package main

import (
	"context"
	"flag"
	"log/slog"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/gin-gonic/gin"
	"git.mchus.pro/mchus/quoteforge/internal/config"
	"git.mchus.pro/mchus/quoteforge/internal/handlers"
	"git.mchus.pro/mchus/quoteforge/internal/middleware"
	"git.mchus.pro/mchus/quoteforge/internal/models"
	"git.mchus.pro/mchus/quoteforge/internal/repository"
	"git.mchus.pro/mchus/quoteforge/internal/services"
	"git.mchus.pro/mchus/quoteforge/internal/services/alerts"
	"git.mchus.pro/mchus/quoteforge/internal/services/pricing"
	"golang.org/x/crypto/bcrypt"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"
)

func main() {
	configPath := flag.String("config", "config.yaml", "path to config file")
	migrate := flag.Bool("migrate", false, "run database migrations")
	flag.Parse()

	cfg, err := config.Load(*configPath)
	if err != nil {
		slog.Error("failed to load config", "error", err)
		os.Exit(1)
	}

	setupLogger(cfg.Logging)

	slog.Info("starting QuoteForge server",
		"host", cfg.Server.Host,
		"port", cfg.Server.Port,
		"mode", cfg.Server.Mode,
	)

	db, err := setupDatabase(cfg.Database)
	if err != nil {
		slog.Error("failed to connect to database", "error", err)
		os.Exit(1)
	}

	if *migrate {
		slog.Info("running database migrations...")
		if err := models.Migrate(db); err != nil {
			slog.Error("migration failed", "error", err)
			os.Exit(1)
		}
		if err := models.SeedCategories(db); err != nil {
			slog.Error("seeding categories failed", "error", err)
			os.Exit(1)
		}
		// Create default admin user (admin / admin123)
		adminHash, _ := bcrypt.GenerateFromPassword([]byte("admin123"), bcrypt.DefaultCost)
		if err := models.SeedAdminUser(db, string(adminHash)); err != nil {
			slog.Error("seeding admin user failed", "error", err)
			os.Exit(1)
		}
		slog.Info("migrations completed")
	}

	gin.SetMode(cfg.Server.Mode)
	router, err := setupRouter(db, cfg)
	if err != nil {
		slog.Error("failed to setup router", "error", err)
		os.Exit(1)
	}

	srv := &http.Server{
		Addr:         cfg.Address(),
		Handler:      router,
		ReadTimeout:  cfg.Server.ReadTimeout,
		WriteTimeout: cfg.Server.WriteTimeout,
	}

	go func() {
		slog.Info("server listening", "address", cfg.Address())
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			slog.Error("server error", "error", err)
			os.Exit(1)
		}
	}()

	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit

	slog.Info("shutting down server...")

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	if err := srv.Shutdown(ctx); err != nil {
		slog.Error("server forced to shutdown", "error", err)
	}

	slog.Info("server stopped")
}

func setupLogger(cfg config.LoggingConfig) {
	var level slog.Level
	switch cfg.Level {
	case "debug":
		level = slog.LevelDebug
	case "warn":
		level = slog.LevelWarn
	case "error":
		level = slog.LevelError
	default:
		level = slog.LevelInfo
	}

	opts := &slog.HandlerOptions{Level: level}

	var handler slog.Handler
	if cfg.Format == "json" {
		handler = slog.NewJSONHandler(os.Stdout, opts)
	} else {
		handler = slog.NewTextHandler(os.Stdout, opts)
	}

	slog.SetDefault(slog.New(handler))
}

func setupDatabase(cfg config.DatabaseConfig) (*gorm.DB, error) {
	gormLogger := logger.Default.LogMode(logger.Silent)

	db, err := gorm.Open(mysql.Open(cfg.DSN()), &gorm.Config{
		Logger: gormLogger,
	})
	if err != nil {
		return nil, err
	}

	sqlDB, err := db.DB()
	if err != nil {
		return nil, err
	}

	sqlDB.SetMaxOpenConns(cfg.MaxOpenConns)
	sqlDB.SetMaxIdleConns(cfg.MaxIdleConns)
	sqlDB.SetConnMaxLifetime(cfg.ConnMaxLifetime)

	return db, nil
}

func setupRouter(db *gorm.DB, cfg *config.Config) (*gin.Engine, error) {
	// Repositories
	userRepo := repository.NewUserRepository(db)
	componentRepo := repository.NewComponentRepository(db)
	categoryRepo := repository.NewCategoryRepository(db)
	priceRepo := repository.NewPriceRepository(db)
	configRepo := repository.NewConfigurationRepository(db)
	alertRepo := repository.NewAlertRepository(db)
	statsRepo := repository.NewStatsRepository(db)

	// Services
	authService := services.NewAuthService(userRepo, cfg.Auth)
	pricingService := pricing.NewService(componentRepo, priceRepo, cfg.Pricing)
	componentService := services.NewComponentService(componentRepo, categoryRepo, statsRepo)
	quoteService := services.NewQuoteService(componentRepo, statsRepo, pricingService)
	configService := services.NewConfigurationService(configRepo, componentRepo, quoteService)
	exportService := services.NewExportService(cfg.Export)
	alertService := alerts.NewService(alertRepo, componentRepo, priceRepo, statsRepo, cfg.Alerts, cfg.Pricing)

	// Handlers
	authHandler := handlers.NewAuthHandler(authService, userRepo)
	componentHandler := handlers.NewComponentHandler(componentService)
	quoteHandler := handlers.NewQuoteHandler(quoteService)
	configHandler := handlers.NewConfigurationHandler(configService, exportService)
	exportHandler := handlers.NewExportHandler(exportService, configService, componentService)
	pricingHandler := handlers.NewPricingHandler(db, pricingService, alertService, componentRepo, priceRepo, statsRepo)

	// Web handler (templates)
	webHandler, err := handlers.NewWebHandler("web/templates", componentService)
	if err != nil {
		return nil, err
	}

	// Router
	router := gin.New()
	router.Use(gin.Recovery())
	router.Use(requestLogger())
	router.Use(middleware.CORS())

	// Static files
	router.Static("/static", "web/static")

	// Health check
	router.GET("/health", func(c *gin.Context) {
		c.JSON(http.StatusOK, gin.H{
			"status": "ok",
			"time":   time.Now().UTC().Format(time.RFC3339),
		})
	})

	// DB status endpoint
	router.GET("/api/db-status", func(c *gin.Context) {
		var lotCount, lotLogCount, metadataCount int64
		var dbOK bool = true
		var dbError string

		sqlDB, err := db.DB()
		if err != nil {
			dbOK = false
			dbError = err.Error()
		} else if err := sqlDB.Ping(); err != nil {
			dbOK = false
			dbError = err.Error()
		}

		db.Table("lot").Count(&lotCount)
		db.Table("lot_log").Count(&lotLogCount)
		db.Table("qt_lot_metadata").Count(&metadataCount)

		c.JSON(http.StatusOK, gin.H{
			"connected":      dbOK,
			"error":          dbError,
			"lot_count":      lotCount,
			"lot_log_count":  lotLogCount,
			"metadata_count": metadataCount,
		})
	})

	// Web pages
	router.GET("/", webHandler.Index)
	router.GET("/login", webHandler.Login)
	router.GET("/configs", webHandler.Configs)
	router.GET("/configurator", webHandler.Configurator)
	router.GET("/admin/pricing", webHandler.AdminPricing)

	// htmx partials
	partials := router.Group("/partials")
	{
		partials.GET("/components", webHandler.ComponentsPartial)
	}

	// API routes
	api := router.Group("/api")
	{
		api.GET("/ping", func(c *gin.Context) {
			c.JSON(http.StatusOK, gin.H{"message": "pong"})
		})

		// Auth (public)
		auth := api.Group("/auth")
		{
			auth.POST("/login", authHandler.Login)
			auth.POST("/refresh", authHandler.Refresh)
			auth.POST("/logout", authHandler.Logout)
			auth.GET("/me", middleware.Auth(authService), authHandler.Me)
		}

		// Components (public read, for quote builder)
		components := api.Group("/components")
		{
			components.GET("", componentHandler.List)
			components.GET("/:lot_name", componentHandler.Get)
		}

		// Categories (public)
		api.GET("/categories", componentHandler.GetCategories)

		// Quote (public, for anonymous quote building)
		quote := api.Group("/quote")
		{
			quote.POST("/validate", quoteHandler.Validate)
			quote.POST("/calculate", quoteHandler.Calculate)
		}

		// Export (public, for anonymous exports)
		export := api.Group("/export")
		{
			export.POST("/csv", exportHandler.ExportCSV)
		}

		// Configurations (requires auth)
		configs := api.Group("/configs")
		configs.Use(middleware.Auth(authService))
		configs.Use(middleware.RequireEditor())
		{
			configs.GET("", configHandler.List)
			configs.POST("", configHandler.Create)
			configs.GET("/:uuid", configHandler.Get)
			configs.PUT("/:uuid", configHandler.Update)
			configs.DELETE("/:uuid", configHandler.Delete)
			configs.GET("/:uuid/export", configHandler.ExportJSON)
			configs.GET("/:uuid/csv", exportHandler.ExportConfigCSV)
			configs.POST("/import", configHandler.ImportJSON)
		}
	}

	// Admin routes
	admin := router.Group("/admin")
	admin.Use(middleware.Auth(authService))
	{
		// Pricing admin
		pricingAdmin := admin.Group("/pricing")
		pricingAdmin.Use(middleware.RequirePricingAdmin())
		{
			pricingAdmin.GET("/stats", pricingHandler.GetStats)
			pricingAdmin.GET("/components", pricingHandler.ListComponents)
			pricingAdmin.GET("/components/:lot_name", pricingHandler.GetComponentPricing)
			pricingAdmin.POST("/update", pricingHandler.UpdatePrice)
			pricingAdmin.POST("/preview", pricingHandler.PreviewPrice)
			pricingAdmin.POST("/recalculate-all", pricingHandler.RecalculateAll)

			pricingAdmin.GET("/alerts", pricingHandler.ListAlerts)
			pricingAdmin.POST("/alerts/:id/acknowledge", pricingHandler.AcknowledgeAlert)
			pricingAdmin.POST("/alerts/:id/resolve", pricingHandler.ResolveAlert)
			pricingAdmin.POST("/alerts/:id/ignore", pricingHandler.IgnoreAlert)
		}
	}

	return router, nil
}

func requestLogger() gin.HandlerFunc {
	return func(c *gin.Context) {
		start := time.Now()
		path := c.Request.URL.Path
		query := c.Request.URL.RawQuery

		c.Next()

		latency := time.Since(start)
		status := c.Writer.Status()

		slog.Info("request",
			"method", c.Request.Method,
			"path", path,
			"query", query,
			"status", status,
			"latency", latency,
			"ip", c.ClientIP(),
		)
	}
}