46 lines
1.2 KiB
Go
46 lines
1.2 KiB
Go
package handler
|
|
|
|
import (
|
|
"encoding/base64"
|
|
"errors"
|
|
"strings"
|
|
"unicode/utf8"
|
|
)
|
|
|
|
const (
|
|
maxTextMessageLength = 2000
|
|
maxImageMessageSize = 5 * 1024 * 1024
|
|
)
|
|
|
|
func validateMessageContent(messageType, content string) (string, error) {
|
|
switch messageType {
|
|
case "text":
|
|
content = strings.TrimSpace(content)
|
|
if content == "" {
|
|
return "", errors.New("消息内容不能为空")
|
|
}
|
|
if utf8.RuneCountInString(content) > maxTextMessageLength {
|
|
return "", errors.New("单条文本消息不能超过 2000 字")
|
|
}
|
|
return content, nil
|
|
case "image":
|
|
parts := strings.SplitN(content, ",", 2)
|
|
if len(parts) != 2 {
|
|
return "", errors.New("图片格式无效")
|
|
}
|
|
if parts[0] != "data:image/jpeg;base64" && parts[0] != "data:image/png;base64" && parts[0] != "data:image/gif;base64" {
|
|
return "", errors.New("仅支持 jpg、png、gif 图片")
|
|
}
|
|
bytes, err := base64.StdEncoding.DecodeString(parts[1])
|
|
if err != nil || len(bytes) == 0 {
|
|
return "", errors.New("图片内容无效")
|
|
}
|
|
if len(bytes) > maxImageMessageSize {
|
|
return "", errors.New("图片不能超过 5 MB")
|
|
}
|
|
return content, nil
|
|
default:
|
|
return "", errors.New("不支持的消息类型")
|
|
}
|
|
}
|