package backend

import (
	"context"
	"errors"
)

// Trillian is the production backend wrapper that will talk to a Trillian
// log server. It is intentionally a stub for now — ADR-0005 lists Trillian
// deployment + keys as a follow-up subtask. Once that lands, this struct
// gains a Trillian LogClient and translates Submit() into
// trillian.QueueLeaves + GetInclusionProofByHash (or the current API shape
// at the time of integration).
//
// Keeping the stub here lets the httpapi + wiring layer treat the two
// backends uniformly and prevents the server from accidentally shipping
// without a prod backend hook.
type Trillian struct {
	// Endpoint will later hold the Trillian LogServer address, e.g.
	// "trillian-log.agent-trust.svc.cluster.local:8090".
	Endpoint string
	// LogID will later hold the Trillian tree id this service writes to.
	LogID int64
}

// Submit returns ErrTrillianUnavailable until the Trillian deployment ships.
// Config loading, auth plumbing and the actual LogClient wiring belong in
// the follow-up Trillian subtask.
func (t Trillian) Submit(_ context.Context, _ Envelope, _ string) (Receipt, bool, error) {
	return Receipt{}, false, ErrTrillianUnavailable
}

// ErrTrillianUnavailable signals that the prod backend is not wired yet.
// Translated to HTTP 503 by the httpapi layer.
var ErrTrillianUnavailable = errors.New("transparency-log: trillian backend not deployed")