package com.bird.main;

import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;

import com.bird.util.Constant;
import com.bird.util.GameUtil;

/**
 * 前景类， 游戏中的遮挡层 包含多朵云
 *
 * @author Kingyu
 */
public class GameForeground {
    private final List<Cloud> clouds; // 云朵的容器

    private final BufferedImage[] cloudImages; // 图片资源

    private long time; // 控制云的逻辑运算周期
    public static final int CLOUD_INTERVAL = 100; //云朵刷新的逻辑运算的周期

    public GameForeground() {
        clouds = new ArrayList<>(); //云朵的容器

        // 读入图片资源
        cloudImages = new BufferedImage[Constant.CLOUD_IMAGE_COUNT];
        for (int i = 0; i < Constant.CLOUD_IMAGE_COUNT; i++) {
            cloudImages[i] = GameUtil.loadBufferedImage(Constant.CLOUDS_IMG_PATH[i]);
        }
        time = System.currentTimeMillis(); // 获取当前时间，用于控制云的逻辑运算周期
    }

    // 绘制方法
    public void draw(Graphics g, Bird bird) {
        cloudLogic();
        for (Cloud cloud : clouds) {
            cloud.draw(g, bird);
        }
    }

    // 云朵的控制
    private void cloudLogic() {
        // 100ms运算一次
        if (System.currentTimeMillis() - time > CLOUD_INTERVAL) {
            time = System.currentTimeMillis(); // 重置time
            // 如果屏幕的云朵的数量小于允许的最大数量，根据给定的概率随机添加云朵
            if (clouds.size() < Constant.MAX_CLOUD_COUNT) {
                try {
                    if (GameUtil.isInProbability(Constant.CLOUD_BORN_PERCENT, 100)) { // 根据给定的概率添加云朵
                        int index = GameUtil.getRandomNumber(0, Constant.CLOUD_IMAGE_COUNT); // 随机选取云朵图片

                        // 云朵刷新的坐标
                        int x = Constant.FRAME_WIDTH; // 从屏幕左侧开始刷新
                        // y坐标随机在上1/3屏选取
                        int y = GameUtil.getRandomNumber(Constant.TOP_BAR_HEIGHT, Constant.FRAME_HEIGHT / 3);

                        //向容器中添加云朵
                        Cloud cloud = new Cloud(cloudImages[index], x, y);
                        clouds.add(cloud);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            } // 添加云朵

            // 若云朵飞出屏幕则从容器中移除
            for (int i = 0; i < clouds.size(); i++) {
                // 遍历容器中的云朵
                Cloud tempCloud = clouds.get(i);
                if (tempCloud.isOutFrame()) {
                    clouds.remove(i);
                    i--;
                }
            }

        }
    }
}
