements Runnable {
    /**背景圖片*/
    private Image bgImage;
    /**軍艦圖片數組，下標0代表向右，1代表向左*/
    private Image boatImage[] = new Image[2];
    /**軍艦對象*/
    Boat boat;
    /**潛艇對象數組*/
    Submarine[] submarine = new Submarine[2];
    /**第一組潛艇圖片*/
    private Image[] sImage1 = new Image[2];
    /**第二組潛艇圖片*/
    private Image[] sImage2 = new Image[2];
    /**爆炸圖片*/
    private Image[] boomImage = new Image[3];
    /**炸彈圖片*/
    private Image bombImage;
    /**炸彈對象*/
    private Bomb bomb;

    //雙緩沖
    /**次畫面*/
    private Image offScreen;
    /**次畫筆*/
    private Graphics offG;
    /**屏幕寬度*/
    private int width;
    /**屏幕高度*/
    private int height;
    /**是否運行*/
    private boolean isRunning = true;
    /**是否連續移動*/
    private boolean isRepeated = false;
    /**軍艦移動方向*/
    private int boatDirection;
    /**游戲得分*/
    private int score = 0;
    public BoatGameCanvas() {
        try {
            //導入背景圖片
            bgImage = Image.createImage("/res/bac.png");
            //導入軍艦圖片
            boatImage[0] = Image.createImage("/res/ship0.png");
            boatImage[1] = Image.createImage("/res/ship1.png");
            //導入炸彈圖片
            bombImage = Image.createImage("/res/boom.png");
            //導入潛艇圖片
            sImage1[0] = Image.createImage("/res/q1.png");
            sImage1[1] = Image.createImage("/res/h2.png");

            sImage2[0] = Image.createImage("/res/r1.png");
            sImage2[1] = Image.createImage("/res/q2.png");
            //導入炸彈圖片
            boomImage[0] = Image.createImage("/res/b.png");
            boomImage[1] = Image.createImage("/res/b1.png");
            boomImage[2] = Image.createImage("/res/b2.png");

        } catch (Exception e) {
            e.printStackTrace();
        }
        //獲得屏幕寬度和高度
        width = this.getWidth();
        height = this.getHeight();
        //創建次畫面和次畫筆
        offScreen = Image.createImage(width, height);
        offG = offScreen.getGraphics();

        //創建軍艦對象
        boat = new Boat(boatImage, width);
        //創建潛艇對象
        init(0);
        init(1);
        //創建炸彈對象
        bomb = new Bomb(bombImage, 0, 0, height);

        //創建線程
        Thread t = new Thread(this);
        //啟動線程
        t.start();
    }

    private void init(int num) {
        if (num == 0) {
            submarine[0] = new Submarine(sImage1, width, height, 0, boomImage);
        }
        if (num == 1) {
            submarine[1] = new Submarine(sImage2, width, height, 1, boomImage);
        }
    }

    /**
     * 繪制方法
     * @param g 系統畫筆
     */
    protected void paint(Graphics g) {
        //清屏
        offG.setColor(0xffffff);
        offG.fillRect(0, 0, width, height);
        offG.setColor(0);

        //繪制背景圖片
        offG.drawImage(bgImage, 0, 0, Graphics.TOP | Graphics.LEFT);

        //繪制軍艦
        boat.paint(offG);
        //繪制潛艇
        submarine[0].paint(offG);
        submarine[1].paint(offG);
        //繪制炸彈
        if (bomb.isDisplay) {
            bomb.paint(offG);
        }
        //繪制得分
        offG.drawString("得分：" + score,4,4,Graphics.TOP | Graphics.LEFT);

        //將次畫面貼到主畫面
        g.drawImage(offScreen, 0, 0, Graphics.TOP | Graphics.LEFT);
    }

    public void keyPressed(int keyCode) {
        //轉換為游戲動作
        int action = this.getGameAction(keyCode);

        switch (action) {
        case Canvas.LEFT: //向左移動軍艦
            isRepeated = true;
            boatDirection = Boat.BOAT_MOVE_LEFT;
            break;
        case Canvas.RIGHT:
            isRepeated = true;
            boatDirection = Boat.BOAT_MOVE_RIGHT;
            break;
        case Canvas.FIRE:

            //判斷是否可以發射
            if (!bomb.isDisplay) {
                bomb.isDisplay = true;
                //設置坐標
                bomb.setX(boat.x + boat.getBoatImageWidth() / 2 -
                          bomb.getImageWidth() / 2);
                bomb.setY(boat.Y + boat.getBoatImageHeight() -
                          bomb.getImageHeight());
            }
            break;
        }
        //重新繪制
        repaint();
    }

    public void keyReleased(int keyCode) {
        //轉換為游戲動作
        int action = this.getGameAction(keyCode);
        switch (action) {
        case Canvas.LEFT: //向左移動軍艦
            isRepeated = false;
            break;
        case Canvas.RIGHT:
            isRepeated = false;
            break;
        }
    }

    /**
     * 運行方法
     */
    public void run() {
        while (isRunning) {
            //暫停
            try {
                Thread.sleep(100);
            } catch (Exception e) {}
            //移動軍艦
            if (isRepeated) {
                boat.move(boatDirection);
            }
            //未爆炸則移動潛艇
            if (!submarine[0].isIsBoom()) {
                submarine[0].move();
            } else { //播放爆炸效果
                submarine[0].boom();
            }
            if (!submarine[1].isIsBoom()) {
                submarine[1].move();
            } else { //播放爆炸效果
                submarine[1].boom();
            }
            //移動炸彈
            if (bomb.isDisplay) {
                bomb.move();
                //判別是否碰撞
                if (bomb.collidesWith(submarine[0])) {
                    bomb.handlecollidesWith(submarine[0]);
                    //分數增加
                    score += 10;
                }
                if (bomb.collidesWith(submarine[1])) {
                    bomb.handlecollidesWith(submarine[1]);
                    //分數增加
                    score += 10;
                }

            }

            //垃圾回收
            System.gc();

            //重繪
            repaint();
        }
    }
}