package qrcode

import (
	"bytes"
	"encoding/base64"
	"github.com/nfnt/resize"
	"github.com/skip2/go-qrcode"
	"golang.org/x/image/draw"
	"image"
	"image/color"
	_ "image/jpeg"
	"image/png"
	"os"
)

type CreateQrCodeBs64WithLogoReq struct {
	Content         string       //二维码内容
	OutPath         *string      //二维码保存路径（可选）
	LogoPath        *string      //logo路径（可选）
	Size            int64        //二维码尺寸
	X               *int64       //二维码整体x偏移
	Y               *int64       //二维码整体Y偏移
	ForegroundColor *color.Color //二维码纹路颜色
	BackgroundColor *color.Color //二维码背景颜色
	DisableBorder   bool         // 是否不要二维码边框
}

func CreateQrCodeBs64WithLogo(req CreateQrCodeBs64WithLogoReq) (data string, err error) {
	code, err := qrcode.New(req.Content, qrcode.High)
	if err != nil {
		return
	}
	if req.DisableBorder {
		code.DisableBorder = true
	}
	//二维码纹路颜色
	if req.ForegroundColor != nil {
		code.ForegroundColor = *req.ForegroundColor
	}
	//背景颜色
	if req.BackgroundColor != nil {
		code.BackgroundColor = *req.BackgroundColor
	}
	//设置文件大小并创建画板
	qrcodeImg := code.Image(int(req.Size))
	outImg := image.NewRGBA(qrcodeImg.Bounds())
	buf := new(bytes.Buffer)
	//无logo
	if req.LogoPath == nil {
		//图像偏移
		if req.X != nil && req.Y != nil {
			draw.Draw(outImg, outImg.Bounds().Add(image.Pt(int(*req.X), int(*req.Y))), qrcodeImg, outImg.Bounds().Min, draw.Src)
		}
		err = png.Encode(buf, outImg)
		if err != nil {
			return "", err
		}
		if req.OutPath != nil {
			// 写入文件
			f, err := os.Create(*req.OutPath)
			if err != nil {
				return "", err
			}
			defer f.Close()
			err = png.Encode(f, outImg)
			if err != nil {
				return "", err
			}
		}
		return base64.StdEncoding.EncodeToString(buf.Bytes()), nil
	}
	//读取logo文件
	logoFile, err := os.Open(*req.LogoPath)
	if err != nil {
		return "", err
	}
	logoImg, _, err := image.Decode(logoFile)
	if err != nil {
		return "", err
	}
	logoImg = resize.Resize(uint(req.Size/5), uint(req.Size/5), logoImg, resize.Lanczos3)
	// 添加边框
	// 图片到边框距离
	pic2FramePadding := logoImg.Bounds().Dx() / 10

	// 新建一个边框图层
	transparentImg := image.NewRGBA(image.Rect(0, 0, logoImg.Bounds().Dx()+pic2FramePadding, logoImg.Bounds().Dy()+pic2FramePadding))
	// 图层颜色设为白色
	draw.Draw(transparentImg, transparentImg.Bounds(), image.White, image.Point{}, draw.Over)
	// 将缩略图放到透明图层上
	draw.Draw(transparentImg,
		image.Rect(pic2FramePadding/2, pic2FramePadding/2, transparentImg.Bounds().Dx(), transparentImg.Bounds().Dy()),
		logoImg,
		image.Point{},
		draw.Over)

	//logo和二维码拼接
	draw.Draw(outImg, outImg.Bounds(), qrcodeImg, image.Pt(0, 0), draw.Over)
	offset := image.Pt((outImg.Bounds().Max.X-transparentImg.Bounds().Max.X)/2, (outImg.Bounds().Max.Y-transparentImg.Bounds().Max.Y)/2)
	draw.Draw(outImg, outImg.Bounds().Add(offset), transparentImg, image.Pt(0, 0), draw.Over)
	//图像偏移
	if req.X != nil && req.Y != nil {
		draw.Draw(outImg, outImg.Bounds().Add(image.Pt(int(*req.X), int(*req.Y))), qrcodeImg, outImg.Bounds().Min, draw.Src)
	}
	err = png.Encode(buf, outImg)
	if err != nil {
		return "", err
	}
	if req.OutPath != nil {
		// 写入文件
		f, err := os.Create(*req.OutPath)
		if err != nil {
			return "", err
		}
		defer f.Close()
		err = png.Encode(f, outImg)
		if err != nil {
			return "", err
		}
	}
	return base64.StdEncoding.EncodeToString(buf.Bytes()), nil
}