/*
이 테스트 파일은 RelyingPartyService의 기능을 검증하기 위한 유닛 테스트입니다.
RelyingPartyService는 HydraAdminService, KetoService, RelyingPartyRepository와 협력하므로
각 의존성을 모킹(Mocking)하여 통합 로직을 검증합니다.

주요 테스트 항목:
1. Create: Hydra 클라이언트 생성 -> DB 저장 -> Keto 권한 설정 (성공 및 롤백 시나리오)
2. Get: DB 및 Hydra에서 정보 조회
3. Update: Hydra 및 DB 업데이트
4. Delete: DB 및 Hydra 삭제
*/

package service

import (
	"baron-sso-backend/internal/domain"
	"context"
	"encoding/json"
	"errors"
	"net/http"
	"strings"
	"testing"

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

// --- Mocks ---

type MockRelyingPartyRepository struct {
	mock.Mock
}

func (m *MockRelyingPartyRepository) Create(ctx context.Context, rp *domain.RelyingParty) error {
	args := m.Called(ctx, rp)
	return args.Error(0)
}

func (m *MockRelyingPartyRepository) Update(ctx context.Context, rp *domain.RelyingParty) error {
	args := m.Called(ctx, rp)
	return args.Error(0)
}

func (m *MockRelyingPartyRepository) Delete(ctx context.Context, clientID string) error {
	args := m.Called(ctx, clientID)
	return args.Error(0)
}

func (m *MockRelyingPartyRepository) FindByID(ctx context.Context, clientID string) (*domain.RelyingParty, error) {
	args := m.Called(ctx, clientID)
	if rp, ok := args.Get(0).(*domain.RelyingParty); ok {
		return rp, args.Error(1)
	}
	return nil, args.Error(1)
}

func (m *MockRelyingPartyRepository) ListByTenantID(ctx context.Context, tenantID string) ([]domain.RelyingParty, error) {
	args := m.Called(ctx, tenantID)
	return args.Get(0).([]domain.RelyingParty), args.Error(1)
}

func (m *MockRelyingPartyRepository) ListAll(ctx context.Context) ([]domain.RelyingParty, error) {
	args := m.Called(ctx)
	return args.Get(0).([]domain.RelyingParty), args.Error(1)
}

type MockKetoService struct {
	mock.Mock
}

func (m *MockKetoService) CheckPermission(ctx context.Context, subject, namespace, object, relation string) (bool, error) {
	args := m.Called(ctx, subject, namespace, object, relation)
	return args.Bool(0), args.Error(1)
}

func (m *MockKetoService) CreateRelation(ctx context.Context, namespace, object, relation, subject string) error {
	args := m.Called(ctx, namespace, object, relation, subject)
	return args.Error(0)
}

func (m *MockKetoService) DeleteRelation(ctx context.Context, namespace, object, relation, subject string) error {
	args := m.Called(ctx, namespace, object, relation, subject)
	return args.Error(0)
}

// --- Tests ---

func TestRelyingPartyService_Create_Success(t *testing.T) {
	// Setup
	mockRepo := new(MockRelyingPartyRepository)
	mockKeto := new(MockKetoService)

	tenantID := "tenant-1"
	inputClient := domain.HydraClient{
		ClientName: "Test App",
	}

	// Hydra Mock
	hydraHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodPost && strings.Contains(r.URL.Path, "/clients") {
			var req domain.HydraClient
			json.NewDecoder(r.Body).Decode(&req)
			
			// Verify metadata injection
			if req.Metadata["tenant_id"] != tenantID {
				t.Errorf("expected tenant_id in metadata")
			}

			req.ClientID = "generated-client-id"
			w.WriteHeader(http.StatusCreated)
			json.NewEncoder(w).Encode(req)
			return
		}
		http.NotFound(w, r)
	})
	hydraSvc := &HydraAdminService{
		AdminURL:   "http://hydra:4445",
		HTTPClient: mockHydraClient(hydraHandler),
	}

	// Expectations
	mockRepo.On("Create", mock.Anything, mock.MatchedBy(func(rp *domain.RelyingParty) bool {
		return rp.ClientID == "generated-client-id" && rp.TenantID == tenantID
	})).Return(nil)

	mockKeto.On("CreateRelation", mock.Anything, "RelyingParty", "generated-client-id", "parent_tenant", "Tenant:"+tenantID).Return(nil)

	// Execute
	svc := NewRelyingPartyService(mockRepo, hydraSvc, mockKeto)
	rp, err := svc.Create(context.Background(), tenantID, inputClient)

	// Verify
	if err != nil {
		t.Fatalf("Create failed: %v", err)
	}
	if rp.ClientID != "generated-client-id" {
		t.Errorf("expected client id generated-client-id, got %s", rp.ClientID)
	}

	mockRepo.AssertExpectations(t)
	mockKeto.AssertExpectations(t)
}

func TestRelyingPartyService_Create_HydraFail(t *testing.T) {
	mockRepo := new(MockRelyingPartyRepository)
	mockKeto := new(MockKetoService)

	hydraHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	})
	hydraSvc := &HydraAdminService{
		AdminURL:   "http://hydra:4445",
		HTTPClient: mockHydraClient(hydraHandler),
	}

	svc := NewRelyingPartyService(mockRepo, hydraSvc, mockKeto)
	_, err := svc.Create(context.Background(), "tenant-1", domain.HydraClient{})

	if err == nil {
		t.Error("expected error from hydra")
	}
}

func TestRelyingPartyService_Create_DBFail_Rollback(t *testing.T) {
	mockRepo := new(MockRelyingPartyRepository)
	mockKeto := new(MockKetoService)

	clientID := "rollback-client-id"

	// Hydra Mock: Create Succeeds, Delete Called
	hydraHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodPost {
			json.NewEncoder(w).Encode(domain.HydraClient{ClientID: clientID})
			return
		}
		if r.Method == http.MethodDelete && strings.Contains(r.URL.Path, clientID) {
			w.WriteHeader(http.StatusNoContent)
			return
		}
		http.NotFound(w, r)
	})
	hydraSvc := &HydraAdminService{
		AdminURL:   "http://hydra:4445",
		HTTPClient: mockHydraClient(hydraHandler),
	}

	// DB Fails
	mockRepo.On("Create", mock.Anything, mock.Anything).Return(errors.New("db error"))

	svc := NewRelyingPartyService(mockRepo, hydraSvc, mockKeto)
	_, err := svc.Create(context.Background(), "tenant-1", domain.HydraClient{})

	if err == nil {
		t.Error("expected error from db")
	}

	mockRepo.AssertExpectations(t)
	// Keto should NOT be called
	mockKeto.AssertNotCalled(t, "CreateRelation")
}

func TestRelyingPartyService_Get_Success(t *testing.T) {
	mockRepo := new(MockRelyingPartyRepository)
	mockKeto := new(MockKetoService)
	clientID := "client-123"

	mockRepo.On("FindByID", mock.Anything, clientID).Return(&domain.RelyingParty{ClientID: clientID, Name: "DB Name"}, nil)

	hydraHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		json.NewEncoder(w).Encode(domain.HydraClient{ClientID: clientID, ClientName: "Hydra Name"})
	})
	hydraSvc := &HydraAdminService{
		AdminURL:   "http://hydra:4445",
		HTTPClient: mockHydraClient(hydraHandler),
	}

	svc := NewRelyingPartyService(mockRepo, hydraSvc, mockKeto)
	rp, hc, err := svc.Get(context.Background(), clientID)

	if err != nil {
		t.Fatalf("Get failed: %v", err)
	}
	if rp.Name != "DB Name" {
		t.Errorf("expected DB Name, got %s", rp.Name)
	}
	if hc.ClientName != "Hydra Name" {
		t.Errorf("expected Hydra Name, got %s", hc.ClientName)
	}
}

func TestRelyingPartyService_Update_Success(t *testing.T) {
	mockRepo := new(MockRelyingPartyRepository)
	mockKeto := new(MockKetoService)
	clientID := "client-123"

	// Hydra Update
	hydraHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodPut {
			var req domain.HydraClient
			json.NewDecoder(r.Body).Decode(&req)
			json.NewEncoder(w).Encode(req)
			return
		}
	})
	hydraSvc := &HydraAdminService{
		AdminURL:   "http://hydra:4445",
		HTTPClient: mockHydraClient(hydraHandler),
	}

	// DB Update
	mockRepo.On("FindByID", mock.Anything, clientID).Return(&domain.RelyingParty{ClientID: clientID, Name: "Old Name"}, nil)
	mockRepo.On("Update", mock.Anything, mock.MatchedBy(func(rp *domain.RelyingParty) bool {
		return rp.Name == "New Name"
	})).Return(nil)

	svc := NewRelyingPartyService(mockRepo, hydraSvc, mockKeto)
	
	updateReq := domain.HydraClient{ClientName: "New Name"}
	rp, err := svc.Update(context.Background(), clientID, updateReq)

	if err != nil {
		t.Fatalf("Update failed: %v", err)
	}
	if rp.Name != "New Name" {
		t.Errorf("expected New Name, got %s", rp.Name)
	}

	mockRepo.AssertExpectations(t)
}

func TestRelyingPartyService_Delete_Success(t *testing.T) {
	mockRepo := new(MockRelyingPartyRepository)
	mockKeto := new(MockKetoService)
	clientID := "client-123"

	mockRepo.On("Delete", mock.Anything, clientID).Return(nil)

	hydraHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodDelete {
			w.WriteHeader(http.StatusNoContent)
		}
	})
	hydraSvc := &HydraAdminService{
		AdminURL:   "http://hydra:4445",
		HTTPClient: mockHydraClient(hydraHandler),
	}

	svc := NewRelyingPartyService(mockRepo, hydraSvc, mockKeto)
	err := svc.Delete(context.Background(), clientID)

	if err != nil {
		t.Fatalf("Delete failed: %v", err)
	}

	mockRepo.AssertExpectations(t)
}