Add per-node translation management: list, edit, destroy, compare

Replaces the old locale-switch-and-edit-the-same-screen workflow,
which conflated presentation locale with content locale and let an
editor silently drift into editing the wrong language with no
persistent signal that anything had changed. Non-default-locale
content now has its own explicit routes and screens, never sharing
a route param with the ambient chrome locale.

- PageTranslationsController: index/show/edit/update/destroy,
  scoped to Page.non_default_locales; update handles first-time
  creation too, so there's no separate new/create step.
- Reads go through the actual PageTranslation row
  (Page#translation_summary), never through the Globalize
  fallback-bearing accessor -- fallback is correct for public
  rendering but wrong for editing, where a missing translation
  needs to look empty, not borrowed from another locale.
- Translations ride on the page's own draft/head cycle; no
  independent publish state.
- nodes#show gains a Translations section (per-locale Lock+Edit /
  Create+Lock, Destroy, a link into the read-only Compare view) and
  a locale indicator on its own default-locale content; nodes#edit,
  nodes#update, and nodes#autosave are pinned to the default locale
  via Globalize.with_locale regardless of the ambient route locale.
- nodes#show no longer double-loads the node or calls wipe_draft!
  on every view (see previous commit for why that's now safe).
- .preview_link_row is renamed .aligned_action_row now that it has
  a second real consumer.

10 files changed, 366 insertions, 10 deletions

diff --git a/app/controllers/nodes_controller.rb b/app/controllers/nodes_controller.rb
index c1468be..249602d 100644
--- a/app/controllers/nodes_controller.rb
+++ b/app/controllers/nodes_controller.rb
@@ -16,6 +16,8 @@ class NodesController < ApplicationController
                               :revert
                             ]
 
+  around_action :pin_to_default_locale, :only => [:show, :edit, :update, :autosave]
+
   def index
     @nodes = Node.root.descendants.includes(:head, :draft)
       .order('id DESC')
@@ -59,9 +61,9 @@ class NodesController < ApplicationController
   end
 
   def show
-    node = Node.find(params[:id])
-    node.wipe_draft!
-    @page = node.draft || node.head
+    @page = @node.draft || @node.head
+    @default_translation = @page.translations.find_by(:locale => I18n.default_locale)
+    @translations = @page.translation_summary
   end
 
   def edit
@@ -248,6 +250,10 @@ class NodesController < ApplicationController
       end
     end
 
+    def pin_to_default_locale
+      Globalize.with_locale(I18n.default_locale) { yield }
+    end
+
     def descendant_counts_for(ordered_with_level)
       counts = Hash.new(0)
       stack = [] # [node, level, index]
diff --git a/app/controllers/page_translations_controller.rb b/app/controllers/page_translations_controller.rb
new file mode 100644
index 0000000..47f01f7
--- /dev/null
+++ b/app/controllers/page_translations_controller.rb
@@ -0,0 +1,98 @@
+class PageTranslationsController < ApplicationController
+  layout 'admin'
+
+  before_action :login_required
+  before_action :find_node
+  before_action :find_locale, :only => [:show, :edit, :update, :destroy]
+
+  def index
+    page = @node.draft || @node.head
+    @translations = page ? page.translation_summary : []
+  end
+
+  def show
+    @page = @node.draft || @node.head
+    @translation         = @page.translations.find_by(:locale => @locale)
+    @default_translation = @page.translations.find_by(:locale => I18n.default_locale)
+  end
+
+  def edit
+    @node.lock_for_editing!(current_user)
+    @page = @node.draft || @node.head
+    @translation = @page.translations.find_by(:locale => @locale)
+  rescue LockedByAnotherUser => e
+    flash[:error] = e.message
+    redirect_to node_path(@node)
+  end
+
+  def update
+    draft = ensure_editable_draft
+    Globalize.with_locale(@locale) { draft.update!(translation_params) }
+    flash[:notice] = "#{@locale.upcase} translation saved. Publish the draft to make it live."
+
+    if params[:commit] == "Save + Unlock + Exit"
+      @node.unlock!
+      redirect_to node_path(@node)
+    else
+      redirect_to edit_node_translation_path(@node, @locale)
+    end
+  rescue LockedByAnotherUser => e
+    flash[:error] = e.message
+    redirect_to node_path(@node)
+  end
+
+  def destroy
+    base = @node.draft || @node.head
+    unless base && base.translated_locales.include?(@locale)
+      flash[:error] = "No #{@locale.to_s.upcase} translation exists to remove."
+      return redirect_to node_path(@node)
+    end
+
+    if (base.translated_locales - [@locale]).empty?
+      flash[:error] = "Can't remove the only remaining translation."
+      return redirect_to node_path(@node)
+    end
+
+    draft = ensure_editable_draft
+    draft.translations.where(:locale => @locale).delete_all
+    draft.reload
+
+    flash[:notice] = "#{@locale.upcase} translation removed from the draft. Publish to make this permanent."
+    redirect_to node_path(@node)
+  rescue LockedByAnotherUser => e
+    flash[:error] = e.message
+    redirect_to node_path(@node)
+  end
+
+  private
+
+    def find_node
+      @node = Node.find(params[:node_id])
+    end
+
+    # Every remaining action's :translation_locale is already
+    # router-constrained to non-default locales, so this should never
+    # actually fire in practice -- it's a deliberate second check, kept
+    # as a drift detector in case the route constraint and this list
+    # (both driven by Page.non_default_locales) ever disagree.
+    def find_locale
+      candidate = params[:translation_locale].to_s.to_sym
+      unless Page.non_default_locales.include?(candidate)
+        raise ActionController::RoutingError, "Unknown or default locale"
+      end
+      @locale = candidate
+    end
+
+    # Never mutates head directly. Locks first (same guard as the
+    # primary editor), then reuses an existing draft or creates one --
+    # deliberately not going through the autosave buffer: this is a
+    # plain, explicit Save, not a live-typing surface.
+    def ensure_editable_draft
+      @node.lock_for_editing!(current_user)
+      @node.draft || @node.create_new_draft(current_user)
+    end
+
+    def translation_params
+      params.fetch(:page, {}).permit(:title, :abstract, :body)
+    end
+end
diff --git a/app/models/page.rb b/app/models/page.rb
index db5b688..f796228 100644
--- a/app/models/page.rb
+++ b/app/models/page.rb
@@ -87,6 +87,27 @@ class Page < ApplicationRecord
     end
   end
 
+  def self.non_default_locales
+    I18n.available_locales - [:root, I18n.default_locale]
+  end
+
+  # One row per non-default locale, read from the actual translation
+  # row -- never through the locale-dependent accessor, so a locale
+  # with no real translation yet reports as absent rather than quietly
+  # showing a fallback value borrowed from another locale.
+  def translation_summary
+    Page.non_default_locales.map do |locale|
+      translation = translations.find_by(:locale => locale)
+      {
+        :locale     => locale,
+        :exists     => translation.present?,
+        :title      => translation&.title,
+        :updated_at => translation&.updated_at,
+        :outdated   => translation.present? && outdated_translations?(:locale => locale)
+      }
+    end
+  end
+
   def self.untranslated(options = {:locale => :de})
     PageTranslation.all.group_by(&:page_id).select do |k,v|
       v.size == 1 && v.map{|x| x.locale}.include?(options[:locale])
diff --git a/app/views/nodes/show.html.erb b/app/views/nodes/show.html.erb
index 54bb38f..e6a922b 100644
--- a/app/views/nodes/show.html.erb
+++ b/app/views/nodes/show.html.erb
@@ -1,6 +1,6 @@
 <% locked_by_other = @node.locked? && @node.lock_owner != current_user %>
 <div id="page_editor" class="show_node">
-  <h1><%= title_for_node(@node) %></h1>
+  <h1><%= title_for_node(@node) %> <small>(<%= I18n.default_locale.to_s.upcase %>)</small></h1>
   <div id="content">
     <div class="node_description">Status</div>
     <div class="node_content node_info_group node_status">
@@ -70,6 +70,46 @@
       <% end %>
     </div>
 
+    <div class="node_description">Translations</div>
+    <div class="node_content node_info_group">
+      <div class="node_info_group_items">
+        <div class="node_info_item">
+          <span class="node_info_label"><%= I18n.default_locale.to_s.upcase %> (default)</span>
+          <%= @page.title %> — updated <%= @default_translation&.updated_at || @page.updated_at %>
+        </div>
+        <% @translations.each do |t| %>
+          <div class="node_info_item">
+            <span class="node_info_label"><%= t[:locale].to_s.upcase %></span>
+            <div class="aligned_action_row">
+              <% if t[:exists] %>
+                <%= link_to t[:title], node_translation_path(@node, t[:locale]) %> — updated <%= t[:updated_at] %>
+                <% if t[:outdated] %>
+                  <span class="warning">may be outdated</span>
+                <% end %>
+              <% else %>
+                <span class="field_hint">Not yet translated.</span>
+              <% end %>
+              <% if locked_by_other %>
+                <span class="disabled_action"><%= t[:exists] ? "Lock + Edit" : "Create translation + Lock" %></span>
+              <% else %>
+                <%= link_to edit_node_translation_path(@node, t[:locale]), class: "action_button" do %>
+                  <%= icon(t[:exists] ? "edit" : "language", library: "tabler", "aria-hidden": true) %>
+                  <%= t[:exists] ? "Lock + Edit" : "Create translation + Lock" %>
+                <% end %>
+                <% if t[:exists] %>
+                  <%= button_to node_translation_path(@node, t[:locale]), method: :delete,
+                        form: { data: { confirm: "This cannot be undone. Continue?" }, class: 'button_to destructive' } do %>
+                    <%= icon("trash", library: "tabler", "aria-hidden": true) %>
+                    Destroy Translation
+                  <% end %>
+                <% end %>
+              <% end %>
+            </div>
+          </div>
+        <% end %>
+      </div>
+    </div>
+
     <div class="node_description">People</div>
     <div class="node_content node_info_group">
       <div class="node_info_group_items">
@@ -122,7 +162,7 @@
           <div class="node_info_item">
             <span class="node_info_label">Public Preview</span>
             <% if @node.draft.preview_token.present? %>
-              <div class="preview_link_row">
+              <div class="aligned_action_row">
                 <%= link_to shared_preview_path(token: @node.draft.preview_token), shared_preview_url(token: @node.draft.preview_token), target: "_blank", rel: "noopener" %>
                 <%= button_to 'Revoke', revoke_shared_preview_node_path(@node), method: :put, form: { data: { confirm: "Revoke this preview link? Anyone currently using it will immediately lose access." }, class: 'button_to state_changing' } %>
               </div>
@@ -205,12 +245,11 @@
       </div>
     <% end %>
 
-    <div class="node_description">Abstract</div>
+    <div class="node_description">Abstract (<%= I18n.default_locale.to_s.upcase %>)</div>
     <div class="node_content"><%= sanitize(@page.abstract) %></div>
 
-    <div class="node_description">Body</div>
+    <div class="node_description">Body (<%= I18n.default_locale.to_s.upcase %>)</div>
     <div class="node_content"><%= sanitize(@page.body) %></div>
-    <%# Assets not yet addressed - no confirmed model/association seen for this page's attached assets %>
 
   </div>
 </div>
diff --git a/app/views/page_translations/edit.html.erb b/app/views/page_translations/edit.html.erb
new file mode 100644
index 0000000..7371a42
--- /dev/null
+++ b/app/views/page_translations/edit.html.erb
@@ -0,0 +1,39 @@
+<div class="translation_banner">
+  Editing the <strong><%= @locale.to_s.upcase %></strong> translation of <strong><%= title_for_node(@node) %></strong>.
+</div>
+
+<p class="field_hint">
+  Metadata such as images, tags, template, and author belong to the page
+  as a whole, not to a single translation — change those from the
+  <%= link_to 'default-locale editor', edit_node_path(@node) %>.
+</p>
+
+<div class="node_action_bar">
+  <%= button_to 'Unlock + Back', unlock_node_path(@node), method: :put,
+        form: { class: 'button_to state_changing' },
+        disabled: @node.autosave.present? %>
+  <%= submit_tag "Save #{@locale.to_s.upcase} translation", form: "translation_edit_form" %>
+  <%= submit_tag "Save + Unlock + Exit", form: "translation_edit_form" %>
+  <%= link_to "Preview ↗", preview_page_path(@page, :locale => @locale), target: "_blank", rel: "noopener", class: "preview_link" %>
+</div>
+
+<div id="page_editor">
+  <%= form_with url: node_translation_path(@node, @locale), method: :patch, local: true, id: "translation_edit_form" do |f| %>
+    <div id="content">
+      <div class="node_description">Title</div>
+      <div class="node_content">
+        <%= text_field_tag "page[title]", @translation&.title %>
+      </div>
+
+      <div class="node_description">Abstract</div>
+      <div class="node_content">
+        <%= text_area_tag "page[abstract]", @translation&.abstract %>
+      </div>
+
+      <div class="node_description">Body</div>
+      <div class="node_content">
+        <%= text_area_tag "page[body]", @translation&.body, :class => 'with_editor' %>
+      </div>
+    </div>
+  <% end %>
+</div>
diff --git a/app/views/page_translations/index.html.erb b/app/views/page_translations/index.html.erb
new file mode 100644
index 0000000..a8c4f5d
--- /dev/null
+++ b/app/views/page_translations/index.html.erb
@@ -0,0 +1,19 @@
+<h1>Translations — <%= title_for_node(@node) %></h1>
+
+<div class="node_content node_info_group">
+  <div class="node_info_group_items">
+    <% @translations.each do |t| %>
+      <div class="node_info_item">
+        <span class="node_info_label"><%= t[:locale].to_s.upcase %></span>
+        <% if t[:exists] %>
+          <%= t[:title] %> — updated <%= t[:updated_at] %>
+          <% if t[:outdated] %><span class="warning">may be outdated</span><% end %>
+          <%= link_to 'Edit', edit_node_translation_path(@node, t[:locale]) %>
+        <% else %>
+          <span class="field_hint">Not yet translated.</span>
+          <%= link_to 'Add', edit_node_translation_path(@node, t[:locale]) %>
+        <% end %>
+      </div>
+    <% end %>
+  </div>
+</div>
diff --git a/app/views/page_translations/show.html.erb b/app/views/page_translations/show.html.erb
new file mode 100644
index 0000000..c5bd151
--- /dev/null
+++ b/app/views/page_translations/show.html.erb
@@ -0,0 +1,27 @@
+<h1>Compare — <%= title_for_node(@node) %></h1>
+
+<div class="translation_compare">
+  <div class="translation_compare_column">
+    <h2><%= @locale.to_s.upcase %></h2>
+    <div class="node_description">Title</div>
+    <div class="node_content"><%= @translation&.title %></div>
+
+    <div class="node_description">Abstract</div>
+    <div class="node_content"><%= sanitize(@translation&.abstract.to_s) %></div>
+
+    <div class="node_description">Body</div>
+    <div class="node_content"><%= sanitize(@translation&.body.to_s) %></div>
+  </div>
+
+  <div class="translation_compare_column">
+    <h2><%= I18n.default_locale.to_s.upcase %> (default)</h2>
+    <div class="node_description">Title</div>
+    <div class="node_content"><%= @default_translation&.title %></div>
+
+    <div class="node_description">Abstract</div>
+    <div class="node_content"><%= sanitize(@default_translation&.abstract.to_s) %></div>
+
+    <div class="node_description">Body</div>
+    <div class="node_content"><%= sanitize(@default_translation&.body.to_s) %></div>
+  </div>
+</div>
diff --git a/config/routes.rb b/config/routes.rb
index 5d61bae..38a497d 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -55,6 +55,12 @@ Cccms::Application.routes.draw do
           put :revert
         end
 
+        resources :translations, controller: 'page_translations',
+          param: :translation_locale,
+          constraints: { translation_locale: /en/ },
+          only: [:index, :show, :edit, :update, :destroy]
+
+
         resources :related_assets, only: [:create, :destroy, :update] do
           collection do
             get :search
diff --git a/public/stylesheets/admin.css b/public/stylesheets/admin.css
index c3c0cb4..f1f4c05 100644
--- a/public/stylesheets/admin.css
+++ b/public/stylesheets/admin.css
@@ -637,6 +637,28 @@ table.revisions_table tr:hover {
   margin: 0;
 }
 
+/* ============================================================
+   Translation compare view (page_translations#show)
+   ============================================================ */
+
+.translation_compare {
+  display: flex;
+  flex-direction: column;
+  gap: 1.5rem;
+}
+
+@media(min-width:1016px) {
+  .translation_compare {
+    flex-direction: row;
+    gap: 2rem;
+  }
+
+  .translation_compare_column {
+    flex: 1;
+    min-width: 0;
+  }
+}
+
 table.user_table td.user_login {
   padding-right: 30px;
 }
@@ -834,14 +856,15 @@ form.button_to button[type="submit"] {
   font-weight: bold;
 }
 
-.preview_link_row {
+.aligned_action_row {
   display: flex;
   flex-wrap: wrap;
   align-items: start;
   gap: 0.5rem;
 }
 
-.preview_link_row form.button_to {
+.aligned_action_row .action_button,
+.aligned_action_row form.button_to {
   margin-top: -5px;
 }
 
diff --git a/test/controllers/page_translations_controller_test.rb b/test/controllers/page_translations_controller_test.rb
new file mode 100644
index 0000000..d84ac45
--- /dev/null
+++ b/test/controllers/page_translations_controller_test.rb
@@ -0,0 +1,78 @@
+require 'test_helper'
+
+class PageTranslationsControllerTest < ActionController::TestCase
+  test "index lists the default locale's existing translation and flags a missing one" do
+    login_as :quentin
+    node = Node.root.children.create!(:slug => "translations_index_test")
+    node.publish_draft!
+
+    get :index, params: { :node_id => node.id }
+
+    assert_response :success
+    assert_equal [:en], assigns(:translations).map { |t| t[:locale] }
+    assert_equal false, assigns(:translations).first[:exists]
+  end
+
+  test "update creates a first-time translation on a fresh draft, leaving head untouched" do
+    login_as :quentin
+    node = Node.root.children.create!(:slug => "translations_create_test")
+    Globalize.with_locale(:de) { node.draft.update!(:title => "Deutscher Titel") }
+    node.publish_draft!
+
+    patch :update, params: { :node_id => node.id, :translation_locale => "en", :page => { :title => "English Title" } }
+
+    node.reload
+    assert_not_nil node.draft
+    assert_includes node.draft.translated_locales, :en
+    assert_not_includes node.head.translated_locales, :en
+  end
+
+  test "no route exists for the default locale under the translations resource" do
+    login_as :quentin
+    node = Node.root.children.create!(:slug => "translations_route_constraint_test")
+
+    assert_raises(ActionController::UrlGenerationError) do
+      patch :update, params: { :node_id => node.id, :translation_locale => "de", :page => { :title => "x" } }
+    end
+  end
+
+  test "update with Save + Unlock + Exit unlocks the node and redirects to nodes#show" do
+    login_as :quentin
+    node = Node.root.children.create!(:slug => "translations_exit_test")
+
+    patch :update, params: { :node_id => node.id, :translation_locale => "en", :page => { :title => "x" }, :commit => "Save + Unlock + Exit" }
+
+    assert_nil node.reload.lock_owner
+    assert_redirected_to node_path(node)
+  end
+
+  test "update saves the translation onto the draft" do
+    login_as :quentin
+    node = Node.root.children.create!(:slug => "translations_update_test")
+    Globalize.with_locale(:en) { node.draft.update!(:title => "Original") }
+
+    patch :update, params: { :node_id => node.id, :translation_locale => "en", :page => { :title => "Revised" } }
+
+    assert_equal "Revised", Globalize.with_locale(:en) { node.draft.reload.title }
+  end
+
+  test "destroy refuses to remove the only remaining translation" do
+    login_as :quentin
+    node = Node.root.children.create!(:slug => "translations_destroy_last_test")
+    Globalize.with_locale(:en) { node.draft.update!(:title => "Only translation") }
+    node.draft.translations.where(:locale => :de).delete_all
+
+    delete :destroy, params: { :node_id => node.id, :translation_locale => "en" }
+
+    assert_equal "Can't remove the only remaining translation.", flash[:error]
+  end
+
+  test "destroy is a safe no-op, not a false success, when the translation doesn't exist" do
+    login_as :quentin
+    node = Node.root.children.create!(:slug => "translations_destroy_missing_test")
+
+    delete :destroy, params: { :node_id => node.id, :translation_locale => "en" }
+
+    assert_match(/No EN translation exists/, flash[:error])
+  end
+end