package livenessreply_test

import (
	"context"
	"errors"
	"sync"
	"testing"
	"time"

	"galaxy/gamemaster/internal/domain/runtime"
	"galaxy/gamemaster/internal/ports"
	"galaxy/gamemaster/internal/service/livenessreply"

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

type fakeRuntimeRecords struct {
	mu     sync.Mutex
	stored map[string]runtime.RuntimeRecord
	getErr error
}

func newFakeRuntimeRecords() *fakeRuntimeRecords {
	return &fakeRuntimeRecords{stored: map[string]runtime.RuntimeRecord{}}
}

func (s *fakeRuntimeRecords) seed(record runtime.RuntimeRecord) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.stored[record.GameID] = record
}

func (s *fakeRuntimeRecords) Get(_ context.Context, gameID string) (runtime.RuntimeRecord, error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.getErr != nil {
		return runtime.RuntimeRecord{}, s.getErr
	}
	record, ok := s.stored[gameID]
	if !ok {
		return runtime.RuntimeRecord{}, runtime.ErrNotFound
	}
	return record, nil
}

func (s *fakeRuntimeRecords) Insert(context.Context, runtime.RuntimeRecord) error {
	return errors.New("not used")
}
func (s *fakeRuntimeRecords) UpdateStatus(context.Context, ports.UpdateStatusInput) error {
	return errors.New("not used")
}
func (s *fakeRuntimeRecords) UpdateScheduling(context.Context, ports.UpdateSchedulingInput) error {
	return errors.New("not used")
}
func (s *fakeRuntimeRecords) UpdateImage(context.Context, ports.UpdateImageInput) error {
	return errors.New("not used")
}
func (s *fakeRuntimeRecords) UpdateEngineHealth(context.Context, ports.UpdateEngineHealthInput) error {
	return errors.New("not used")
}
func (s *fakeRuntimeRecords) Delete(context.Context, string) error {
	return errors.New("not used")
}
func (s *fakeRuntimeRecords) ListDueRunning(context.Context, time.Time) ([]runtime.RuntimeRecord, error) {
	return nil, errors.New("not used")
}
func (s *fakeRuntimeRecords) ListByStatus(context.Context, runtime.Status) ([]runtime.RuntimeRecord, error) {
	return nil, errors.New("not used")
}
func (s *fakeRuntimeRecords) List(context.Context) ([]runtime.RuntimeRecord, error) {
	return nil, errors.New("not used")
}

func newService(t *testing.T, store *fakeRuntimeRecords) *livenessreply.Service {
	t.Helper()
	service, err := livenessreply.NewService(livenessreply.Dependencies{
		RuntimeRecords: store,
	})
	require.NoError(t, err)
	return service
}

func runningRecord(gameID string) runtime.RuntimeRecord {
	now := time.Date(2026, time.May, 1, 12, 0, 0, 0, time.UTC)
	return runtime.RuntimeRecord{
		GameID:               gameID,
		Status:               runtime.StatusRunning,
		EngineEndpoint:       "http://galaxy-game-" + gameID + ":8080",
		CurrentImageRef:      "ghcr.io/galaxy/game:v1.2.3",
		CurrentEngineVersion: "v1.2.3",
		TurnSchedule:         "0 18 * * *",
		CurrentTurn:          5,
		CreatedAt:            now,
		UpdatedAt:            now,
	}
}

func TestNewServiceRejectsNilRuntimeRecords(t *testing.T) {
	_, err := livenessreply.NewService(livenessreply.Dependencies{})
	require.Error(t, err)
}

func TestHandleRunningReturnsReadyTrue(t *testing.T) {
	store := newFakeRuntimeRecords()
	store.seed(runningRecord("game-001"))
	service := newService(t, store)

	result, err := service.Handle(context.Background(), livenessreply.Input{GameID: "game-001"})
	require.NoError(t, err)
	assert.True(t, result.Ready)
	assert.Equal(t, runtime.StatusRunning, result.Status)
}

func TestHandleNonRunningReturnsReadyFalseWithStatus(t *testing.T) {
	cases := []runtime.Status{
		runtime.StatusStarting,
		runtime.StatusGenerationInProgress,
		runtime.StatusGenerationFailed,
		runtime.StatusEngineUnreachable,
		runtime.StatusStopped,
		runtime.StatusFinished,
	}
	for _, status := range cases {
		t.Run(string(status), func(t *testing.T) {
			store := newFakeRuntimeRecords()
			rec := runningRecord("game-001")
			rec.Status = status
			store.seed(rec)
			service := newService(t, store)

			result, err := service.Handle(context.Background(), livenessreply.Input{GameID: "game-001"})
			require.NoError(t, err)
			assert.False(t, result.Ready)
			assert.Equal(t, status, result.Status)
		})
	}
}

func TestHandleRuntimeNotFoundReturnsEmptyStatus(t *testing.T) {
	store := newFakeRuntimeRecords()
	service := newService(t, store)

	result, err := service.Handle(context.Background(), livenessreply.Input{GameID: "missing"})
	require.NoError(t, err, "runtime_not_found is absorbed into 200 response per Stage 17 D5")
	assert.False(t, result.Ready)
	assert.Equal(t, runtime.Status(""), result.Status)
}

func TestHandleStoreReadFailureReturnsServiceUnavailable(t *testing.T) {
	store := newFakeRuntimeRecords()
	store.getErr = errors.New("connection refused")
	service := newService(t, store)

	_, err := service.Handle(context.Background(), livenessreply.Input{GameID: "game-001"})
	require.Error(t, err)
	assert.Contains(t, err.Error(), livenessreply.ErrorCodeServiceUnavailable)
}

func TestHandleEmptyGameIDReturnsInvalidRequest(t *testing.T) {
	store := newFakeRuntimeRecords()
	service := newService(t, store)

	_, err := service.Handle(context.Background(), livenessreply.Input{GameID: ""})
	require.Error(t, err)
	assert.Contains(t, err.Error(), livenessreply.ErrorCodeInvalidRequest)
}

func TestHandleNilContextReturnsError(t *testing.T) {
	store := newFakeRuntimeRecords()
	service := newService(t, store)

	_, err := service.Handle(nil, livenessreply.Input{GameID: "game-001"}) //nolint:staticcheck // guard test
	require.Error(t, err)
}