package openenrollment_test

import (
	"context"
	"io"
	"log/slog"
	"testing"
	"time"

	"galaxy/lobby/internal/adapters/gamestub"
	"galaxy/lobby/internal/domain/common"
	"galaxy/lobby/internal/domain/game"
	"galaxy/lobby/internal/ports"
	"galaxy/lobby/internal/service/openenrollment"
	"galaxy/lobby/internal/service/shared"

	"github.com/stretchr/testify/require"
)

func silentLogger() *slog.Logger {
	return slog.New(slog.NewTextHandler(io.Discard, nil))
}

func fixedClock(at time.Time) func() time.Time {
	return func() time.Time { return at }
}

func seedDraftGame(
	t *testing.T,
	store *gamestub.Store,
	id common.GameID,
	gameType game.GameType,
	ownerUserID string,
	now time.Time,
) game.Game {
	t.Helper()

	record, err := game.New(game.NewGameInput{
		GameID:              id,
		GameName:            "Seed",
		GameType:            gameType,
		OwnerUserID:         ownerUserID,
		MinPlayers:          2,
		MaxPlayers:          4,
		StartGapHours:       4,
		StartGapPlayers:     1,
		EnrollmentEndsAt:    now.Add(24 * time.Hour),
		TurnSchedule:        "0 */6 * * *",
		TargetEngineVersion: "1.0.0",
		Now:                 now,
	})
	require.NoError(t, err)
	require.NoError(t, store.Save(context.Background(), record))

	return record
}

func newService(t *testing.T, store ports.GameStore, clock func() time.Time) *openenrollment.Service {
	t.Helper()

	svc, err := openenrollment.NewService(openenrollment.Dependencies{
		Games:  store,
		Clock:  clock,
		Logger: silentLogger(),
	})
	require.NoError(t, err)
	return svc
}

func TestHandleAdminHappyPath(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gamestub.NewStore()
	seedDraftGame(t, store, "game-alpha", game.GameTypePublic, "", now)

	service := newService(t, store, fixedClock(now.Add(time.Hour)))

	updated, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.NewAdminActor(),
		GameID: "game-alpha",
	})
	require.NoError(t, err)
	require.Equal(t, game.StatusEnrollmentOpen, updated.Status)
	require.Equal(t, now.Add(time.Hour).UTC(), updated.UpdatedAt)
}

func TestHandleOwnerHappyPath(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gamestub.NewStore()
	seedDraftGame(t, store, "game-p", game.GameTypePrivate, "user-1", now)

	service := newService(t, store, fixedClock(now.Add(time.Hour)))

	updated, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.NewUserActor("user-1"),
		GameID: "game-p",
	})
	require.NoError(t, err)
	require.Equal(t, game.StatusEnrollmentOpen, updated.Status)
}

func TestHandleNonOwnerForbidden(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gamestub.NewStore()
	seedDraftGame(t, store, "game-p", game.GameTypePrivate, "user-1", now)

	service := newService(t, store, fixedClock(now.Add(time.Hour)))

	_, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.NewUserActor("user-2"),
		GameID: "game-p",
	})
	require.ErrorIs(t, err, shared.ErrForbidden)
}

func TestHandleUserCannotOpenPublicGame(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gamestub.NewStore()
	seedDraftGame(t, store, "game-pub", game.GameTypePublic, "", now)

	service := newService(t, store, fixedClock(now.Add(time.Hour)))

	_, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.NewUserActor("user-1"),
		GameID: "game-pub",
	})
	require.ErrorIs(t, err, shared.ErrForbidden)
}

func TestHandleFromEnrollmentOpenConflict(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gamestub.NewStore()
	record := seedDraftGame(t, store, "game-x", game.GameTypePublic, "", now)
	require.NoError(t, store.UpdateStatus(context.Background(), ports.UpdateStatusInput{
		GameID:       record.GameID,
		ExpectedFrom: game.StatusDraft,
		To:           game.StatusEnrollmentOpen,
		Trigger:      game.TriggerCommand,
		At:           now.Add(5 * time.Minute),
	}))

	service := newService(t, store, fixedClock(now.Add(time.Hour)))

	_, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.NewAdminActor(),
		GameID: record.GameID,
	})
	require.ErrorIs(t, err, game.ErrConflict)
}

func TestHandleFromReadyToStartInvalidTransition(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gamestub.NewStore()
	record := seedDraftGame(t, store, "game-rts", game.GameTypePublic, "", now)
	require.NoError(t, store.UpdateStatus(context.Background(), ports.UpdateStatusInput{
		GameID:       record.GameID,
		ExpectedFrom: game.StatusDraft,
		To:           game.StatusEnrollmentOpen,
		Trigger:      game.TriggerCommand,
		At:           now.Add(5 * time.Minute),
	}))
	require.NoError(t, store.UpdateStatus(context.Background(), ports.UpdateStatusInput{
		GameID:       record.GameID,
		ExpectedFrom: game.StatusEnrollmentOpen,
		To:           game.StatusReadyToStart,
		Trigger:      game.TriggerManual,
		At:           now.Add(10 * time.Minute),
	}))

	service := newService(t, store, fixedClock(now.Add(time.Hour)))

	// ExpectedFrom=draft but actual=ready_to_start → conflict via CAS.
	_, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.NewAdminActor(),
		GameID: record.GameID,
	})
	require.ErrorIs(t, err, game.ErrConflict)
}

func TestHandleNotFound(t *testing.T) {
	t.Parallel()

	store := gamestub.NewStore()
	service := newService(t, store, fixedClock(time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)))

	_, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.NewAdminActor(),
		GameID: "game-missing",
	})
	require.ErrorIs(t, err, game.ErrNotFound)
}

func TestHandleInvalidActor(t *testing.T) {
	t.Parallel()

	store := gamestub.NewStore()
	service := newService(t, store, fixedClock(time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)))

	_, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.Actor{Kind: shared.ActorKindUser},
		GameID: "game-x",
	})
	require.Error(t, err)
	require.Contains(t, err.Error(), "actor")
}

func TestHandleInvalidGameID(t *testing.T) {
	t.Parallel()

	store := gamestub.NewStore()
	service := newService(t, store, fixedClock(time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)))

	_, err := service.Handle(context.Background(), openenrollment.Input{
		Actor:  shared.NewAdminActor(),
		GameID: "bad-id",
	})
	require.Error(t, err)
}