package app

import (
	"context"
	"fmt"
	"time"

	"gitea.dwysokinski.me/twhelp/core/internal/domain"
)

type PlayerSnapshotRepository interface {
	// Create persists player snapshots in a store (e.g. Postgres).
	// Duplicates are ignored.
	Create(ctx context.Context, params ...domain.CreatePlayerSnapshotParams) error
	ListWithRelations(
		ctx context.Context,
		params domain.ListPlayerSnapshotsParams,
	) (domain.ListPlayerSnapshotsWithRelationsResult, error)
	Delete(ctx context.Context, serverKey string, dateLTE time.Time) error
}

type PlayerSnapshotService struct {
	repo      PlayerSnapshotRepository
	playerSvc *PlayerService
	pub       SnapshotPublisher
}

func NewPlayerSnapshotService(
	repo PlayerSnapshotRepository,
	playerSvc *PlayerService,
	pub SnapshotPublisher,
) *PlayerSnapshotService {
	return &PlayerSnapshotService{repo: repo, playerSvc: playerSvc, pub: pub}
}

//nolint:gocyclo
func (svc *PlayerSnapshotService) Create(
	ctx context.Context,
	createSnapshotsCmdPayload domain.CreateSnapshotsCmdPayload,
) error {
	serverKey := createSnapshotsCmdPayload.ServerKey()
	date := createSnapshotsCmdPayload.Date()

	listPlayersParams := domain.NewListPlayersParams()
	if err := listPlayersParams.SetServerKeys([]string{serverKey}); err != nil {
		return fmt.Errorf("%s: %w", serverKey, err)
	}
	if err := listPlayersParams.SetDeleted(domain.NullBool{
		V:     false,
		Valid: true,
	}); err != nil {
		return fmt.Errorf("%s: %w", serverKey, err)
	}
	if err := listPlayersParams.SetSort([]domain.PlayerSort{domain.PlayerSortIDASC}); err != nil {
		return fmt.Errorf("%s: %w", serverKey, err)
	}
	if err := listPlayersParams.SetLimit(domain.PlayerListMaxLimit); err != nil {
		return fmt.Errorf("%s: %w", serverKey, err)
	}

	for {
		res, err := svc.playerSvc.List(ctx, listPlayersParams)
		if err != nil {
			return fmt.Errorf("%s: %w", serverKey, err)
		}
		players := res.Players()

		if len(players) == 0 {
			break
		}

		params, err := domain.NewCreatePlayerSnapshotParams(players, date)
		if err != nil {
			return fmt.Errorf("%s: %w", serverKey, err)
		}

		if err = svc.repo.Create(ctx, params...); err != nil {
			return fmt.Errorf("%s: %w", serverKey, err)
		}

		if res.Next().IsZero() {
			break
		}

		if err = listPlayersParams.SetCursor(res.Next()); err != nil {
			return fmt.Errorf("%s: %w", serverKey, err)
		}
	}

	payload, err := domain.NewSnapshotsCreatedEventPayload(serverKey, createSnapshotsCmdPayload.VersionCode())
	if err != nil {
		return fmt.Errorf("%s: couldn't construct domain.SnapshotsCreatedEventPayload: %w", serverKey, err)
	}

	if err = svc.pub.EventCreated(ctx, payload); err != nil {
		return fmt.Errorf("%s: %w", serverKey, err)
	}

	return nil
}

func (svc *PlayerSnapshotService) ListWithRelations(
	ctx context.Context,
	params domain.ListPlayerSnapshotsParams,
) (domain.ListPlayerSnapshotsWithRelationsResult, error) {
	return svc.repo.ListWithRelations(ctx, params)
}

func (svc *PlayerSnapshotService) CleanUp(ctx context.Context, payload domain.CleanUpDataCmdPayload) error {
	if !payload.CanCleanUpPlayerSnapshots() {
		return nil
	}

	if err := svc.repo.Delete(
		ctx,
		payload.Server().Key(),
		time.Now().Add(-domain.PlayerSnapshotRetentionForClosedServers),
	); err != nil {
		return fmt.Errorf("%s: %w", payload.Server().Key(), err)
	}

	return nil
}