const (
	// ExportResponseManifestDesc is a key for the map returned from Exporter.Finalize.
	// The map value is a JSON string of an OCI desciptor of a manifest.
	ExporterResponseManifestDesc = "cache.manifest"
)

type CacheType int

const (
	NotSet CacheType = iota
	ManifestList
	ImageManifest
)

type Config struct {
	Compression compression.Config
}

type DistributionSourceLabelSetter interface {
	SetDistributionSourceLabel(context.Context, digest.Digest) error
	SetDistributionSourceAnnotation(desc ocispecs.Descriptor) ocispecs.Descriptor
}

type ExportableCache struct {
	// This cache describes two distinct styles of exportable cache, one is an Index (or Manifest List) of blobs,
	// or as an artifact using the OCI image manifest format.
	ExportedManifest ocispecs.Manifest
	ExportedIndex    ocispecs.Index
	CacheType        CacheType
	OCI              bool
}

type Exporter interface {
	solver.CacheExporterTarget
	// Name uniquely identifies the exporter
	Name() string
	// Finalize finalizes and return metadata that are returned to the client
	// e.g. ExporterResponseManifestDesc
	Finalize(ctx context.Context) (map[string]string, error)
	Config() Config
}

type Importer interface {
	Resolve(ctx context.Context, desc ocispecs.Descriptor, id string, w worker.Worker) (solver.CacheManager, error)
}

type ResolveCacheExporterFunc func(ctx context.Context, g session.Group, attrs map[string]string) (Exporter, error)

type ResolveCacheImporterFunc func(ctx context.Context, g session.Group, attrs map[string]string) (Importer, ocispecs.Descriptor, error)