package ports

import "context"

// StreamOffsetStore persists the last successfully processed Redis
// Stream entry id per consumer label. 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. The label is the short logical identifier of
// the consumer (e.g. `start_jobs`, `stop_jobs`), not the full stream
// name; it stays stable when the underlying stream key is renamed.
type StreamOffsetStore interface {
	// Load returns the last processed entry id for the consumer
	// labelled 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 the
	// consumer labelled stream. Implementations overwrite any previous
	// value unconditionally.
	Save(ctx context.Context, stream, entryID string) error
}