Add S3 configuration and presigned URL logic for file upload and download

app/internal/logic/downloadpresignedurllogic.go

@@ -2,10 +2,12 @@ package logic
 
 import (
 	"context"
+	"time"
 
 	"git.cialloo.com/CiallooWeb/Blog/app/internal/svc"
 	"git.cialloo.com/CiallooWeb/Blog/app/internal/types"
 
+	"github.com/aws/aws-sdk-go-v2/service/s3"
 	"github.com/zeromicro/go-zero/core/logx"
 )
 
@@ -25,7 +27,29 @@ func NewDownloadPresignedURLLogic(ctx context.Context, svcCtx *svc.ServiceContex
 }
 
 func (l *DownloadPresignedURLLogic) DownloadPresignedURL(req *types.DownloadPresignedURLReq) (resp *types.DownloadPresignedURLResp, err error) {
-	// todo: add your logic here and delete this line
+	// Calculate expiration time
+	expiration := time.Duration(l.svcCtx.Config.S3.PresignedURLExpiration) * time.Second
+	expireAt := time.Now().Add(expiration).Unix()
 
-	return
+	// Create presigned client
+	presignClient := s3.NewPresignClient(l.svcCtx.S3Client)
+
+	// Generate presigned GET URL
+	getObjectInput := &s3.GetObjectInput{
+		Bucket: &l.svcCtx.Config.S3.Bucket,
+		Key:    &req.File_key,
+	}
+
+	presignedReq, err := presignClient.PresignGetObject(l.ctx, getObjectInput, func(opts *s3.PresignOptions) {
+		opts.Expires = expiration
+	})
+	if err != nil {
+		l.Errorf("Failed to generate presigned URL: %v", err)
+		return nil, err
+	}
+
+	return &types.DownloadPresignedURLResp{
+		Url:       presignedReq.URL,
+		Expire_at: expireAt,
+	}, nil
 }