package main

import (
	"context"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"
	"runtime"

	"github.com/go-chi/chi/v5"
	"github.com/rs/cors"

	"messenger/internal/api/handlers"
	"messenger/internal/api/middleware"
	"messenger/internal/config"
	"messenger/internal/crypto"
	"messenger/internal/pkg/logger"
	"messenger/internal/repository/sqlite"
	"messenger/internal/service"
	"messenger/internal/websocket"
)


func main() {
	// Загружаем конфиг
	cfg := config.Load()
	
	// Инициализируем логгер
	logger.Init(cfg.Environment)
	
	// Подключаемся к БД
	db, err := sqlite.NewDB(cfg.DBPath)
	if err != nil {
		logger.Error("Failed to connect to database", "error", err)
		os.Exit(1)
	}
	defer db.Close()
	
	// Инициализируем шифрование
	encryptor, err := crypto.NewEncryptor(cfg.EncryptionKey)
	if err != nil {
		logger.Error("Failed to initialize encryption", "error", err)
		os.Exit(1)
	}
	
	// Создаем репозитории
	userRepo := sqlite.NewUserRepository(db)
	profileRepo := sqlite.NewProfileRepository(db)
	chatRepo := sqlite.NewChatRepository(db)
	messageRepo := sqlite.NewMessageRepository(db)
	attachmentRepo := sqlite.NewAttachmentRepository(db)
	
	// Создаем сервисы
	authService := service.NewAuthService(userRepo, profileRepo, cfg.JWTSecret, cfg.JWTExpiryHours)
	userService := service.NewUserService(userRepo, profileRepo)
	chatService := service.NewChatService(chatRepo, userRepo, messageRepo)
	messageService := service.NewMessageService(messageRepo, chatRepo, userRepo, attachmentRepo, encryptor)
	fileService := service.NewFileService(attachmentRepo, chatRepo, cfg.StoragePath, cfg.MaxFileSizeMB)
	adminService := service.NewAdminService(userRepo, chatRepo, messageRepo, fileService)
	
	// Создаем WebSocket Hub
	wsHub := websocket.NewHub(messageService, chatService)
	go wsHub.Run()
	
	// Создаем хендлеры
	authHandler := handlers.NewAuthHandler(authService)
	userHandler := handlers.NewUserHandler(userService)
	chatHandler := handlers.NewChatHandler(chatService, userService)
	messageHandler := handlers.NewMessageHandler(messageService, chatService)
	fileHandler := handlers.NewFileHandler(fileService)
	adminHandler := handlers.NewAdminHandler(adminService)
	wsHandler := handlers.NewWebSocketHandler(wsHub, authService)
	
	// Создаем основной роутер для API
	apiRouter := chi.NewRouter()
	
	// Middleware для API (кроме WebSocket)
	apiRouter.Use(middleware.Recovery)
	apiRouter.Use(middleware.Logging)
	apiRouter.Use(cors.New(cors.Options{
		AllowedOrigins:   cfg.CORSAllowedOrigins,
		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
		AllowedHeaders:   []string{"Content-Type", "Authorization"},
		AllowCredentials: true,
	}).Handler)
	
	// Публичные роуты API
	apiRouter.Post("/api/register", authHandler.Register)
	apiRouter.Post("/api/login", authHandler.Login)
	apiRouter.Get("/health", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte(`{"status":"ok"}`))
	})
	
	// Защищенные API роуты
	apiRouter.Group(func(r chi.Router) {
		r.Use(middleware.JWTAuth(authService))
		
		r.Get("/api/me", authHandler.GetMe)
		r.Get("/api/profile", userHandler.GetProfile)
		r.Put("/api/profile", userHandler.UpdateProfile)
		r.Get("/api/users", userHandler.SearchUsers)
		
		r.Post("/api/chats/private", chatHandler.CreatePrivateChat)
		r.Post("/api/chats/group", chatHandler.CreateGroupChat)
		r.Get("/api/chats", chatHandler.GetMyChats)
		r.Get("/api/chats/{id}", chatHandler.GetChatByID)
		r.Get("/api/chats/{id}/members", chatHandler.GetChatMembers)
		r.Post("/api/chats/{id}/members", chatHandler.AddMembers)
		r.Delete("/api/chats/{id}/members/{user_id}", chatHandler.RemoveMember)
		r.Put("/api/chats/{id}/title", chatHandler.UpdateChatTitle)
		
		r.Get("/api/chats/{id}/messages", messageHandler.GetMessages)
		r.Put("/api/messages/{id}/read", messageHandler.MarkAsRead)
		
		r.Post("/api/chats/{id}/upload", fileHandler.UploadFile)
		r.Get("/api/attachments/{id}", fileHandler.DownloadFile)
		
		r.Group(func(r chi.Router) {
			r.Use(middleware.RequireGlobalAdmin)
			r.Delete("/api/admin/users/{id}", adminHandler.DeleteUser)
			r.Delete("/api/admin/messages/{id}", adminHandler.DeleteMessage)
		})
	})
	
	// Создаем отдельный роутер для WebSocket (без middleware)
	wsRouter := http.NewServeMux()
	wsRouter.HandleFunc("/ws", wsHandler.HandleWebSocket)
	
	// Объединяем роутеры
	mainRouter := http.NewServeMux()
	mainRouter.Handle("/", apiRouter)
	mainRouter.Handle("/ws", wsRouter)
	
	// Запускаем сервер
	srv := &http.Server{
		Addr:         ":" + cfg.ServerPort,
		Handler:      mainRouter,
		ReadTimeout:  15 * time.Second,
		WriteTimeout: 15 * time.Second,
		IdleTimeout:  60 * time.Second,
	}
	
	// Graceful shutdown
	go func() {
		logger.Info("Server starting", "port", cfg.ServerPort)
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			logger.Error("Server failed", "error", err)
			os.Exit(1)
		}
	}()

	// Запускаем периодический сборщик мусора для оптимизации памяти
	go func() {
		ticker := time.NewTicker(5 * time.Minute)
		defer ticker.Stop()
		
		for range ticker.C {
			runtime.GC()
			logger.Debug("Garbage collection triggered")
		}
	}()
	
	// Ожидаем сигнал завершения
	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	
	logger.Info("Shutting down server...")
	
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()
	
	wsHub.Stop()
	
	if err := srv.Shutdown(ctx); err != nil {
		logger.Error("Server forced to shutdown", "error", err)
	}
	
	logger.Info("Server stopped")
}