link

type DurableChannel interface {
	Send(*v1.DurableTaskRequest) error
	Recv() (*v1.DurableTaskResponse, error)
	Close() error
}

type Link interface {
	// Open registers a worker for the tenant and adds opts.Actions to it before returning, so a
	// registration is never observable with an empty action set.
	Open(ctx context.Context, tenantId uuid.UUID, opts OpenOpts) (Registration, error)
}

type OpenOpts struct {
	Actions    []string
	SlotConfig map[string]int32
	Labels     map[string]interface{}
}

type Registration interface {
	// WorkerId is the engine worker id backing this registration.
	WorkerId() string

	// Actions starts the action stream. May be called once. The channels close when ctx is
	// cancelled, the registration is closed, or the link fails permanently, in which case the
	// failure is reported on the error channel.
	Actions(ctx context.Context) (<-chan *contracts.AssignedAction, <-chan error, error)

	// PutWorkflow registers or updates one namespaced workflow and returns the action ids its
	// tasks derive, normalized the way the engine stores them. It does not touch the worker's
	// action set: the caller adds the derived ids with AddActions.
	PutWorkflow(ctx context.Context, wf *v1.CreateWorkflowVersionRequest) ([]string, error)

	// AddActions adds ids to the worker's action set. Ids already in the set are ignored. A
	// link may apply the delta asynchronously; Flush waits for it.
	AddActions(ctx context.Context, ids []string) error

	// RemoveActions removes ids from the worker's action set. Ids not in the set are ignored. A
	// link may apply the delta asynchronously; Flush waits for it.
	RemoveActions(ctx context.Context, ids []string) error

	// Flush blocks until every delta issued so far has been applied by the engine and reports
	// the failure, if any. Links that apply deltas synchronously return immediately.
	Flush(ctx context.Context) error

	// SendStepActionEvent reports task progress (STARTED, COMPLETED, FAILED, CANCELLED).
	SendStepActionEvent(ctx context.Context, ev *contracts.StepActionEvent) error

	// OpenDurable opens the request/response pipe of one durable invocation.
	OpenDurable(ctx context.Context, taskExternalId string, invocation int32) (DurableChannel, error)

	// Close ends the registration; the engine deactivates the worker.
	Close() error
}

type TenantReleaser interface {
	ReleaseTenant(tenantId uuid.UUID)
}