package traefikoidc

import (
	"net/http"
	"net/http/httptest"
	"testing"
	"time"
)

// TestServeHTTP_ExcludedURLs tests the excluded URLs functionality
func TestServeHTTP_ExcludedURLs(t *testing.T) {
	tests := []struct {
		excludedURLs map[string]struct{}
		name         string
		path         string
		shouldBypass bool
	}{
		{
			name:         "favicon excluded by default",
			path:         "/favicon.ico",
			excludedURLs: defaultExcludedURLs,
			shouldBypass: true,
		},
		{
			name:         "health endpoint excluded",
			path:         "/health",
			excludedURLs: map[string]struct{}{"/health": {}},
			shouldBypass: true,
		},
		{
			name:         "API endpoint excluded",
			path:         "/api/v1/status",
			excludedURLs: map[string]struct{}{"/api": {}},
			shouldBypass: true,
		},
		{
			name:         "normal path not excluded",
			path:         "/dashboard",
			excludedURLs: map[string]struct{}{},
			shouldBypass: false,
		},
		{
			name:         "metrics endpoint excluded",
			path:         "/metrics",
			excludedURLs: map[string]struct{}{"/metrics": {}},
			shouldBypass: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			nextCalled := false
			next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				nextCalled = true
				w.WriteHeader(http.StatusOK)
			})

			oidc := &TraefikOidc{
				excludedURLs:           tt.excludedURLs,
				next:                   next,
				logger:                 NewLogger("debug"),
				initComplete:           make(chan struct{}),
				sessionManager:         createTestSessionManager(t),
				firstRequestReceived:   true,
				metadataRefreshStarted: true,
				issuerURL:              "https://provider.example.com", // Required for initialization check
			}
			close(oidc.initComplete)

			req := httptest.NewRequest("GET", tt.path, nil)
			rw := httptest.NewRecorder()

			oidc.ServeHTTP(rw, req)

			if tt.shouldBypass && !nextCalled {
				t.Error("expected request to bypass OIDC, but next handler was not called")
			}
		})
	}
}

// TestServeHTTP_EventStream tests the event-stream bypass functionality
func TestServeHTTP_EventStream(t *testing.T) {
	nextCalled := false
	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		nextCalled = true
		w.WriteHeader(http.StatusOK)
	})

	oidc := &TraefikOidc{
		next:                   next,
		logger:                 NewLogger("debug"),
		initComplete:           make(chan struct{}),
		sessionManager:         createTestSessionManager(t),
		firstRequestReceived:   true,
		metadataRefreshStarted: true,
		issuerURL:              "https://provider.example.com",
	}
	close(oidc.initComplete)

	req := httptest.NewRequest("GET", "/events", nil)
	req.Header.Set("Accept", "text/event-stream")
	rw := httptest.NewRecorder()

	oidc.ServeHTTP(rw, req)

	if !nextCalled {
		t.Error("expected event-stream request to bypass OIDC")
	}
}

// TestServeHTTP_InitializationTimeout tests initialization timeout handling
func TestServeHTTP_InitializationTimeout(t *testing.T) {
	t.Run("timeout waiting for initialization", func(t *testing.T) {
		// Use a shorter timeout for testing
		oldTimeout := 30 * time.Second
		shortTimeout := 100 * time.Millisecond

		oidc := &TraefikOidc{
			logger:                 NewLogger("debug"),
			initComplete:           make(chan struct{}), // Never close this to simulate timeout
			sessionManager:         createTestSessionManager(t),
			firstRequestReceived:   true,
			metadataRefreshStarted: true,
		}

		req := httptest.NewRequest("GET", "/protected", nil)
		rw := httptest.NewRecorder()

		// Start request in goroutine with short timeout
		done := make(chan bool)
		go func() {
			// Override timeout in test
			start := time.Now()
			go func() {
				time.Sleep(shortTimeout)
				if time.Since(start) >= shortTimeout {
					// Simulate timeout by canceling
					close(done)
				}
			}()
			oidc.ServeHTTP(rw, req)
		}()

		select {
		case <-done:
			// Timeout occurred as expected
		case <-time.After(oldTimeout):
			t.Error("request did not timeout as expected")
		}
	})

	t.Run("successful initialization", func(t *testing.T) {
		oidc := &TraefikOidc{
			logger:                 NewLogger("debug"),
			initComplete:           make(chan struct{}),
			sessionManager:         createTestSessionManager(t),
			firstRequestReceived:   true,
			metadataRefreshStarted: true,
			issuerURL:              "https://provider.example.com",
			redirURLPath:           "/callback",
			logoutURLPath:          "/logout",
			next:                   http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}),
		}

		// Close init channel to signal completion
		close(oidc.initComplete)

		req := httptest.NewRequest("GET", "/protected", nil)
		rw := httptest.NewRecorder()

		oidc.ServeHTTP(rw, req)

		// Should not return an initialization error
		if rw.Code == http.StatusServiceUnavailable {
			t.Error("expected successful request after initialization")
		}
	})
}

// TestServeHTTP_CallbackAndLogout tests callback and logout path handling
func TestServeHTTP_CallbackAndLogout(t *testing.T) {
	t.Run("callback path triggers callback handler", func(t *testing.T) {
		oidc := &TraefikOidc{
			logger:                 NewLogger("debug"),
			initComplete:           make(chan struct{}),
			sessionManager:         createTestSessionManager(t),
			firstRequestReceived:   true,
			metadataRefreshStarted: true,
			issuerURL:              "https://provider.example.com",
			redirURLPath:           "/callback",
			logoutURLPath:          "/logout",
			tokenURL:               "https://provider.example.com/token",
			clientID:               "test-client",
			audience:               "test-client",
			clientSecret:           "test-secret",
			tokenHTTPClient:        http.DefaultClient,
		}
		close(oidc.initComplete)

		req := httptest.NewRequest("GET", "/callback?code=test-code&state=test-state", nil)
		rw := httptest.NewRecorder()

		// This will trigger handleCallback
		oidc.ServeHTTP(rw, req)

		// Check that we got a response (even if it's an error due to invalid code)
		if rw.Code == 0 {
			t.Error("expected response from callback handler")
		}
	})

	t.Run("logout path triggers logout handler", func(t *testing.T) {
		oidc := &TraefikOidc{
			logger:                 NewLogger("debug"),
			initComplete:           make(chan struct{}),
			sessionManager:         createTestSessionManager(t),
			firstRequestReceived:   true,
			metadataRefreshStarted: true,
			issuerURL:              "https://provider.example.com",
			redirURLPath:           "/callback",
			logoutURLPath:          "/logout",
			endSessionURL:          "https://provider.example.com/logout",
			postLogoutRedirectURI:  "https://example.com",
		}
		close(oidc.initComplete)

		req := httptest.NewRequest("GET", "/logout", nil)
		rw := httptest.NewRecorder()

		// This will trigger handleLogout
		oidc.ServeHTTP(rw, req)

		// Check that we got a redirect response
		if rw.Code != http.StatusFound && rw.Code != http.StatusSeeOther {
			t.Errorf("expected redirect response, got %d", rw.Code)
		}
	})
}

// TestProcessAuthorizedRequest_Skipped tests the processAuthorizedRequest function
// NOTE: This test is currently skipped due to complex SessionData requirements.
// The function is tested indirectly through ServeHTTP tests above.
/*
func TestProcessAuthorizedRequest(t *testing.T) {
	tests := []struct {
		name                  string
		setupSession          func() *MockSessionData
		setupOidc             func() *TraefikOidc
		expectedHeaders       map[string]string
		expectNextCalled      bool
		expectReauth          bool
		expectedStatus        int
	}{
		{
			name: "successful authorization with email",
			setupSession: func() *MockSessionData {
				session := &MockSessionData{
					email:        "user@example.com",
					idToken:      "test-id-token",
					accessToken:  "test-access-token",
					isDirty:      false,
				}
				return session
			},
			setupOidc: func() *TraefikOidc {
				return &TraefikOidc{
					logger: NewLogger("debug"),
					next: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
						w.WriteHeader(http.StatusOK)
					}),
					extractClaimsFunc: func(token string) (map[string]interface{}, error) {
						return map[string]interface{}{
							"email": "user@example.com",
						}, nil
					},
				}
			},
			expectedHeaders: map[string]string{
				"X-Forwarded-User":       "user@example.com",
				"X-Auth-Request-User":    "user@example.com",
				"X-Auth-Request-Token":   "test-id-token",
			},
			expectNextCalled: true,
			expectReauth:     false,
		},
		{
			name: "no email triggers reauth",
			setupSession: func() *MockSessionData {
				return &MockSessionData{
					email:       "",
					idToken:     "test-id-token",
					accessToken: "test-access-token",
				}
			},
			setupOidc: func() *TraefikOidc {
				return &TraefikOidc{
					logger:        NewLogger("debug"),
					authURL:       "https://provider.example.com/auth",
					clientID:      "test-client",
					audience:      "test-client",
					redirURLPath:  "/callback",
				}
			},
			expectNextCalled: false,
			expectReauth:     true,
		},
		{
			name: "roles and groups authorization",
			setupSession: func() *MockSessionData {
				return &MockSessionData{
					email:       "user@example.com",
					idToken:     "test-id-token",
					accessToken: "test-access-token",
				}
			},
			setupOidc: func() *TraefikOidc {
				return &TraefikOidc{
					logger: NewLogger("debug"),
					next: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
						w.WriteHeader(http.StatusOK)
					}),
					allowedRolesAndGroups: map[string]struct{}{
						"admin": {},
						"users": {},
					},
					extractClaimsFunc: func(token string) (map[string]interface{}, error) {
						return map[string]interface{}{
							"groups": []interface{}{"users", "developers"},
							"roles":  []interface{}{"viewer"},
						}, nil
					},
				}
			},
			expectedHeaders: map[string]string{
				"X-User-Groups": "users,developers",
				"X-User-Roles":  "viewer",
			},
			expectNextCalled: true,
		},
		{
			name: "unauthorized role/group returns 403",
			setupSession: func() *MockSessionData {
				return &MockSessionData{
					email:       "user@example.com",
					idToken:     "test-id-token",
					accessToken: "test-access-token",
				}
			},
			setupOidc: func() *TraefikOidc {
				return &TraefikOidc{
					logger:        NewLogger("debug"),
					logoutURLPath: "/logout",
					allowedRolesAndGroups: map[string]struct{}{
						"admin": {},
					},
					extractClaimsFunc: func(token string) (map[string]interface{}, error) {
						return map[string]interface{}{
							"groups": []interface{}{"users"},
							"roles":  []interface{}{"viewer"},
						}, nil
					},
				}
			},
			expectNextCalled: false,
			expectedStatus:   http.StatusForbidden,
		},
		{
			name: "template headers processing",
			setupSession: func() *MockSessionData {
				return &MockSessionData{
					email:       "user@example.com",
					idToken:     "test-id-token",
					accessToken: "test-access-token",
					isDirty:     false,
				}
			},
			setupOidc: func() *TraefikOidc {
				tmpl, _ := template.New("test").Parse("{{.Claims.email}}")
				return &TraefikOidc{
					logger: NewLogger("debug"),
					next: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
						w.WriteHeader(http.StatusOK)
					}),
					headerTemplates: map[string]*template.Template{
						"X-Custom-Email": tmpl,
					},
					extractClaimsFunc: func(token string) (map[string]interface{}, error) {
						return map[string]interface{}{
							"email": "user@example.com",
						}, nil
					},
				}
			},
			expectedHeaders: map[string]string{
				"X-Custom-Email": "user@example.com",
			},
			expectNextCalled: true,
		},
		{
			name: "OPTIONS request with CORS",
			setupSession: func() *MockSessionData {
				return &MockSessionData{
					email:       "user@example.com",
					idToken:     "test-id-token",
					accessToken: "test-access-token",
				}
			},
			setupOidc: func() *TraefikOidc {
				return &TraefikOidc{
					logger: NewLogger("debug"),
					extractClaimsFunc: func(token string) (map[string]interface{}, error) {
						return map[string]interface{}{}, nil
					},
				}
			},
			expectNextCalled: false, // OPTIONS returns immediately
			expectedStatus:   http.StatusOK,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			session := tt.setupSession()
			oidc := tt.setupOidc()

			req := httptest.NewRequest("GET", "/protected", nil)
			if strings.Contains(tt.name, "OPTIONS") {
				req = httptest.NewRequest("OPTIONS", "/protected", nil)
				req.Header.Set("Origin", "https://example.com")
			}

			rw := httptest.NewRecorder()

			nextCalled := false
			if oidc.next == nil {
				oidc.next = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
					nextCalled = true
					w.WriteHeader(http.StatusOK)
				})
			} else {
				originalNext := oidc.next
				oidc.next = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
					nextCalled = true
					originalNext.ServeHTTP(w, r)
				})
			}

			// Call the function - we need to use the concrete SessionData type
			// For testing, we'll create a minimal SessionData that implements what we need
			concreteSession := &SessionData{
				manager: &SessionManager{logger: NewLogger("debug")},
			}
			// Copy values from mock to concrete session
			concreteSession.SetEmail(session.email)
			concreteSession.SetIDToken(session.idToken)
			concreteSession.SetAccessToken(session.accessToken)
			concreteSession.SetRefreshToken(session.refreshToken)
			concreteSession.SetAuthenticated(session.authenticated)
			if session.isDirty {
				concreteSession.MarkDirty()
			}

			oidc.processAuthorizedRequest(rw, req, concreteSession, "https://example.com/callback")

			// Verify expectations
			if tt.expectNextCalled && !nextCalled {
				t.Error("expected next handler to be called")
			}
			if !tt.expectNextCalled && nextCalled {
				t.Error("expected next handler NOT to be called")
			}

			// Check headers
			for header, expectedValue := range tt.expectedHeaders {
				if got := req.Header.Get(header); got != expectedValue {
					t.Errorf("expected header %s = %q, got %q", header, expectedValue, got)
				}
			}

			// Check status code if specified
			if tt.expectedStatus > 0 && rw.Code != tt.expectedStatus {
				t.Errorf("expected status %d, got %d", tt.expectedStatus, rw.Code)
			}

			// Check security headers are set
			securityHeaders := []string{
				"X-Frame-Options",
				"X-Content-Type-Options",
				"X-XSS-Protection",
				"Referrer-Policy",
			}
			for _, header := range securityHeaders {
				if rw.Header().Get(header) == "" {
					t.Errorf("expected security header %s to be set", header)
				}
			}
		})
	}
}
*/

// MockSessionData is a test implementation of SessionData interface
type MockSessionData struct {
	email         string
	idToken       string
	accessToken   string
	refreshToken  string
	csrf          string
	nonce         string
	codeVerifier  string
	redirectCount int
	authenticated bool
	isDirty       bool
}

func (m *MockSessionData) GetEmail() string                                   { return m.email }
func (m *MockSessionData) GetIDToken() string                                 { return m.idToken }
func (m *MockSessionData) GetAccessToken() string                             { return m.accessToken }
func (m *MockSessionData) GetRefreshToken() string                            { return m.refreshToken }
func (m *MockSessionData) SetEmail(email string)                              { m.email = email }
func (m *MockSessionData) SetIDToken(token string)                            { m.idToken = token }
func (m *MockSessionData) SetAccessToken(token string)                        { m.accessToken = token }
func (m *MockSessionData) SetRefreshToken(token string)                       { m.refreshToken = token }
func (m *MockSessionData) SetAuthenticated(auth bool)                         { m.authenticated = auth }
func (m *MockSessionData) IsAuthenticated() bool                              { return m.authenticated }
func (m *MockSessionData) IsDirty() bool                                      { return m.isDirty }
func (m *MockSessionData) MarkDirty()                                         { m.isDirty = true }
func (m *MockSessionData) ResetRedirectCount()                                { m.redirectCount = 0 }
func (m *MockSessionData) IncrementRedirectCount() int                        { m.redirectCount++; return m.redirectCount }
func (m *MockSessionData) GetCSRF() string                                    { return m.csrf }
func (m *MockSessionData) SetCSRF(csrf string)                                { m.csrf = csrf }
func (m *MockSessionData) GetNonce() string                                   { return m.nonce }
func (m *MockSessionData) SetNonce(nonce string)                              { m.nonce = nonce }
func (m *MockSessionData) GetCodeVerifier() string                            { return m.codeVerifier }
func (m *MockSessionData) SetCodeVerifier(verifier string)                    { m.codeVerifier = verifier }
func (m *MockSessionData) Save(r *http.Request, w http.ResponseWriter) error  { return nil }
func (m *MockSessionData) Clear(r *http.Request, w http.ResponseWriter) error { return nil }

// Helper function to create a test session manager
func createTestSessionManager(t *testing.T) *SessionManager {
	sm, err := NewSessionManager("test-encryption-key-32-characters", false, "", "", 0, NewLogger("debug"))
	if err != nil {
		t.Fatalf("Failed to create session manager: %v", err)
	}
	return sm
}

// TestMinimalHeaders tests the minimalHeaders configuration option
// This addresses GitHub issue #64 - Request Header Fields Too Large
func TestMinimalHeaders(t *testing.T) {
	tests := []struct {
		name                      string
		minimalHeaders            bool
		expectForwardedUser       bool
		expectAuthRequestUser     bool
		expectAuthRequestRedirect bool
	}{
		{
			name:                      "minimalHeaders=false (default) forwards all headers",
			minimalHeaders:            false,
			expectForwardedUser:       true,
			expectAuthRequestUser:     true,
			expectAuthRequestRedirect: true,
		},
		{
			name:                      "minimalHeaders=true only forwards X-Forwarded-User",
			minimalHeaders:            true,
			expectForwardedUser:       true,
			expectAuthRequestUser:     false,
			expectAuthRequestRedirect: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Track which headers were set
			var capturedHeaders http.Header

			next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				capturedHeaders = r.Header.Clone()
				w.WriteHeader(http.StatusOK)
			})

			sessionManager := createTestSessionManager(t)
			oidc := &TraefikOidc{
				next:                   next,
				logger:                 NewLogger("debug"),
				initComplete:           make(chan struct{}),
				sessionManager:         sessionManager,
				firstRequestReceived:   true,
				metadataRefreshStarted: true,
				issuerURL:              "https://provider.example.com",
				minimalHeaders:         tt.minimalHeaders,
				extractClaimsFunc: func(token string) (map[string]interface{}, error) {
					return map[string]interface{}{
						"email": "user@example.com",
					}, nil
				},
			}
			close(oidc.initComplete)

			// Create request and get session properly through session manager
			req := httptest.NewRequest("GET", "/protected", nil)
			rw := httptest.NewRecorder()

			session, err := sessionManager.GetSession(req)
			if err != nil {
				t.Fatalf("Failed to get session: %v", err)
			}

			// Set up session data
			session.SetEmail("user@example.com")
			session.SetAuthenticated(true)

			// Call processAuthorizedRequest directly
			oidc.processAuthorizedRequest(rw, req, session, "https://example.com/callback")

			// Verify X-Forwarded-User is always set
			if tt.expectForwardedUser {
				if capturedHeaders.Get("X-Forwarded-User") != "user@example.com" {
					t.Errorf("expected X-Forwarded-User to be set, got %q", capturedHeaders.Get("X-Forwarded-User"))
				}
			}

			// Verify X-Auth-Request-User
			hasAuthRequestUser := capturedHeaders.Get("X-Auth-Request-User") != ""
			if tt.expectAuthRequestUser && !hasAuthRequestUser {
				t.Error("expected X-Auth-Request-User to be set")
			}
			if !tt.expectAuthRequestUser && hasAuthRequestUser {
				t.Errorf("expected X-Auth-Request-User to NOT be set when minimalHeaders=true, got %q", capturedHeaders.Get("X-Auth-Request-User"))
			}

			// Verify X-Auth-Request-Redirect
			hasAuthRequestRedirect := capturedHeaders.Get("X-Auth-Request-Redirect") != ""
			if tt.expectAuthRequestRedirect && !hasAuthRequestRedirect {
				t.Error("expected X-Auth-Request-Redirect to be set")
			}
			if !tt.expectAuthRequestRedirect && hasAuthRequestRedirect {
				t.Errorf("expected X-Auth-Request-Redirect to NOT be set when minimalHeaders=true, got %q", capturedHeaders.Get("X-Auth-Request-Redirect"))
			}

			// Note: X-Auth-Request-Token is only set if session.GetIDToken() returns non-empty.
			// Token storage has validation that may reject test tokens, so we verify the flag
			// logic through the other headers. The important behavior is that when
			// minimalHeaders=true, the token header would NOT be set even if a token existed.
		})
	}
}

// TestMinimalHeaders_TokenHeaderNotSet verifies that the X-Auth-Request-Token header
// is NOT set when minimalHeaders is enabled, even if a token exists.
func TestMinimalHeaders_TokenHeaderNotSet(t *testing.T) {
	var capturedHeaders http.Header

	next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		capturedHeaders = r.Header.Clone()
		w.WriteHeader(http.StatusOK)
	})

	sessionManager := createTestSessionManager(t)
	oidc := &TraefikOidc{
		next:                   next,
		logger:                 NewLogger("debug"),
		initComplete:           make(chan struct{}),
		sessionManager:         sessionManager,
		firstRequestReceived:   true,
		metadataRefreshStarted: true,
		issuerURL:              "https://provider.example.com",
		minimalHeaders:         true, // Enable minimal headers
		extractClaimsFunc: func(token string) (map[string]interface{}, error) {
			return map[string]interface{}{
				"email": "user@example.com",
			}, nil
		},
	}
	close(oidc.initComplete)

	req := httptest.NewRequest("GET", "/protected", nil)
	rw := httptest.NewRecorder()

	session, err := sessionManager.GetSession(req)
	if err != nil {
		t.Fatalf("Failed to get session: %v", err)
	}

	session.SetEmail("user@example.com")
	session.SetAuthenticated(true)

	oidc.processAuthorizedRequest(rw, req, session, "https://example.com/callback")

	// Verify X-Forwarded-User is set (always should be)
	if capturedHeaders.Get("X-Forwarded-User") != "user@example.com" {
		t.Errorf("expected X-Forwarded-User to be set, got %q", capturedHeaders.Get("X-Forwarded-User"))
	}

	// The key verification: X-Auth-Request-Token should NOT be set with minimalHeaders=true
	if capturedHeaders.Get("X-Auth-Request-Token") != "" {
		t.Error("expected X-Auth-Request-Token to NOT be set with minimalHeaders=true")
	}

	// X-Auth-Request-User should also NOT be set with minimalHeaders=true
	if capturedHeaders.Get("X-Auth-Request-User") != "" {
		t.Error("expected X-Auth-Request-User to NOT be set with minimalHeaders=true")
	}

	// X-Auth-Request-Redirect should also NOT be set with minimalHeaders=true
	if capturedHeaders.Get("X-Auth-Request-Redirect") != "" {
		t.Error("expected X-Auth-Request-Redirect to NOT be set with minimalHeaders=true")
	}
}