transfer

type AuthChallenge struct {
	Realm   string
	Service string
	Scope   string
}

type Blob struct {
	Digest string // sha256:...
	Size   int64

	// From enables cross-repository blob mounting (upload only).
	// When set, the upload will first attempt to mount the blob from this source
	// repository instead of uploading the data. This is a Docker Registry v2 API
	// feature that avoids re-uploading blobs that already exist elsewhere.
	//
	// Example: From="library/source-model" will add ?mount=<digest>&from=library/source-model
	// to the POST /blobs/uploads/ request. If the registry returns 201 Created,
	// the blob was mounted successfully and no upload is needed.
	//
	// See: https://distribution.github.io/distribution/spec/api/#cross-repository-blob-mount
	From string
}

type DownloadOptions struct {
	Blobs           []Blob                                                             // Blobs to download
	BaseURL         string                                                             // Registry base URL
	DestDir         string                                                             // Destination directory for blobs
	Repository      string                                                             // Repository path for blob URLs (e.g., "library/model")
	Concurrency     int                                                                // Max parallel downloads (default DefaultDownloadConcurrency)
	BodyConcurrency int                                                                // Max simultaneous body-bearing transfers; 0 or negative serializes (capacity 1)
	Progress        func(completed, total int64)                                       // Progress callback (optional)
	Client          *http.Client                                                       // HTTP client (optional, uses default)
	Token           string                                                             // Auth token (optional)
	GetToken        func(ctx context.Context, challenge AuthChallenge) (string, error) // Token refresh callback
	Logger          *slog.Logger                                                       // Optional structured logger
	UserAgent       string                                                             // User-Agent header (optional, has default)
	StallTimeout    time.Duration                                                      // Timeout for stall detection (default 10s)
}

type UploadOptions struct {
	Blobs           []Blob                                                             // Blobs to upload
	BaseURL         string                                                             // Registry base URL
	SrcDir          string                                                             // Source directory containing blobs
	Concurrency     int                                                                // Max parallel uploads (default DefaultUploadConcurrency)
	BodyConcurrency int                                                                // Max simultaneous body-bearing transfers; 0 or negative serializes (capacity 1)
	Progress        func(completed, total int64)                                       // Progress callback (optional)
	Client          *http.Client                                                       // HTTP client (optional, uses default)
	Token           string                                                             // Auth token (optional)
	GetToken        func(ctx context.Context, challenge AuthChallenge) (string, error) // Token refresh callback
	Logger          *slog.Logger                                                       // Optional structured logger
	UserAgent       string                                                             // User-Agent header (optional, has default)

	// Manifest fields (optional) - if set, manifest is pushed after all blobs complete
	Manifest    []byte // Raw manifest JSON to push
	ManifestRef string // Tag or digest for the manifest (e.g., "latest", "sha256:...")
	Repository  string // Repository path for manifest URL (e.g., "library/model")
}