add live page editor sidebar with collapsible UI

Admins can now edit pages directly on the live shop by clicking the
pencil icon in the header. A sidebar slides in with block management
controls (add, remove, reorder, edit settings, save, reset, done).

Key features:
- PageEditorHook on_mount with handle_params/event/info hooks
- BlockEditor pure functions extracted from admin editor
- Shared BlockEditorComponents with event_prefix namespacing
- Collapsible sidebar: X closes it, header pencil reopens it
- Backdrop overlay dismisses sidebar on tap
- Conditional admin.css loading for logged-in users
- content_body block now portable (textarea setting + rich text fallback)

13 integration tests, 26 unit tests, 1370 total passing.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/berrypod_web/page_editor_hook.ex

@@ -0,0 +1,360 @@
+defmodule BerrypodWeb.PageEditorHook do
+  @moduledoc """
+  LiveView on_mount hook for the live page editor sidebar.
+
+  Mounted in the public_shop live_session. When an admin visits any shop
+  page with `?edit=true` in the URL, this hook activates editing mode:
+  loads a working copy of the page's blocks, attaches event handlers for
+  block manipulation, and sets assigns that trigger the editor sidebar
+  in `PageRenderer.render_page/1`.
+
+  Non-admin users are unaffected — the hook just assigns `editing: false`.
+
+  ## Actions
+
+  - `:mount_page_editor` — sets up editing assigns and attaches hooks
+  """
+
+  import Phoenix.Component, only: [assign: 3]
+  import Phoenix.LiveView, only: [attach_hook: 4, put_flash: 3, push_navigate: 2]
+
+  alias Berrypod.Pages
+  alias Berrypod.Pages.{BlockEditor, BlockTypes}
+
+  def on_mount(:mount_page_editor, _params, _session, socket) do
+    socket =
+      socket
+      |> assign(:editing, false)
+      |> assign(:editing_blocks, nil)
+      |> assign(:editor_dirty, false)
+      |> assign(:editor_expanded, MapSet.new())
+      |> assign(:editor_show_picker, false)
+      |> assign(:editor_picker_filter, "")
+      |> assign(:editor_allowed_blocks, nil)
+      |> assign(:editor_live_region_message, nil)
+      |> assign(:editor_current_path, nil)
+      |> assign(:editor_sidebar_open, true)
+      |> attach_hook(:editor_params, :handle_params, &handle_editor_params/3)
+      |> attach_hook(:editor_events, :handle_event, &handle_editor_event/3)
+      |> attach_hook(:editor_info, :handle_info, &handle_editor_info/2)
+
+    {:cont, socket}
+  end
+
+  # ── handle_params: detect ?edit=true ─────────────────────────────
+
+  defp handle_editor_params(_params, uri, socket) do
+    parsed = URI.parse(uri)
+    query = URI.decode_query(parsed.query || "")
+    wants_edit = query["edit"] == "true"
+
+    # Always store the current path for the edit button and "done" navigation
+    socket = assign(socket, :editor_current_path, parsed.path)
+
+    cond do
+      wants_edit and socket.assigns.is_admin and socket.assigns[:page] ->
+        # Page already loaded — enter edit mode and halt (no need for module handle_params)
+        {:halt, enter_edit_mode(socket)}
+
+      wants_edit and socket.assigns.is_admin ->
+        # Page not loaded yet (e.g. Shop.Content loads in handle_params),
+        # defer initialisation until after the LiveView sets @page
+        send(self(), :editor_deferred_init)
+        {:cont, assign(socket, :editing, true)}
+
+      socket.assigns.editing and not wants_edit ->
+        # Exiting edit mode — halt since we've handled the transition
+        {:halt, exit_edit_mode(socket)}
+
+      true ->
+        {:cont, socket}
+    end
+  end
+
+  # ── handle_info: deferred init ───────────────────────────────────
+
+  defp handle_editor_info(:editor_deferred_init, socket) do
+    if socket.assigns.editing and is_nil(socket.assigns.editing_blocks) and socket.assigns[:page] do
+      {:halt, enter_edit_mode(socket)}
+    else
+      {:cont, socket}
+    end
+  end
+
+  defp handle_editor_info(_msg, socket), do: {:cont, socket}
+
+  # ── handle_event: editor_* events ────────────────────────────────
+
+  defp handle_editor_event("editor_" <> action, params, socket) do
+    if socket.assigns.editing do
+      handle_editor_action(action, params, socket)
+    else
+      {:cont, socket}
+    end
+  end
+
+  defp handle_editor_event(_event, _params, socket), do: {:cont, socket}
+
+  # ── Block manipulation actions ───────────────────────────────────
+
+  defp handle_editor_action("move_up", %{"id" => id}, socket) do
+    case BlockEditor.move_up(socket.assigns.editing_blocks, id) do
+      {:ok, new_blocks, message} ->
+        {:halt, apply_mutation(socket, new_blocks, message, :reorder)}
+
+      :noop ->
+        {:halt, socket}
+    end
+  end
+
+  defp handle_editor_action("move_down", %{"id" => id}, socket) do
+    case BlockEditor.move_down(socket.assigns.editing_blocks, id) do
+      {:ok, new_blocks, message} ->
+        {:halt, apply_mutation(socket, new_blocks, message, :reorder)}
+
+      :noop ->
+        {:halt, socket}
+    end
+  end
+
+  defp handle_editor_action("remove_block", %{"id" => id}, socket) do
+    {:ok, new_blocks, message} = BlockEditor.remove_block(socket.assigns.editing_blocks, id)
+    {:halt, apply_mutation(socket, new_blocks, message, :content)}
+  end
+
+  defp handle_editor_action("duplicate_block", %{"id" => id}, socket) do
+    case BlockEditor.duplicate_block(socket.assigns.editing_blocks, id) do
+      {:ok, new_blocks, message} ->
+        {:halt, apply_mutation(socket, new_blocks, message, :content)}
+
+      :noop ->
+        {:halt, socket}
+    end
+  end
+
+  defp handle_editor_action("add_block", %{"type" => type}, socket) do
+    case BlockEditor.add_block(socket.assigns.editing_blocks, type) do
+      {:ok, new_blocks, message} ->
+        socket =
+          socket
+          |> assign(:editing_blocks, new_blocks)
+          |> assign(:editor_dirty, true)
+          |> assign(:editor_show_picker, false)
+          |> assign(:editor_live_region_message, message)
+          |> reload_block_data(new_blocks)
+
+        {:halt, socket}
+
+      :noop ->
+        {:halt, socket}
+    end
+  end
+
+  defp handle_editor_action("update_block_settings", params, socket) do
+    block_id = params["block_id"]
+    new_settings = params["block_settings"] || %{}
+
+    case BlockEditor.update_settings(socket.assigns.editing_blocks, block_id, new_settings) do
+      {:ok, new_blocks} ->
+        socket =
+          socket
+          |> assign(:editing_blocks, new_blocks)
+          |> assign(:editor_dirty, true)
+          |> reload_block_data(new_blocks)
+
+        {:halt, socket}
+
+      :noop ->
+        {:halt, socket}
+    end
+  end
+
+  # ── Repeater actions ─────────────────────────────────────────────
+
+  defp handle_editor_action(
+         "repeater_add",
+         %{"block-id" => block_id, "field" => field_key},
+         socket
+       ) do
+    case BlockEditor.repeater_add(socket.assigns.editing_blocks, block_id, field_key) do
+      {:ok, new_blocks, message} ->
+        {:halt, apply_mutation(socket, new_blocks, message, :content)}
+
+      :noop ->
+        {:halt, socket}
+    end
+  end
+
+  defp handle_editor_action(
+         "repeater_remove",
+         %{"block-id" => block_id, "field" => field_key, "index" => index_str},
+         socket
+       ) do
+    index = String.to_integer(index_str)
+
+    case BlockEditor.repeater_remove(socket.assigns.editing_blocks, block_id, field_key, index) do
+      {:ok, new_blocks, message} ->
+        {:halt, apply_mutation(socket, new_blocks, message, :content)}
+
+      :noop ->
+        {:halt, socket}
+    end
+  end
+
+  defp handle_editor_action(
+         "repeater_move",
+         %{"block-id" => block_id, "field" => field_key, "index" => index_str, "dir" => dir},
+         socket
+       ) do
+    index = String.to_integer(index_str)
+
+    case BlockEditor.repeater_move(
+           socket.assigns.editing_blocks,
+           block_id,
+           field_key,
+           index,
+           dir
+         ) do
+      {:ok, new_blocks, message} ->
+        {:halt, apply_mutation(socket, new_blocks, message, :reorder)}
+
+      :noop ->
+        {:halt, socket}
+    end
+  end
+
+  # ── UI state actions ─────────────────────────────────────────────
+
+  defp handle_editor_action("toggle_expand", %{"id" => block_id}, socket) do
+    expanded = socket.assigns.editor_expanded
+    block = Enum.find(socket.assigns.editing_blocks, &(&1["id"] == block_id))
+    block_name = BlockEditor.block_display_name(block)
+
+    {new_expanded, action} =
+      if MapSet.member?(expanded, block_id) do
+        {MapSet.delete(expanded, block_id), "collapsed"}
+      else
+        {MapSet.put(expanded, block_id), "expanded"}
+      end
+
+    {:halt,
+     socket
+     |> assign(:editor_expanded, new_expanded)
+     |> assign(:editor_live_region_message, "#{block_name} settings #{action}")}
+  end
+
+  defp handle_editor_action("toggle_sidebar", _params, socket) do
+    {:halt, assign(socket, :editor_sidebar_open, !socket.assigns.editor_sidebar_open)}
+  end
+
+  defp handle_editor_action("show_picker", _params, socket) do
+    {:halt,
+     socket
+     |> assign(:editor_show_picker, true)
+     |> assign(:editor_picker_filter, "")}
+  end
+
+  defp handle_editor_action("hide_picker", _params, socket) do
+    {:halt, assign(socket, :editor_show_picker, false)}
+  end
+
+  defp handle_editor_action("filter_picker", %{"value" => value}, socket) do
+    {:halt, assign(socket, :editor_picker_filter, value)}
+  end
+
+  # ── Page actions ─────────────────────────────────────────────────
+
+  defp handle_editor_action("save", _params, socket) do
+    %{page: page, editing_blocks: blocks} = socket.assigns
+
+    case Pages.save_page(page.slug, %{title: page.title, blocks: blocks}) do
+      {:ok, _saved_page} ->
+        updated_page = Pages.get_page(page.slug)
+
+        socket =
+          socket
+          |> assign(:page, updated_page)
+          |> assign(:editing_blocks, updated_page.blocks)
+          |> assign(:editor_dirty, false)
+          |> put_flash(:info, "Page saved")
+
+        {:halt, socket}
+
+      {:error, _changeset} ->
+        {:halt, put_flash(socket, :error, "Failed to save page")}
+    end
+  end
+
+  defp handle_editor_action("reset_defaults", _params, socket) do
+    slug = socket.assigns.page.slug
+    :ok = Pages.reset_page(slug)
+    page = Pages.get_page(slug)
+
+    socket =
+      socket
+      |> assign(:page, page)
+      |> assign(:editing_blocks, page.blocks)
+      |> assign(:editor_dirty, false)
+      |> reload_block_data(page.blocks)
+      |> put_flash(:info, "Page reset to defaults")
+
+    {:halt, socket}
+  end
+
+  defp handle_editor_action("done", _params, socket) do
+    path = socket.assigns.editor_current_path || "/"
+    {:halt, push_navigate(socket, to: path)}
+  end
+
+  # Catch-all for unknown editor actions
+  defp handle_editor_action(_action, _params, socket), do: {:halt, socket}
+
+  # ── Private helpers ──────────────────────────────────────────────
+
+  defp enter_edit_mode(socket) do
+    page = socket.assigns.page
+    allowed = BlockTypes.allowed_for(page.slug)
+
+    socket
+    |> assign(:editing, true)
+    |> assign(:editing_blocks, page.blocks)
+    |> assign(:editor_dirty, false)
+    |> assign(:editor_expanded, MapSet.new())
+    |> assign(:editor_show_picker, false)
+    |> assign(:editor_picker_filter, "")
+    |> assign(:editor_allowed_blocks, allowed)
+    |> assign(:editor_live_region_message, nil)
+    |> assign(:editor_sidebar_open, true)
+  end
+
+  defp exit_edit_mode(socket) do
+    socket
+    |> assign(:editing, false)
+    |> assign(:editing_blocks, nil)
+    |> assign(:editor_dirty, false)
+    |> assign(:editor_expanded, MapSet.new())
+    |> assign(:editor_show_picker, false)
+    |> assign(:editor_picker_filter, "")
+    |> assign(:editor_allowed_blocks, nil)
+    |> assign(:editor_live_region_message, nil)
+    |> assign(:editor_sidebar_open, true)
+  end
+
+  defp apply_mutation(socket, new_blocks, message, type) do
+    socket =
+      socket
+      |> assign(:editing_blocks, new_blocks)
+      |> assign(:editor_dirty, true)
+      |> assign(:editor_live_region_message, message)
+
+    case type do
+      :content -> reload_block_data(socket, new_blocks)
+      :reorder -> socket
+    end
+  end
+
+  defp reload_block_data(socket, blocks) do
+    extra = Pages.load_block_data(blocks, socket.assigns)
+    Enum.reduce(extra, socket, fn {key, value}, acc -> assign(acc, key, value) end)
+  end
+end