/*
Copyright 2025 linux.do
Modified by Arctel.net, 2026

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package oauth

import (
	"bytes"
	"context"
	"crypto/rand"
	"crypto/rsa"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strconv"
	"strings"
	"testing"
	"time"

	"github.com/coreos/go-oidc/v3/oidc"
	"github.com/gin-contrib/sessions"
	"github.com/gin-contrib/sessions/cookie"
	"github.com/gin-gonic/gin"
	"github.com/go-jose/go-jose/v4"
	"github.com/google/uuid"
	"github.com/redis/go-redis/v9"
	"golang.org/x/oauth2"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"

	"github.com/Rain-kl/Wavelet/internal/config"
	"github.com/Rain-kl/Wavelet/internal/db"
	"github.com/Rain-kl/Wavelet/internal/model"
	"github.com/Rain-kl/Wavelet/internal/util"
)

// -----------------------------------------------------------------------------
// Mocks Setup
// -----------------------------------------------------------------------------

type mockRedisClient struct {
	redis.UniversalClient
	store map[string]string
}

func newMockRedisClient() *mockRedisClient {
	return &mockRedisClient{
		store: make(map[string]string),
	}
}

func (m *mockRedisClient) Set(ctx context.Context, key string, value interface{}, expiration time.Duration) *redis.StatusCmd {
	cmd := redis.NewStatusCmd(ctx)
	var val string
	switch v := value.(type) {
	case []byte:
		val = string(v)
	case string:
		val = v
	default:
		val = fmt.Sprintf("%v", v)
	}
	m.store[key] = val
	cmd.SetVal("OK")
	return cmd
}

func (m *mockRedisClient) Get(ctx context.Context, key string) *redis.StringCmd {
	cmd := redis.NewStringCmd(ctx)
	val, ok := m.store[key]
	if !ok {
		cmd.SetErr(redis.Nil)
	} else {
		cmd.SetVal(val)
	}
	return cmd
}

func (m *mockRedisClient) Del(ctx context.Context, keys ...string) *redis.IntCmd {
	cmd := redis.NewIntCmd(ctx)
	var count int64
	for _, key := range keys {
		if _, ok := m.store[key]; ok {
			delete(m.store, key)
			count++
		}
	}
	cmd.SetVal(count)
	return cmd
}

func (m *mockRedisClient) HSet(ctx context.Context, key string, values ...interface{}) *redis.IntCmd {
	cmd := redis.NewIntCmd(ctx)
	if len(values) >= 2 {
		field := fmt.Sprintf("%v", values[0])
		var val string
		switch v := values[1].(type) {
		case []byte:
			val = string(v)
		case string:
			val = v
		default:
			val = fmt.Sprintf("%v", v)
		}
		compositeKey := key + ":" + field
		m.store[compositeKey] = val
		cmd.SetVal(1)
	} else {
		cmd.SetVal(0)
	}
	return cmd
}

func (m *mockRedisClient) HGet(ctx context.Context, key string, field string) *redis.StringCmd {
	cmd := redis.NewStringCmd(ctx)
	compositeKey := key + ":" + field
	val, ok := m.store[compositeKey]
	if !ok {
		cmd.SetErr(redis.Nil)
	} else {
		cmd.SetVal(val)
	}
	return cmd
}

type mockRoundTripper struct {
	roundTripFunc func(req *http.Request) (*http.Response, error)
}

func (m *mockRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
	return m.roundTripFunc(req)
}

// Global cryptographic tools for custom OIDC mocking
var (
	testRSAPrivateKey *rsa.PrivateKey
	testJWKS          jose.JSONWebKeySet
)

const (
	testIssuerURL     = "https://connect.linux.do"
	testAuthURL       = "https://connect.linux.do/oauth2/authorize"
	testTokenURL      = "https://connect.linux.do/oauth2/token"
	testJWKSURL       = "https://connect.linux.do/oauth2/keys"
	testClientID      = "test_client_id"
	testClientSecret  = "test_client_secret"
	testSourceName    = "linuxdo"
	testSourceDisplay = "LINUX DO"
)

func init() {
	var err error
	testRSAPrivateKey, err = rsa.GenerateKey(rand.Reader, 2048)
	if err != nil {
		panic(fmt.Sprintf("failed to generate RSA key: %v", err))
	}
	jwk := jose.JSONWebKey{
		Key:       &testRSAPrivateKey.PublicKey,
		KeyID:     "test-key-id",
		Algorithm: string(jose.RS256),
		Use:       "sig",
	}
	testJWKS = jose.JSONWebKeySet{
		Keys: []jose.JSONWebKey{jwk},
	}
}

func seedTestAuthSource(t *testing.T, dbConn *gorm.DB) {
	t.Helper()
	if err := dbConn.Create(&model.AuthSource{
		ID:                 100,
		Name:               testSourceName,
		Type:               model.AuthSourceTypeOIDC,
		DisplayName:        testSourceDisplay,
		IsActive:           true,
		ClientID:           testClientID,
		ClientSecret:       testClientSecret,
		OpenIDDiscoveryURL: testIssuerURL,
	}).Error; err != nil {
		t.Fatalf("failed to seed auth source: %v", err)
	}
}

func oidcDiscoveryResponse() *http.Response {
	body := fmt.Sprintf(`{
		"issuer": %q,
		"authorization_endpoint": %q,
		"token_endpoint": %q,
		"jwks_uri": %q,
		"response_types_supported": ["code"],
		"subject_types_supported": ["public"],
		"id_token_signing_alg_values_supported": ["RS256"]
	}`, testIssuerURL, testAuthURL, testTokenURL, testJWKSURL)
	return &http.Response{
		StatusCode: http.StatusOK,
		Body:       io.NopCloser(strings.NewReader(body)),
		Header:     make(http.Header),
	}
}

func jwksResponse() *http.Response {
	jwksJSON, _ := json.Marshal(testJWKS)
	return &http.Response{
		StatusCode: http.StatusOK,
		Body:       io.NopCloser(bytes.NewReader(jwksJSON)),
		Header:     make(http.Header),
	}
}

type mockClaims struct {
	ID       uint64 `json:"id"`
	Issuer   string `json:"iss"`
	Subject  string `json:"sub"`
	Audience string `json:"aud"`
	Expiry   int64  `json:"exp"`
	IssuedAt int64  `json:"iat"`
	Nonce    string `json:"nonce"`
	Username string `json:"preferred_username"`
	Email    string `json:"email"`
	Name     string `json:"name"`
	Active   bool   `json:"active"`
}

func generateMockIDToken(issuer, sub, aud, nonce, username, email, name string) string {
	signer, err := jose.NewSigner(jose.SigningKey{Algorithm: jose.RS256, Key: testRSAPrivateKey}, (&jose.SignerOptions{}).WithType("JWT"))
	if err != nil {
		panic(err)
	}
	id, _ := strconv.ParseUint(sub, 10, 64)
	claims := mockClaims{
		ID:       id,
		Issuer:   issuer,
		Subject:  sub,
		Audience: aud,
		Expiry:   time.Now().Add(time.Hour).Unix(),
		IssuedAt: time.Now().Unix(),
		Nonce:    nonce,
		Username: username,
		Email:    email,
		Name:     name,
		Active:   true,
	}
	payload, _ := json.Marshal(claims)
	object, err := signer.Sign(payload)
	if err != nil {
		panic(err)
	}
	tokenStr, _ := object.CompactSerialize()
	return tokenStr
}

// -----------------------------------------------------------------------------
// Test Helpers
func newMockOIDCClient(issuer, clientID, expectedState, sub, username, email, name string) *http.Client {
	cleanIssuer := strings.TrimRight(issuer, "/")
	return &http.Client{
		Transport: &mockRoundTripper{
			roundTripFunc: func(req *http.Request) (*http.Response, error) {
				urlStr := req.URL.String()
				if req.Method == http.MethodGet && strings.Contains(urlStr, "/.well-known/openid-configuration") {
					body := fmt.Sprintf(`{
						"issuer": %q,
						"authorization_endpoint": %q,
						"token_endpoint": %q,
						"jwks_uri": %q,
						"response_types_supported": ["code"],
						"subject_types_supported": ["public"],
						"id_token_signing_alg_values_supported": ["RS256"]
					}`, cleanIssuer, cleanIssuer+"/oauth2/authorize", cleanIssuer+"/oauth2/token", cleanIssuer+"/oauth2/keys")
					return &http.Response{
						StatusCode: http.StatusOK,
						Body:       io.NopCloser(strings.NewReader(body)),
						Header:     make(http.Header),
					}, nil
				}
				if req.Method == http.MethodGet && (strings.Contains(urlStr, "/keys") || strings.Contains(urlStr, "/jwks")) {
					jwksJSON, _ := json.Marshal(testJWKS)
					return &http.Response{
						StatusCode: http.StatusOK,
						Body:       io.NopCloser(bytes.NewReader(jwksJSON)),
						Header:     make(http.Header),
					}, nil
				}
				if req.Method == http.MethodPost && (strings.Contains(urlStr, "/token") || strings.Contains(urlStr, "/access_token")) {
					idToken := generateMockIDToken(issuer, sub, clientID, expectedState, username, email, name)
					body := fmt.Sprintf(`{"access_token":"mock_access_token","token_type":"Bearer","expires_in":3600,"id_token":"%s"}`, idToken)
					return &http.Response{
						StatusCode: http.StatusOK,
						Body:       io.NopCloser(strings.NewReader(body)),
						Header:     make(http.Header),
					}, nil
				}
				return nil, fmt.Errorf("unexpected mock request: %s %s", req.Method, req.URL)
			},
		},
	}
}

func setupTestDB(t *testing.T) *gorm.DB {
	dbConn, err := gorm.Open(sqlite.Open(":memory:"), &gorm.Config{})
	if err != nil {
		t.Fatalf("failed to open sqlite in memory: %v", err)
	}
	err = dbConn.AutoMigrate(
		&model.User{},
		&model.AuthSource{},
		&model.ExternalAccount{},
		&model.SystemConfig{},
	)
	if err != nil {
		t.Fatalf("failed to migrate schema: %v", err)
	}

	// 注入测试所需的服务器地址配置
	if err := dbConn.Create(&model.SystemConfig{
		Key:   model.ConfigKeyServerAddress,
		Value: "http://localhost:3000",
	}).Error; err != nil {
		t.Fatalf("failed to seed server_address config: %v", err)
	}

	return dbConn
}

func mockContextMiddleware(mockClient *http.Client) gin.HandlerFunc {
	return func(c *gin.Context) {
		ctx := c.Request.Context()
		ctx = context.WithValue(ctx, oauth2.HTTPClient, mockClient)
		ctx = oidc.ClientContext(ctx, mockClient)
		c.Request = c.Request.WithContext(ctx)
		c.Next()
	}
}

func setupTestRouter(dbConn *gorm.DB, mockRedis *mockRedisClient, mockClient *http.Client) *gin.Engine {
	gin.SetMode(gin.TestMode)
	r := gin.New()
	r.Use(gin.Recovery())

	// Inject context mock middleware
	r.Use(mockContextMiddleware(mockClient))

	store := cookie.NewStore([]byte(config.Config.App.SessionSecret))
	store.Options(util.GetSessionOptions(3600))
	r.Use(sessions.Sessions(config.Config.App.SessionCookieName, store))

	db.SetDB(dbConn)
	db.Redis = mockRedis

	api := r.Group("/api/v1")
	{
		api.GET("/oauth/sources", GetLoginSources)
		api.GET("/oauth/login", GetLoginURL)
		api.GET("/oauth/:source/authorize", Authorize)
		api.GET("/oauth/logout", Logout)
		api.POST("/oauth/callback", Callback)
		api.GET("/oauth/user-info", LoginRequired(), UserInfo)
		api.GET("/oauth/external-accounts", LoginRequired(), ListExternalAccounts)
		api.POST("/oauth/external-accounts/:id/delete", LoginRequired(), DeleteExternalAccount)
	}

	return r
}

func performRequest(r http.Handler, method, path string, body []byte, headers map[string]string, cookies []*http.Cookie) *httptest.ResponseRecorder {
	var bodyReader io.Reader
	if body != nil {
		bodyReader = bytes.NewReader(body)
	}
	req, _ := http.NewRequest(method, path, bodyReader)
	for k, v := range headers {
		req.Header.Set(k, v)
	}
	for _, cookie := range cookies {
		if cookie != nil {
			req.AddCookie(cookie)
		}
	}
	w := httptest.NewRecorder()
	r.ServeHTTP(w, req)
	return w
}

func initializeTestConfig() {
	config.Config.App.Env = "testing"
	config.Config.App.SessionCookieName = "test_session_id"
	config.Config.App.SessionSecret = "test_session_secret"
	config.Config.App.APIPrefix = "/api"
}

// -----------------------------------------------------------------------------
// Tests
// -----------------------------------------------------------------------------

func TestGetLoginSources(t *testing.T) {
	initializeTestConfig()
	dbConn := setupTestDB(t)
	mockRedis := newMockRedisClient()

	// Setup empty HTTP Mock
	httpMock := &http.Client{
		Transport: &mockRoundTripper{
			roundTripFunc: func(req *http.Request) (*http.Response, error) {
				return nil, fmt.Errorf("unexpected request")
			},
		},
	}
	util.SetHTTPClient(httpMock)
	router := setupTestRouter(dbConn, mockRedis, httpMock)

	// Inject OIDC login enabled config
	dbConn.Create(&model.SystemConfig{
		Key:   model.ConfigKeyOIDCLoginEnabled,
		Value: "true",
	})

	// Inject active DB auth source
	dbConn.Create(&model.AuthSource{
		ID:                 101,
		Name:               "github",
		Type:               model.AuthSourceTypeOIDC,
		DisplayName:        "GitHub OAuth",
		IsActive:           true,
		ClientID:           "gh_client",
		ClientSecret:       "gh_secret",
		OpenIDDiscoveryURL: "https://github.com",
	})

	// Perform GET request
	w := performRequest(router, http.MethodGet, "/api/v1/oauth/sources", nil, nil, nil)
	if w.Code != http.StatusOK {
		t.Fatalf("expected status 200, got %d", w.Code)
	}

	var resp struct {
		Data []AuthSourceView `json:"data"`
	}
	err := json.Unmarshal(w.Body.Bytes(), &resp)
	if err != nil {
		t.Fatalf("failed to unmarshal response: %v", err)
	}

	if len(resp.Data) != 1 {
		t.Fatalf("expected 1 active source, got %d", len(resp.Data))
	}

	if resp.Data[0].Name != "github" {
		t.Errorf("expected github source, got %s", resp.Data[0].Name)
	}

	// Test disabling OIDC
	dbConn.Model(&model.SystemConfig{}).Where("key = ?", model.ConfigKeyOIDCLoginEnabled).Update("value", "false")
	mockRedis.store = make(map[string]string)

	w2 := performRequest(router, http.MethodGet, "/api/v1/oauth/sources", nil, nil, nil)
	var resp2 struct {
		Data []AuthSourceView `json:"data"`
	}
	_ = json.Unmarshal(w2.Body.Bytes(), &resp2)
	if len(resp2.Data) != 0 {
		t.Errorf("expected 0 sources when OIDC is disabled, got %d", len(resp2.Data))
	}
}

func TestGetLoginURL(t *testing.T) {
	initializeTestConfig()
	dbConn := setupTestDB(t)
	mockRedis := newMockRedisClient()
	seedTestAuthSource(t, dbConn)

	httpMock := &http.Client{
		Transport: &mockRoundTripper{
			roundTripFunc: func(req *http.Request) (*http.Response, error) {
				if req.Method == http.MethodGet && strings.Contains(req.URL.String(), "/.well-known/openid-configuration") {
					return oidcDiscoveryResponse(), nil
				}
				return nil, fmt.Errorf("unexpected request")
			},
		},
	}
	util.SetHTTPClient(httpMock)
	router := setupTestRouter(dbConn, mockRedis, httpMock)

	// Case 1: Default Login URL
	w := performRequest(router, http.MethodGet, "/api/v1/oauth/login", nil, nil, nil)
	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}

	var resp struct {
		Data OAuthAuthorizeResponse `json:"data"`
	}
	err := json.Unmarshal(w.Body.Bytes(), &resp)
	if err != nil {
		t.Fatalf("failed to unmarshal response: %v", err)
	}

	if !strings.Contains(resp.Data.AuthorizeURL, testAuthURL) {
		t.Errorf("invalid authorize URL: %s", resp.Data.AuthorizeURL)
	}

	parsedURL, _ := url.Parse(resp.Data.AuthorizeURL)
	state := parsedURL.Query().Get("state")
	if state == "" {
		t.Error("missing state in URL")
	}

	redisKey := db.PrefixedKey(fmt.Sprintf(OAuthStateCacheKeyFormat, state))
	stateVal, err := mockRedis.Get(context.Background(), redisKey).Result()
	if err != nil {
		t.Fatalf("state not found in redis: %v", err)
	}

	payload, err := decodeOAuthStatePayload(stateVal)
	if err != nil {
		t.Fatalf("failed to decode state payload: %v", err)
	}
	if payload.SourceName != testSourceName || payload.Purpose != OAuthPurposeLogin {
		t.Errorf("unexpected payload: %+v", payload)
	}

	// Case 2: Unknown Source Login URL
	w2 := performRequest(router, http.MethodGet, "/api/v1/oauth/login?source=nonexistent", nil, nil, nil)
	if w2.Code != http.StatusBadRequest {
		t.Errorf("expected 400 for unknown source, got %d", w2.Code)
	}
}

func TestAuthorize(t *testing.T) {
	initializeTestConfig()
	dbConn := setupTestDB(t)
	mockRedis := newMockRedisClient()

	// Setup GitHub active source
	dbConn.Create(&model.AuthSource{
		ID:                 101,
		Name:               "github",
		Type:               model.AuthSourceTypeOIDC,
		DisplayName:        "GitHub OAuth",
		IsActive:           true,
		ClientID:           "gh_client",
		ClientSecret:       "gh_secret",
		OpenIDDiscoveryURL: "https://github.com",
	})

	// Mock OIDC Discovery request
	httpMock := &http.Client{
		Transport: &mockRoundTripper{
			roundTripFunc: func(req *http.Request) (*http.Response, error) {
				if req.Method == http.MethodGet && strings.Contains(req.URL.String(), "/.well-known/openid-configuration") {
					body := `{
						"issuer": "https://github.com",
						"authorization_endpoint": "https://github.com/login/oauth/authorize",
						"token_endpoint": "https://github.com/login/oauth/access_token",
						"jwks_uri": "https://github.com/oauth/keys",
						"response_types_supported": ["code"],
						"subject_types_supported": ["public"],
						"id_token_signing_alg_values_supported": ["RS256"]
					}`
					return &http.Response{
						StatusCode: http.StatusOK,
						Body:       io.NopCloser(strings.NewReader(body)),
						Header:     make(http.Header),
					}, nil
				}
				return nil, fmt.Errorf("unexpected request: %s", req.URL)
			},
		},
	}
	util.SetHTTPClient(httpMock)
	router := setupTestRouter(dbConn, mockRedis, httpMock)

	// Case 1: Active Source Authorize with purpose=bind
	w := performRequest(router, http.MethodGet, "/api/v1/oauth/github/authorize?purpose=bind", nil, nil, nil)
	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d, body: %s", w.Code, w.Body.String())
	}

	var resp struct {
		Data OAuthAuthorizeResponse `json:"data"`
	}
	_ = json.Unmarshal(w.Body.Bytes(), &resp)

	parsedURL, _ := url.Parse(resp.Data.AuthorizeURL)
	state := parsedURL.Query().Get("state")
	redisKey := db.PrefixedKey(fmt.Sprintf(OAuthStateCacheKeyFormat, state))
	stateVal, _ := mockRedis.Get(context.Background(), redisKey).Result()
	payload, _ := decodeOAuthStatePayload(stateVal)

	if payload.SourceName != "github" || payload.Purpose != OAuthPurposeBind {
		t.Errorf("expected source github with purpose bind, got %+v", payload)
	}

	// Case 2: Inactive Source Authorize
	dbConn.Model(&model.AuthSource{}).Where("id = ?", 101).Update("is_active", false)
	w2 := performRequest(router, http.MethodGet, "/api/v1/oauth/github/authorize", nil, nil, nil)
	if w2.Code != http.StatusBadRequest {
		t.Errorf("expected 400 for inactive source, got %d", w2.Code)
	}
}

func TestLogout(t *testing.T) {
	initializeTestConfig()
	dbConn := setupTestDB(t)
	mockRedis := newMockRedisClient()
	httpMock := &http.Client{}
	router := setupTestRouter(dbConn, mockRedis, httpMock)

	w := performRequest(router, http.MethodGet, "/api/v1/oauth/logout", nil, nil, nil)
	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}
}

func TestCallbackLoginAndUserInfo(t *testing.T) {
	initializeTestConfig()
	dbConn := setupTestDB(t)
	mockRedis := newMockRedisClient()
	seedTestAuthSource(t, dbConn)
	state := uuid.NewString()

	// 1. Mock the outgoing HTTP client for token exchange and user info fetching
	httpMock := newMockOIDCClient(testIssuerURL, testClientID, state, "88888", "test_oauth_user", "oauth@linux.do", "Oauth Test User")
	util.SetHTTPClient(httpMock)
	router := setupTestRouter(dbConn, mockRedis, httpMock)

	// 2. Setup state in Redis
	payloadValue, _ := encodeOAuthStatePayload(oauthStatePayload{
		SourceName: testSourceName,
		Purpose:    OAuthPurposeLogin,
	})
	mockRedis.Set(context.Background(), db.PrefixedKey(fmt.Sprintf(OAuthStateCacheKeyFormat, state)), payloadValue, OAuthStateCacheKeyExpiration)

	// 3. Trigger Callback (Login flow - new user)
	reqBody := fmt.Sprintf(`{"state":"%s","code":"test_auth_code"}`, state)
	w := performRequest(router, http.MethodPost, "/api/v1/oauth/callback", []byte(reqBody), map[string]string{
		"Content-Type": "application/json",
	}, nil)

	if w.Code != http.StatusOK {
		t.Fatalf("callback failed with status %d, body: %s", w.Code, w.Body.String())
	}

	var callbackResp struct {
		Data OAuthCallbackResult `json:"data"`
	}
	_ = json.Unmarshal(w.Body.Bytes(), &callbackResp)

	if callbackResp.Data.Status != "logged_in" {
		t.Errorf("expected logged_in status, got %s", callbackResp.Data.Status)
	}

	if callbackResp.Data.User.Username != "test_oauth_user" || callbackResp.Data.User.ID != 88888 {
		t.Errorf("unexpected user returned: %+v", callbackResp.Data.User)
	}

	// Verify user is created in database
	var user model.User
	if err := dbConn.First(&user, "id = ?", 88888).Error; err != nil {
		t.Fatalf("user was not created in DB: %v", err)
	}

	// Extract session cookie
	cookies := w.Result().Cookies()
	var sessionCookie *http.Cookie
	for _, cookie := range cookies {
		if cookie.Name == config.Config.App.SessionCookieName {
			sessionCookie = cookie
			break
		}
	}
	if sessionCookie == nil {
		t.Fatal("session cookie not found in response")
	}

	// 4. Test GET user-info
	w2 := performRequest(router, http.MethodGet, "/api/v1/oauth/user-info", nil, nil, []*http.Cookie{sessionCookie})
	if w2.Code != http.StatusOK {
		t.Fatalf("failed to fetch user info, status %d", w2.Code)
	}

	// 5. Test Callback (Login flow - existing user, username collision check)
	state2 := uuid.NewString()
	mockRedis.Set(context.Background(), db.PrefixedKey(fmt.Sprintf(OAuthStateCacheKeyFormat, state2)), payloadValue, OAuthStateCacheKeyExpiration)

	// Callback with same username but different external ID (99999)
	httpMock2 := newMockOIDCClient(testIssuerURL, testClientID, state2, "99999", "test_oauth_user", "another@linux.do", "Another User")
	util.SetHTTPClient(httpMock2)

	// Create another router for this mock client
	router2 := setupTestRouter(dbConn, mockRedis, httpMock2)

	reqBody2 := fmt.Sprintf(`{"state":"%s","code":"test_auth_code"}`, state2)
	w3 := performRequest(router2, http.MethodPost, "/api/v1/oauth/callback", []byte(reqBody2), map[string]string{
		"Content-Type": "application/json",
	}, nil)

	if w3.Code != http.StatusOK {
		t.Fatalf("callback for collision failed: %d, body: %s", w3.Code, w3.Body.String())
	}

	var collisionResp struct {
		Data OAuthCallbackResult `json:"data"`
	}
	_ = json.Unmarshal(w3.Body.Bytes(), &collisionResp)

	if collisionResp.Data.User.Username != "test_oauth_user-1" {
		t.Errorf("expected collision renamed username, got %s", collisionResp.Data.User.Username)
	}

	t.Run("OIDC login when registration disabled - need bind", func(t *testing.T) {
		// Disable registration in database
		dbConn.Create(&model.SystemConfig{
			Key:   model.ConfigKeyRegistrationEnabled,
			Value: "false",
		})
		defer func() {
			dbConn.Where("key = ?", model.ConfigKeyRegistrationEnabled).Delete(&model.SystemConfig{})
		}()

		state4 := uuid.NewString()
		payloadValue4, _ := encodeOAuthStatePayload(oauthStatePayload{
			SourceName: testSourceName,
			Purpose:    OAuthPurposeLogin,
		})
		mockRedis.Set(context.Background(), db.PrefixedKey(fmt.Sprintf(OAuthStateCacheKeyFormat, state4)), payloadValue4, OAuthStateCacheKeyExpiration)

		httpMock4 := newMockOIDCClient(testIssuerURL, testClientID, state4, "77777", "need_bind_user", "needbind@linux.do", "Need Bind User")
		util.SetHTTPClient(httpMock4)
		router4 := setupTestRouter(dbConn, mockRedis, httpMock4)

		reqBody4 := fmt.Sprintf(`{"state":"%s","code":"test_auth_code"}`, state4)
		w4 := performRequest(router4, http.MethodPost, "/api/v1/oauth/callback", []byte(reqBody4), map[string]string{
			"Content-Type": "application/json",
		}, nil)

		if w4.Code != http.StatusOK {
			t.Fatalf("callback failed: %d, body: %s", w4.Code, w4.Body.String())
		}

		var needBindResp struct {
			Data OAuthCallbackResult `json:"data"`
		}
		_ = json.Unmarshal(w4.Body.Bytes(), &needBindResp)

		if needBindResp.Data.Status != "need_bind" {
			t.Errorf("expected status 'need_bind', got %s", needBindResp.Data.Status)
		}
		if needBindResp.Data.User != nil {
			t.Errorf("expected User to be nil, got %+v", needBindResp.Data.User)
		}
	})
}

func TestCallbackBind(t *testing.T) {
	initializeTestConfig()
	dbConn := setupTestDB(t)
	mockRedis := newMockRedisClient()

	// Create user
	user := model.User{
		ID:          777,
		Username:    "existing_member",
		Nickname:    "Existing Member",
		IsActive:    true,
		LastLoginAt: time.Now(),
	}
	dbConn.Create(&user)

	// Create auth source "github"
	dbConn.Create(&model.AuthSource{
		ID:                 2,
		Name:               "github",
		Type:               model.AuthSourceTypeOIDC,
		DisplayName:        "GitHub",
		IsActive:           true,
		ClientID:           "gh_client",
		ClientSecret:       "gh_secret",
		OpenIDDiscoveryURL: "https://github.com",
	})

	// Inject state in Redis with purpose=bind
	state := uuid.NewString()
	payloadValue, _ := encodeOAuthStatePayload(oauthStatePayload{
		SourceName: "github",
		Purpose:    OAuthPurposeBind,
	})
	mockRedis.Set(context.Background(), db.PrefixedKey(fmt.Sprintf(OAuthStateCacheKeyFormat, state)), payloadValue, OAuthStateCacheKeyExpiration)

	// Mock OIDC discovery, JWKS, and Token exchange for custom source (GitHub)
	httpMock := newMockOIDCClient("https://github.com", "gh_client", state, "github_user_123", "github_tester", "tester@github.com", "GitHub Tester")
	util.SetHTTPClient(httpMock)
	router := setupTestRouter(dbConn, mockRedis, httpMock)

	// Case 1: Bind attempt without session -> 401
	reqBody := fmt.Sprintf(`{"state":"%s","code":"test_code"}`, state)
	w1 := performRequest(router, http.MethodPost, "/api/v1/oauth/callback", []byte(reqBody), map[string]string{
		"Content-Type": "application/json",
	}, nil)

	if w1.Code != http.StatusUnauthorized {
		t.Errorf("expected 401 for unauthenticated bind, got %d, body: %s", w1.Code, w1.Body.String())
	}

	// Case 2: Bind success (authenticated)
	router.GET("/test-helper/login-777", func(c *gin.Context) {
		session := sessions.Default(c)
		session.Set(UserIDKey, uint64(777))
		session.Save()
		c.String(200, "ok")
	})

	wLogin := performRequest(router, http.MethodGet, "/test-helper/login-777", nil, nil, nil)
	var activeCookie *http.Cookie
	for _, cookie := range wLogin.Result().Cookies() {
		if cookie.Name == config.Config.App.SessionCookieName {
			activeCookie = cookie
			break
		}
	}

	// Restore state key in redis
	mockRedis.Set(context.Background(), db.PrefixedKey(fmt.Sprintf(OAuthStateCacheKeyFormat, state)), payloadValue, OAuthStateCacheKeyExpiration)

	w2 := performRequest(router, http.MethodPost, "/api/v1/oauth/callback", []byte(reqBody), map[string]string{
		"Content-Type": "application/json",
	}, []*http.Cookie{activeCookie})

	if w2.Code != http.StatusOK {
		t.Fatalf("expected 200 for bind callback, got %d, body: %s", w2.Code, w2.Body.String())
	}

	var bindResult struct {
		Data OAuthCallbackResult `json:"data"`
	}
	_ = json.Unmarshal(w2.Body.Bytes(), &bindResult)
	if bindResult.Data.Status != "bound" {
		t.Errorf("expected status bound, got %s", bindResult.Data.Status)
	}

	// Verify DB binding
	var binding model.ExternalAccount
	if err := dbConn.First(&binding, "user_id = ? AND external_id = ?", 777, "github_user_123").Error; err != nil {
		t.Fatalf("DB binding record not found: %v", err)
	}

	// Case 3: Bind already bound account to another user
	// Create another user
	user2 := model.User{
		ID:          888,
		Username:    "another_member",
		Nickname:    "Another Member",
		IsActive:    true,
		LastLoginAt: time.Now(),
	}
	dbConn.Create(&user2)

	router.GET("/test-helper/login-888", func(c *gin.Context) {
		session := sessions.Default(c)
		session.Set(UserIDKey, uint64(888))
		session.Save()
		c.String(200, "ok")
	})

	wLogin2 := performRequest(router, http.MethodGet, "/test-helper/login-888", nil, nil, nil)
	var activeCookie2 *http.Cookie
	for _, cookie := range wLogin2.Result().Cookies() {
		if cookie.Name == config.Config.App.SessionCookieName {
			activeCookie2 = cookie
			break
		}
	}

	state3 := uuid.NewString()
	mockRedis.Set(context.Background(), db.PrefixedKey(fmt.Sprintf(OAuthStateCacheKeyFormat, state3)), payloadValue, OAuthStateCacheKeyExpiration)

	// Re-sign token for new state (since state serves as OIDC Nonce)
	httpMock3 := newMockOIDCClient("https://github.com", "gh_client", state3, "github_user_123", "github_tester", "tester@github.com", "GitHub Tester")
	util.SetHTTPClient(httpMock3)
	router3 := setupTestRouter(dbConn, mockRedis, httpMock3)

	reqBody3 := fmt.Sprintf(`{"state":"%s","code":"test_code"}`, state3)
	w3 := performRequest(router3, http.MethodPost, "/api/v1/oauth/callback", []byte(reqBody3), map[string]string{
		"Content-Type": "application/json",
	}, []*http.Cookie{activeCookie2})

	if w3.Code != http.StatusBadRequest {
		t.Errorf("expected 400 for already bound account, got %d, body: %s", w3.Code, w3.Body.String())
	}
}

func TestExternalAccountsListAndDelete(t *testing.T) {
	initializeTestConfig()
	dbConn := setupTestDB(t)
	mockRedis := newMockRedisClient()
	httpMock := &http.Client{}
	router := setupTestRouter(dbConn, mockRedis, httpMock)

	// Create user and external accounts
	dbConn.Create(&model.User{
		ID:       555,
		Username: "account_holder",
		IsActive: true,
	})

	dbConn.Create(&model.AuthSource{
		ID:       10,
		Name:     "gitlab",
		Type:     model.AuthSourceTypeOIDC,
		IsActive: true,
	})

	dbConn.Create(&model.ExternalAccount{
		ID:               2001,
		AuthSourceID:     10,
		UserID:           555,
		ExternalID:       "gitlab_123",
		ExternalUsername: "gitlab_user",
	})

	router.GET("/test-helper/login-555", func(c *gin.Context) {
		session := sessions.Default(c)
		session.Set(UserIDKey, uint64(555))
		session.Save()
		c.String(200, "ok")
	})

	wLogin := performRequest(router, http.MethodGet, "/test-helper/login-555", nil, nil, nil)
	var activeCookie *http.Cookie
	for _, cookie := range wLogin.Result().Cookies() {
		if cookie.Name == config.Config.App.SessionCookieName {
			activeCookie = cookie
			break
		}
	}

	// 1. List accounts
	wList := performRequest(router, http.MethodGet, "/api/v1/oauth/external-accounts", nil, nil, []*http.Cookie{activeCookie})
	if wList.Code != http.StatusOK {
		t.Fatalf("failed to list external accounts: %d", wList.Code)
	}

	var listResp struct {
		Data []model.ExternalAccountView `json:"data"`
	}
	_ = json.Unmarshal(wList.Body.Bytes(), &listResp)
	if len(listResp.Data) != 1 || listResp.Data[0].ExternalUsername != "gitlab_user" {
		t.Errorf("unexpected list response: %+v", listResp.Data)
	}

	// 2. Delete/Unbind account
	wDelete := performRequest(router, http.MethodPost, "/api/v1/oauth/external-accounts/2001/delete", nil, nil, []*http.Cookie{activeCookie})
	if wDelete.Code != http.StatusOK {
		t.Fatalf("failed to delete external account binding: %d, body: %s", wDelete.Code, wDelete.Body.String())
	}

	var count int64
	dbConn.Model(&model.ExternalAccount{}).Where("id = ?", 2001).Count(&count)
	if count != 0 {
		t.Error("binding record was not deleted from DB")
	}
}