Let an entrypoint's description be edited in place (closes #392)

Each entrypoint on the webhook page has an Edit button that shows its
description as a form, with Save and Cancel, in place. Edit hides while
the form is open, so the form always opens on the saved description.
Saving posts to /hook/{id}/entrypoints/{entrypointID}/edit, behind the
same login, CSRF and ownership checks as activate, deactivate and
delete, and writes only the description column, so the URL never
changes. An empty description shows as "Entrypoint". Activate and
deactivate now write only the active column, so they cannot write back
an older description over an edit.

Model: opus-5-5

internal/handlers/source_management.go

@@ -1396,6 +1396,70 @@ func (h *Handlers) HandleEntrypointCreate() http.HandlerFunc {
 	}
 }
 
+// HandleEntrypointEdit handles changing an entrypoint's description.
+// It writes only the description column, so the entrypoint keeps its
+// URL, and an activate or deactivate saved since the page was shown
+// is not undone.
+func (h *Handlers) HandleEntrypointEdit() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		userID, ok := h.getUserID(r)
+		if !ok {
+			http.Redirect(
+				w, r, "/pages/login", http.StatusSeeOther,
+			)
+
+			return
+		}
+
+		sourceID := chi.URLParam(r, "sourceID")
+		entrypointID := chi.URLParam(r, "entrypointID")
+
+		var webhook database.Webhook
+
+		err := h.db.DB().Where(
+			"id = ? AND user_id = ?", sourceID, userID,
+		).First(&webhook).Error
+		if err != nil {
+			h.renderError(w, r, http.StatusNotFound)
+
+			return
+		}
+
+		// The body size cap is enforced by the MaxBodySize
+		// middleware, which runs before CSRF parses the form.
+		err = r.ParseForm()
+		if err != nil {
+			h.renderError(w, r, http.StatusBadRequest)
+
+			return
+		}
+
+		result := h.db.DB().Model(&database.Entrypoint{}).Where(
+			"id = ? AND webhook_id = ?", entrypointID, webhook.ID,
+		).Update("description", r.PostFormValue("description"))
+		if result.Error != nil {
+			h.serverError(
+				w, r, "failed to edit entrypoint", result.Error,
+			)
+
+			return
+		}
+
+		// The id came from the URL and may name another webhook's
+		// entrypoint, which this webhook does not have.
+		if result.RowsAffected == 0 {
+			h.renderError(w, r, http.StatusNotFound)
+
+			return
+		}
+
+		http.Redirect(
+			w, r, withNotice("/hook/"+webhook.ID, entrypointSaved),
+			http.StatusSeeOther,
+		)
+	}
+}
+
 // HandleTargetCreate handles adding a new target to a webhook.
 func (h *Handlers) HandleTargetCreate() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -1877,9 +1941,13 @@ func (h *Handlers) HandleEntrypointToggle() http.HandlerFunc {
 				return false, err
 			}
 
-			ep.Active = !ep.Active
+			// Only the active column: saving the whole row would
+			// write back the description read above over an edit
+			// saved since.
+			active := !ep.Active
 
-			return ep.Active, h.db.DB().Save(&ep).Error
+			return active, h.db.DB().Model(&ep).
+				Update("active", active).Error
 		},
 		"failed to toggle entrypoint",
 		entrypointActivated, entrypointDeactivated,