package main

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

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

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

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

	db, err := repository.Open(cfg.DatabaseDSN)
	if err != nil {
		slog.Error("open database failed", "err", err)
		os.Exit(1)
	}
	defer func() {
		_ = db.Close()
	}()
	if err := migrate.EnsureSchema(db, cfg.MigrationsDir); err != nil {
		slog.Error("apply migrations failed", "err", err)
		os.Exit(1)
	}
	if err := migrate.ValidateOwnershipSchema(db); err != nil {
		slog.Error("schema validation failed", "err", err)
		os.Exit(1)
	}
	slog.Info("database schema ready")

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

	errCh := make(chan error, 1)
	go func() {
		slog.Info("starting API server", "addr", cfg.HTTPAddr)
		errCh <- srv.Start()
	}()

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

	select {
	case sig := <-signalCh:
		slog.Info("received signal, shutting down", "signal", sig)
	case err := <-errCh:
		if err == nil || errors.Is(err, http.ErrServerClosed) {
			return
		}
		slog.Error("server error", "err", err)
		os.Exit(1)
	}

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

	if err := srv.Shutdown(ctx); err != nil {
		slog.Error("shutdown server failed", "err", err)
		os.Exit(1)
	}

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