package utils

import (
	"github.com/disintegration/imaging"
	"image"
	"image/png"
	"log"
	"os"
	"path/filepath"
	"strings"
)

func ImageResize(imageSrc string, maxDimension int) (string, error) {
	file, err := os.Open(imageSrc)
	if err != nil {
		log.Printf("打开图片失败: %v", err)
		return "", err
	}
	defer file.Close()

	// 解码图片
	img, _, err := image.Decode(file)
	if err != nil {
		log.Printf("解码图片失败: %v", err)
		return "", err
	}

	// 调整图片大小
	resizedImg := imaging.Thumbnail(img, maxDimension, maxDimension, imaging.Lanczos)

	// 获取输入文件的扩展名
	ext := filepath.Ext(imageSrc)
	ext = strings.ToLower(ext)

	// 生成输出文件名
	outputFileName := strings.TrimSuffix(imageSrc, ext) + "_resized" + ext
	outFile, err := os.Create(outputFileName)
	if err != nil {
		log.Printf("创建输出文件失败: %v", err)
		return "", err
	}
	defer outFile.Close()

	// 根据文件扩展名选择编码格式
	switch ext {
	case ".jpg", ".jpeg":
		err = imaging.Encode(outFile, resizedImg, imaging.JPEG, imaging.JPEGQuality(75))
	case ".png":
		err = imaging.Encode(outFile, resizedImg, imaging.PNG, imaging.PNGCompressionLevel(png.BestCompression))
	//case ".gif":
	//	err = imaging.Encode(outFile, resizedImg, imaging.GIF, imaging.GIFNumColors(DW))
	default:
		log.Printf("不支持的图片格式: %s", ext)
		return "", err
	}

	if err != nil {
		log.Printf("编码图片失败: %v", err)
		return "", err
	}

	log.Println("图片压缩并保存成功:", outputFileName)
	return outputFileName, nil
}