package main

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

	"reanimator/internal/api"
	"reanimator/internal/config"
	"reanimator/internal/repository"
	"reanimator/internal/repository/migrate"
)

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

	db, err := repository.Open(cfg.DatabaseDSN)
	if err != nil {
		log.Fatalf("open database: %v", err)
	}
	defer func() {
		_ = db.Close()
	}()
	if err := migrate.EnsureSchema(db, cfg.MigrationsDir); err != nil {
		log.Fatalf("apply migrations: %v", err)
	}
	if err := migrate.ValidateOwnershipSchema(db); err != nil {
		log.Fatalf("schema validation failed: %v", err)
	}
	log.Printf("database schema ready")

	srv := api.NewServer(cfg.HTTPAddr, cfg.ReadTimeout, cfg.WriteTimeout, db)

	errCh := make(chan error, 1)
	go func() {
		log.Printf("starting API server on %s", cfg.HTTPAddr)
		errCh <- srv.Start()
	}()

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

	select {
	case sig := <-signalCh:
		log.Printf("received signal %s, shutting down", sig)
	case err := <-errCh:
		if err == nil || errors.Is(err, http.ErrServerClosed) {
			return
		}
		log.Fatalf("server error: %v", err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), cfg.ShutdownGrace)
	defer cancel()

	if err := srv.Shutdown(ctx); err != nil {
		log.Fatalf("shutdown server: %v", err)
	}

	// Ensure in-flight logs flush before exit in short-lived environments.
	time.Sleep(25 * time.Millisecond)
}