weijuesen
107 lines
3.2 KiB
Go
107 lines
3.2 KiB
Go
package handler
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import (
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"crypto/rand"
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"encoding/hex"
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"errors"
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"fmt"
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"net/http"
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"path/filepath"
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"strings"
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"time"
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"silk-server-go/internal/middleware"
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"silk-server-go/internal/service"
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"github.com/gin-gonic/gin"
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"gorm.io/gorm"
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)
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// maxImageSize 知识库图片大小上限（5MB）
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const maxImageSize = 5 << 20
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// imageContentType 根据扩展名返回图片 Content-Type
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func imageContentType(ext string) (string, bool) {
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switch strings.ToLower(ext) {
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case ".jpg", ".jpeg":
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return "image/jpeg", true
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case ".png":
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return "image/png", true
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case ".webp":
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return "image/webp", true
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}
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return "", false
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}
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// validateImageFile 校验图片文件名扩展名与大小
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func validateImageFile(filename string, size int64) error {
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if size <= 0 || size > maxImageSize {
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return errors.New("图片大小需在 1B~5MB 之间")
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}
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ext := strings.ToLower(filepath.Ext(filename))
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if _, ok := imageContentType(ext); !ok {
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return errors.New("仅支持 jpg/jpeg/png/webp 图片")
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}
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return nil
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}
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// buildObjectKey 生成 <prefix>/<日期>/<随机>.ext 的对象键
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func buildObjectKey(prefix, filename string) (string, string, error) {
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ext := strings.ToLower(filepath.Ext(filename))
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if _, ok := imageContentType(ext); !ok {
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return "", "", errors.New("仅支持 jpg/jpeg/png/webp 图片")
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}
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buf := make([]byte, 8)
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if _, err := rand.Read(buf); err != nil {
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return "", "", err
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}
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date := time.Now().Format("20060102")
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key := fmt.Sprintf("%s/%s/%s%s", prefix, date, hex.EncodeToString(buf), ext)
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return key, ext, nil
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}
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// buildImageKey 生成 knowledge/<日期>/<随机>.ext 的对象键
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func buildImageKey(filename string) (string, string, error) {
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return buildObjectKey("knowledge", filename)
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}
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// uploadKnowledgeImage 上传知识库图片（multipart 字段名 file）
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func uploadKnowledgeImage(s3 *service.S3Service, bucket string) gin.HandlerFunc {
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return func(c *gin.Context) {
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file, header, err := c.Request.FormFile("file")
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if err != nil {
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c.JSON(http.StatusBadRequest, gin.H{"error": "请选择图片文件（字段名 file）"})
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return
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}
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defer file.Close()
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if err := validateImageFile(header.Filename, header.Size); err != nil {
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c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
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return
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}
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key, ext, err := buildImageKey(header.Filename)
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if err != nil {
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c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
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return
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}
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contentType, _ := imageContentType(ext)
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if err := s3.EnsureBucket(bucket); err != nil {
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c.JSON(http.StatusInternalServerError, gin.H{"error": "图片存储不可用: " + err.Error()})
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return
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}
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if err := s3.UploadImage(bucket, key, file, contentType); err != nil {
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c.JSON(http.StatusInternalServerError, gin.H{"error": "图片上传失败: " + err.Error()})
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return
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}
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url := fmt.Sprintf("%s/%s/%s", s3.Endpoint(), bucket, key)
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c.JSON(http.StatusOK, gin.H{"url": url, "name": header.Filename, "size": header.Size})
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}
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}
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// uploadImageRoute 在知识库路由组中注册图片上传（由 RegisterKnowledgeRoutes 调用）
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func registerKnowledgeImageRoute(rg *gin.RouterGroup, db *gorm.DB, s3 *service.S3Service, bucket string) {
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rg.POST("/knowledge/images", middleware.RequirePermission(db, "knowledge:write"), uploadKnowledgeImage(s3, bucket))
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}
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