package ports

import "context"

// StreamOffsetStore persists the last successfully processed Redis
// Stream entry id per stream. Workers call Load on startup to resume
// from the persisted offset and Save after every successful message
// handling so the next iteration advances past the just-processed
// entry. Lobby uses one logical store with the per-stream key encoded
// inside the implementation.
type StreamOffsetStore interface {
	// Load returns the last processed entry id for stream when one is
	// stored. The boolean return reports whether a value was present;
	// implementations must not return an error for a missing key.
	Load(ctx context.Context, stream string) (entryID string, found bool, err error)

	// Save stores entryID as the new last processed offset for stream.
	// Implementations overwrite any previous value unconditionally.
	Save(ctx context.Context, stream, entryID string) error
}