package main

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

	"github.com/food-ai/backend/internal/infra/config"
	"github.com/food-ai/backend/internal/infra/database"
	"github.com/food-ai/backend/internal/infra/locale"
)

func main() {
	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{
		Level: slog.LevelInfo,
	}))
	slog.SetDefault(logger)

	if runError := run(); runError != nil {
		slog.Error("fatal error", "err", runError)
		os.Exit(1)
	}
}

func run() error {
	appConfig, configError := config.Load()
	if configError != nil {
		return fmt.Errorf("load config: %w", configError)
	}

	applicationContext, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()

	pool, poolError := database.NewPool(applicationContext, appConfig.DatabaseURL)
	if poolError != nil {
		return fmt.Errorf("connect to database: %w", poolError)
	}
	defer pool.Close()
	slog.Info("connected to database")

	if loadError := locale.LoadFromDB(applicationContext, pool); loadError != nil {
		return fmt.Errorf("load languages: %w", loadError)
	}
	slog.Info("languages loaded", "count", len(locale.Languages))

	router, initError := initRouter(appConfig, pool)
	if initError != nil {
		return fmt.Errorf("init router: %w", initError)
	}

	httpServer := &http.Server{
		Addr:         fmt.Sprintf(":%d", appConfig.Port),
		Handler:      router,
		ReadTimeout:  10 * time.Second,
		WriteTimeout: 120 * time.Second, // menu generation can take ~60s
		IdleTimeout:  60 * time.Second,
	}

	go func() {
		slog.Info("server starting", "port", appConfig.Port)
		if serverError := httpServer.ListenAndServe(); serverError != nil && serverError != http.ErrServerClosed {
			slog.Error("server error", "err", serverError)
		}
	}()

	<-applicationContext.Done()
	slog.Info("shutting down...")

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

	return httpServer.Shutdown(shutdownContext)
}