package server

import (
	"fmt"
	"log"
	"os"
	"os/signal"
	"path/filepath"
	"syscall"

	"dk/internal/auth"
	"dk/internal/database"
	"dk/internal/middleware"
	"dk/internal/router"
	"dk/internal/routes"
	"dk/internal/template"

	"github.com/valyala/fasthttp"
)

func Start(port string) error {
	cwd, err := os.Getwd()
	if err != nil {
		return fmt.Errorf("failed to get current working directory: %w", err)
	}
	// Initialize template singleton
	template.InitializeCache(cwd)

	// Initialize database singleton
	if err := database.Init("dk.db"); err != nil {
		return fmt.Errorf("failed to initialize database: %w", err)
	}
	defer database.Close()

	auth.Init("sessions.json") // Initialize auth.Manager

	r := router.New()
	r.Use(middleware.Timing())
	r.Use(middleware.Auth(auth.Manager))
	r.Use(middleware.CSRF(auth.Manager))

	r.Get("/", routes.Index)
	routes.RegisterAuthRoutes(r)
	routes.RegisterTownRoutes(r)

	// Use current working directory for static files
	assetsDir := filepath.Join(cwd, "assets")

	// Static file server for /assets
	fs := &fasthttp.FS{
		Root:     assetsDir,
		Compress: false,
	}
	assetsHandler := fs.NewRequestHandler()

	// Combined handler
	requestHandler := func(ctx *fasthttp.RequestCtx) {
		path := string(ctx.Path())

		// Handle static assets - strip /assets prefix
		if len(path) >= 7 && path[:7] == "/assets" {
			// Strip the /assets prefix for the file system handler
			originalPath := ctx.Path()
			ctx.Request.URI().SetPath(path[7:]) // Remove "/assets" prefix
			assetsHandler(ctx)
			ctx.Request.URI().SetPathBytes(originalPath) // Restore original path
			return
		}

		// Handle routes
		r.ServeHTTP(ctx)
	}

	addr := ":" + port
	log.Printf("Server starting on %s", addr)

	// Setup graceful shutdown
	server := &fasthttp.Server{
		Handler: requestHandler,
	}

	// Channel to listen for interrupt signal
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt, syscall.SIGTERM)

	// Start server in a goroutine
	go func() {
		if err := server.ListenAndServe(addr); err != nil {
			log.Printf("Server error: %v", err)
		}
	}()

	// Wait for interrupt signal
	<-c
	log.Println("Received shutdown signal, shutting down gracefully...")

	// Save sessions before shutdown
	log.Println("Saving sessions...")
	if err := auth.Manager.Close(); err != nil {
		log.Printf("Error saving sessions: %v", err)
	}

	// FastHTTP doesn't have a graceful Shutdown method like net/http
	// We just let the server stop naturally when the main function exits
	log.Println("Server stopped")
	return nil
}