package main

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

	"internal-mail-skill/internal/api"
	"internal-mail-skill/internal/config"
	"internal-mail-skill/internal/db"
	"internal-mail-skill/internal/pop3"
	"internal-mail-skill/internal/service"
	mailsmtp "internal-mail-skill/internal/smtp"
)

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

func run() error {
	cfgPath := os.Getenv("CONFIG_PATH")
	if cfgPath == "" {
		cfgPath = ".env"
	}
	cfg, err := config.Load(cfgPath)
	if err != nil {
		return err
	}
	if err := ensureDataDirs(cfg); err != nil {
		return err
	}

	store, err := db.Open(cfg.Data.DatabasePath)
	if err != nil {
		return err
	}
	defer store.Close()

	ctx := context.Background()
	if err := store.Migrate(ctx); err != nil {
		return err
	}

	popFetcher := pop3.NewFetcher(cfg.POP3)
	smtpSender := mailsmtp.NewSender(cfg.SMTP)
	mailService := service.NewWithOptions(store, popFetcher, smtpSender, cfg.AccountID, service.Options{
		RawDir:        cfg.Data.RawMailDir,
		AttachmentDir: cfg.Data.AttachmentDir,
		FromAddress:   cfg.SMTP.FromAddress,
		FromName:      cfg.SMTP.FromName,
	})
	apiServer := api.New(cfg, store, mailService)

	httpServer := &http.Server{
		Addr:              api.ListenAddr(cfg),
		Handler:           apiServer.Handler(),
		ReadHeaderTimeout: 10 * time.Second,
	}

	errCh := make(chan error, 1)
	go func() {
		slog.Info("internal mail skill listening", "addr", httpServer.Addr, "account_id", cfg.AccountID)
		errCh <- httpServer.ListenAndServe()
	}()

	stopCh := make(chan os.Signal, 1)
	signal.Notify(stopCh, syscall.SIGINT, syscall.SIGTERM)
	select {
	case sig := <-stopCh:
		slog.Info("shutdown requested", "signal", sig.String())
		shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
		defer cancel()
		return httpServer.Shutdown(shutdownCtx)
	case err := <-errCh:
		if errors.Is(err, http.ErrServerClosed) {
			return nil
		}
		return err
	}
}

func ensureDataDirs(cfg *config.Config) error {
	for _, dir := range []string{cfg.Data.DataDir, cfg.Data.RawMailDir, cfg.Data.AttachmentDir} {
		if err := os.MkdirAll(dir, 0750); err != nil {
			return err
		}
	}
	return nil
}