package outbox

import (
	"context"
	"time"
)

type Status string

const (
	StatusPending    Status = "pending"
	StatusProcessing Status = "processing"
	StatusCompleted  Status = "completed"
	StatusFailed     Status = "failed"
)

type Event struct {
	Seq            int64
	EventType      string
	PartitionKey   string
	IdempotencyKey *string
	Payload        []byte
	CreatedAt      time.Time
}

type Task struct {
	Seq          int64
	Consumer     string
	PartitionKey string
	Status       Status
	ProcessAfter *time.Time
	LeaseUntil   *time.Time
	CompletedAt  *time.Time
	Attempts     int
}

type EmitOptions struct {
	ProcessAfter   *time.Time
	IdempotencyKey *string
}

// Emitter writes events to the outbox. Called within a business transaction.
type Emitter interface {
	Emit(ctx context.Context, eventType, partitionKey string, payload []byte, opts *EmitOptions) error
}

// Claimed pairs an event with its task.
type Claimed struct {
	Event Event
	Task  Task
}

// Consumer claims and completes tasks. Used by the worker.
type Consumer interface {
	Claim(ctx context.Context, consumer string, leaseDuration time.Duration, limit int) ([]Claimed, error)

	Complete(ctx context.Context, seq int64, consumer string) error

	// Nack requeues a task for retry. If retryAfter is non-nil,
	// the task won't be claimed again until after that time.
	Nack(ctx context.Context, seq int64, consumer string, retryAfter *time.Time) error

	// Fail permanently marks a task as failed, stopping all future attempts.
	Fail(ctx context.Context, seq int64, consumer string) error
}