llm browser

backend/internal/api/browse.go

@@ -0,0 +1,49 @@
+package api
+
+import (
+	"context"
+	"errors"
+	"log/slog"
+	"net/http"
+	"strings"
+
+	"git.k6n.net/mats/fullstack-template/internal/browse"
+)
+
+// browseHandler adapts HTTP requests to the browse service: read the url
+// query parameter, call Inspect, map errors to the wire. No fetching or
+// conversion logic lives here.
+type browseHandler struct {
+	svc    *browse.Service
+	logger *slog.Logger
+}
+
+func (h *browseHandler) get(w http.ResponseWriter, r *http.Request) {
+	raw := strings.TrimSpace(r.URL.Query().Get("url"))
+	snap, err := h.svc.Inspect(r.Context(), raw)
+	if err != nil {
+		h.fail(w, err)
+		return
+	}
+	writeJSON(w, http.StatusOK, snap)
+}
+
+// fail is the translation point from browse errors to the wire:
+// *ValidationError → 400, *FetchError → 502 (the site is the problem),
+// context deadline → 504, anything else → 500 (logged).
+func (h *browseHandler) fail(w http.ResponseWriter, err error) {
+	var vErr *browse.ValidationError
+	var fErr *browse.FetchError
+	switch {
+	case errors.As(err, &vErr):
+		writeError(w, http.StatusBadRequest, "validation_failed", vErr.Error())
+	case errors.As(err, &fErr):
+		h.logger.Info("browse fetch failed", "url", fErr.URL, "err", fErr.Err)
+		writeError(w, http.StatusBadGateway, "unavailable", "could not fetch "+fErr.URL)
+	case errors.Is(err, context.DeadlineExceeded):
+		writeError(w, http.StatusGatewayTimeout, "timeout", "the site took too long to answer")
+	default:
+		h.logger.Error("browse failed", "err", err)
+		writeError(w, http.StatusInternalServerError, "internal_error", "an internal error occurred")
+	}
+}