package com.aoleyun.sn.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PointF;
import android.util.AttributeSet;
import android.view.View;

import androidx.annotation.Nullable;

import java.util.Locale;

public class FaceOverlayView extends View {
    private Paint pointPaint;
    private Paint textPaint;
    private PointF leftEye;
    private PointF rightEye;
    private double distance;
    private int imageWidth;
    private int imageHeight;

    public FaceOverlayView(Context context) {
        super(context);
        init();
    }

    public FaceOverlayView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        pointPaint = new Paint();
        pointPaint.setColor(Color.RED);
        pointPaint.setStyle(Paint.Style.FILL);
        pointPaint.setStrokeWidth(10f);

        textPaint = new Paint();
        textPaint.setColor(Color.YELLOW);
        textPaint.setTextSize(60f);
        textPaint.setFakeBoldText(true);
        textPaint.setShadowLayer(5, 0, 0, Color.BLACK);
    }

    public void updateData(double distance, PointF leftEye, PointF rightEye, int imageWidth, int imageHeight) {
        this.distance = distance;
        this.leftEye = leftEye;
        this.rightEye = rightEye;
        this.imageWidth = imageWidth;
        this.imageHeight = imageHeight;
        postInvalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (leftEye == null || rightEye == null || imageWidth <= 0 || imageHeight <= 0) {
            canvas.drawText("未检测到人脸", 50, 100, textPaint);
            return;
        }

        // 1. 获取 View 的尺寸
        float viewWidth = getWidth();
        float viewHeight = getHeight();

        // 2. 计算缩放比例 (适配 PreviewView 的 FILL_CENTER 逻辑)
        // FILL_CENTER：取宽高缩放比例中较大的一个，使图像填满 View 且不拉伸，多出的部分被裁剪
        float scale = Math.max(viewWidth / imageWidth, viewHeight / imageHeight);

        // 3. 计算偏移量（由居中裁剪产生）
        float postScaleWidth = imageWidth * scale;
        float postScaleHeight = imageHeight * scale;
        float offsetX = (viewWidth - postScaleWidth) / 2f;
        float offsetY = (viewHeight - postScaleHeight) / 2f;

        // 4. 坐标映射并处理镜像
        // CameraX 的 PreviewView 显示前置摄像头时默认是镜像的
        // 映射公式： viewX = viewWidth - (imageX * scale + offsetX)
        float lx = viewWidth - (leftEye.x * scale + offsetX);
        float ly = leftEye.y * scale + offsetY;
        float rx = viewWidth - (rightEye.x * scale + offsetX);
        float ry = rightEye.y * scale + offsetY;

        // 绘制眼睛点位
        canvas.drawCircle(lx, ly, 15, pointPaint);
        canvas.drawCircle(rx, ry, 15, pointPaint);

        // 绘制连线，更直观
        canvas.drawLine(lx, ly, rx, ry, pointPaint);

        canvas.drawText(String.format(Locale.getDefault(), "瞳距: %.2f", distance), 50, 100, textPaint);
    }
}