package enrollmentautomation_test

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

	"galaxy/lobby/internal/adapters/gameinmem"
	"galaxy/lobby/internal/adapters/gapactivationinmem"
	"galaxy/lobby/internal/adapters/inviteinmem"
	"galaxy/lobby/internal/adapters/membershipinmem"
	"galaxy/lobby/internal/adapters/mocks"
	"galaxy/lobby/internal/domain/common"
	"galaxy/lobby/internal/domain/game"
	"galaxy/lobby/internal/domain/invite"
	"galaxy/lobby/internal/domain/membership"
	"galaxy/lobby/internal/worker/enrollmentautomation"
	"galaxy/notificationintent"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/mock/gomock"
)

type intentRec struct {
	mu        sync.Mutex
	published []notificationintent.Intent
}

func (r *intentRec) record(_ context.Context, intent notificationintent.Intent) (string, error) {
	r.mu.Lock()
	defer r.mu.Unlock()
	r.published = append(r.published, intent)
	return "1", nil
}

func (r *intentRec) snapshot() []notificationintent.Intent {
	r.mu.Lock()
	defer r.mu.Unlock()
	return append([]notificationintent.Intent(nil), r.published...)
}

func newIntentMock(t *testing.T, rec *intentRec) *mocks.MockIntentPublisher {
	t.Helper()
	m := mocks.NewMockIntentPublisher(gomock.NewController(t))
	m.EXPECT().Publish(gomock.Any(), gomock.Any()).DoAndReturn(rec.record).AnyTimes()
	return m
}

const (
	gameID      = common.GameID("game-private")
	ownerUserID = "user-owner"
)

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 } }

type fixture struct {
	now         time.Time
	games       *gameinmem.Store
	invites     *inviteinmem.Store
	memberships *membershipinmem.Store
	gapStore    *gapactivationinmem.Store
	intentRec   *intentRec
	intents     *mocks.MockIntentPublisher
	game        game.Game
}

type fixtureOptions struct {
	minPlayers       int
	maxPlayers       int
	startGapHours    int
	startGapPlayers  int
	enrollmentEndsAt time.Time
}

func newFixture(t *testing.T, opts fixtureOptions) *fixture {
	t.Helper()
	now := time.Date(2026, 4, 25, 10, 0, 0, 0, time.UTC)
	if opts.minPlayers == 0 {
		opts.minPlayers = 2
	}
	if opts.maxPlayers == 0 {
		opts.maxPlayers = 4
	}
	if opts.startGapHours == 0 {
		opts.startGapHours = 2
	}
	if opts.startGapPlayers == 0 {
		opts.startGapPlayers = 1
	}
	if opts.enrollmentEndsAt.IsZero() {
		opts.enrollmentEndsAt = now.Add(24 * time.Hour)
	}

	rec, err := game.New(game.NewGameInput{
		GameID:              gameID,
		GameName:            "Friends Only",
		GameType:            game.GameTypePrivate,
		OwnerUserID:         ownerUserID,
		MinPlayers:          opts.minPlayers,
		MaxPlayers:          opts.maxPlayers,
		StartGapHours:       opts.startGapHours,
		StartGapPlayers:     opts.startGapPlayers,
		EnrollmentEndsAt:    opts.enrollmentEndsAt,
		TurnSchedule:        "0 */6 * * *",
		TargetEngineVersion: "1.0.0",
		Now:                 now,
	})
	require.NoError(t, err)
	rec.Status = game.StatusEnrollmentOpen

	games := gameinmem.NewStore()
	require.NoError(t, games.Save(context.Background(), rec))

	intentRecord := &intentRec{}
	return &fixture{
		now:         now,
		games:       games,
		invites:     inviteinmem.NewStore(),
		memberships: membershipinmem.NewStore(),
		gapStore:    gapactivationinmem.NewStore(),
		intentRec:   intentRecord,
		intents:     newIntentMock(t, intentRecord),
		game:        rec,
	}
}

func (f *fixture) addActiveMember(t *testing.T, membershipID common.MembershipID, userID string) {
	t.Helper()
	mem, err := membership.New(membership.NewMembershipInput{
		MembershipID: membershipID,
		GameID:       gameID,
		UserID:       userID,
		RaceName:     "Race " + userID,
		CanonicalKey: "race-" + userID,
		Now:          f.now,
	})
	require.NoError(t, err)
	require.NoError(t, f.memberships.Save(context.Background(), mem))
}

func (f *fixture) addCreatedInvite(t *testing.T, inviteID common.InviteID, invitee string) {
	t.Helper()
	rec, err := invite.New(invite.NewInviteInput{
		InviteID:      inviteID,
		GameID:        gameID,
		InviterUserID: ownerUserID,
		InviteeUserID: invitee,
		Now:           f.now,
		ExpiresAt:     f.game.EnrollmentEndsAt,
	})
	require.NoError(t, err)
	require.NoError(t, f.invites.Save(context.Background(), rec))
}

func (f *fixture) markGapActivatedAt(t *testing.T, at time.Time) {
	t.Helper()
	require.NoError(t, f.gapStore.MarkActivated(context.Background(), gameID, at))
}

func (f *fixture) newWorker(t *testing.T, tickAt time.Time) *enrollmentautomation.Worker {
	t.Helper()
	worker, err := enrollmentautomation.NewWorker(enrollmentautomation.Dependencies{
		Games:       f.games,
		Memberships: f.memberships,
		Invites:     f.invites,
		Intents:     f.intents,
		GapStore:    f.gapStore,
		Interval:    time.Minute,
		Clock:       fixedClock(tickAt),
		Logger:      silentLogger(),
	})
	require.NoError(t, err)
	return worker
}

func currentStatus(t *testing.T, f *fixture) game.Status {
	t.Helper()
	rec, err := f.games.Get(context.Background(), gameID)
	require.NoError(t, err)
	return rec.Status
}

func TestNewWorkerRejectsZeroInterval(t *testing.T) {
	t.Parallel()
	_, err := enrollmentautomation.NewWorker(enrollmentautomation.Dependencies{
		Games:       gameinmem.NewStore(),
		Memberships: membershipinmem.NewStore(),
		Invites:     inviteinmem.NewStore(),
		Intents:     newIntentMock(t, &intentRec{}),
		GapStore:    gapactivationinmem.NewStore(),
		Interval:    0,
	})
	require.Error(t, err)
}

func TestTickDeadlineTriggers(t *testing.T) {
	t.Parallel()
	f := newFixture(t, fixtureOptions{minPlayers: 2})
	f.addActiveMember(t, "membership-1", "user-a")
	f.addActiveMember(t, "membership-2", "user-b")
	f.addCreatedInvite(t, "invite-1", "user-c")

	tickAt := f.game.EnrollmentEndsAt.Add(time.Minute)
	f.newWorker(t, tickAt).Tick(context.Background())

	assert.Equal(t, game.StatusReadyToStart, currentStatus(t, f))

	expired, err := f.invites.Get(context.Background(), "invite-1")
	require.NoError(t, err)
	assert.Equal(t, invite.StatusExpired, expired.Status)

	intents := f.intentRec.snapshot()
	require.Len(t, intents, 1)
	assert.Equal(t, notificationintent.NotificationTypeLobbyInviteExpired, intents[0].NotificationType)
}

func TestTickDeadlineSkipsBelowMinPlayers(t *testing.T) {
	t.Parallel()
	f := newFixture(t, fixtureOptions{minPlayers: 3})
	f.addActiveMember(t, "membership-1", "user-a")
	f.addActiveMember(t, "membership-2", "user-b")

	tickAt := f.game.EnrollmentEndsAt.Add(time.Minute)
	f.newWorker(t, tickAt).Tick(context.Background())

	assert.Equal(t, game.StatusEnrollmentOpen, currentStatus(t, f))
	assert.Empty(t, f.intentRec.snapshot())
}

func TestTickGapTimeTriggers(t *testing.T) {
	t.Parallel()
	f := newFixture(t, fixtureOptions{minPlayers: 2, maxPlayers: 4, startGapHours: 2, startGapPlayers: 2})
	f.addActiveMember(t, "membership-1", "user-a")
	f.addActiveMember(t, "membership-2", "user-b")
	f.addActiveMember(t, "membership-3", "user-c")
	f.addActiveMember(t, "membership-4", "user-d")
	f.markGapActivatedAt(t, f.now)

	tickAt := f.now.Add(2 * time.Hour).Add(time.Minute)
	f.newWorker(t, tickAt).Tick(context.Background())

	assert.Equal(t, game.StatusReadyToStart, currentStatus(t, f))
}

func TestTickGapPlayersTriggersBeforeTime(t *testing.T) {
	t.Parallel()
	f := newFixture(t, fixtureOptions{minPlayers: 2, maxPlayers: 4, startGapHours: 24, startGapPlayers: 1})
	f.addActiveMember(t, "membership-1", "user-a")
	f.addActiveMember(t, "membership-2", "user-b")
	f.addActiveMember(t, "membership-3", "user-c")
	f.addActiveMember(t, "membership-4", "user-d")
	f.addActiveMember(t, "membership-5", "user-e")
	f.markGapActivatedAt(t, f.now)

	tickAt := f.now.Add(15 * time.Minute)
	f.newWorker(t, tickAt).Tick(context.Background())

	assert.Equal(t, game.StatusReadyToStart, currentStatus(t, f))
}

func TestTickGapInactiveSkipsBeforeDeadline(t *testing.T) {
	t.Parallel()
	f := newFixture(t, fixtureOptions{minPlayers: 2, maxPlayers: 4, startGapHours: 1})
	f.addActiveMember(t, "membership-1", "user-a")
	f.addActiveMember(t, "membership-2", "user-b")

	tickAt := f.now.Add(2 * time.Hour)
	f.newWorker(t, tickAt).Tick(context.Background())

	assert.Equal(t, game.StatusEnrollmentOpen, currentStatus(t, f))
}

func TestTickIsIdempotent(t *testing.T) {
	t.Parallel()
	f := newFixture(t, fixtureOptions{minPlayers: 2})
	f.addActiveMember(t, "membership-1", "user-a")
	f.addActiveMember(t, "membership-2", "user-b")
	f.addCreatedInvite(t, "invite-1", "user-c")

	tickAt := f.game.EnrollmentEndsAt.Add(time.Minute)
	worker := f.newWorker(t, tickAt)

	worker.Tick(context.Background())
	worker.Tick(context.Background())

	assert.Equal(t, game.StatusReadyToStart, currentStatus(t, f))
	assert.Len(t, f.intentRec.snapshot(), 1)
}

func TestRunStopsOnContextCancel(t *testing.T) {
	t.Parallel()
	f := newFixture(t, fixtureOptions{minPlayers: 2})
	worker := f.newWorker(t, f.now)

	ctx, cancel := context.WithCancel(context.Background())
	done := make(chan error, 1)
	go func() { done <- worker.Run(ctx) }()
	cancel()

	select {
	case err := <-done:
		require.ErrorIs(t, err, context.Canceled)
	case <-time.After(time.Second):
		t.Fatal("worker did not stop after context cancel")
	}
}