package imageproc

import (
	"fmt"
	"time"

	"github.com/airbusgeo/godal"
	log "github.com/sirupsen/logrus"
)

func calculateProj(topLeftX, topLeftY, width, height, resolution float64) string {
	// 计算图像的地理范围
	bottomRightX := topLeftX + float64(width)*resolution
	bottomRightY := topLeftY + float64(height)*resolution

	// 根据地理范围和分辨率选择适当的投影信息
	// 这里只是一个示例，你需要根据实际情况选择合适的投影系统和参数
	projection := fmt.Sprintf(`PROJCS["Custom Projection",
	GEOGCS["WGS 84",
		DATUM["WGS_1984",
			SPHEROID["WGS 84",6378137,298.257223563,
				AUTHORITY["EPSG","7030"]],
			AUTHORITY["EPSG","6326"]],
		PRIMEM["Greenwich",0,
			AUTHORITY["EPSG","8901"]],
		UNIT["degree",0.0174532925199433,
			AUTHORITY["EPSG","9122"]],
		AUTHORITY["EPSG","4326"]],
	PROJECTION["Transverse_Mercator"],
	PARAMETER["latitude_of_origin",0],
	PARAMETER["central_meridian",%f],
	PARAMETER["scale_factor",0.9996],
	PARAMETER["false_easting",%f],
	PARAMETER["false_northing",0],
	UNIT["metre",1,
		AUTHORITY["EPSG","9001"]],
	AXIS["Easting",EAST],
	AXIS["Northing",NORTH]]`,
		(topLeftX+bottomRightX)/2, (topLeftY+bottomRightY)/2)

	projection = `PROJCS["WGS 84 / UTM zone 51N",
	GEOGCS["WGS 84",
		DATUM["WGS_1984",
			SPHEROID["WGS 84",6378137,298.257223563,
				AUTHORITY["EPSG","7030"]],
			AUTHORITY["EPSG","6326"]],
		PRIMEM["Greenwich",0,
			AUTHORITY["EPSG","8901"]],
		UNIT["degree",0.0174532925199433,
			AUTHORITY["EPSG","9122"]],
		AUTHORITY["EPSG","4326"]],
	PROJECTION["Transverse_Mercator"],
	PARAMETER["latitude_of_origin",0],
	PARAMETER["central_meridian",123],
	PARAMETER["scale_factor",0.9996],
	PARAMETER["false_easting",500000],
	PARAMETER["false_northing",0],
	UNIT["metre",1,
		AUTHORITY["EPSG","9001"]],
	AXIS["Easting",EAST],
	AXIS["Northing",NORTH],
	AUTHORITY["EPSG","32651"]]`

	// 输出投影信息
	return projection
}

func setGeoTransform(ds *godal.Dataset, topLeftX, topLeftY, width, height, resolution float64) {
	// 设置地理变换（假设左上角坐标为(0,0)，PAN每个像素分辨率为1.2米）
	geotransform := [6]float64{
		0,           // top left x
		resolution,  // w-e pixel resolution
		0,           // rotation, 0 if image is "north up"
		0,           // top left y
		0,           // rotation, 0 if image is "north up"
		-resolution, // n-s pixel resolution (negative value)
	}
	err := ds.SetGeoTransform(geotransform)
	if err != nil {
		log.Errorf("Failed to set GeoTransform: %v", err)
	}

	// 设置投影信息（WGS84）
	err = ds.SetProjection(calculateProj(topLeftX, topLeftY, width, height, resolution))
	if err != nil {
		log.Errorf("Failed to set projection: %v", err)
	}

	// 设置一些常见的元数据（可选）
	ds.SetMetadata("TIFFTAG_DATETIME", time.Now().String())
	ds.SetMetadata("TIFFTAG_SOFTWARE", "StarWiz-SJY01-IMAGE-PROC")
}