// ==============================================
// 文件：AnimationModel.java
// 包名：com.example.venetianblinds
// 功能：Model 層，管理動畫參數(shù)與進度
// ==============================================
package com.example.venetianblinds;
 
import java.awt.image.BufferedImage;
import javax.swing.Timer;
import java.awt.event.ActionListener;
 
public class AnimationModel {
    public enum Mode { HORIZONTAL, VERTICAL }
    private BufferedImage sourceImage;
    private int stripeCount;
    private long duration;         // 毫秒
    private Mode mode;
    private boolean fade;          // 是否漸變
    private long startTime;
    private double progress;       // 0.0–1.0
    private Timer timer;
 
    /**
     * 初始化模型
     */
    public AnimationModel(BufferedImage img, int stripeCount, long duration,
                          Mode mode, boolean fade, ActionListener tickListener) {
        this.sourceImage = img;
        this.stripeCount = stripeCount;
        this.duration = duration;
        this.mode = mode;
        this.fade = fade;
        this.progress = 0.0;
        // 60 FPS
        this.timer = new Timer(1000/60, tickListener);
        this.timer.setInitialDelay(0);
    }
 
    /** 啟動動畫 */
    public void start() {
        this.startTime = System.currentTimeMillis();
        this.progress = 0.0;
        this.timer.start();
    }
 
    /** 暫停動畫 */
    public void pause() {
        this.timer.stop();
    }
 
    /** 重置動畫 */
    public void reset() {
        this.progress = 0.0;
        this.timer.stop();
    }
 
    /** 停止動畫 */
    public void stop() {
        this.timer.stop();
        this.progress = 1.0;
    }
 
    /** 更新當前進度 */
    public void update() {
        long now = System.currentTimeMillis();
        double p = (now - startTime) / (double)duration;
        this.progress = Math.min(1.0, p);
        if (progress >= 1.0) {
            timer.stop();
        }
    }
 
    public BufferedImage getSourceImage() { return sourceImage; }
    public int getStripeCount() { return stripeCount; }
    public double getProgress() { return progress; }
    public Mode getMode() { return mode; }
    public boolean isFade() { return fade; }
}

// ==============================================
// 文件：AnimationView.java
// 包名：com.example.venetianblinds
// 功能：View 層，負責渲染百葉窗特效
// ==============================================
package com.example.venetianblinds;
 
import javax.swing.JPanel;
import java.awt.*;
import java.awt.image.BufferedImage;
 
public class AnimationView extends JPanel {
    private AnimationModel model;
    private Rectangle[] stripes; // 預計算條帶區(qū)域
 
    public AnimationView(AnimationModel model) {
        this.model = model;
        precomputeStripes();
    }
 
    /** 預計算條帶區(qū)域列表 */
    private void precomputeStripes() {
        int count = model.getStripeCount();
        BufferedImage img = model.getSourceImage();
        int w = img.getWidth(), h = img.getHeight();
        stripes = new Rectangle[count];
        if (model.getMode() == AnimationModel.Mode.HORIZONTAL) {
            int stripeH = h / count;
            for (int i = 0; i < count; i++) {
                stripes[i] = new Rectangle(0, i * stripeH, w, stripeH);
            }
        } else {
            int stripeW = w / count;
            for (int i = 0; i < count; i++) {
                stripes[i] = new Rectangle(i * stripeW, 0, stripeW, h);
            }
        }
    }
 
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        BufferedImage img = model.getSourceImage();
        double p = model.getProgress();
        Graphics2D g2 = (Graphics2D) g.create();
        for (int i = 0; i < stripes.length; i++) {
            Rectangle r = stripes[i];
            int len = model.getMode() == AnimationModel.Mode.HORIZONTAL
                    ? (int)(r.height * p)
                    : (int)(r.width * p);
            if (len <= 0) continue;
            // 設置剪輯區(qū)域
            if (model.getMode() == AnimationModel.Mode.HORIZONTAL) {
                g2.setClip(r.x, r.y, r.width, len);
            } else {
                g2.setClip(r.x, r.y, len, r.height);
            }
            // 漸變控制
            if (model.isFade()) {
                float alpha = (float)p;
                AlphaComposite ac = AlphaComposite.getInstance(
                        AlphaComposite.SRC_OVER, alpha);
                g2.setComposite(ac);
            }
            g2.drawImage(img, 0, 0, null);
        }
        g2.dispose();
    }
}

// ==============================================
// 文件：AnimationController.java
// 包名：com.example.venetianblinds
// 功能：Controller 層，綁定事件并控制動畫流程
// ==============================================
package com.example.venetianblinds;
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
 
public class AnimationController {
    private AnimationModel model;
    private AnimationView view;
    private JFrame frame;
    // 控件
    private JComboBox<String> modeCombo;
    private JTextField stripeCountField, durationField;
    private JCheckBox fadeCheck;
    private JButton loadBtn, startBtn, pauseBtn, resetBtn, saveBtn;
 
    public AnimationController() {
        initUI();
    }
 
    /** 初始化界面 */
    private void initUI() {
        frame = new JFrame("Java 百葉窗特效演示");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLayout(new BorderLayout());
 
        // 控件面板
        JPanel ctrl = new JPanel(new GridLayout(0,2,5,5));
        ctrl.add(new JLabel("模式:")); modeCombo = new JComboBox<>(
                new String[]{"水平(HORIZONTAL)","垂直(VERTICAL)"});
        ctrl.add(modeCombo);
        ctrl.add(new JLabel("條帶數(shù):")); stripeCountField = new JTextField("10");
        ctrl.add(stripeCountField);
        ctrl.add(new JLabel("時長(ms):")); durationField = new JTextField("2000");
        ctrl.add(durationField);
        fadeCheck = new JCheckBox("漸變", true);
        ctrl.add(fadeCheck);
        loadBtn = new JButton("加載圖片"); startBtn = new JButton("開始");
        pauseBtn = new JButton("暫停"); resetBtn = new JButton("重置");
        saveBtn = new JButton("保存當前幀");
        ctrl.add(loadBtn); ctrl.add(startBtn); ctrl.add(pauseBtn);
        ctrl.add(resetBtn); ctrl.add(saveBtn);
        frame.add(ctrl, BorderLayout.NORTH);
 
        // 占位 view
        view = new AnimationView(null);
        frame.add(view, BorderLayout.CENTER);
 
        bindEvents();
        frame.setSize(800,600);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
 
    /** 綁定事件 */
    private void bindEvents() {
        loadBtn.addActionListener(e -> onLoad());
        startBtn.addActionListener(e -> onStart());
        pauseBtn.addActionListener(e -> onPause());
        resetBtn.addActionListener(e -> onReset());
        saveBtn.addActionListener(e -> onSave());
    }
 
    private void onLoad() {
        JFileChooser fc = new JFileChooser();
        if (fc.showOpenDialog(frame)==JFileChooser.APPROVE_OPTION) {
            try {
                BufferedImage img = ImageIO.read(fc.getSelectedFile());
                int stripes = Integer.parseInt(stripeCountField.getText());
                long dur = Long.parseLong(durationField.getText());
                AnimationModel.Mode mode = modeCombo.getSelectedIndex()==0
                        ? AnimationModel.Mode.HORIZONTAL
                        : AnimationModel.Mode.VERTICAL;
                boolean fade = fadeCheck.isSelected();
                // 清除舊 model
                if (model!=null) model.stop();
                model = new AnimationModel(img, stripes, dur, mode, fade,
                        evt -> { model.update(); view.repaint(); });
                view = new AnimationView(model);
                frame.getContentPane().remove(1);
                frame.add(view, BorderLayout.CENTER);
                frame.validate();
                frame.repaint();
            } catch (Exception ex) {
                JOptionPane.showMessageDialog(frame, "加載失敗: "+ex.getMessage());
            }
        }
    }
 
    private void onStart() {
        if (model!=null) model.start();
    }
    private void onPause() {
        if (model!=null) model.pause();
    }
    private void onReset() {
        if (model!=null) {
            model.reset();
            view.repaint();
        }
    }
    private void onSave() {
        if (model==null) return;
        JFileChooser fc = new JFileChooser();
        if (fc.showSaveDialog(frame)==JFileChooser.APPROVE_OPTION) {
            try {
                ImageIO.write(model.getSourceImage(), "png",
                        new File(fc.getSelectedFile().getAbsolutePath()));
                JOptionPane.showMessageDialog(frame, "保存成功");
            } catch (Exception ex) {
                JOptionPane.showMessageDialog(frame, "保存失敗: "+ex.getMessage());
            }
        }
    }
 
    public static void main(String[] args) {
        SwingUtilities.invokeLater(AnimationController::new);
    }
}