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

주요 테스트 항목:
1. Create: Hydra 클라이언트 생성 -> Keto 권한 설정
2. Get: Hydra에서 정보 조회
3. Update: Hydra 업데이트
4. Delete: Hydra 삭제 + Keto 권한 정리
*/

package service

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

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

// --- Mocks ---

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)
}

func (m *MockKetoService) ListRelations(ctx context.Context, namespace, object, relation, subject string) ([]RelationTuple, error) {
	args := m.Called(ctx, namespace, object, relation, subject)
	if args.Get(0) == nil {
		return nil, args.Error(1)
	}
	return args.Get(0).([]RelationTuple), args.Error(1)
}

func (m *MockKetoService) ListObjects(ctx context.Context, namespace, relation, subject string) ([]string, error) {
	args := m.Called(ctx, namespace, relation, subject)
	if args.Get(0) == nil {
		return nil, args.Error(1)
	}
	return args.Get(0).([]string), args.Error(1)
}

// --- Test Helpers ---

type hydraRoundTripperFunc func(*http.Request) (*http.Response, error)

func (f hydraRoundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) {
	return f(req)
}

func mockHydraClient(handler http.Handler) *http.Client {
	return &http.Client{
		Transport: hydraRoundTripperFunc(func(req *http.Request) (*http.Response, error) {
			rec := httptest.NewRecorder()
			handler.ServeHTTP(rec, req)
			return rec.Result(), nil
		}),
	}
}

// --- Tests ---

func TestRelyingPartyService_Create_Success(t *testing.T) {
	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)

			// 메타데이터 tenant_id 주입 확인
			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),
	}

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

	svc := NewRelyingPartyService(hydraSvc, mockKeto)
	rp, err := svc.Create(context.Background(), tenantID, inputClient)
	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)
	}
	if rp.TenantID != tenantID {
		t.Errorf("expected tenant id %s, got %s", tenantID, rp.TenantID)
	}

	mockKeto.AssertExpectations(t)
}

func TestRelyingPartyService_Create_HydraFail(t *testing.T) {
	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(hydraSvc, mockKeto)
	_, err := svc.Create(context.Background(), "tenant-1", domain.HydraClient{})

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

func TestRelyingPartyService_Create_KetoFail_Rollback(t *testing.T) {
	mockKeto := new(MockKetoService)

	clientID := "rollback-client-id"
	deleteCalled := false

	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) {
			deleteCalled = true
			w.WriteHeader(http.StatusNoContent)
			return
		}
		http.NotFound(w, r)
	})
	hydraSvc := &HydraAdminService{
		AdminURL:   "http://hydra:4445",
		HTTPClient: mockHydraClient(hydraHandler),
	}

	mockKeto.On("CreateRelation", mock.Anything, "RelyingParty", clientID, "parent_tenant", "Tenant:tenant-1").Return(errors.New("keto error"))

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

	if err == nil {
		t.Error("expected error from keto")
	}
	if !deleteCalled {
		t.Error("expected hydra client cleanup on keto failure")
	}

	mockKeto.AssertExpectations(t)
}

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

	hydraHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		_ = json.NewEncoder(w).Encode(domain.HydraClient{
			ClientID:   clientID,
			ClientName: "Hydra Name",
			Metadata: map[string]interface{}{
				"tenant_id": "tenant-1",
			},
		})
	})
	hydraSvc := &HydraAdminService{
		AdminURL:   "http://hydra:4445",
		HTTPClient: mockHydraClient(hydraHandler),
	}

	svc := NewRelyingPartyService(hydraSvc, mockKeto)
	rp, hc, err := svc.Get(context.Background(), clientID)
	if err != nil {
		t.Fatalf("Get failed: %v", err)
	}
	if rp.Name != "Hydra Name" {
		t.Errorf("expected Hydra 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) {
	mockKeto := new(MockKetoService)
	clientID := "client-123"

	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),
	}

	svc := NewRelyingPartyService(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)
	}
}

func TestRelyingPartyService_Delete_Success(t *testing.T) {
	mockKeto := new(MockKetoService)
	clientID := "client-123"
	tenantID := "tenant-1"

	hydraHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodGet && strings.Contains(r.URL.Path, clientID) {
			_ = json.NewEncoder(w).Encode(domain.HydraClient{
				ClientID: clientID,
				Metadata: map[string]interface{}{
					"tenant_id": tenantID,
				},
			})
			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),
	}

	mockKeto.On("DeleteRelation", mock.Anything, "RelyingParty", clientID, "parent_tenant", "Tenant:"+tenantID).Return(nil)

	svc := NewRelyingPartyService(hydraSvc, mockKeto)
	err := svc.Delete(context.Background(), clientID)
	if err != nil {
		t.Fatalf("Delete failed: %v", err)
	}

	mockKeto.AssertExpectations(t)
}