support gemini-pro-vision

common/image.go

@@ -12,7 +12,7 @@ import (
 	"strings"
 )
 
-func DecodeBase64ImageData(base64String string) (image.Config, error) {
+func DecodeBase64ImageData(base64String string) (image.Config, string, error) {
 	// 去除base64数据的URL前缀（如果有）
 	if idx := strings.Index(base64String, ","); idx != -1 {
 		base64String = base64String[idx+1:]
@@ -22,20 +22,51 @@ func DecodeBase64ImageData(base64String string) (image.Config, error) {
 	decodedData, err := base64.StdEncoding.DecodeString(base64String)
 	if err != nil {
 		fmt.Println("Error: Failed to decode base64 string")
-		return image.Config{}, err
+		return image.Config{}, "", err
 	}
 
 	// 创建一个bytes.Buffer用于存储解码后的数据
 	reader := bytes.NewReader(decodedData)
-	config, err := getImageConfig(reader)
-	return config, err
+	config, format, err := getImageConfig(reader)
+	return config, format, err
 }
 
-func DecodeUrlImageData(imageUrl string) (image.Config, error) {
+func IsImageUrl(url string) (bool, error) {
+	resp, err := http.Head(url)
+	if err != nil {
+		return false, err
+	}
+	if !strings.HasPrefix(resp.Header.Get("Content-Type"), "image/") {
+		return false, nil
+	}
+	return true, nil
+}
+
+func GetImageFromUrl(url string) (mimeType string, data string, err error) {
+	isImage, err := IsImageUrl(url)
+	if !isImage {
+		return
+	}
+	resp, err := http.Get(url)
+	if err != nil {
+		return
+	}
+	defer resp.Body.Close()
+	buffer := bytes.NewBuffer(nil)
+	_, err = buffer.ReadFrom(resp.Body)
+	if err != nil {
+		return
+	}
+	mimeType = resp.Header.Get("Content-Type")
+	data = base64.StdEncoding.EncodeToString(buffer.Bytes())
+	return
+}
+
+func DecodeUrlImageData(imageUrl string) (image.Config, string, error) {
 	response, err := http.Get(imageUrl)
 	if err != nil {
 		SysLog(fmt.Sprintf("fail to get image from url: %s", err.Error()))
-		return image.Config{}, err
+		return image.Config{}, "", err
 	}
 
 	// 限制读取的字节数，防止下载整个图片
@@ -45,14 +76,14 @@ func DecodeUrlImageData(imageUrl string) (image.Config, error) {
 	//	log.Fatal(err)
 	//}
 	//log.Printf("%x", data)
-	config, err := getImageConfig(limitReader)
+	config, format, err := getImageConfig(limitReader)
 	response.Body.Close()
-	return config, err
+	return config, format, err
 }
 
-func getImageConfig(reader io.Reader) (image.Config, error) {
+func getImageConfig(reader io.Reader) (image.Config, string, error) {
 	// 读取图片的头部信息来获取图片尺寸
-	config, _, err := image.DecodeConfig(reader)
+	config, format, err := image.DecodeConfig(reader)
 	if err != nil {
 		err = errors.New(fmt.Sprintf("fail to decode image config(gif, jpg, png): %s", err.Error()))
 		SysLog(err.Error())
@@ -61,9 +92,10 @@ func getImageConfig(reader io.Reader) (image.Config, error) {
 			err = errors.New(fmt.Sprintf("fail to decode image config(webp): %s", err.Error()))
 			SysLog(err.Error())
 		}
+		format = "webp"
 	}
 	if err != nil {
-		return image.Config{}, err
+		return image.Config{}, "", err
 	}
-	return config, nil
+	return config, format, nil
 }