package main

import (
	"context"
	"database/sql"
	"flag"
	"fmt"
	"net/http"
	"os"
	"os/signal"
	"strings"
	"syscall"
	"time"

	"github.com/gin-gonic/gin"
	_ "github.com/lib/pq"

	"github.com/rwadurian/mpc-system/pkg/config"
	"github.com/rwadurian/mpc-system/pkg/jwt"
	"github.com/rwadurian/mpc-system/pkg/logger"
	"github.com/rwadurian/mpc-system/pkg/middleware"
	httphandler "github.com/rwadurian/mpc-system/services/account/adapters/input/http"
	grpcadapter "github.com/rwadurian/mpc-system/services/account/adapters/output/grpc"
	jwtadapter "github.com/rwadurian/mpc-system/services/account/adapters/output/jwt"
	"github.com/rwadurian/mpc-system/services/account/adapters/output/memory"
	"github.com/rwadurian/mpc-system/services/account/adapters/output/postgres"
	"github.com/rwadurian/mpc-system/services/account/application/use_cases"
	"github.com/rwadurian/mpc-system/services/account/domain/repositories"
	"github.com/rwadurian/mpc-system/services/account/domain/services"
	"go.uber.org/zap"
)

func main() {
	// Parse flags
	configPath := flag.String("config", "", "Path to config file")
	flag.Parse()

	// Load configuration
	cfg, err := config.Load(*configPath)
	if err != nil {
		fmt.Printf("Failed to load config: %v\n", err)
		os.Exit(1)
	}

	// Initialize logger
	if err := logger.Init(&logger.Config{
		Level:    cfg.Logger.Level,
		Encoding: cfg.Logger.Encoding,
	}); err != nil {
		fmt.Printf("Failed to initialize logger: %v\n", err)
		os.Exit(1)
	}
	defer logger.Sync()

	logger.Info("Starting Account Service",
		zap.String("environment", cfg.Server.Environment),
		zap.Int("http_port", cfg.Server.HTTPPort))

	// Initialize database connection
	db, err := initDatabase(cfg.Database)
	if err != nil {
		logger.Fatal("Failed to connect to database", zap.Error(err))
	}
	defer db.Close()

	// Initialize gRPC client for session coordinator
	sessionCoordinatorAddr := os.Getenv("MPC_COORDINATOR_URL")
	if sessionCoordinatorAddr == "" {
		sessionCoordinatorAddr = "mpc-session-coordinator:50051"
	}
	sessionCoordinatorClient, err := grpcadapter.NewSessionCoordinatorClient(sessionCoordinatorAddr)
	if err != nil {
		logger.Fatal("Failed to connect to session coordinator", zap.Error(err))
	}
	defer sessionCoordinatorClient.Close()

	// Initialize repositories
	accountRepo := postgres.NewAccountPostgresRepo(db)
	shareRepo := postgres.NewAccountSharePostgresRepo(db)
	recoveryRepo := postgres.NewRecoverySessionPostgresRepo(db)
	sessionEventRepo := postgres.NewSessionEventPostgresRepo(db)

	// Initialize adapters (using in-memory implementations)
	eventPublisher := memory.NewEventPublisherAdapter()
	cacheAdapter := memory.NewCacheAdapter()

	// Initialize JWT service
	jwtService := jwt.NewJWTService(
		cfg.JWT.SecretKey,
		cfg.JWT.Issuer,
		cfg.JWT.TokenExpiry,
		cfg.JWT.RefreshExpiry,
	)
	tokenService := jwtadapter.NewTokenServiceAdapter(jwtService)

	// Initialize domain service
	domainService := services.NewAccountDomainService(accountRepo, shareRepo, recoveryRepo)

	// Initialize use cases
	createAccountUC := use_cases.NewCreateAccountUseCase(accountRepo, shareRepo, domainService, eventPublisher)
	getAccountUC := use_cases.NewGetAccountUseCase(accountRepo, shareRepo)
	updateAccountUC := use_cases.NewUpdateAccountUseCase(accountRepo, eventPublisher)
	listAccountsUC := use_cases.NewListAccountsUseCase(accountRepo)
	getAccountSharesUC := use_cases.NewGetAccountSharesUseCase(accountRepo, shareRepo)
	deactivateShareUC := use_cases.NewDeactivateShareUseCase(accountRepo, shareRepo, eventPublisher)
	loginUC := use_cases.NewLoginUseCase(accountRepo, shareRepo, tokenService, eventPublisher)
	refreshTokenUC := use_cases.NewRefreshTokenUseCase(accountRepo, tokenService)
	generateChallengeUC := use_cases.NewGenerateChallengeUseCase(cacheAdapter)
	initiateRecoveryUC := use_cases.NewInitiateRecoveryUseCase(accountRepo, recoveryRepo, domainService, eventPublisher)
	completeRecoveryUC := use_cases.NewCompleteRecoveryUseCase(accountRepo, shareRepo, recoveryRepo, domainService, eventPublisher)
	getRecoveryStatusUC := use_cases.NewGetRecoveryStatusUseCase(recoveryRepo)
	cancelRecoveryUC := use_cases.NewCancelRecoveryUseCase(accountRepo, recoveryRepo)

	// Create shutdown context
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// Start HTTP server
	errChan := make(chan error, 1)
	go func() {
		if err := startHTTPServer(
			cfg,
			jwtService,
			accountRepo,
			sessionEventRepo,
			createAccountUC,
			getAccountUC,
			updateAccountUC,
			listAccountsUC,
			getAccountSharesUC,
			deactivateShareUC,
			loginUC,
			refreshTokenUC,
			generateChallengeUC,
			initiateRecoveryUC,
			completeRecoveryUC,
			getRecoveryStatusUC,
			cancelRecoveryUC,
			sessionCoordinatorClient,
			db,
		); err != nil {
			errChan <- fmt.Errorf("HTTP server error: %w", err)
		}
	}()

	// Wait for shutdown signal
	sigChan := make(chan os.Signal, 1)
	signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM)

	select {
	case sig := <-sigChan:
		logger.Info("Received shutdown signal", zap.String("signal", sig.String()))
	case err := <-errChan:
		logger.Error("Server error", zap.Error(err))
	}

	// Graceful shutdown
	logger.Info("Shutting down...")
	cancel()

	// Give services time to shutdown gracefully
	time.Sleep(5 * time.Second)
	logger.Info("Shutdown complete")

	_ = ctx
}

func initDatabase(cfg config.DatabaseConfig) (*sql.DB, error) {
	const maxRetries = 10
	const retryDelay = 2 * time.Second

	var db *sql.DB
	var err error

	for i := 0; i < maxRetries; i++ {
		db, err = sql.Open("postgres", cfg.DSN())
		if err != nil {
			logger.Warn("Failed to open database connection, retrying...",
				zap.Int("attempt", i+1),
				zap.Int("max_retries", maxRetries),
				zap.Error(err))
			time.Sleep(retryDelay * time.Duration(i+1))
			continue
		}

		db.SetMaxOpenConns(cfg.MaxOpenConns)
		db.SetMaxIdleConns(cfg.MaxIdleConns)
		db.SetConnMaxLifetime(cfg.ConnMaxLife)

		// Test connection with Ping
		if err = db.Ping(); err != nil {
			logger.Warn("Failed to ping database, retrying...",
				zap.Int("attempt", i+1),
				zap.Int("max_retries", maxRetries),
				zap.Error(err))
			db.Close()
			time.Sleep(retryDelay * time.Duration(i+1))
			continue
		}

		// Verify database is actually usable with a simple query
		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
		var result int
		err = db.QueryRowContext(ctx, "SELECT 1").Scan(&result)
		cancel()
		if err != nil {
			logger.Warn("Database ping succeeded but query failed, retrying...",
				zap.Int("attempt", i+1),
				zap.Int("max_retries", maxRetries),
				zap.Error(err))
			db.Close()
			time.Sleep(retryDelay * time.Duration(i+1))
			continue
		}

		logger.Info("Connected to PostgreSQL and verified connectivity",
			zap.Int("attempt", i+1))
		return db, nil
	}

	return nil, fmt.Errorf("failed to connect to database after %d retries: %w", maxRetries, err)
}

func startHTTPServer(
	cfg *config.Config,
	jwtService *jwt.JWTService,
	accountRepo repositories.AccountRepository,
	sessionEventRepo repositories.SessionEventRepository,
	createAccountUC *use_cases.CreateAccountUseCase,
	getAccountUC *use_cases.GetAccountUseCase,
	updateAccountUC *use_cases.UpdateAccountUseCase,
	listAccountsUC *use_cases.ListAccountsUseCase,
	getAccountSharesUC *use_cases.GetAccountSharesUseCase,
	deactivateShareUC *use_cases.DeactivateShareUseCase,
	loginUC *use_cases.LoginUseCase,
	refreshTokenUC *use_cases.RefreshTokenUseCase,
	generateChallengeUC *use_cases.GenerateChallengeUseCase,
	initiateRecoveryUC *use_cases.InitiateRecoveryUseCase,
	completeRecoveryUC *use_cases.CompleteRecoveryUseCase,
	getRecoveryStatusUC *use_cases.GetRecoveryStatusUseCase,
	cancelRecoveryUC *use_cases.CancelRecoveryUseCase,
	sessionCoordinatorClient *grpcadapter.SessionCoordinatorClient,
	db *sql.DB,
) error {
	// Set Gin mode
	if cfg.Server.Environment == "production" {
		gin.SetMode(gin.ReleaseMode)
	}

	router := gin.New()
	router.Use(gin.Recovery())
	router.Use(gin.Logger())

	// Apply security headers middleware
	router.Use(middleware.SecureHeaders())

	// Apply CORS middleware
	// Parse allowed origins from environment or use defaults
	allowedOrigins := []string{}
	if origins := os.Getenv("CORS_ALLOWED_ORIGINS"); origins != "" {
		allowedOrigins = strings.Split(origins, ",")
	}
	if cfg.Server.Environment != "production" {
		// Allow all origins in development
		router.Use(middleware.AllowAllCORS())
	} else if len(allowedOrigins) > 0 {
		router.Use(middleware.CORS(middleware.CORSConfig{
			AllowOrigins:     allowedOrigins,
			AllowMethods:     []string{"GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"},
			AllowHeaders:     []string{"Origin", "Content-Type", "Accept", "Authorization", "X-Requested-With"},
			ExposeHeaders:    []string{"Content-Length", "X-Request-ID"},
			AllowCredentials: true,
			MaxAge:           86400,
		}))
	}

	// Create HTTP handler with session coordinator client
	httpHandler := httphandler.NewAccountHTTPHandler(
		accountRepo,
		sessionEventRepo,
		createAccountUC,
		getAccountUC,
		updateAccountUC,
		listAccountsUC,
		getAccountSharesUC,
		deactivateShareUC,
		loginUC,
		refreshTokenUC,
		generateChallengeUC,
		initiateRecoveryUC,
		completeRecoveryUC,
		getRecoveryStatusUC,
		cancelRecoveryUC,
		sessionCoordinatorClient,
	)

	// Health check (public)
	router.GET("/health", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{
			"status":  "healthy",
			"service": "account",
		})
	})

	// Create co-managed wallet handler (independent from existing functionality)
	// Uses database connection for invite_code lookups
	coManagedHandler := httphandler.NewCoManagedHTTPHandlerWithDB(sessionCoordinatorClient, db)

	// Configure authentication middleware
	// Skip paths that don't require authentication
	authConfig := middleware.AuthConfig{
		JWTService: jwtService,
		SkipPaths: []string{
			"/health",
			"/api/v1/auth/*",               // Auth endpoints (login, refresh, challenge)
			"/api/v1/accounts/from-keygen", // Internal API from coordinator
			"/api/v1/co-managed/*",         // Co-managed wallet API (public for Service Party App)
		},
		AllowAnonymous: false,
	}

	// API routes with authentication
	api := router.Group("/api/v1")
	api.Use(middleware.BearerAuth(authConfig))
	httpHandler.RegisterRoutes(api)

	// Register co-managed wallet routes (public API)
	coManagedHandler.RegisterRoutes(api)

	logger.Info("Starting HTTP server",
		zap.Int("port", cfg.Server.HTTPPort),
		zap.String("environment", cfg.Server.Environment),
		zap.Bool("cors_enabled", len(allowedOrigins) > 0 || cfg.Server.Environment != "production"))
	return router.Run(fmt.Sprintf(":%d", cfg.Server.HTTPPort))
}