Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/repository/image_storage_s3.go

@@ -0,0 +1,80 @@
+package repository
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/aws/aws-sdk-go-v2/service/s3"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/servertiming"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+)
+
+// S3ImageStorage 用 S3 兼容对象存储实现 service.ImageStorage。
+type S3ImageStorage struct {
+	client        *s3.Client
+	bucket        string
+	publicBaseURL string
+	presignExpiry time.Duration
+}
+
+var _ service.ImageStorage = (*S3ImageStorage)(nil)
+
+// NewS3ImageStorage 依据配置构造 S3 图片存储（调用方应先确认 cfg.Active()）。
+func NewS3ImageStorage(ctx context.Context, cfg *config.ImageStorageConfig) (*S3ImageStorage, error) {
+	client, err := newS3Client(ctx, s3ClientParams{
+		Endpoint:        cfg.Endpoint,
+		Region:          cfg.Region,
+		AccessKeyID:     cfg.AccessKeyID,
+		SecretAccessKey: cfg.SecretAccessKey,
+		ForcePathStyle:  cfg.ForcePathStyle,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	expiry := time.Duration(cfg.PresignExpiry) * time.Hour
+	if expiry <= 0 {
+		expiry = 24 * time.Hour
+	}
+
+	return &S3ImageStorage{
+		client:        client,
+		bucket:        cfg.Bucket,
+		publicBaseURL: strings.TrimRight(cfg.PublicBaseURL, "/"),
+		presignExpiry: expiry,
+	}, nil
+}
+
+// Save 上传图片字节，返回可访问 URL：配了 public_base_url 则返回公开直链，否则返回 presigned 临时链接。
+func (s *S3ImageStorage) Save(ctx context.Context, key, contentType string, data []byte) (string, error) {
+	finish := servertiming.ObserveDependency(ctx, "s3")
+	_, err := s.client.PutObject(ctx, &s3.PutObjectInput{
+		Bucket:      &s.bucket,
+		Key:         &key,
+		Body:        bytes.NewReader(data),
+		ContentType: &contentType,
+	})
+	finish()
+	if err != nil {
+		return "", fmt.Errorf("S3 PutObject: %w", err)
+	}
+
+	if s.publicBaseURL != "" {
+		return s.publicBaseURL + "/" + strings.TrimLeft(key, "/"), nil
+	}
+
+	presignClient := s3.NewPresignClient(s.client)
+	result, err := presignClient.PresignGetObject(ctx, &s3.GetObjectInput{
+		Bucket: &s.bucket,
+		Key:    &key,
+	}, s3.WithPresignExpires(s.presignExpiry))
+	if err != nil {
+		return "", fmt.Errorf("presign url: %w", err)
+	}
+	return result.URL, nil
+}