package service

import (
	"context"
	"net"
	"testing"
	"time"

	"github.com/user-management-system/internal/domain"
	gormsqlite "gorm.io/driver/sqlite"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

// =============================================================================
// Webhook Service Tests
// =============================================================================

func setupWebhookTestEnv(t *testing.T) (*WebhookService, *gorm.DB) {
	t.Helper()

	db, err := gorm.Open(gormsqlite.New(gormsqlite.Config{
		DriverName: "sqlite",
		DSN:        "file:webhook_test?mode=memory&cache=shared",
	}), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		t.Fatalf("failed to connect database: %v", err)
	}

	if err := db.AutoMigrate(&domain.Webhook{}, &domain.WebhookDelivery{}); err != nil {
		t.Fatalf("failed to migrate: %v", err)
	}

	// Create service with disabled workers to avoid goroutine issues in tests
	svc := NewWebhookService(db, WebhookServiceConfig{
		Enabled:     false,
		WorkerCount: 0,
		QueueSize:   10,
		MaxRetries:  0,
	})

	return svc, db
}

func TestWebhookService_NewWebhookService(t *testing.T) {
	t.Run("Create webhook service with default config", func(t *testing.T) {
		db, err := gorm.Open(gormsqlite.New(gormsqlite.Config{
			DriverName: "sqlite",
			DSN:        "file:webhook_default_test?mode=memory&cache=shared",
		}), &gorm.Config{
			Logger: logger.Default.LogMode(logger.Silent),
		})
		if err != nil {
			t.Fatalf("failed to connect database: %v", err)
		}

		svc := NewWebhookService(db)
		if svc == nil {
			t.Error("Expected non-nil service")
		}
	})

	t.Run("Create webhook service with custom config", func(t *testing.T) {
		db, err := gorm.Open(gormsqlite.New(gormsqlite.Config{
			DriverName: "sqlite",
			DSN:        "file:webhook_custom_test?mode=memory&cache=shared",
		}), &gorm.Config{
			Logger: logger.Default.LogMode(logger.Silent),
		})
		if err != nil {
			t.Fatalf("failed to connect database: %v", err)
		}

		svc := NewWebhookService(db, WebhookServiceConfig{
			Enabled:      false, // Disable workers to avoid goroutine issues
			SecretHeader: "X-Custom-Signature",
			TimeoutSec:   30,
			MaxRetries:   5,
			WorkerCount:  0,
			QueueSize:    100,
		})
		if svc == nil {
			t.Error("Expected non-nil service")
		}
		if svc.config.SecretHeader != "X-Custom-Signature" {
			t.Errorf("Expected SecretHeader 'X-Custom-Signature', got %s", svc.config.SecretHeader)
		}
	})
}

func TestWebhookService_CreateWebhook(t *testing.T) {
	svc, _ := setupWebhookTestEnv(t)
	ctx := context.Background()

	t.Run("Create webhook success", func(t *testing.T) {
		req := &CreateWebhookRequest{
			Name:   "test-webhook",
			URL:    "https://example.com/webhook",
			Secret: "test-secret",
			Events: []domain.WebhookEventType{domain.EventUserRegistered, domain.EventUserUpdated},
		}
		webhook, err := svc.CreateWebhook(ctx, req, 1)
		if err != nil {
			t.Fatalf("CreateWebhook failed: %v", err)
		}
		if webhook.ID == 0 {
			t.Error("Expected webhook ID to be set")
		}
	})
}

func TestWebhookService_GetWebhook(t *testing.T) {
	svc, _ := setupWebhookTestEnv(t)
	ctx := context.Background()

	// Create test webhook
	req := &CreateWebhookRequest{
		Name:   "get-test-webhook",
		URL:    "https://example.com/webhook",
		Secret: "test-secret",
		Events: []domain.WebhookEventType{domain.EventUserRegistered},
	}
	webhook, _ := svc.CreateWebhook(ctx, req, 1)

	t.Run("Get webhook success", func(t *testing.T) {
		result, err := svc.GetWebhook(ctx, webhook.ID)
		if err != nil {
			t.Fatalf("GetWebhook failed: %v", err)
		}
		if result.Name != "get-test-webhook" {
			t.Errorf("Expected name 'get-test-webhook', got %s", result.Name)
		}
	})

	t.Run("Get non-existent webhook", func(t *testing.T) {
		_, err := svc.GetWebhook(ctx, 9999)
		if err == nil {
			t.Error("Expected error for non-existent webhook")
		}
	})
}

func TestWebhookService_ListWebhooks(t *testing.T) {
	svc, _ := setupWebhookTestEnv(t)
	ctx := context.Background()

	// Create test webhooks
	for i := 0; i < 3; i++ {
		req := &CreateWebhookRequest{
			Name:   "list-test-webhook",
			URL:    "https://example.com/webhook",
			Secret: "test-secret",
			Events: []domain.WebhookEventType{domain.EventUserRegistered},
		}
		svc.CreateWebhook(ctx, req, 1)
	}

	t.Run("List webhooks", func(t *testing.T) {
		webhooks, err := svc.ListWebhooks(ctx, 1)
		if err != nil {
			t.Fatalf("ListWebhooks failed: %v", err)
		}
		if len(webhooks) < 3 {
			t.Errorf("Expected at least 3 webhooks, got %d", len(webhooks))
		}
	})
}

func TestWebhookService_UpdateWebhook(t *testing.T) {
	svc, _ := setupWebhookTestEnv(t)
	ctx := context.Background()

	// Create test webhook
	createReq := &CreateWebhookRequest{
		Name:   "update-test-webhook",
		URL:    "https://example.com/webhook",
		Secret: "test-secret",
		Events: []domain.WebhookEventType{domain.EventUserRegistered},
	}
	webhook, _ := svc.CreateWebhook(ctx, createReq, 1)

	t.Run("Update webhook", func(t *testing.T) {
		updateReq := &UpdateWebhookRequest{
			Name: "updated-webhook",
		}
		err := svc.UpdateWebhook(ctx, webhook.ID, updateReq)
		if err != nil {
			t.Fatalf("UpdateWebhook failed: %v", err)
		}

		result, _ := svc.GetWebhook(ctx, webhook.ID)
		if result.Name != "updated-webhook" {
			t.Errorf("Expected name 'updated-webhook', got %s", result.Name)
		}
	})
}

func TestWebhookService_DeleteWebhook(t *testing.T) {
	svc, _ := setupWebhookTestEnv(t)
	ctx := context.Background()

	// Create test webhook
	req := &CreateWebhookRequest{
		Name:   "delete-test-webhook",
		URL:    "https://example.com/webhook",
		Secret: "test-secret",
		Events: []domain.WebhookEventType{domain.EventUserRegistered},
	}
	webhook, _ := svc.CreateWebhook(ctx, req, 1)

	t.Run("Delete webhook", func(t *testing.T) {
		err := svc.DeleteWebhook(ctx, webhook.ID)
		if err != nil {
			t.Fatalf("DeleteWebhook failed: %v", err)
		}

		_, err = svc.GetWebhook(ctx, webhook.ID)
		if err == nil {
			t.Error("Expected error for deleted webhook")
		}
	})
}

func TestWebhookService_Shutdown(t *testing.T) {
	db, err := gorm.Open(gormsqlite.New(gormsqlite.Config{
		DriverName: "sqlite",
		DSN:        "file:webhook_shutdown_test?mode=memory&cache=shared",
	}), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		t.Fatalf("failed to connect database: %v", err)
	}

	svc := NewWebhookService(db, WebhookServiceConfig{
		Enabled:     false, // Disable workers to avoid goroutine issues
		WorkerCount: 0,
		QueueSize:   10,
		MaxRetries:  0,
	})

	// Shutdown should not block
	done := make(chan bool)
	go func() {
		svc.Shutdown(context.Background())
		done <- true
	}()

	select {
	case <-done:
		// Success
	case <-time.After(5 * time.Second):
		t.Error("Shutdown took too long")
	}
}

// =============================================================================
// Webhook Security Functions Tests
// =============================================================================

func TestIsPrivateIP(t *testing.T) {
	tests := []struct {
		name     string
		ip       string
		expected bool
	}{
		// Private ranges - 10.0.0.0/8
		{"10.0.0.0", "10.0.0.0", true},
		{"10.255.255.255", "10.255.255.255", true},
		{"10.1.2.3", "10.1.2.3", true},

		// Private ranges - 172.16.0.0/12
		{"172.16.0.0", "172.16.0.0", true},
		{"172.31.255.255", "172.31.255.255", true},
		{"172.20.1.1", "172.20.1.1", true},

		// Private ranges - 192.168.0.0/16
		{"192.168.0.0", "192.168.0.0", true},
		{"192.168.255.255", "192.168.255.255", true},
		{"192.168.1.100", "192.168.1.100", true},

		// Loopback
		{"127.0.0.1", "127.0.0.1", true},
		{"127.255.255.255", "127.255.255.255", true},
		{"::1", "::1", true},

		// Public IPs
		{"8.8.8.8", "8.8.8.8", false},
		{"1.1.1.1", "1.1.1.1", false},
		{"93.184.216.34", "93.184.216.34", false},
		{"142.250.80.46", "142.250.80.46", false},

		// Edge cases
		{"", "", false},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			ip := net.ParseIP(tt.ip)
			if tt.ip == "" {
				// Empty IP should return false
				result := isPrivateIP(nil)
				if result != false {
					t.Errorf("isPrivateIP(nil) = %v, want %v", result, false)
				}
				return
			}
			if ip == nil {
				t.Skipf("could not parse IP: %s", tt.ip)
			}
			result := isPrivateIP(ip)
			if result != tt.expected {
				t.Errorf("isPrivateIP(%s) = %v, want %v", tt.ip, result, tt.expected)
			}
		})
	}
}

func TestIsSafeURL(t *testing.T) {
	tests := []struct {
		name     string
		url      string
		expected bool
	}{
		// Valid public HTTPS URLs
		{"https example.com", "https://example.com/webhook", true},
		{"https with path", "https://example.com/api/v1/hook", true},
		{"https with query", "https://example.com/hook?a=1&b=2", true},
		{"https with port", "https://example.com:8443/hook", true},
		{"https subdomains", "https://sub.example.com/hook", true},

		// HTTP (allowed but public only)
		{"http public", "http://example.com/hook", true},
		{"http with port", "http://example.com:8080/hook", true},

		// Invalid schemes
		{"ftp scheme", "ftp://example.com/hook", false},
		{"file scheme", "file:///etc/passwd", false},
		{"data scheme", "data:text/html,<script>alert(1)</script>", false},
		{"javascript scheme", "javascript:alert(1)", false},

		// Localhost blocked
		{"localhost http", "http://localhost/hook", false},
		{"localhost https", "https://localhost/hook", false},
		{"127.0.0.1", "http://127.0.0.1/hook", false},
		{"::1", "http://[::1]/hook", false},

		// Private IPs blocked
		{"10.x.x.x", "http://10.0.0.1/hook", false},
		{"172.16.x.x", "http://172.16.0.1/hook", false},
		{"192.168.x.x", "http://192.168.1.1/hook", false},

		// Internal domains blocked
		{"internal domain", "https://server.internal/hook", false},
		{"local domain", "https://host.local/hook", false},
		{"corp domain", "https://host.corp/hook", false},
		{"lan domain", "https://host.lan/hook", false},
		{"intranet domain", "https://host.intranet/hook", false},

		// Cloud metadata IPs blocked
		{"gcp metadata", "http://metadata.google.internal/", false},
		{"aws metadata", "http://169.254.169.254/latest/meta-data/", false},
		{"azure metadata", "http://metadata.azure.internal/", false},
		{"aliyun metadata", "http://100.100.100.200/latest/meta-data/", false},

		// Invalid URLs
		{"empty", "", false},
		{"no scheme", "example.com/hook", false},
		{"relative", "/hook", false},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := isSafeURL(tt.url)
			if result != tt.expected {
				t.Errorf("isSafeURL(%q) = %v, want %v", tt.url, result, tt.expected)
			}
		})
	}
}

func TestComputeHMAC(t *testing.T) {
	tests := []struct {
		name    string
		payload []byte
		secret  string
	}{
		{
			name:    "simple payload",
			payload: []byte(`{"event":"user.created"}`),
			secret:  "test-secret",
		},
		{
			name:    "empty payload",
			payload: []byte{},
			secret:  "test-secret",
		},
		{
			name:    "empty secret",
			payload: []byte(`{"event":"user.deleted"}`),
			secret:  "",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result1 := computeHMAC(tt.payload, tt.secret)
			result2 := computeHMAC(tt.payload, tt.secret)

			// Same input should produce same output
			if result1 != result2 {
				t.Errorf("computeHMAC not deterministic: got %s and %s", result1, result2)
			}

			// Result should not be empty for non-empty payload
			if len(tt.payload) > 0 && result1 == "" {
				t.Error("computeHMAC returned empty string for non-empty payload")
			}

			// Result should be hex-encoded (64 chars for SHA256)
			if len(result1) != 64 {
				t.Errorf("computeHMAC returned %d chars, want 64 (SHA256 hex)", len(result1))
			}
		})
	}
}

func TestComputeHMAC_DifferentInputs(t *testing.T) {
	payload1 := []byte(`{"event":"user.created"}`)
	payload2 := []byte(`{"event":"user.deleted"}`)
	secret := "test-secret"

	result1 := computeHMAC(payload1, secret)
	result2 := computeHMAC(payload2, secret)

	if result1 == result2 {
		t.Error("Different payloads should produce different HMACs")
	}
}

func TestComputeHMAC_DifferentSecrets(t *testing.T) {
	payload := []byte(`{"event":"user.created"}`)

	result1 := computeHMAC(payload, "secret1")
	result2 := computeHMAC(payload, "secret2")

	if result1 == result2 {
		t.Error("Different secrets should produce different HMACs")
	}
}

// =============================================================================
// Webhook Publish and Deliver Tests
// =============================================================================

func TestWebhookService_Publish(t *testing.T) {
	svc, _ := setupWebhookTestEnv(t)
	ctx := context.Background()

	// Create test webhook
	req := &CreateWebhookRequest{
		Name:   "publish-test-webhook",
		URL:    "https://example.com/webhook",
		Secret: "test-secret",
		Events: []domain.WebhookEventType{domain.EventUserRegistered},
	}
	svc.CreateWebhook(ctx, req, 1)

	t.Run("Publish event when disabled", func(t *testing.T) {
		// Service is disabled in setupWebhookTestEnv
		svc.Publish(ctx, domain.EventUserRegistered, map[string]interface{}{"user_id": 1})
		// Should not panic or error
	})
}

func TestWebhookService_ListWebhooksPaginated(t *testing.T) {
	svc, _ := setupWebhookTestEnv(t)
	ctx := context.Background()

	// Create test webhooks
	for i := 0; i < 5; i++ {
		req := &CreateWebhookRequest{
			Name:   "paginated-webhook-" + string(rune('0'+i)),
			URL:    "https://example.com/webhook",
			Secret: "test-secret",
			Events: []domain.WebhookEventType{domain.EventUserRegistered},
		}
		svc.CreateWebhook(ctx, req, 1)
	}

	t.Run("List webhooks paginated", func(t *testing.T) {
		webhooks, total, err := svc.ListWebhooksPaginated(ctx, 1, 0, 10)
		if err != nil {
			t.Fatalf("ListWebhooksPaginated failed: %v", err)
		}
		if total < 5 {
			t.Errorf("Expected at least 5 webhooks, got %d", total)
		}
		if len(webhooks) < 5 {
			t.Errorf("Expected at least 5 webhooks in result, got %d", len(webhooks))
		}
	})
}

func TestWebhookService_GetWebhookDeliveries(t *testing.T) {
	svc, _ := setupWebhookTestEnv(t)
	ctx := context.Background()

	// Create test webhook
	req := &CreateWebhookRequest{
		Name:   "delivery-test-webhook",
		URL:    "https://example.com/webhook",
		Secret: "test-secret",
		Events: []domain.WebhookEventType{domain.EventUserRegistered},
	}
	webhook, _ := svc.CreateWebhook(ctx, req, 1)

	t.Run("Get webhook deliveries", func(t *testing.T) {
		deliveries, err := svc.GetWebhookDeliveries(ctx, webhook.ID, 10)
		if err != nil {
			t.Fatalf("GetWebhookDeliveries failed: %v", err)
		}
		// May be 0 if no deliveries recorded
		_ = deliveries
	})
}