feat: 重构消息处理模块，引入统一的消息接口和类型安全的消息解析

util/picture.go

@@ -0,0 +1,166 @@
+package util
+
+import (
+	"errors"
+	"image"
+	"image/jpeg"
+	"image/png"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/nfnt/resize"
+)
+
+func ResizeImage(imagePath string, width int, height int) (outputPath string, err error) {
+	// 打开源图片文件
+	file, err := os.Open(imagePath)
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+
+	// 解码图片
+	var img image.Image
+	var decodeErr error
+
+	ext := strings.ToLower(filepath.Ext(imagePath))
+	switch ext {
+	case ".jpg", ".jpeg":
+		img, decodeErr = jpeg.Decode(file)
+	case ".png":
+		img, decodeErr = png.Decode(file)
+	default:
+		return "", errors.New("unsupported image format")
+	}
+
+	if decodeErr != nil {
+		return "", decodeErr
+	}
+
+	// 调整图片大小
+	resized := resize.Resize(uint(width), uint(height), img, resize.Lanczos3)
+
+	// 创建输出文件
+	outputPath = strings.TrimSuffix(imagePath, ext) + "_resized" + ext
+	out, err := os.Create(outputPath)
+	if err != nil {
+		return "", err
+	}
+	defer out.Close()
+
+	// 根据文件扩展名选择编码方式
+	switch ext {
+	case ".jpg", ".jpeg":
+		return outputPath, jpeg.Encode(out, resized, nil)
+	case ".png":
+		return outputPath, png.Encode(out, resized)
+	default:
+		return "", errors.New("unsupported image format")
+	}
+}
+
+// ResizeImageByMaxWidth 按最大宽度缩放图片，保持宽高比
+func ResizeImageByMaxWidth(imagePath string, maxWidth uint) (outputPath string, err error) {
+	// 打开源图片文件
+	file, err := os.Open(imagePath)
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+
+	// 解码图片
+	var img image.Image
+	var decodeErr error
+
+	ext := strings.ToLower(filepath.Ext(imagePath))
+	switch ext {
+	case ".jpg", ".jpeg":
+		img, decodeErr = jpeg.Decode(file)
+	case ".png":
+		img, decodeErr = png.Decode(file)
+	default:
+		return "", errors.New("unsupported image format")
+	}
+
+	if decodeErr != nil {
+		return "", decodeErr
+	}
+
+	// 计算缩放后的尺寸，保持宽高比
+	// 传入0作为高度，resize包会自动计算等比例的高度
+	resized := resize.Resize(maxWidth, 0, img, resize.Lanczos3)
+
+	// 创建输出文件
+	outputPath = strings.TrimSuffix(imagePath, ext) + "_resized" + ext
+	out, err := os.Create(outputPath)
+	if err != nil {
+		return "", err
+	}
+	defer out.Close()
+
+	// 根据文件扩展名选择编码方式
+	switch ext {
+	case ".jpg", ".jpeg":
+		return outputPath, jpeg.Encode(out, resized, nil)
+	case ".png":
+		return outputPath, png.Encode(out, resized)
+	default:
+		return "", errors.New("unsupported image format")
+	}
+}
+
+// ResizeImageByMaxHeight 按最大高度缩放图片，保持宽高比
+func ResizeImageByMaxHeight(imagePath string, maxHeight uint) (outputPath string, err error) {
+	// 打开源图片文件
+	file, err := os.Open(imagePath)
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+
+	// 解码图片
+	var img image.Image
+	var decodeErr error
+
+	ext := strings.ToLower(filepath.Ext(imagePath))
+	switch ext {
+	case ".jpg", ".jpeg":
+		img, decodeErr = jpeg.Decode(file)
+	case ".png":
+		img, decodeErr = png.Decode(file)
+	default:
+		return "", errors.New("unsupported image format")
+	}
+
+	if decodeErr != nil {
+		return "", decodeErr
+	}
+
+	// 计算缩放后的尺寸，保持宽高比
+	// 传入0作为宽度，resize包会自动计算等比例的宽度
+	resized := resize.Resize(0, maxHeight, img, resize.Lanczos3)
+
+	// 创建输出文件
+	outputPath = strings.TrimSuffix(imagePath, ext) + "_resized" + ext
+	out, err := os.Create(outputPath)
+	if err != nil {
+		return "", err
+	}
+	defer out.Close()
+
+	// 根据文件扩展名选择编码方式
+	switch ext {
+	case ".jpg", ".jpeg":
+		return outputPath, jpeg.Encode(out, resized, nil)
+	case ".png":
+		return outputPath, png.Encode(out, resized)
+	default:
+		return "", errors.New("unsupported image format")
+	}
+}
+
+func GetResizedIamgePathByOrgPath(orgPath string) string {
+	ext := strings.ToLower(filepath.Ext(orgPath))
+	return strings.TrimSuffix(orgPath, ext) + "_resized" + ext
+}

util/url.go

@@ -36,11 +36,10 @@ func normalizeURL(rawURL string) string {
 	return u.String()
 }
 
-func DownloadFile(url string, filepath string) error {
+func DownloadFile(url string, filepath string) (err error) {
 	// 发送 HTTP GET 请求
 	// resp, err := http.Get(url)
 	var resp *http.Response
-	var err error
 	var maxRetry = 100
 	var retry = 0
 	for resp, err = http.Get(url); err != nil && retry < maxRetry; resp, err = http.Get(url) {