package service

import (
	"context"
	"fmt"
	"testing"

	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"github.com/gochat/gochat/internal/auth"
	"github.com/gochat/gochat/internal/config"
	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	"github.com/gochat/gochat/pkg/crypto"
)

// setupBenchmarkDB creates an isolated in-memory SQLite database for benchmarks.
func setupBenchmarkDB(b *testing.B) *gorm.DB {
	b.Helper()
	db, err := gorm.Open(sqlite.Open("file::memory:?cache=shared"), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	if err != nil {
		b.Fatalf("failed to open benchmark db: %v", err)
	}
	if err := db.AutoMigrate(
		&model.Account{},
		&model.User{},
		&model.Inbox{},
		&model.Contact{},
		&model.Conversation{},
		&model.Message{},
		&model.Notification{},
		&model.NotificationPreference{},
	); err != nil {
		b.Fatalf("failed to migrate: %v", err)
	}
	return db
}

// createBenchmarkAccount creates a test account for benchmarks.
func createBenchmarkAccount(b *testing.B, db *gorm.DB, name string) *model.Account {
	b.Helper()
	account := &model.Account{Name: name, Locale: "en", Active: true}
	if err := db.Create(account).Error; err != nil {
		b.Fatalf("failed to create account: %v", err)
	}
	return account
}

// createBenchmarkUser creates a test user for benchmarks.
func createBenchmarkUser(b *testing.B, db *gorm.DB, accountID uint, email string) *model.User {
	b.Helper()
	password, err := crypto.HashPassword("BenchmarkPass123!")
	if err != nil {
		b.Fatalf("failed to hash password: %v", err)
	}
	user := &model.User{
		AccountID: accountID,
		Name:      "Benchmark User",
		Email:     email,
		Password:  password,
		Role:      "agent",
		Active:    true,
	}
	if err := db.Create(user).Error; err != nil {
		b.Fatalf("failed to create user: %v", err)
	}
	return user
}

// createBenchmarkInbox creates a test inbox for benchmarks.
func createBenchmarkInbox(b *testing.B, db *gorm.DB, accountID uint, name string) *model.Inbox {
	b.Helper()
	inbox := &model.Inbox{
		AccountID:    accountID,
		Name:         name,
		ChannelType:  "web_widget",
		EnableAutoAssignment: false,
	}
	if err := db.Create(inbox).Error; err != nil {
		b.Fatalf("failed to create inbox: %v", err)
	}
	return inbox
}

// createBenchmarkContact creates a test contact for benchmarks.
func createBenchmarkContact(b *testing.B, db *gorm.DB, accountID uint, email string) *model.Contact {
	b.Helper()
	contact := &model.Contact{
		AccountID: accountID,
		Name:      "Benchmark Contact",
		Email:     email,
	}
	if err := db.Create(contact).Error; err != nil {
		b.Fatalf("failed to create contact: %v", err)
	}
	return contact
}

// ============================================================================
// Auth Service Benchmarks
// ============================================================================

// BenchmarkAuthServiceLogin benchmarks the full auth login flow (DB lookup + password verify).
// Reference: Chatwoot's Devise login — Ruby bcrypt + ActiveRecord query takes ~50-80ms.
func BenchmarkAuthServiceLogin(b *testing.B) {
	db := setupBenchmarkDB(b)
	account := createBenchmarkAccount(b, db, "Auth Login Bench Org")
	password, err := crypto.HashPassword("BenchmarkPass123!")
	if err != nil {
		b.Fatal(err)
	}
	user := &model.User{
		AccountID: account.ID,
		Name:      "Benchmark User",
		Email:     "bench_auth_login@test.com",
		Password:  password,
		Role:      "agent",
		Active:    true,
	}
	if err := db.Create(user).Error; err != nil {
		b.Fatal(err)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		// Simulate login: find user + verify password
		var found model.User
		db.Where("email = ?", "bench_auth_login@test.com").First(&found)
		crypto.CheckPassword("BenchmarkPass123!", found.Password)
	}
}

// BenchmarkAuthServicePasswordHashing benchmarks bcrypt password hashing (expensive operation).
// Reference: Chatwoot Devise bcrypt — Ruby takes ~100-200ms per hash (cost=10).
func BenchmarkAuthServicePasswordHashing(b *testing.B) {
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := crypto.HashPassword("benchmark_password_123!")
		if err != nil {
			b.Fatal(err)
		}
	}
}

// BenchmarkAuthServicePasswordVerification benchmarks bcrypt password check.
// Reference: Chatwoot Devise bcrypt verify — Ruby takes ~50-100ms per verify.
func BenchmarkAuthServicePasswordVerification(b *testing.B) {
	hash, err := crypto.HashPassword("benchmark_password_123!")
	if err != nil {
		b.Fatal(err)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		crypto.CheckPassword("benchmark_password_123!", hash)
	}
}

// ============================================================================
// JWT Token Benchmarks
// ============================================================================

// BenchmarkJWTGenerateTokenPair benchmarks JWT token pair generation (access + refresh).
// Reference: Chatwoot DeviseTokenAuth — Ruby JWT generation takes ~5-15ms.
func BenchmarkJWTGenerateTokenPair(b *testing.B) {
	cfg := &config.JWTConfig{
		Secret:             "benchmark-secret-key-for-testing",
		ExpiryHours:        1,
		RefreshExpiryHours: 168,
	}
	svc := auth.NewJWTService(cfg)
	user := &model.User{
		Base:    model.Base{ID: 42},
		Name:    "Benchmark Agent",
		Email:   "bench_jwt@test.com",
		Provider: "email",
		Role:    "agent",
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := svc.GenerateTokenPair(user, 1, "agent")
		if err != nil {
			b.Fatal(err)
		}
	}
}

// BenchmarkJWTValidateAccessToken benchmarks JWT access token validation.
// Reference: Chatwoot DeviseTokenAuth token validation — Ruby takes ~3-10ms.
func BenchmarkJWTValidateAccessToken(b *testing.B) {
	cfg := &config.JWTConfig{
		Secret:             "benchmark-secret-key-for-testing",
		ExpiryHours:        1,
		RefreshExpiryHours: 168,
	}
	svc := auth.NewJWTService(cfg)
	user := &model.User{
		Base:    model.Base{ID: 42},
		Name:    "Benchmark Agent",
		Email:   "bench_jwt@test.com",
		Provider: "email",
		Role:    "agent",
	}

	pair, err := svc.GenerateTokenPair(user, 1, "agent")
	if err != nil {
		b.Fatal(err)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := svc.ValidateAccessToken(pair.AccessToken)
		if err != nil {
			b.Fatal(err)
		}
	}
}

// ============================================================================
// Conversation Service Benchmarks
// ============================================================================

// BenchmarkConversationService_Create benchmarks conversation creation via service.
func BenchmarkConversationService_Create(b *testing.B) {
	db := setupBenchmarkDB(b)
	account := createBenchmarkAccount(b, db, "Conv Svc Bench Org")
	inbox := createBenchmarkInbox(b, db, account.ID, "Conv Svc Bench Inbox")
	contact := createBenchmarkContact(b, db, account.ID, "conv_svc@contact.com")

	convRepo := repository.NewConversationRepo(db)
	msgRepo := repository.NewMessageRepo(db)
	svc := NewConversationService(convRepo, msgRepo, nil)
	ctx := context.Background()

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := svc.Create(ctx, account.ID, CreateConversationRequest{
			InboxID:   inbox.ID,
			ContactID: contact.ID,
			Status:    "open",
		})
		if err != nil {
			b.Fatal(err)
		}
	}
}

// BenchmarkConversationService_ListByAccount benchmarks conversation listing via service.
func BenchmarkConversationService_ListByAccount(b *testing.B) {
	db := setupBenchmarkDB(b)
	account := createBenchmarkAccount(b, db, "Conv List Svc Bench Org")
	inbox := createBenchmarkInbox(b, db, account.ID, "Conv List Svc Bench Inbox")
	contact := createBenchmarkContact(b, db, account.ID, "conv_list_svc@contact.com")

	convRepo := repository.NewConversationRepo(db)
	msgRepo := repository.NewMessageRepo(db)
	svc := NewConversationService(convRepo, msgRepo, nil)
	ctx := context.Background()

	// Pre-create 50 conversations
	for i := 0; i < 50; i++ {
		svc.Create(ctx, account.ID, CreateConversationRequest{
			InboxID:   inbox.ID,
			ContactID: contact.ID,
			Status:    "open",
		})
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, _, err := svc.ListByAccount(ctx, account.ID, 0, 25)
		if err != nil {
			b.Fatal(err)
		}
	}
}

// ============================================================================
// Message Service Benchmarks
// ============================================================================

// BenchmarkMessageService_Send benchmarks message creation via service.
func BenchmarkMessageService_Send(b *testing.B) {
	db := setupBenchmarkDB(b)
	account := createBenchmarkAccount(b, db, "Msg Svc Bench Org")
	inbox := createBenchmarkInbox(b, db, account.ID, "Msg Svc Bench Inbox")
	contact := createBenchmarkContact(b, db, account.ID, "msg_svc@contact.com")
	conv := &model.Conversation{
		AccountID:   account.ID,
		InboxID:     inbox.ID,
		ContactID:   contact.ID,
		Status:      "open",
		ChannelType: "web_widget",
		Channel:     "web_widget",
	}
	if err := db.Create(conv).Error; err != nil {
		b.Fatal(err)
	}
	user := createBenchmarkUser(b, db, account.ID, "msg_svc_user@test.com")

	msgRepo := repository.NewMessageRepo(db)
	svc := NewMessageService(msgRepo, nil)
	ctx := context.Background()

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, err := svc.Create(ctx, account.ID, user.ID, CreateMessageRequest{
			ConversationID: conv.ID,
			Content:        fmt.Sprintf("Benchmark send message %d", i),
			MessageType:    "outgoing",
			ContentType:    "text",
		})
		if err != nil {
			b.Fatal(err)
		}
	}
}

// BenchmarkMessageService_ListByConversation benchmarks message listing via service.
func BenchmarkMessageService_ListByConversation(b *testing.B) {
	db := setupBenchmarkDB(b)
	account := createBenchmarkAccount(b, db, "Msg List Svc Bench Org")
	inbox := createBenchmarkInbox(b, db, account.ID, "Msg List Svc Bench Inbox")
	contact := createBenchmarkContact(b, db, account.ID, "msg_list_svc@contact.com")
	conv := &model.Conversation{
		AccountID:   account.ID,
		InboxID:     inbox.ID,
		ContactID:   contact.ID,
		Status:      "open",
		ChannelType: "web_widget",
		Channel:     "web_widget",
	}
	if err := db.Create(conv).Error; err != nil {
		b.Fatal(err)
	}
	user := createBenchmarkUser(b, db, account.ID, "msg_list_svc_user@test.com")

	msgRepo := repository.NewMessageRepo(db)
	svc := NewMessageService(msgRepo, nil)
	ctx := context.Background()

	// Pre-create 50 messages
	for i := 0; i < 50; i++ {
		svc.Create(ctx, account.ID, user.ID, CreateMessageRequest{
			ConversationID: conv.ID,
			Content:        fmt.Sprintf("Pre-created message %d", i),
			MessageType:    "outgoing",
			ContentType:    "text",
		})
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, _, err := svc.ListByConversation(ctx, conv.ID, 0, 25)
		if err != nil {
			b.Fatal(err)
		}
	}
}

// ============================================================================
// Notification Service Benchmarks
// ============================================================================

// BenchmarkNotificationService_Create benchmarks notification creation via service.
func BenchmarkNotificationService_Create(b *testing.B) {
	db := setupBenchmarkDB(b)
	account := createBenchmarkAccount(b, db, "Notif Svc Bench Org")
	user := createBenchmarkUser(b, db, account.ID, "notif_svc@test.com")

	notifRepo := repository.NewNotificationRepo(db)
	prefRepo := repository.NewNotificationPreferenceRepo(db)
	svc := NewNotificationService(db, notifRepo, prefRepo)
	ctx := context.Background()

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		notif := &model.Notification{
			AccountID:        &account.ID,
			UserID:           user.ID,
			NotificationType: "conversation_created",
			PrimaryActorType: "Conversation",
			PrimaryActorID:   uint(i % 1000),
		}
		if err := svc.CreateNotification(ctx, notif); err != nil {
			b.Fatal(err)
		}
	}
}

// BenchmarkNotificationService_ListByUser benchmarks notification listing via service.
func BenchmarkNotificationService_ListByUser(b *testing.B) {
	db := setupBenchmarkDB(b)
	account := createBenchmarkAccount(b, db, "Notif List Svc Bench Org")
	user := createBenchmarkUser(b, db, account.ID, "notif_list_svc@test.com")

	notifRepo := repository.NewNotificationRepo(db)
	prefRepo := repository.NewNotificationPreferenceRepo(db)
	svc := NewNotificationService(db, notifRepo, prefRepo)
	ctx := context.Background()

	// Pre-create 50 notifications
	for i := 0; i < 50; i++ {
		notif := &model.Notification{
			AccountID:        &account.ID,
			UserID:           user.ID,
			NotificationType: "conversation_created",
			PrimaryActorType: "Conversation",
			PrimaryActorID:   uint(i),
		}
		svc.CreateNotification(ctx, notif)
	}

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, _, err := svc.ListNotifications(ctx, user.ID, 1, 25)
		if err != nil {
			b.Fatal(err)
		}
	}
}