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

internal/server/middleware.go

@@ -0,0 +1,59 @@
+package server
+
+import (
+	"log/slog"
+	"net/http"
+	"time"
+
+	chimiddleware "github.com/go-chi/chi/v5/middleware"
+)
+
+func MaxBytesMiddleware(limit int64) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if r.Body != nil {
+				r.Body = http.MaxBytesReader(w, r.Body, limit)
+			}
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+func CORSMiddleware() func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			headers := w.Header()
+			headers.Set("Access-Control-Allow-Origin", "*")
+			headers.Set("Access-Control-Allow-Methods", "POST, GET, OPTIONS")
+			headers.Set("Access-Control-Allow-Headers", "content-type")
+
+			if r.Method == http.MethodOptions {
+				w.WriteHeader(http.StatusOK)
+				return
+			}
+
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+func RequestLogger(log *slog.Logger) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			ww := chimiddleware.NewWrapResponseWriter(w, r.ProtoMajor)
+			start := time.Now()
+
+			next.ServeHTTP(ww, r)
+
+			log.Info(
+				"http_request",
+				"request_id", chimiddleware.GetReqID(r.Context()),
+				"method", r.Method,
+				"path", r.URL.Path,
+				"status", ww.Status(),
+				"bytes", ww.BytesWritten(),
+				"duration", time.Since(start),
+			)
+		})
+	}
+}