package agent

import (
	"context"
	"errors"

	rvboxv1 "github.com/rvbox/rvbox/gen/go/rvbox/v1"
	"github.com/rvbox/rvbox/internal/domain"
)

var ErrInvalidEventAck = errors.New("invalid event acknowledgement")

type EventAckStore interface {
	Ack(context.Context, domain.UUID, uint64) error
}

// ApplyEventAck releases only the cumulative, server-confirmed event prefix.
// The spool remains the source of truth if the process stops before this call
// returns; a repeated acknowledgement is intentionally harmless.
func ApplyEventAck(ctx context.Context, store EventAckStore, ack *rvboxv1.EventAck) error {
	if store == nil || ack == nil || ack.GetThroughEventSeq() == 0 {
		return ErrInvalidEventAck
	}
	issue, err := domain.ParseUUIDv7(ack.GetIssueUuid())
	if err != nil {
		return ErrInvalidEventAck
	}
	return store.Ack(ctx, issue, ack.GetThroughEventSeq())
}