package adminbanish_test

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

	"galaxy/gamemaster/internal/adapters/mocks"
	"galaxy/gamemaster/internal/domain/operation"
	"galaxy/gamemaster/internal/domain/playermapping"
	"galaxy/gamemaster/internal/domain/runtime"
	"galaxy/gamemaster/internal/ports"
	"galaxy/gamemaster/internal/service/adminbanish"
	"galaxy/gamemaster/internal/telemetry"

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

// --- test doubles -----------------------------------------------------

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")
}

type fakePlayerMappings struct {
	mu       sync.Mutex
	races    map[string]map[string]playermapping.PlayerMapping
	getErr   error
}

func newFakePlayerMappings() *fakePlayerMappings {
	return &fakePlayerMappings{races: map[string]map[string]playermapping.PlayerMapping{}}
}

func (s *fakePlayerMappings) seedRace(gameID, raceName, userID, uuid string) {
	s.mu.Lock()
	defer s.mu.Unlock()
	if _, ok := s.races[gameID]; !ok {
		s.races[gameID] = map[string]playermapping.PlayerMapping{}
	}
	s.races[gameID][raceName] = playermapping.PlayerMapping{
		GameID: gameID, UserID: userID, RaceName: raceName, EnginePlayerUUID: uuid,
		CreatedAt: time.Now(),
	}
}

func (s *fakePlayerMappings) BulkInsert(context.Context, []playermapping.PlayerMapping) error {
	return errors.New("not used")
}
func (s *fakePlayerMappings) Get(context.Context, string, string) (playermapping.PlayerMapping, error) {
	return playermapping.PlayerMapping{}, errors.New("not used")
}
func (s *fakePlayerMappings) GetByRace(_ context.Context, gameID, raceName string) (playermapping.PlayerMapping, error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	if s.getErr != nil {
		return playermapping.PlayerMapping{}, s.getErr
	}
	gameRaces, ok := s.races[gameID]
	if !ok {
		return playermapping.PlayerMapping{}, playermapping.ErrNotFound
	}
	rec, ok := gameRaces[raceName]
	if !ok {
		return playermapping.PlayerMapping{}, playermapping.ErrNotFound
	}
	return rec, nil
}
func (s *fakePlayerMappings) ListByGame(context.Context, string) ([]playermapping.PlayerMapping, error) {
	return nil, errors.New("not used")
}
func (s *fakePlayerMappings) DeleteByGame(context.Context, string) error {
	return errors.New("not used")
}

type fakeOperationLogs struct {
	mu      sync.Mutex
	entries []operation.OperationEntry
}

func (s *fakeOperationLogs) Append(_ context.Context, entry operation.OperationEntry) (int64, error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	if err := entry.Validate(); err != nil {
		return 0, err
	}
	s.entries = append(s.entries, entry)
	return int64(len(s.entries)), nil
}
func (s *fakeOperationLogs) ListByGame(context.Context, string, int) ([]operation.OperationEntry, error) {
	return nil, errors.New("not used")
}
func (s *fakeOperationLogs) lastEntry() (operation.OperationEntry, bool) {
	s.mu.Lock()
	defer s.mu.Unlock()
	if len(s.entries) == 0 {
		return operation.OperationEntry{}, false
	}
	return s.entries[len(s.entries)-1], true
}

// --- harness ----------------------------------------------------------

type harness struct {
	t         *testing.T
	ctrl      *gomock.Controller
	runtime   *fakeRuntimeRecords
	mappings  *fakePlayerMappings
	logs      *fakeOperationLogs
	engine    *mocks.MockEngineClient
	telemetry *telemetry.Runtime
	now       time.Time
	service   *adminbanish.Service
}

func newHarness(t *testing.T) *harness {
	t.Helper()
	ctrl := gomock.NewController(t)
	telemetryRuntime, err := telemetry.NewWithProviders(nil, nil)
	require.NoError(t, err)
	h := &harness{
		t:         t,
		ctrl:      ctrl,
		runtime:   newFakeRuntimeRecords(),
		mappings:  newFakePlayerMappings(),
		logs:      &fakeOperationLogs{},
		engine:    mocks.NewMockEngineClient(ctrl),
		telemetry: telemetryRuntime,
		now:       time.Date(2026, time.May, 1, 12, 0, 0, 0, time.UTC),
	}
	service, err := adminbanish.NewService(adminbanish.Dependencies{
		RuntimeRecords: h.runtime,
		PlayerMappings: h.mappings,
		OperationLogs:  h.logs,
		Engine:         h.engine,
		Telemetry:      h.telemetry,
		Clock:          func() time.Time { return h.now },
	})
	require.NoError(t, err)
	h.service = service
	return h
}

const (
	testGameID    = "game-001"
	testRaceName  = "Aelinari"
	testEndpoint  = "http://galaxy-game-game-001:8080"
)

func (h *harness) seedRuntime(status runtime.Status) {
	created := h.now.Add(-time.Hour)
	started := h.now.Add(-30 * time.Minute)
	record := runtime.RuntimeRecord{
		GameID:               testGameID,
		Status:               status,
		EngineEndpoint:       testEndpoint,
		CurrentImageRef:      "ghcr.io/galaxy/game:v1.2.3",
		CurrentEngineVersion: "v1.2.3",
		TurnSchedule:         "0 18 * * *",
		CurrentTurn:          7,
		CreatedAt:            created,
		UpdatedAt:            started,
		StartedAt:            &started,
	}
	h.runtime.seed(record)
}

func baseInput() adminbanish.Input {
	return adminbanish.Input{
		GameID:    testGameID,
		RaceName:  testRaceName,
		OpSource:  operation.OpSourceLobbyInternal,
		SourceRef: "req-banish-001",
	}
}

// --- tests ------------------------------------------------------------

func TestNewServiceRejectsMissingDeps(t *testing.T) {
	telemetryRuntime, err := telemetry.NewWithProviders(nil, nil)
	require.NoError(t, err)
	cases := []struct {
		name string
		mut  func(*adminbanish.Dependencies)
	}{
		{"runtime records", func(d *adminbanish.Dependencies) { d.RuntimeRecords = nil }},
		{"player mappings", func(d *adminbanish.Dependencies) { d.PlayerMappings = nil }},
		{"operation logs", func(d *adminbanish.Dependencies) { d.OperationLogs = nil }},
		{"engine", func(d *adminbanish.Dependencies) { d.Engine = nil }},
		{"telemetry", func(d *adminbanish.Dependencies) { d.Telemetry = nil }},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			ctrl := gomock.NewController(t)
			deps := adminbanish.Dependencies{
				RuntimeRecords: newFakeRuntimeRecords(),
				PlayerMappings: newFakePlayerMappings(),
				OperationLogs:  &fakeOperationLogs{},
				Engine:         mocks.NewMockEngineClient(ctrl),
				Telemetry:      telemetryRuntime,
			}
			tc.mut(&deps)
			service, err := adminbanish.NewService(deps)
			require.Error(t, err)
			require.Nil(t, service)
		})
	}
}

func TestHandleHappyPath(t *testing.T) {
	h := newHarness(t)
	h.seedRuntime(runtime.StatusRunning)
	h.mappings.seedRace(testGameID, testRaceName, "user-1", "uuid-1")

	h.engine.EXPECT().BanishRace(gomock.Any(), testEndpoint, testRaceName).Return(nil)

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	require.True(t, result.IsSuccess(), "want success, got %+v", result)

	entry, ok := h.logs.lastEntry()
	require.True(t, ok)
	assert.Equal(t, operation.OpKindBanish, entry.OpKind)
	assert.Equal(t, operation.OpSourceLobbyInternal, entry.OpSource)
	assert.Equal(t, operation.OutcomeSuccess, entry.Outcome)
}

func TestHandleHappyPathOnStoppedRuntime(t *testing.T) {
	// README §Banish does not check status; the engine call may fail
	// later with engine_unreachable, but the service runs the call.
	h := newHarness(t)
	h.seedRuntime(runtime.StatusStopped)
	h.mappings.seedRace(testGameID, testRaceName, "user-1", "uuid-1")
	h.engine.EXPECT().BanishRace(gomock.Any(), testEndpoint, testRaceName).Return(nil)

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	require.True(t, result.IsSuccess())
}

func TestHandleRuntimeNotFound(t *testing.T) {
	h := newHarness(t)
	h.mappings.seedRace(testGameID, testRaceName, "user-1", "uuid-1")

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	assert.Equal(t, adminbanish.ErrorCodeRuntimeNotFound, result.ErrorCode)
}

func TestHandleForbiddenWhenRaceMissing(t *testing.T) {
	h := newHarness(t)
	h.seedRuntime(runtime.StatusRunning)

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	assert.Equal(t, adminbanish.ErrorCodeForbidden, result.ErrorCode)

	entry, ok := h.logs.lastEntry()
	require.True(t, ok)
	assert.Equal(t, operation.OutcomeFailure, entry.Outcome)
	assert.Equal(t, adminbanish.ErrorCodeForbidden, entry.ErrorCode)
}

func TestHandleEngineUnreachable(t *testing.T) {
	h := newHarness(t)
	h.seedRuntime(runtime.StatusRunning)
	h.mappings.seedRace(testGameID, testRaceName, "user-1", "uuid-1")
	h.engine.EXPECT().BanishRace(gomock.Any(), testEndpoint, testRaceName).
		Return(ports.ErrEngineUnreachable)

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	assert.Equal(t, adminbanish.ErrorCodeEngineUnreachable, result.ErrorCode)
}

func TestHandleEngineValidation(t *testing.T) {
	h := newHarness(t)
	h.seedRuntime(runtime.StatusRunning)
	h.mappings.seedRace(testGameID, testRaceName, "user-1", "uuid-1")
	h.engine.EXPECT().BanishRace(gomock.Any(), testEndpoint, testRaceName).
		Return(ports.ErrEngineValidation)

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	assert.Equal(t, adminbanish.ErrorCodeEngineValidationError, result.ErrorCode)
}

func TestHandleEngineProtocolViolation(t *testing.T) {
	h := newHarness(t)
	h.seedRuntime(runtime.StatusRunning)
	h.mappings.seedRace(testGameID, testRaceName, "user-1", "uuid-1")
	h.engine.EXPECT().BanishRace(gomock.Any(), testEndpoint, testRaceName).
		Return(ports.ErrEngineProtocolViolation)

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	assert.Equal(t, adminbanish.ErrorCodeEngineProtocolViolation, result.ErrorCode)
}

func TestHandleStoreReadFailure(t *testing.T) {
	h := newHarness(t)
	h.runtime.getErr = errors.New("connection refused")

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	assert.Equal(t, adminbanish.ErrorCodeServiceUnavailable, result.ErrorCode)
}

func TestHandleMappingStoreFailure(t *testing.T) {
	h := newHarness(t)
	h.seedRuntime(runtime.StatusRunning)
	h.mappings.getErr = errors.New("connection refused")

	result, err := h.service.Handle(context.Background(), baseInput())
	require.NoError(t, err)
	assert.Equal(t, adminbanish.ErrorCodeServiceUnavailable, result.ErrorCode)
}

func TestHandleInvalidRequest(t *testing.T) {
	cases := []struct {
		name  string
		input adminbanish.Input
	}{
		{"empty game id", adminbanish.Input{GameID: "", RaceName: "X", OpSource: operation.OpSourceLobbyInternal}},
		{"empty race", adminbanish.Input{GameID: testGameID, RaceName: "", OpSource: operation.OpSourceLobbyInternal}},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			h := newHarness(t)
			result, err := h.service.Handle(context.Background(), tc.input)
			require.NoError(t, err)
			assert.Equal(t, adminbanish.ErrorCodeInvalidRequest, result.ErrorCode)
		})
	}
}

func TestHandleNilContextReturnsError(t *testing.T) {
	h := newHarness(t)
	_, err := h.service.Handle(nil, baseInput()) //nolint:staticcheck // guard test
	require.Error(t, err)
}

func TestHandleDefaultsOpSourceToLobbyInternal(t *testing.T) {
	h := newHarness(t)
	h.seedRuntime(runtime.StatusRunning)
	h.mappings.seedRace(testGameID, testRaceName, "user-1", "uuid-1")
	h.engine.EXPECT().BanishRace(gomock.Any(), testEndpoint, testRaceName).Return(nil)

	input := baseInput()
	input.OpSource = ""
	result, err := h.service.Handle(context.Background(), input)
	require.NoError(t, err)
	require.True(t, result.IsSuccess())

	entry, ok := h.logs.lastEntry()
	require.True(t, ok)
	assert.Equal(t, operation.OpSourceLobbyInternal, entry.OpSource)
}