package diplomail

import (
	"context"
	"time"

	"galaxy/backend/internal/config"

	"github.com/google/uuid"
	"go.uber.org/zap"
)

// Deps aggregates every collaborator the diplomail Service depends on.
//
// Store and Memberships are required. Logger and Now default to
// zap.NewNop / time.Now when nil. Notification falls back to a no-op
// publisher so unit tests can construct a Service with only the
// required collaborators populated.
type Deps struct {
	Store        *Store
	Memberships  MembershipLookup
	Notification NotificationPublisher
	Config       config.DiplomailConfig
	Logger       *zap.Logger
	Now          func() time.Time
}

// ActiveMembership is the slim view of a single (user, game) roster
// row the diplomail package needs at send time: it confirms the
// participant is active in the game and captures the snapshot fields
// (`game_name`, `user_name`, `race_name`) that we persist on each new
// message / recipient row.
type ActiveMembership struct {
	UserID   uuid.UUID
	GameID   uuid.UUID
	GameName string
	UserName string
	RaceName string
}

// MembershipLookup is the read-only surface diplomail uses to verify
// "is this user an active member of this game" and to snapshot the
// roster metadata. The canonical implementation in `cmd/backend/main`
// adapts the `*lobby.Service` membership cache to this interface.
//
// Implementations must return ErrNotFound (the diplomail sentinel)
// when the user is not an active member of the game; the service
// boundary maps that to 403 forbidden.
type MembershipLookup interface {
	GetActiveMembership(ctx context.Context, gameID, userID uuid.UUID) (ActiveMembership, error)
}

// NotificationPublisher is the outbound surface diplomail uses to
// emit the `diplomail.message.received` push event. The canonical
// implementation in `cmd/backend/main` adapts the notification.Service
// the same way it adapts `lobby.NotificationPublisher`; tests pass
// the no-op publisher below to avoid wiring the dispatcher.
type NotificationPublisher interface {
	PublishDiplomailEvent(ctx context.Context, ev DiplomailNotification) error
}

// DiplomailNotification is the open shape carried by a per-recipient
// push intent. The struct lives in the diplomail package so the
// producer vocabulary stays here; the publisher adapter translates it
// into a `notification.Intent` at the wiring boundary.
type DiplomailNotification struct {
	Kind           string
	IdempotencyKey string
	Recipient      uuid.UUID
	Payload        map[string]any
}

// NewNoopNotificationPublisher returns a publisher that logs every
// call at debug level and returns nil. Used by unit tests and as the
// fallback inside NewService when callers leave Deps.Notification nil.
func NewNoopNotificationPublisher(logger *zap.Logger) NotificationPublisher {
	if logger == nil {
		logger = zap.NewNop()
	}
	return &noopNotificationPublisher{logger: logger.Named("diplomail.notify.noop")}
}

type noopNotificationPublisher struct {
	logger *zap.Logger
}

func (p *noopNotificationPublisher) PublishDiplomailEvent(_ context.Context, ev DiplomailNotification) error {
	p.logger.Debug("noop notification",
		zap.String("kind", ev.Kind),
		zap.String("idempotency_key", ev.IdempotencyKey),
		zap.String("recipient", ev.Recipient.String()),
	)
	return nil
}