package util

import (
	"bytes"
	"image"
	"time"

	"gat1400Exchange/vo"

	"basic.com/pubsub/protomsg.git"
	"basic.com/valib/godraw.git"
)

// 按尺寸去切图
func SubCutImg(srcImage []byte, rect *vo.Rect, enlarge int) ([]byte, error) {
	i, err := readFromUploadImg(srcImage)

	bkImg, _ := godraw.ToImage(srcImage, int(i.Width), int(i.Height))
	newRect := EnlargeCut(rect, int(i.Width), int(i.Height), enlarge)
	squareRect := LetterBox(newRect, int(i.Width), int(i.Height))
	rectNew := image.Rect(squareRect.Left, squareRect.Top, squareRect.Right, squareRect.Bottom)
	subImg := bkImg.(*image.RGBA).SubImage(rectNew)

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

	return bytes, nil
}

// letterbox 按照宽边修改目标框为正方形
func LetterBox(rect *vo.Rect, maxW, maxH int) *vo.Rect {
	width := rect.Right - rect.Left
	height := rect.Bottom - rect.Top

	// 计算目标框的中心点坐标
	centerX := (rect.Left + rect.Right) / 2
	centerY := (rect.Top + rect.Bottom) / 2

	// 如果宽度大于高度，则以高度为基准调整宽度，使其成为正方形
	if width > height {
		newWidth := height
		newLeft := centerX - newWidth/2
		newRight := centerX + newWidth/2

		// 调整后的正方形框超出图像边界时的处理
		if newLeft < 0 {
			// 如果左边界超出，向右移动右边界
			newRight += -newLeft
			newLeft = 0
		}
		if newRight > maxW {
			// 如果右边界超出，向左移动左边界
			newLeft -= newRight - maxW
			newRight = maxW
		}

		return &vo.Rect{
			Left:   newLeft,
			Top:    rect.Top,
			Right:  newRight,
			Bottom: rect.Bottom,
		}
	}

	// 如果高度大于宽度，则以宽度为基准调整高度，使其成为正方形
	if height > width {
		newHeight := width
		newTop := centerY - newHeight/2
		newBottom := centerY + newHeight/2

		// 调整后的正方形框超出图像边界时的处理
		if newTop < 0 {
			// 如果上边界超出，向下移动下边界
			newBottom += -newTop
			newTop = 0
		}
		if newBottom > maxH {
			// 如果下边界超出，向上移动上边界
			newTop -= newBottom - maxH
			newBottom = maxH
		}

		return &vo.Rect{
			Left:   rect.Left,
			Top:    newTop,
			Right:  rect.Right,
			Bottom: newBottom,
		}
	}

	// 如果宽度和高度相等，则已经是正方形，直接返回原始矩形
	return rect
}

// 长宽变为一比一，每边各扩百分之...
func EnlargeCut(rect *vo.Rect, maxW, maxH int, enlargePer int) *vo.Rect {
	var x0New, x1New, y0New, y1New int

	// 先把长宽变为一比一
	x0 := rect.Left
	y0 := rect.Top
	x1 := rect.Right
	y1 := rect.Bottom

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

	// 再把每边各扩大百分之...
	enlarge := float32(enlargePer) / 100
	x0New = int((1+enlarge)*float32(x0) - enlarge*float32(x1))
	if x0New < 0 {
		x0New = 0
	}

	x1New = int((1+enlarge)*float32(x1) - enlarge*float32(x0))
	if x1New > maxW {
		x1New = maxW
	}

	y0New = int((1+enlarge)*float32(y0) - enlarge*float32(y1))
	if y0New < 0 {
		y0New = 0
	}

	y1New = int((1+enlarge)*float32(y1) - enlarge*float32(y0))
	if y1New > maxH {
		y1New = maxH
	}

	return &vo.Rect{
		Left:   x0New,
		Top:    y0New,
		Right:  y0New,
		Bottom: y1New,
	}
}

func readFromUploadImg(imageFile []byte) (*protomsg.Image, error) {
	bt := bytes.NewBuffer(imageFile)
	img, _, err := image.Decode(bt)
	if err != nil {
		return nil, err
	}
	bgr := godraw.Image2BGR(img)

	timeUnix := time.Now().Unix()
	formatTimeStr := time.Unix(timeUnix, 0).Format("2006-01-02 15:04:05")

	return &protomsg.Image{
		Width:     int32(img.Bounds().Dx()),
		Height:    int32(img.Bounds().Dy()),
		Timestamp: formatTimeStr,
		Data:      bgr,
		Id:        time.Now().Unix(),
		Cid:       "gat1400",
	}, nil
}