package main

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

	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/admin"
	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/api"
	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/auth"
	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/cas"
	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/config"
	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/database"
	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/middleware"
	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/session"
	"gitea.mrixs.me/Mrixs/MrixsCraft-server/internal/templates"
)

func main() {
	ctx := context.Background()

	cfg, err := config.Load()
	if err != nil {
		log.Fatalf("Failed to load config: %v", err)
	}

	db, err := database.Open(ctx, cfg.DatabaseURL)
	if err != nil {
		log.Fatalf("Failed to connect to database: %v", err)
	}
	defer db.Close()

	// Start session cleanup worker (runs every hour in the background).
	cleanupCancel := session.StartCleanupWorker(db, 1*time.Hour)
	defer cleanupCancel()

	mux := http.NewServeMux()

	// Health check — no auth needed.
	mux.HandleFunc("GET /health", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("ok"))
	})

	// Yggdrasil API.
	authHandler := auth.NewHandler(db, cfg)
	authHandler.RegisterRoutes(mux)

	// Public API.
	apiHandler := api.NewHandler(db, cfg)
	apiHandler.RegisterRoutes(mux)

	// CAS (Content-Addressable Storage) file serving.
	casHandler := cas.NewHandler(db, cfg)
	casHandler.RegisterRoutes(mux)

	// Admin panel.
	adminHandler := admin.NewHandler(db, cfg)
	adminHandler.RegisterRoutes(mux)

	// Templates (web UI).
	templatesHandler := templates.NewHandler(db, cfg)
	templatesHandler.RegisterRoutes(mux)

	// Wrapper chain: Recovery → Logging → RateLimit → CORS → mux.
	// Recovery must be outermost so it catches panics in all inner layers.
	var handler http.Handler = mux
	handler = middleware.CORS(handler)
	handler = middleware.NewRateLimiter(30, time.Minute, 60).Limit(handler)
	handler = middleware.Logging(handler)
	handler = middleware.Recovery(handler)

	addr := ":" + itoa(cfg.Port)
	srv := &http.Server{
		Addr:    addr,
		Handler: handler,
	}

	// Graceful shutdown.
	done := make(chan os.Signal, 1)
	signal.Notify(done, syscall.SIGINT, syscall.SIGTERM)

	go func() {
		log.Printf("MrixsCraft Server starting on %s", addr)
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("Server error: %v", err)
		}
	}()

	<-done
	log.Println("Shutting down…")

	shutdownCtx, cancel := context.WithTimeout(ctx, 10*time.Second)
	defer cancel()
	if err := srv.Shutdown(shutdownCtx); err != nil {
		log.Printf("Shutdown error: %v", err)
	}
	log.Println("Stopped.")
}

// itoa converts int to string (stdlib alias to avoid fmt import just for this).
func itoa(n int) string {
	return strconv.Itoa(n)
}