package traefikoidc

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"runtime"
	"strings"
	"sync"
	"testing"
	"time"
)

// ============================================================================
// End-to-End Integration Tests
// ============================================================================

func TestE2EAuthenticationFlow(t *testing.T) {
	t.Run("CompleteAuthFlow", func(t *testing.T) {
		// This test is temporarily disabled due to missing integration setup
		t.Skip("Skipping test until proper integration setup is available")

		// Mock OIDC server would be set up here
		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		config := &MockConfig{
			providerURL:          testServer.URL + "/.well-known/openid-configuration",
			clientID:             "test-client",
			clientSecret:         "test-secret",
			callbackURL:          "/auth/callback",
			sessionEncryptionKey: "test-encryption-key-32-bytes-long",
			logLevel:             "debug",
			scopes:               []string{"openid", "profile", "email"},
		}

		// Create middleware would be done here
		ctx := context.Background()
		protectedHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusOK)
			w.Write([]byte("Protected content"))
		})

		// Test would create middleware here
		_ = ctx
		_ = protectedHandler
		_ = config

		client := &http.Client{
			CheckRedirect: func(req *http.Request, via []*http.Request) error {
				return http.ErrUseLastResponse
			},
		}

		// Test steps would be executed here
		_ = client
	})

	t.Run("SessionManagement", func(t *testing.T) {
		// This test is temporarily disabled due to missing session management setup
		t.Skip("Skipping test until proper session management is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		// Test would validate session lifecycle
	})

	t.Run("TokenValidation", func(t *testing.T) {
		// This test is temporarily disabled due to missing token validation setup
		t.Skip("Skipping test until proper token validation is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		// Test would validate token handling
	})

	t.Run("ErrorHandling", func(t *testing.T) {
		// This test is temporarily disabled due to missing error handling setup
		t.Skip("Skipping test until proper error handling is available")

		// Test would validate error scenarios
	})
}

// ============================================================================
// Provider Compatibility Tests
// ============================================================================

func TestProviderCompatibility(t *testing.T) {
	providers := []struct {
		name           string
		wellKnownURL   string
		setupFunc      func(*testing.T) *httptest.Server
		expectedClaims []string
	}{
		{
			name:           "Generic OIDC Provider",
			wellKnownURL:   "/.well-known/openid-configuration",
			setupFunc:      setupGenericOIDCServer,
			expectedClaims: []string{"sub", "email", "name"},
		},
		{
			name:           "Azure AD",
			wellKnownURL:   "/.well-known/openid-configuration",
			setupFunc:      setupAzureADServer,
			expectedClaims: []string{"sub", "email", "name", "oid", "tid"},
		},
		{
			name:           "Google",
			wellKnownURL:   "/.well-known/openid-configuration",
			setupFunc:      setupGoogleServer,
			expectedClaims: []string{"sub", "email", "name", "picture"},
		},
	}

	for _, provider := range providers {
		t.Run(provider.name, func(t *testing.T) {
			// This test is temporarily disabled due to missing provider setup
			t.Skip("Skipping test until proper provider setup is available")

			server := provider.setupFunc(t)
			defer server.Close()

			config := &MockConfig{
				providerURL:          server.URL + provider.wellKnownURL,
				clientID:             "test-client-" + strings.ToLower(provider.name),
				clientSecret:         "test-secret",
				callbackURL:          "/auth/callback",
				sessionEncryptionKey: "test-encryption-key-32-bytes-long",
			}

			// Test would validate provider-specific behavior
			_ = config
			_ = provider.expectedClaims
		})
	}
}

// ============================================================================
// Load and Stress Tests
// ============================================================================

func TestLoadHandling(t *testing.T) {
	if testing.Short() {
		t.Skip("Skipping load tests in short mode")
	}

	t.Run("ConcurrentAuthentications", func(t *testing.T) {
		// This test is temporarily disabled due to missing load testing setup
		t.Skip("Skipping test until proper load testing is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		config := &MockConfig{
			providerURL:          testServer.URL + "/.well-known/openid-configuration",
			clientID:             "test-client",
			clientSecret:         "test-secret",
			callbackURL:          "/auth/callback",
			sessionEncryptionKey: "test-encryption-key-32-bytes-long",
		}

		concurrentUsers := 100
		var wg sync.WaitGroup
		results := make(chan TestResult, concurrentUsers)

		for i := 0; i < concurrentUsers; i++ {
			wg.Add(1)
			go func(userID int) {
				defer wg.Done()

				result := TestResult{
					UserID:    userID,
					StartTime: time.Now(),
				}

				// Simulate authentication flow
				client := &http.Client{
					CheckRedirect: func(req *http.Request, via []*http.Request) error {
						return http.ErrUseLastResponse
					},
				}

				// Test would execute authentication flow here
				_ = client
				_ = config

				result.EndTime = time.Now()
				result.Duration = result.EndTime.Sub(result.StartTime)
				result.Success = true // Would be determined by actual test

				results <- result
			}(i)
		}

		wg.Wait()
		close(results)

		// Analyze results
		successCount := 0
		totalDuration := time.Duration(0)
		maxDuration := time.Duration(0)

		for result := range results {
			if result.Success {
				successCount++
			}
			totalDuration += result.Duration
			if result.Duration > maxDuration {
				maxDuration = result.Duration
			}
		}

		successRate := float64(successCount) / float64(concurrentUsers) * 100
		avgDuration := totalDuration / time.Duration(concurrentUsers)

		t.Logf("Load test results:")
		t.Logf("  Concurrent users: %d", concurrentUsers)
		t.Logf("  Success rate: %.2f%%", successRate)
		t.Logf("  Average duration: %v", avgDuration)
		t.Logf("  Max duration: %v", maxDuration)

		if successRate < 95.0 {
			t.Errorf("Success rate too low: %.2f%% (expected >= 95%%)", successRate)
		}
	})

	t.Run("SessionScaling", func(t *testing.T) {
		// This test is temporarily disabled due to missing session scaling setup
		t.Skip("Skipping test until proper session scaling is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		maxSessions := 1000
		var activeSessions []*MockSession

		for i := 0; i < maxSessions; i++ {
			session := &MockSession{
				id:       fmt.Sprintf("session-%d", i),
				userID:   fmt.Sprintf("user-%d", i),
				created:  time.Now(),
				lastUsed: time.Now(),
				data:     make(map[string]interface{}),
			}

			activeSessions = append(activeSessions, session)

			// Simulate session operations
			session.data["authenticated"] = true
			session.data["email"] = fmt.Sprintf("user%d@example.com", i)
		}

		t.Logf("Created %d active sessions", len(activeSessions))

		// Measure memory usage
		var m1, m2 runtime.MemStats
		runtime.ReadMemStats(&m1)

		// Simulate session cleanup
		for i := len(activeSessions) - 1; i >= 0; i-- {
			activeSessions[i] = nil
			activeSessions = activeSessions[:i]
		}

		runtime.GC()
		runtime.ReadMemStats(&m2)

		memoryFreed := m1.Alloc - m2.Alloc
		t.Logf("Memory freed after session cleanup: %d bytes", memoryFreed)
	})
}

// ============================================================================
// Security and Edge Case Tests
// ============================================================================

func TestSecurityScenarios(t *testing.T) {
	t.Run("CSRFProtection", func(t *testing.T) {
		// This test is temporarily disabled due to missing CSRF protection setup
		t.Skip("Skipping test until proper CSRF protection is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		// Test would validate CSRF protection
	})

	t.Run("StateParameterValidation", func(t *testing.T) {
		// This test is temporarily disabled due to missing state parameter setup
		t.Skip("Skipping test until proper state parameter validation is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		// Test would validate state parameter handling
	})

	t.Run("TokenReplayAttack", func(t *testing.T) {
		// This test is temporarily disabled due to missing token replay protection
		t.Skip("Skipping test until proper token replay protection is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		// Test would validate protection against token replay
	})

	t.Run("SessionHijacking", func(t *testing.T) {
		// This test is temporarily disabled due to missing session hijacking protection
		t.Skip("Skipping test until proper session hijacking protection is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		// Test would validate protection against session hijacking
	})
}

func TestEdgeCases(t *testing.T) {
	t.Run("NetworkInterruption", func(t *testing.T) {
		// This test is temporarily disabled due to missing network interruption handling
		t.Skip("Skipping test until proper network interruption handling is available")

		// Test would simulate network issues during auth flow
	})

	t.Run("ProviderDowntime", func(t *testing.T) {
		// This test is temporarily disabled due to missing provider downtime handling
		t.Skip("Skipping test until proper provider downtime handling is available")

		// Test would simulate provider unavailability
	})

	t.Run("MalformedTokens", func(t *testing.T) {
		// This test is temporarily disabled due to missing malformed token handling
		t.Skip("Skipping test until proper malformed token handling is available")

		malformedTokens := []string{
			"",                        // Empty token
			"invalid-jwt",             // Invalid format
			"header.payload",          // Missing signature
			"invalid.base64.encoding", // Invalid base64
		}

		for _, token := range malformedTokens {
			t.Run(fmt.Sprintf("Token: %s", token), func(t *testing.T) {
				// Test would validate error handling for malformed tokens
				_ = token
			})
		}
	})

	t.Run("ExpiredTokens", func(t *testing.T) {
		// This test is temporarily disabled due to missing expired token handling
		t.Skip("Skipping test until proper expired token handling is available")

		// Test would validate handling of expired tokens
	})
}

// ============================================================================
// Performance and Resource Tests
// ============================================================================

func TestResourceManagement(t *testing.T) {
	t.Run("MemoryLeaks", func(t *testing.T) {
		// This test is temporarily disabled due to missing memory leak detection
		t.Skip("Skipping test until proper memory leak detection is available")

		testServer := setupMockOIDCServer(t)
		defer testServer.Close()

		var m1, m2 runtime.MemStats
		runtime.ReadMemStats(&m1)

		// Simulate multiple authentication cycles
		for i := 0; i < 100; i++ {
			// Create and destroy sessions
			session := &MockSession{
				id:   fmt.Sprintf("session-%d", i),
				data: make(map[string]interface{}),
			}

			// Simulate session lifecycle
			session.data["authenticated"] = true
			session.data["tokens"] = map[string]string{
				"access_token": "mock-token",
				"id_token":     "mock-id-token",
			}

			// Cleanup
			session.data = nil
			session = nil
		}

		runtime.GC()
		runtime.ReadMemStats(&m2)

		memoryGrowth := m2.Alloc - m1.Alloc
		t.Logf("Memory growth after 100 cycles: %d bytes", memoryGrowth)

		// Allow some memory growth, but not excessive
		if memoryGrowth > 1024*1024 { // 1MB threshold
			t.Errorf("Excessive memory growth detected: %d bytes", memoryGrowth)
		}
	})

	t.Run("GoroutineLeaks", func(t *testing.T) {
		// This test is temporarily disabled due to missing goroutine leak detection
		t.Skip("Skipping test until proper goroutine leak detection is available")

		initialGoroutines := runtime.NumGoroutine()

		// Simulate operations that might create goroutines
		for i := 0; i < 10; i++ {
			// Mock operations would go here
		}

		time.Sleep(100 * time.Millisecond) // Allow goroutines to finish
		runtime.GC()

		finalGoroutines := runtime.NumGoroutine()
		goroutineGrowth := finalGoroutines - initialGoroutines

		t.Logf("Goroutine count - Initial: %d, Final: %d, Growth: %d",
			initialGoroutines, finalGoroutines, goroutineGrowth)

		if goroutineGrowth > 2 { // Allow small variance
			t.Errorf("Potential goroutine leak detected: %d new goroutines", goroutineGrowth)
		}
	})
}

// ============================================================================
// Mock Implementations
// ============================================================================

type MockConfig struct {
	providerURL          string
	clientID             string
	clientSecret         string
	callbackURL          string
	sessionEncryptionKey string
	logLevel             string
	scopes               []string
}

type MockSession struct {
	id       string
	userID   string
	created  time.Time
	lastUsed time.Time
	data     map[string]interface{}
}

type TestResult struct {
	UserID    int
	StartTime time.Time
	EndTime   time.Time
	Duration  time.Duration
	Success   bool
	Error     error
}

// ============================================================================
// Mock Server Setup Functions
// ============================================================================

func setupMockOIDCServer(t *testing.T) *httptest.Server {
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/.well-known/openid-configuration":
			handleWellKnownEndpoint(w, r)
		case "/authorize":
			handleAuthorizeEndpoint(w, r)
		case "/token":
			handleTokenEndpoint(w, r)
		case "/userinfo":
			handleUserInfoEndpoint(w, r)
		case "/jwks":
			handleJWKSEndpoint(w, r)
		default:
			http.NotFound(w, r)
		}
	}))
}

func setupGenericOIDCServer(t *testing.T) *httptest.Server {
	return setupMockOIDCServer(t)
}

func setupAzureADServer(t *testing.T) *httptest.Server {
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Azure AD specific mock responses
		switch r.URL.Path {
		case "/.well-known/openid-configuration":
			handleAzureWellKnownEndpoint(w, r)
		default:
			handleWellKnownEndpoint(w, r)
		}
	}))
}

func setupGoogleServer(t *testing.T) *httptest.Server {
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Google specific mock responses
		switch r.URL.Path {
		case "/.well-known/openid-configuration":
			handleGoogleWellKnownEndpoint(w, r)
		default:
			handleWellKnownEndpoint(w, r)
		}
	}))
}

// ============================================================================
// Mock Endpoint Handlers
// ============================================================================

func handleWellKnownEndpoint(w http.ResponseWriter, r *http.Request) {
	response := map[string]interface{}{
		"issuer":                   "https://mock-provider.example.com",
		"authorization_endpoint":   "https://mock-provider.example.com/authorize",
		"token_endpoint":           "https://mock-provider.example.com/token",
		"userinfo_endpoint":        "https://mock-provider.example.com/userinfo",
		"jwks_uri":                 "https://mock-provider.example.com/jwks",
		"scopes_supported":         []string{"openid", "profile", "email"},
		"response_types_supported": []string{"code"},
		"grant_types_supported":    []string{"authorization_code"},
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(response)
}

func handleAzureWellKnownEndpoint(w http.ResponseWriter, r *http.Request) {
	response := map[string]interface{}{
		"issuer":                   "https://login.microsoftonline.com/tenant/v2.0",
		"authorization_endpoint":   "https://login.microsoftonline.com/tenant/oauth2/v2.0/authorize",
		"token_endpoint":           "https://login.microsoftonline.com/tenant/oauth2/v2.0/token",
		"userinfo_endpoint":        "https://graph.microsoft.com/oidc/userinfo",
		"jwks_uri":                 "https://login.microsoftonline.com/tenant/discovery/v2.0/keys",
		"scopes_supported":         []string{"openid", "profile", "email"},
		"response_types_supported": []string{"code"},
		"grant_types_supported":    []string{"authorization_code"},
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(response)
}

func handleGoogleWellKnownEndpoint(w http.ResponseWriter, r *http.Request) {
	response := map[string]interface{}{
		"issuer":                   "https://accounts.google.com",
		"authorization_endpoint":   "https://accounts.google.com/o/oauth2/v2/auth",
		"token_endpoint":           "https://oauth2.googleapis.com/token",
		"userinfo_endpoint":        "https://openidconnect.googleapis.com/v1/userinfo",
		"jwks_uri":                 "https://www.googleapis.com/oauth2/v3/certs",
		"scopes_supported":         []string{"openid", "profile", "email"},
		"response_types_supported": []string{"code"},
		"grant_types_supported":    []string{"authorization_code"},
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(response)
}

func handleAuthorizeEndpoint(w http.ResponseWriter, r *http.Request) {
	// Mock authorization endpoint
	state := r.URL.Query().Get("state")
	redirectURI := r.URL.Query().Get("redirect_uri")

	if redirectURI == "" {
		http.Error(w, "Missing redirect_uri", http.StatusBadRequest)
		return
	}

	// Simulate successful authorization
	callbackURL := fmt.Sprintf("%s?code=mock-auth-code&state=%s", redirectURI, state)
	http.Redirect(w, r, callbackURL, http.StatusFound)
}

func handleTokenEndpoint(w http.ResponseWriter, r *http.Request) {
	// Mock token endpoint
	response := map[string]interface{}{
		"access_token":  "mock-access-token",
		"id_token":      "mock.id.token",
		"refresh_token": "mock-refresh-token",
		"token_type":    "Bearer",
		"expires_in":    3600,
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(response)
}

func handleUserInfoEndpoint(w http.ResponseWriter, r *http.Request) {
	// Mock userinfo endpoint
	response := map[string]interface{}{
		"sub":   "mock-user-id",
		"email": "test@example.com",
		"name":  "Test User",
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(response)
}

func handleJWKSEndpoint(w http.ResponseWriter, r *http.Request) {
	// Mock JWKS endpoint
	response := map[string]interface{}{
		"keys": []interface{}{},
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(response)
}