// Package main is the entrypoint for the mitbringsl backend HTTP server.
package main

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

	"github.com/jackc/pgx/v5/pgxpool"

	"github.com/mitbringsl/backend/internal/config"
	"github.com/mitbringsl/backend/internal/httpapi"
	"github.com/mitbringsl/backend/internal/logging"
	"github.com/mitbringsl/backend/internal/store"
)

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

func run() error {
	cfg, err := config.Load()
	if err != nil {
		return err
	}
	logging.Init(cfg.LogLevel)
	slog.Info("starting mitbringsl backend",
		"env", cfg.AppEnv,
		"addr", cfg.HTTPAddr,
		"google_oidc_enabled", cfg.GoogleOIDC.Enabled,
		"generic_oidc_enabled", cfg.GenericOIDC.Enabled,
	)

	rootCtx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()

	pool, err := store.New(rootCtx, cfg)
	if err != nil {
		return err
	}
	defer pool.Close()
	slog.Info("database connected")

	api := httpapi.NewAPI(cfg, pool)
	srv := &http.Server{
		Addr:              cfg.HTTPAddr,
		Handler:           api.Handler(),
		ReadHeaderTimeout: 5 * time.Second,
		ReadTimeout:       15 * time.Second,
		WriteTimeout:      30 * time.Second,
		IdleTimeout:       60 * time.Second,
	}

	errCh := make(chan error, 1)
	go func() {
		slog.Info("http server listening", "addr", cfg.HTTPAddr)
		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			errCh <- err
		}
	}()

	select {
	case <-rootCtx.Done():
		slog.Info("shutdown signal received")
	case err := <-errCh:
		return err
	}

	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	if err := srv.Shutdown(shutdownCtx); err != nil {
		slog.Error("graceful shutdown failed", "error", err)
	}
	slog.Info("bye")
	return nil
}

// keep pgxpool import referenced even when API holds the pool directly (future-proof).
var _ = (*pgxpool.Pool)(nil)