package util

import (
	"basic.com/pubsub/protomsg.git"
	"basic.com/valib/godraw.git"
	"image"
	"image/color"
)

// 按尺寸去切图
func SubCutImg(src *protomsg.Image, rect *protomsg.Rect, enlarge int) ([]byte, error){
	bkImg, _ := godraw.ToImage(src.Data, int(src.Width), int(src.Height))

	rectNew := image.Rect(EnlargeCut(rect, int(src.Width), int(src.Height), enlarge))
	subImg := bkImg.(*image.RGBA).SubImage(rectNew)

	bytes,err := godraw.ImageToJpeg(subImg, nil)
	if err != nil {
		return nil, err
	}
	return bytes, nil
}

// 长宽变为一比一，每边各扩百分之...
func EnlargeCut(rect *protomsg.Rect, maxW,maxH int, enlargePer int) (x0_new, y0_new, x1_new, y1_new int) {
	// 先把长宽变为一比一
	x0 := int(rect.Left)
	y0 := int(rect.Top)
	x1 := int(rect.Right)
	y1 := int(rect.Bottom)

	chazhi := (y1 - y0) - (x1 - x0)
	x0 = x0 - chazhi/2
	if x0 < 0 {
		x0 = 0
	}
	x1 = x1 + chazhi/2
	if x1 > maxW {
		x1 = maxW
	}

	// 再把每边各扩大百分之...
	enlarge := float32(enlargePer / 100)
	x0_new = int((1+enlarge)*float32(x0) - enlarge*float32(x1))
	if x0_new < 0 {
		x0_new = 0
	}
	x1_new = int((1+enlarge)*float32(x1) - enlarge*float32(x0))
	if x1_new > maxW {
		x1_new = maxW
	}
	y0_new = int((1+enlarge)*float32(y0) - enlarge*float32(y1))
	if y0_new < 0 {
		y0_new = 0
	}
	y1_new = int((1+enlarge)*float32(y1) - enlarge*float32(y0))
	if y1_new > maxH {
		y1_new = maxH
	}

	return x0_new, y0_new, x1_new, y1_new
}

func DrawRect(img *protomsg.Image, rect *protomsg.Rect) ([]byte, error) {
	red := color.RGBA{255, 0, 0, 0}

	targetRect := image.Rect(int(rect.Left), int(rect.Top), int(rect.Right), int(rect.Bottom))
	bgImg, err := godraw.ToImage(img.Data, int(img.Width), int(img.Height))
	if err == nil {
		err1 := godraw.DrawRectangle(bgImg, targetRect, red, 2)
		if err1 != nil {
			return nil, err1
		} else {
			bytes,err := godraw.ImageToJpeg(bgImg, nil)
			if err != nil {
				return nil, err
			}
			return bytes, nil
		}
	}

	return nil, err
}

func DrawPolygon(img *protomsg.Image, points []protomsg.Point) ([]byte, error) {

	var pts []image.Point
	for _, pt := range points {
		pts = append(pts, image.Point{
			X: int(pt.X),
			Y: int(pt.Y),
		})
	}
	yellow := color.RGBA{255, 255, 0, 0}

	bgImg, err := godraw.ToImage(img.Data, int(img.Width), int(img.Height))
	if err == nil {
		err1 := godraw.DrawPolygon(bgImg, pts, yellow,2)
		if err1 != nil {
			return nil, err1
		} else {
			bytes,err := godraw.ImageToJpeg(bgImg, nil)
			if err != nil {
				return nil, err
			}
			return bytes, nil
		}
	}

	return nil, err
}