package main

import (
	"bufio"
	"fmt"
	"image"
	"os"

	"github.com/chai2010/tiff"
	log "github.com/sirupsen/logrus"
	"gocv.io/x/gocv"
)

type Registrate interface{}

const (
	MssBands   = 4
	PixelBytes = 2
	PanWidth   = 9344 // 像素宽度
	MssWidth   = 2336
	BlockNum   = 5
)

type Registrator struct {
	PanImage  gocv.Mat
	PanHeight int
	PanWidth  int

	MssImages        [4]gocv.Mat
	MssHeight        int
	MssWidth         int
	registeredImages [4]gocv.Mat
	rgbirImage       gocv.Mat
}

func NewRegistrator() *Registrator {
	var r Registrator

	return &r
}

func (r *Registrator) LoadPanRaw(raw string) error {
	data, err := os.ReadFile(raw)
	if err != nil {
		log.Error("Error reading raw file: ", err)
		return err
	}

	height := len(data) / (PanWidth * PixelBytes)
	r.PanImage, err = gocv.NewMatFromBytes(height, PanWidth, gocv.MatTypeCV16U, data)
	if err != nil {
		log.Error("Error creating Mat from bytes: ", err)
		return err
	}

	r.PanHeight = height
	r.PanWidth = PanWidth

	return nil
}

func (r *Registrator) LoadMssRaw(raw string) error {
	data, err := os.ReadFile(raw)
	if err != nil {
		log.Error("Error reading raw file: ", err)
		return err
	}

	height := len(data) / (MssWidth * PixelBytes * MssBands)
	mssData := make([][]byte, MssBands)
	for h := 0; h < height; h++ {
		row := data[h*MssWidth*MssBands*PixelBytes : (h+1)*MssWidth*MssBands*PixelBytes]
		for i := 0; i < MssBands; i++ {
			mssData[i] = append(mssData[i], row[i*MssWidth*PixelBytes:(i+1)*MssWidth*PixelBytes]...)
		}
	}

	for i := 0; i < MssBands; i++ {
		r.MssImages[i], err = gocv.NewMatFromBytes(height, MssWidth, gocv.MatTypeCV16U, mssData[i])
		if err != nil {
			log.Error("Error creating Mat from bytes: ", err)
			return err
		}
	}

	r.MssHeight = height
	r.MssWidth = MssWidth

	return nil
}

func (r *Registrator) DoPhaseCorrelation() error {
	// 确保 MSS 高度是 PAN 高度的 1/4
	if r.MssHeight*4 != r.PanHeight {
		err := fmt.Errorf("MSS height is not 1/4 of PAN height, invalid raw file")
		log.Error(err)
		return err
	}

	// 将PAN将采样作为轮廓匹配基准图像
	downsampledPanImage := gocv.NewMat()
	gocv.Resize(r.PanImage, &downsampledPanImage,
		image.Point{X: r.MssWidth, Y: r.MssHeight}, 0, 0, gocv.InterpolationLinear)

	// 对每个 MSS 波段图像进行上采样
	upsampledMSSImages := make([]gocv.Mat, MssBands)
	for i := 0; i < MssBands; i++ {
		upsampledMSSImages[i] = gocv.NewMat()
		gocv.Resize(r.MssImages[i], &upsampledMSSImages[i],
			image.Point{X: r.PanWidth, Y: r.PanHeight}, 0, 0, gocv.InterpolationLinear)

		// r.msToRaw(upsampledMSSImages[i].ToBytes(), fmt.Sprintf("MSS%d.RAW", i+1))
	}

	fmt.Println("PAN images size:", r.PanImage.Size())
	fmt.Println("upsampled MSS1 images size:", upsampledMSSImages[0].Size())
	fmt.Println("upsampled MSS2 images size:", upsampledMSSImages[0].Size())
	fmt.Println("upsampled MSS3 images size:", upsampledMSSImages[0].Size())
	fmt.Println("upsampled MSS4 images size:", upsampledMSSImages[0].Size())

	// 分块高度
	blockHeight := r.PanHeight / BlockNum

	alignedMssData := make([][]byte, MssBands)

	for band := 0; band < MssBands; band++ {
		var alignedMSSImage gocv.Mat
		for block := 0; block < BlockNum; block++ {
			// 读取 PAN 和 MSS 分块数据
			y1 := (block + 1) * blockHeight
			if block == BlockNum-1 {
				y1 = r.PanHeight
			}

			log.Println("Processing block", block, image.Rect(0, block*blockHeight, r.PanWidth, y1))
			panBlock := r.PanImage.Region(image.Rect(0, block*blockHeight, r.PanWidth, y1))
			mssBlock := upsampledMSSImages[band].Region(image.Rect(0, block*blockHeight, r.PanWidth, y1))

			// 处理每个分块
			alignedBlock := r.processBlock(panBlock, mssBlock)

			alignedBlockData := alignedBlock.ToBytes()
			alignedMssData[band] = append(alignedMssData[band], alignedBlockData...)

			if alignedMSSImage.Empty() {
				alignedMSSImage = alignedBlock.Clone()
			} else {
				gocv.Vconcat(alignedMSSImage, alignedBlock, &alignedMSSImage)
				alignedBlock.Close()
			}

			panBlock.Close()
			mssBlock.Close()
		}

		r.registeredImages[band] = alignedMSSImage
	}

	r.mssToRaw(alignedMssData, "mss.raw")

	return nil
}

func (r *Registrator) processBlock(panBlock, mssBlock gocv.Mat) gocv.Mat {
	pan := gocv.NewMat()
	mss := gocv.NewMat()

	panBlock.ConvertTo(&pan, gocv.MatTypeCV32FC1)
	defer pan.Close()
	mssBlock.ConvertTo(&mss, gocv.MatTypeCV32FC1)
	defer mss.Close()

	hann := gocv.NewMat()
	shift, response := gocv.PhaseCorrelate(pan, mss, hann)
	hann.Close()

	dx := shift.X
	dy := shift.Y
	log.Printf("Block shift: dx = %f, dy = %f. response = %f \n", dx, dy, response)

	//  cv::Mat translationMatrix = (cv::Mat_<double>(2, 3) << 1, 0, shift.x, 0, 1, shift.y);
	translationMat := gocv.NewMatWithSize(2, 3, gocv.MatTypeCV32F)
	translationMat.SetFloatAt(0, 0, 1)
	translationMat.SetFloatAt(0, 1, 0)
	translationMat.SetFloatAt(0, 2, shift.X)
	translationMat.SetFloatAt(1, 0, 0)
	translationMat.SetFloatAt(1, 1, 1)
	translationMat.SetFloatAt(1, 2, shift.Y)

	alignedBlock := gocv.NewMat()
	gocv.WarpAffine(mss, &alignedBlock, translationMat, image.Pt(panBlock.Size()[0], panBlock.Size()[1]))

	translationMat.Close()
	alignedBlock.ConvertTo(&alignedBlock, gocv.MatTypeCV16U)

	return alignedBlock
}

func (r *Registrator) panToTiff(panImage gocv.Mat, filePath string) error {
	return nil
}

func (r *Registrator) mssToTiff(registeredImages [4]gocv.Mat, filePath string) error {
	// 创建合并后的图像（RGBIR）
	rgbirImage := gocv.NewMatWithSize(r.PanHeight, r.PanWidth, gocv.MatTypeCV16UC4) // 4通道，16位

	for y := 0; y < r.PanHeight; y++ {
		for x := 0; x < r.PanWidth; x++ {
			r := registeredImages[0].GetShortAt(y, x)
			g := registeredImages[1].GetShortAt(y, x)
			b := registeredImages[2].GetShortAt(y, x)
			ir := registeredImages[3].GetShortAt(y, x)
			rgbirImage.SetShortAt(y, x*4+0, r)
			rgbirImage.SetShortAt(y, x*4+1, g)
			rgbirImage.SetShortAt(y, x*4+2, b)
			rgbirImage.SetShortAt(y, x*4+3, ir)
		}
	}

	// 将合并后的图像保存为TIFF文件
	fileName := "registered_rgbir.tiff"
	tiffFile, err := os.Create(fileName)
	if err != nil {
		fmt.Println("Error creating TIFF file:", err)
		return err
	}
	defer tiffFile.Close()

	// 使用tiff库保存图像
	img, err := rgbirImage.ToImage()
	if err != nil {
		fmt.Println("Error converting Mat to image:", err)
		return err
	}
	if err := tiff.Encode(tiffFile, img, nil); err != nil {
		fmt.Println("Error encoding TIFF file:", err)
		return err
	}

	fmt.Println("Saved", fileName)
	return nil
}

func (r *Registrator) mssToRaw(mssData [][]byte, filePath string) error {
	f, err := os.OpenFile("mss.RAW", os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0777)
	if err != nil {
		return err
	}
	w := bufio.NewWriter(f)
	for row := 0; row < r.PanHeight; row++ {
		w.Write(mssData[0][row*r.PanWidth*PixelBytes : (row+1)*r.PanWidth*PixelBytes])
		w.Write(mssData[1][row*r.PanWidth*PixelBytes : (row+1)*r.PanWidth*PixelBytes])
		w.Write(mssData[2][row*r.PanWidth*PixelBytes : (row+1)*r.PanWidth*PixelBytes])
		w.Write(mssData[3][row*r.PanWidth*PixelBytes : (row+1)*r.PanWidth*PixelBytes])
	}

	return nil
}

func (r *Registrator) msToRaw(mssData []byte, filePath string) error {
	f, err := os.OpenFile(filePath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0777)
	if err != nil {
		return err
	}
	w := bufio.NewWriter(f)
	w.Write(mssData)

	return nil
}