package com.application.zhangshi_app_android.widget;

import android.animation.ObjectAnimator;
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.OverScroller;
import android.widget.RelativeLayout;

import androidx.annotation.Nullable;

import com.application.zhangshi_app_android.R;

/**
 * @author Ljj
 * @date 2023.04.08. 20:03
 * @desc
 */
public class TreeView extends RelativeLayout {

    private Context mContext;
    // 最小缩放比例
    float smallScale = 0f;
    // 正常缩放比例
    float normalScale = 0f;
    // 最大缩放比例
    float bigScale = 0f;

    // 当前比例
    float currentScale = 0f;

    // 缩放倍数
    private static final float ZOOM_SCALE = 2f;
    private final View treeView;
    private final GestureDetector mGestureDetector;
    // 双指操作
    private final ScaleGestureDetector mScaleGestureDetector;
    // 惯性滑动
    private final OverScroller mOverScroller;
    private final FlingRunner mFlingRunner;
    // 是否放大 [默认是缩小，双击改变状态]
    boolean isZoomIn = false;
    // 放大后手指移动位置
    private final OffSet moveOffset = new OffSet();
    private boolean isDoubleClickZoomIn = false;
    
    public TreeView(Context context) {
        this(context, null);
    }

    public TreeView(Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public TreeView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    public TreeView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        setWillNotDraw(false);
        mContext = context;
        treeView = LayoutInflater.from(context).inflate(R.layout.layout_tree_view,this,false);
        LayoutParams layoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        layoutParams.alignWithParent = true;
        layoutParams.addRule(CENTER_IN_PARENT);
        addView(treeView,layoutParams);
        mGestureDetector = new GestureDetector(context, new MyGestureListener());
        mScaleGestureDetector = new ScaleGestureDetector(context, new MyScaleGestureListener());
        mOverScroller = new OverScroller(context);
        mFlingRunner = new FlingRunner();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);

        // view比例
        float viewScale = (float) getWidth() / (float) getHeight();

        // 图片比例
        float bitScale = (float) treeView.getMeasuredWidth() / (float) treeView.getMeasuredHeight();

//        // 如果图片比例大于view比例
//        if (bitScale > viewScale) {
//            // 横向图片
//            smallScale = (float) getWidth() / (float) treeView.getMeasuredWidth();
//            bigScale = (float) getHeight() / (float) treeView.getMeasuredHeight() * ZOOM_SCALE;
//        } else {
//            // 纵向图片
//            smallScale = (float) getHeight() / (float) treeView.getMeasuredHeight();
//            bigScale = (float) getWidth() / (float) treeView.getMeasuredWidth() * ZOOM_SCALE;
//        }

        smallScale = (float) getWidth() / (float) treeView.getMeasuredWidth();
        smallScale = (float) getHeight() / (float) treeView.getMeasuredHeight();
        bigScale = (float) getHeight() / (float) treeView.getMeasuredHeight() * ZOOM_SCALE;

        // 当前缩放比例 = 缩放前的比例
        currentScale = smallScale;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.scale(currentScale, currentScale, getWidth() / 2f, getHeight() / 2f);
        // 移动画布
        if (isDoubleClickZoomIn){
            if (currentScale <= bigScale) {//双击改变状态时偏移量随着缩放比例变化
                float a = (currentScale - smallScale) / (bigScale - smallScale);
                moveOffset.setPhyX(moveOffset.getPhyX() * a);
                moveOffset.setPhyY(moveOffset.getPhyY() * a);
            }
        }
        canvas.translate(moveOffset.getLogX(currentScale), moveOffset.getLogY(currentScale));
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        // 双指操作
        boolean scaleTouchEvent = mScaleGestureDetector.onTouchEvent(event);
        // 是否是双指操作
        if (mScaleGestureDetector.isInProgress()) {
            return scaleTouchEvent;
        }
        // 双击操作
        return mGestureDetector.onTouchEvent(event);
    }

    private class MyGestureListener extends GestureDetector.SimpleOnGestureListener {
        // 单击情况 : 抬起[ACTION_UP]时候触发
        // 双击情况 : 第二次抬起[ACTION_POINTER_UP]时候触发
        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return super.onSingleTapUp(e);
        }

        // 长按时触发 [300ms]
        @Override
        public void onLongPress(MotionEvent e) {
            super.onLongPress(e);
        }

        // 滑动时候触发 类似 ACTION_MOVE 事件
        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            // 如果是放大状态才能移动
//            if (isZoomIn) {
                moveOffset.setPhyX(moveOffset.getPhyX() - distanceX);
                moveOffset.setPhyY(moveOffset.getPhyY() - distanceY);
                // 修正偏移量，防止图片移动时边缘出现白色背景
                fixOffset();

                invalidate();
//            }
            return super.onScroll(e1, e2, distanceX, distanceY);
        }

        // 滑翔/飞翔 [惯性滑动]
        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
//            mOverScroller.fling(
//                    (int) moveOffset.getX(),
//                    (int) moveOffset.getY(),
//                    (int) velocityX,
//                    (int) velocityY,
//                    (int) (-(treeView.getMeasuredWidth() * bigScale - getWidth()) / 2),
//                    (int) ((treeView.getMeasuredHeight() * bigScale - getWidth()) / 2),
//                    (int) (-(treeView.getMeasuredHeight() * bigScale - getHeight()) / 2),
//                    (int) ((treeView.getMeasuredHeight() * bigScale - getHeight()) / 2),
//                    300,
//                    300
//            );
//            // 设置fling效果
//            mFlingRunner.run();
            return super.onFling(e1, e2, velocityX, velocityY);
        }

        // 延时触发 [100ms] -- 常用与水波纹等效果
        @Override
        public void onShowPress(MotionEvent e) {
            super.onShowPress(e);
        }

        // 按下 这里必须返回true 因为所有事件都是由按下出发的
        @Override
        public boolean onDown(MotionEvent e) {
            return true;
        }

        // 双击 -- 第二次按下时候触发 (40ms - 300ms) [小于40ms是为了防止抖动]
        @Override
        public boolean onDoubleTap(MotionEvent e) {
            if (isDoubleClickZoomIn){
                // 判断双击的位置是否在treeView上
                float fixedWidth =  treeView.getWidth()*(1-currentScale)/2;
                float fixedHeight =  treeView.getHeight()*(1-currentScale)/2;
                if (treeView.getLeft()+fixedWidth <= e.getX() && e.getX()  <= treeView.getRight()-fixedWidth  && treeView.getTop()+fixedHeight <= e.getY() && e.getY() <= treeView.getBottom()-fixedHeight){
                    // 先改为放大,第一次双击是放大效果
                    isZoomIn = !isZoomIn;
                    if (isZoomIn) {
                        // 双击放大时定位到放大后双击的位置
//                    float currentX = e.getX() - (float) treeView.getWidth() / 2f;
//                    float currentY = e.getY() - (float) treeView.getHeight() / 2f;
//                    moveOffset.setX(currentX - currentX * bigScale);
//                    moveOffset.setY(currentY - currentY * bigScale);
//                    // 修正偏移量，防止图片移动时边缘出现白色背景
//                    fixOffset();

                        // 放大 放大到最大比例
                        //添加动画，更加流畅
                        scaleAnimation(currentScale, bigScale).start();
                    } else {
                        // 缩小 缩小为原先留白的比例
                        scaleAnimation(bigScale, smallScale).start();
                    }
                }
            }
            return super.onDoubleTap(e);
        }

        // 双击 第二次的事件处理 DOWN MOVE UP 都会执行到这里
        @Override
        public boolean onDoubleTapEvent(MotionEvent e) {
            return super.onDoubleTapEvent(e);
        }

        // 单击时触发 双击时不触发
        @Override
        public boolean onSingleTapConfirmed(MotionEvent e) {
            return super.onSingleTapConfirmed(e);
        }
    }
    // 缩放动画
    public ObjectAnimator scaleAnimation(float start, float end) {
        ObjectAnimator animator = ObjectAnimator.ofFloat(this, "currentScale", start, end);
        // 动画时间
        animator.setDuration(500);
        return animator;
    }

    // 属性动画的关键!!  内部通过反射调用set方法来赋值
    public void setCurrentScale(float currentScale) {
        this.currentScale = currentScale;
        invalidate();
    }

    public void fixOffset() {
        // 当前图片放大后的宽
        float currentWidth = treeView.getMeasuredWidth() * currentScale;
        // 当前图片放大后的高
        float currentHeight = treeView.getMeasuredHeight() * currentScale;

        System.out.println("currentScale = " + currentScale);
        System.out.println("moveOffset.getLogX(currentScale) = " + moveOffset.getLogX(currentScale));
        System.out.println("moveOffset.getLogY(currentScale) = " + moveOffset.getLogY(currentScale));
        System.out.println("moveOffset.getPhyX() = " + moveOffset.getPhyX());
        System.out.println("moveOffset.getPhyY() = " + moveOffset.getPhyY());
        System.out.println("currentWidth = " + currentWidth);
        System.out.println("currentHeight = " + currentHeight);
        System.out.println(-(currentWidth - getWidth()) / 2 / bigScale);
        System.out.println(-(currentWidth - getWidth()) / 2 / currentScale);
        System.out.println(-(currentWidth - getWidth()) / 2 );
        System.out.println(moveOffset.getPhyX());
        // 右侧限制
        moveOffset.setPhyX(Math.max(moveOffset.getPhyX(), -(currentWidth - getWidth()) / 2));

        // 左侧限制 [左侧moveOffset.getX()为负数]
        moveOffset.setPhyX(Math.min(moveOffset.getPhyX(), (currentWidth - getWidth()) / 2 ));

        // 下侧限制
        moveOffset.setPhyY(Math.max(moveOffset.getPhyY(), -(currentHeight - getHeight()) / 2 ));

        // 上侧限制 [上侧moveOffset.getY()为负数]
        moveOffset.setPhyY(Math.min(moveOffset.getPhyY(), (currentHeight - getHeight()) / 2 ));
    }

    class MyScaleGestureListener implements ScaleGestureDetector.OnScaleGestureListener {
        // 在双指操作开始时候获取当前缩放值
        private float scaleFactor = 0f;


        // 双指操作
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            // detector.getScaleFactor 缩放因子
            currentScale = scaleFactor * detector.getScaleFactor();

            // 刷新
            invalidate();
            return false;
        }

        // 双指操作开始
        @Override
        public boolean onScaleBegin(ScaleGestureDetector detector) {
            scaleFactor = currentScale;
            // 注意这里要为true 表示开始双指操作
            return true;
        }

        // 双指操作结束
        @Override
        public void onScaleEnd(ScaleGestureDetector detector) {
            // 当前图片宽
            float currentWidth = treeView.getMeasuredWidth() * currentScale;
            // 缩放前的图片宽
            float smallWidth = treeView.getMeasuredWidth() * smallScale;
            // 缩放后的图片宽
            float bigWidth = treeView.getMeasuredWidth() * bigScale;

            // 如果当前图片 < 缩放前的图片
            if (currentWidth < smallWidth) {
                // 图片缩小
                isZoomIn = false;
                scaleAnimation(currentScale, smallScale).start();
            }else if (currentWidth > bigWidth) {// 如果当前状态 > 缩放后的图片 那么就让他改变为最大的状态
                scaleAnimation(currentScale, bigScale).start();
                // 双击时候 图片放大
                isZoomIn = true;
            } else{
                // 图片缩小
                isZoomIn = true;
            }


        }
    }

    // 惯性滑动辅助
    class FlingRunner implements Runnable {

        @Override
        public void run() {
            // 判断当前是否是执行
            if (mOverScroller.computeScrollOffset()) {
                // 设置fling的值
                moveOffset.setPhyX(mOverScroller.getCurrX());
                moveOffset.setPhyY(mOverScroller.getCurrY());

                // 继续执行FlingRunner.run
                postOnAnimation(this);
                // 刷新
                invalidate();
            }
        }
    }


    private static class OffSet {
        float phyX;
        float phyY;


        public OffSet() {
        }

        public float getPhyX() {
            return phyX;
        }

        public void setPhyX(float phyX) {
            this.phyX = phyX;
        }

        public float getPhyY() {
            return phyY;
        }

        public void setPhyY(float phyY) {
            this.phyY = phyY;
        }

        public float getLogX(float scale) {
            return phyX / scale;
        }

        public float getLogY(float scale) {
            return phyY / scale;
        }

    }

    /**
     * 是否双击放大
     */
    public void setDoubleClickZoomIn(boolean doubleClickZoomIn) {
        isDoubleClickZoomIn = doubleClickZoomIn;
    }
}