From 06d6531569fc485fd3cb6957aef3e062f6ab96dc Mon Sep 17 00:00:00 2001
From: Moritz <moritz.m@local-it.org>
Date: Fri, 30 Jan 2026 11:13:28 +0100
Subject: [PATCH] UserLive.Form: gate Member-Linking to admin, use :update for
 non-admin

- Show Member-Linking UI only when can_manage_member_linking (admin)
- perform_member_link_action runs only for admin
- assign_form: non-admin uses :update (email), admin uses :update_user
- Load members for linking only when can_manage_member_linking
---
 lib/mv_web/live/user_live/form.ex | 290 ++++++++++++++++--------------
 1 file changed, 160 insertions(+), 130 deletions(-)

diff --git a/lib/mv_web/live/user_live/form.ex b/lib/mv_web/live/user_live/form.ex
index 0a286c9..b24b214 100644
--- a/lib/mv_web/live/user_live/form.ex
+++ b/lib/mv_web/live/user_live/form.ex
@@ -36,6 +36,7 @@ defmodule MvWeb.UserLive.Form do
   require Jason
 
   import MvWeb.LiveHelpers, only: [current_actor: 1, submit_form: 3]
+  import MvWeb.Authorization, only: [can?: 3]
 
   @impl true
   def render(assigns) do
@@ -125,129 +126,133 @@ defmodule MvWeb.UserLive.Form do
           <% end %>
         </div>
         
-    <!-- Member Linking Section -->
-        <div class="mt-6">
-          <h2 class="mb-3 text-base font-semibold">{gettext("Linked Member")}</h2>
+    <!-- Member Linking Section (admin only: only admins can link/unlink users to members) -->
+        <%= if @can_manage_member_linking do %>
+          <div class="mt-6">
+            <h2 class="mb-3 text-base font-semibold">{gettext("Linked Member")}</h2>
 
-          <%= if @user && @user.member && !@unlink_member do %>
-            <!-- Show linked member with unlink button -->
-            <div class="p-4 border border-green-200 rounded-lg bg-green-50">
-              <div class="flex items-center justify-between">
-                <div>
-                  <p class="font-medium text-green-900">
-                    {MvWeb.Helpers.MemberHelpers.display_name(@user.member)}
-                  </p>
-                  <p class="text-sm text-green-700">{@user.member.email}</p>
-                </div>
-                <button
-                  type="button"
-                  phx-click="unlink_member"
-                  class="btn btn-sm btn-error"
-                >
-                  {gettext("Unlink Member")}
-                </button>
-              </div>
-            </div>
-          <% else %>
-            <%= if @unlink_member do %>
-              <!-- Show unlink pending message -->
-              <div class="p-4 border border-yellow-200 rounded-lg bg-yellow-50">
-                <p class="text-sm text-yellow-800">
-                  <strong>{gettext("Unlinking scheduled")}:</strong> {gettext(
-                    "Member will be unlinked when you save. Cannot select new member until saved."
-                  )}
-                </p>
-              </div>
-            <% end %>
-            <!-- Show member search/selection for unlinked users -->
-            <div class="space-y-3">
-              <div class="relative">
-                <input
-                  type="text"
-                  id="member-search-input"
-                  role="combobox"
-                  phx-hook="ComboBox"
-                  phx-focus="show_member_dropdown"
-                  phx-change="search_members"
-                  phx-debounce="300"
-                  phx-window-keydown="member_dropdown_keydown"
-                  value={@member_search_query}
-                  placeholder={gettext("Search for a member to link...")}
-                  class="w-full input"
-                  name="member_search"
-                  disabled={@unlink_member}
-                  aria-label={gettext("Search for member to link")}
-                  aria-describedby={if @selected_member_name, do: "member-selected", else: nil}
-                  aria-autocomplete="list"
-                  aria-controls="member-dropdown"
-                  aria-expanded={to_string(@show_member_dropdown)}
-                  aria-activedescendant={
-                    if @focused_member_index,
-                      do: "member-option-#{@focused_member_index}",
-                      else: nil
-                  }
-                  autocomplete="off"
-                />
-
-                <%= if length(@available_members) > 0 do %>
-                  <div
-                    id="member-dropdown"
-                    role="listbox"
-                    aria-label={gettext("Available members")}
-                    class={"absolute z-10 w-full mt-1 bg-base-100 border border-base-300 rounded-lg shadow-lg max-h-60 overflow-auto #{if !@show_member_dropdown, do: "hidden"}"}
-                    phx-click-away="hide_member_dropdown"
-                  >
-                    <%= for {member, index} <- Enum.with_index(@available_members) do %>
-                      <div
-                        id={"member-option-#{index}"}
-                        role="option"
-                        tabindex="0"
-                        aria-selected={to_string(@focused_member_index == index)}
-                        phx-click="select_member"
-                        phx-value-id={member.id}
-                        data-member-id={member.id}
-                        class={[
-                          "px-4 py-3 cursor-pointer border-b border-base-300 last:border-b-0",
-                          if(@focused_member_index == index,
-                            do: "bg-base-300",
-                            else: "hover:bg-base-200"
-                          )
-                        ]}
-                      >
-                        <p class="font-medium">{MvWeb.Helpers.MemberHelpers.display_name(member)}</p>
-                        <p class="text-sm text-base-content/70">{member.email}</p>
-                      </div>
-                    <% end %>
+            <%= if @user && @user.member && !@unlink_member do %>
+              <!-- Show linked member with unlink button -->
+              <div class="p-4 border border-green-200 rounded-lg bg-green-50">
+                <div class="flex items-center justify-between">
+                  <div>
+                    <p class="font-medium text-green-900">
+                      {MvWeb.Helpers.MemberHelpers.display_name(@user.member)}
+                    </p>
+                    <p class="text-sm text-green-700">{@user.member.email}</p>
                   </div>
-                <% end %>
+                  <button
+                    type="button"
+                    phx-click="unlink_member"
+                    class="btn btn-sm btn-error"
+                  >
+                    {gettext("Unlink Member")}
+                  </button>
+                </div>
               </div>
-
-              <%= if @user && @user.email && @available_members != [] && Enum.all?(@available_members, &(&1.email == to_string(@user.email))) do %>
-                <div class="p-3 border border-yellow-200 rounded bg-yellow-50">
+            <% else %>
+              <%= if @unlink_member do %>
+                <!-- Show unlink pending message -->
+                <div class="p-4 border border-yellow-200 rounded-lg bg-yellow-50">
                   <p class="text-sm text-yellow-800">
-                    <strong>{gettext("Note")}:</strong> {gettext(
-                      "A member with this email already exists. To link with a different member, please change one of the email addresses first."
+                    <strong>{gettext("Unlinking scheduled")}:</strong> {gettext(
+                      "Member will be unlinked when you save. Cannot select new member until saved."
                     )}
                   </p>
                 </div>
               <% end %>
+              <!-- Show member search/selection for unlinked users -->
+              <div class="space-y-3">
+                <div class="relative">
+                  <input
+                    type="text"
+                    id="member-search-input"
+                    role="combobox"
+                    phx-hook="ComboBox"
+                    phx-focus="show_member_dropdown"
+                    phx-change="search_members"
+                    phx-debounce="300"
+                    phx-window-keydown="member_dropdown_keydown"
+                    value={@member_search_query}
+                    placeholder={gettext("Search for a member to link...")}
+                    class="w-full input"
+                    name="member_search"
+                    disabled={@unlink_member}
+                    aria-label={gettext("Search for member to link")}
+                    aria-describedby={if @selected_member_name, do: "member-selected", else: nil}
+                    aria-autocomplete="list"
+                    aria-controls="member-dropdown"
+                    aria-expanded={to_string(@show_member_dropdown)}
+                    aria-activedescendant={
+                      if @focused_member_index,
+                        do: "member-option-#{@focused_member_index}",
+                        else: nil
+                    }
+                    autocomplete="off"
+                  />
 
-              <%= if @selected_member_id && @selected_member_name do %>
-                <div
-                  id="member-selected"
-                  class="p-3 mt-2 border border-blue-200 rounded-lg bg-blue-50"
-                >
-                  <p class="text-sm text-blue-800">
-                    <strong>{gettext("Selected")}:</strong> {@selected_member_name}
-                  </p>
-                  <p class="mt-1 text-xs text-blue-600">
-                    {gettext("Save to confirm linking.")}
-                  </p>
+                  <%= if length(@available_members) > 0 do %>
+                    <div
+                      id="member-dropdown"
+                      role="listbox"
+                      aria-label={gettext("Available members")}
+                      class={"absolute z-10 w-full mt-1 bg-base-100 border border-base-300 rounded-lg shadow-lg max-h-60 overflow-auto #{if !@show_member_dropdown, do: "hidden"}"}
+                      phx-click-away="hide_member_dropdown"
+                    >
+                      <%= for {member, index} <- Enum.with_index(@available_members) do %>
+                        <div
+                          id={"member-option-#{index}"}
+                          role="option"
+                          tabindex="0"
+                          aria-selected={to_string(@focused_member_index == index)}
+                          phx-click="select_member"
+                          phx-value-id={member.id}
+                          data-member-id={member.id}
+                          class={[
+                            "px-4 py-3 cursor-pointer border-b border-base-300 last:border-b-0",
+                            if(@focused_member_index == index,
+                              do: "bg-base-300",
+                              else: "hover:bg-base-200"
+                            )
+                          ]}
+                        >
+                          <p class="font-medium">
+                            {MvWeb.Helpers.MemberHelpers.display_name(member)}
+                          </p>
+                          <p class="text-sm text-base-content/70">{member.email}</p>
+                        </div>
+                      <% end %>
+                    </div>
+                  <% end %>
                 </div>
-              <% end %>
-            </div>
-          <% end %>
-        </div>
+
+                <%= if @user && @user.email && @available_members != [] && Enum.all?(@available_members, &(&1.email == to_string(@user.email))) do %>
+                  <div class="p-3 border border-yellow-200 rounded bg-yellow-50">
+                    <p class="text-sm text-yellow-800">
+                      <strong>{gettext("Note")}:</strong> {gettext(
+                        "A member with this email already exists. To link with a different member, please change one of the email addresses first."
+                      )}
+                    </p>
+                  </div>
+                <% end %>
+
+                <%= if @selected_member_id && @selected_member_name do %>
+                  <div
+                    id="member-selected"
+                    class="p-3 mt-2 border border-blue-200 rounded-lg bg-blue-50"
+                  >
+                    <p class="text-sm text-blue-800">
+                      <strong>{gettext("Selected")}:</strong> {@selected_member_name}
+                    </p>
+                    <p class="mt-1 text-xs text-blue-600">
+                      {gettext("Save to confirm linking.")}
+                    </p>
+                  </div>
+                <% end %>
+              </div>
+            <% end %>
+          </div>
+        <% end %>
 
         <div class="mt-4">
           <.button phx-disable-with={gettext("Saving...")} variant="primary">
@@ -289,14 +294,19 @@ defmodule MvWeb.UserLive.Form do
   end
 
   defp mount_continue(user, params, socket) do
+    actor = current_actor(socket)
     action = if is_nil(user), do: gettext("New"), else: gettext("Edit")
     page_title = action <> " " <> gettext("User")
 
+    # Only admins can link/unlink users to members (permission docs; prevents privilege escalation).
+    can_manage_member_linking = can?(actor, :destroy, Mv.Accounts.User)
+
     {:ok,
      socket
      |> assign(:return_to, return_to(params["return_to"]))
      |> assign(user: user)
      |> assign(:page_title, page_title)
+     |> assign(:can_manage_member_linking, can_manage_member_linking)
      |> assign(:show_password_fields, false)
      |> assign(:member_search_query, "")
      |> assign(:available_members, [])
@@ -329,9 +339,9 @@ defmodule MvWeb.UserLive.Form do
   def handle_event("validate", %{"user" => user_params}, socket) do
     validated_form = AshPhoenix.Form.validate(socket.assigns.form, user_params)
 
-    # Reload members if email changed (for email-match priority)
+    # Reload members if email changed (for email-match priority; only when member linking UI is shown)
     socket =
-      if Map.has_key?(user_params, "email") do
+      if Map.has_key?(user_params, "email") and socket.assigns[:can_manage_member_linking] do
         user_email = user_params["email"]
         members = load_members_for_linking(user_email, socket.assigns.member_search_query, socket)
 
@@ -480,20 +490,25 @@ defmodule MvWeb.UserLive.Form do
   end
 
   defp perform_member_link_action(socket, user, actor) do
-    cond do
-      # Selected member ID takes precedence (new link)
-      socket.assigns.selected_member_id ->
-        Mv.Accounts.update_user(user, %{member: %{id: socket.assigns.selected_member_id}},
-          actor: actor
-        )
+    # Only admins may link/unlink (backend policy also restricts update_user; UI must not call it).
+    if can?(actor, :destroy, Mv.Accounts.User) do
+      cond do
+        # Selected member ID takes precedence (new link)
+        socket.assigns.selected_member_id ->
+          Mv.Accounts.update_user(user, %{member: %{id: socket.assigns.selected_member_id}},
+            actor: actor
+          )
 
-      # Unlink flag is set
-      socket.assigns[:unlink_member] ->
-        Mv.Accounts.update_user(user, %{member: nil}, actor: actor)
+        # Unlink flag is set
+        socket.assigns[:unlink_member] ->
+          Mv.Accounts.update_user(user, %{member: nil}, actor: actor)
 
-      # No changes to member relationship
-      true ->
-        {:ok, user}
+        # No changes to member relationship
+        true ->
+          {:ok, user}
+      end
+    else
+      {:ok, user}
     end
   end
 
@@ -552,13 +567,28 @@ defmodule MvWeb.UserLive.Form do
   end
 
   @spec assign_form(Phoenix.LiveView.Socket.t()) :: Phoenix.LiveView.Socket.t()
-  defp assign_form(%{assigns: %{user: user, show_password_fields: show_password_fields}} = socket) do
+  defp assign_form(
+         %{
+           assigns: %{
+             user: user,
+             show_password_fields: show_password_fields,
+             can_manage_member_linking: can_manage_member_linking
+           }
+         } = socket
+       ) do
     actor = current_actor(socket)
 
     form =
       if user do
-        # For existing users, use admin password action if password fields are shown
-        action = if show_password_fields, do: :admin_set_password, else: :update_user
+        # For existing users: admin uses update_user (email + member); non-admin uses update (email only).
+        # Password change uses admin_set_password for both.
+        action =
+          cond do
+            show_password_fields -> :admin_set_password
+            can_manage_member_linking -> :update_user
+            true -> :update
+          end
+
         AshPhoenix.Form.for_update(user, action, domain: Mv.Accounts, as: "user", actor: actor)
       else
         # For new users, use password registration if password fields are shown