pansy/cmd/pansy/main.go

// Command pansy is the single static binary: it loads configuration, opens and
// migrates the SQLite database, builds the HTTP server (JSON API + embedded SPA),
// and serves until interrupted.
package main

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

	"gitea.stevedudenhoeffer.com/steve/pansy/internal/api"
	"gitea.stevedudenhoeffer.com/steve/pansy/internal/config"
	"gitea.stevedudenhoeffer.com/steve/pansy/internal/service"
	"gitea.stevedudenhoeffer.com/steve/pansy/internal/store"
	"gitea.stevedudenhoeffer.com/steve/pansy/internal/webdist"
)

// sessionSweepInterval is how often expired sessions are purged in the
// background (they are also dropped lazily on access).
const sessionSweepInterval = 6 * time.Hour

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

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

func run() error {
	cfg := config.Load()

	db, err := store.Open(cfg.DBPath)
	if err != nil {
		return fmt.Errorf("open database: %w", err)
	}
	defer db.Close()

	// Migrations run against a short-lived context so a hung DB can't block boot
	// forever; the schema is tiny so this is generous.
	migCtx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()
	if err := db.Migrate(migCtx); err != nil {
		return fmt.Errorf("migrate database: %w", err)
	}
	slog.Info("pansy: database ready", "path", cfg.DBPath)

	svc := service.New(db, cfg)

	r := api.New(cfg, svc)
	api.RegisterSPA(r, webdist.Dist())

	srv := &http.Server{
		Addr:              fmt.Sprintf(":%d", cfg.Port),
		Handler:           r,
		ReadTimeout:       15 * time.Second,
		ReadHeaderTimeout: 5 * time.Second,
		WriteTimeout:      30 * time.Second,
		IdleTimeout:       60 * time.Second,
	}

	// Serve in the background; the main goroutine waits for a signal, then drains.
	serveErr := make(chan error, 1)
	go func() {
		slog.Info("pansy: listening", "addr", srv.Addr)
		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			serveErr <- err
		}
	}()

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

	go sweepSessions(ctx, svc)

	select {
	case err := <-serveErr:
		return fmt.Errorf("http server: %w", err)
	case <-ctx.Done():
		slog.Info("pansy: shutting down")
		stop() // restore default signal handling so a second Ctrl-C force-quits
		shutdownCtx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
		defer cancel()
		if err := srv.Shutdown(shutdownCtx); err != nil {
			return fmt.Errorf("graceful shutdown: %w", err)
		}
	}
	return nil
}

// sweepSessions periodically purges expired sessions until ctx is cancelled. It
// runs one sweep immediately so a long-lived process doesn't wait a full
// interval after startup. Failures are logged, never fatal.
func sweepSessions(ctx context.Context, svc *service.Service) {
	ticker := time.NewTicker(sessionSweepInterval)
	defer ticker.Stop()
	for {
		if n, err := svc.CleanupExpiredSessions(ctx); err != nil {
			if ctx.Err() == nil {
				slog.Warn("pansy: session sweep failed", "error", err)
			}
		} else if n > 0 {
			slog.Info("pansy: purged expired sessions", "count", n)
		}
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
		}
	}
}