phase3: HTTP server with converter, one-shot preview store, and middleware

internal/server/server.go

@@ -0,0 +1,90 @@
+package server
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/fserg/md-to-html/internal/converter"
+	"github.com/go-chi/chi/v5"
+	chimiddleware "github.com/go-chi/chi/v5/middleware"
+)
+
+func New(cfg Config, conv *converter.Converter) (*Server, error) {
+	if conv == nil {
+		return nil, errors.New("converter is required")
+	}
+
+	logger := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
+		Level: slog.LevelInfo,
+	}))
+
+	return &Server{
+		cfg:   cfg,
+		conv:  conv,
+		store: NewPreviewStore(cfg.PreviewTTL),
+		log:   logger,
+	}, nil
+}
+
+func (s *Server) Router() http.Handler {
+	r := chi.NewRouter()
+	r.Use(chimiddleware.RequestID)
+	r.Use(CORSMiddleware())
+	r.Use(MaxBytesMiddleware(s.cfg.MaxRequestBytes))
+	r.Use(RequestLogger(s.log))
+	r.Use(chimiddleware.Recoverer)
+	r.Use(chimiddleware.Timeout(30 * time.Second))
+
+	r.Get("/", s.handleHome)
+	r.Post("/convert", s.handleConvert)
+	r.Get("/health", s.handleHealth)
+	r.Get("/version", s.handleVersion)
+	r.Get("/ready", s.handleReady)
+	r.Post("/ui/convert", s.handleUIConvert)
+	r.Get("/preview/{id}", s.handlePreview)
+	r.Get("/download/{id}", s.handleDownload)
+
+	return r
+}
+
+func (s *Server) Run(ctx context.Context) error {
+	httpServer := &http.Server{
+		Addr:    s.cfg.Addr,
+		Handler: s.Router(),
+	}
+
+	errCh := make(chan error, 1)
+
+	go s.store.janitor(ctx)
+	go func() {
+		s.log.Info("server starting", "addr", s.cfg.Addr)
+		errCh <- httpServer.ListenAndServe()
+	}()
+
+	select {
+	case <-ctx.Done():
+		s.log.Info("shutting down", "timeout", s.cfg.ShutdownTimeout)
+
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), s.cfg.ShutdownTimeout)
+		defer cancel()
+
+		if err := httpServer.Shutdown(shutdownCtx); err != nil {
+			return fmt.Errorf("shutdown server: %w", err)
+		}
+
+		if err := <-errCh; err != nil && !errors.Is(err, http.ErrServerClosed) {
+			return fmt.Errorf("server exited after shutdown: %w", err)
+		}
+		return nil
+	case err := <-errCh:
+		if err == nil || errors.Is(err, http.ErrServerClosed) {
+			return nil
+		}
+		return fmt.Errorf("serve: %w", err)
+	}
+}