Rewrite documentation URL mapping to use the TOC

Upstream builds various guides and each guide is built as a single large
page. That page has many chapters. Technically every guide is also built
into 3 flavors (foreman-deb, foreman-el, katello).

Downstream builds various guides, which mostly come from upstream. Most
guides are a simple translation where they're downcased, but some are
rewritten to something else.

A bigger difference is that each guide is built into multiple pages.
This means we need to find the right page containing the chapter. The
Table of Content contains a complete mapping with this information, so
it can be looked up dynamically.

If this still can't be found, we use the html-single where everything is
built into a single page. We then just hope it exists. Otherwise the
browser will just show the whole page. This is an unexpected case, so a
warning is logged.

The result is that a lot less maintenance is needed, because in most
cases it will "just work". A downside is that it becomes hard to verify
links are correct. It becomes needed to crawl through all of the source
code for any documentation links, similar to how we crawl through it for
translations.

app/controllers/concerns/documentation_controller_branding.rb

@@ -33,8 +33,7 @@ def wiki_url(section: '')
   # We do not use flavor downstream, but keeping it here for the same method signature
   # rubocop:disable Lint/UnusedMethodArgument
   def docs_url(guide:, flavor:, chapter: nil)
-    url = ForemanThemeSatellite::Documentation::DOCS_GUIDES_LINKS.dig(guide, chapter)
-    url || "#{ForemanThemeSatellite.documentation_root}/#{guide.downcase}/#{chapter}"
+    ForemanThemeSatellite::Documentation.docs_url(guide, chapter)
   end
   # rubocop:enable Lint/UnusedMethodArgument
 end

lib/foreman_theme_satellite/documentation.rb

@@ -77,28 +77,57 @@ module Documentation
       'foreman_discovery' => "#{ForemanThemeSatellite.documentation_root}/provisioning_hosts/discovering-hosts-on-a-network_provisioning",
     }.freeze
 
-    DOCS_GUIDES_LINKS = {
-      'Managing_Content' => {
-        'Products_and_Repositories_content-management' => "#{ForemanThemeSatellite.documentation_root}/managing_content/importing_content_content-management#Products_and_Repositories_content-management",
-      },
+    # Guide mapping. If no entry is present, it should be assumed that it can
+    # be downcased
+    DOCS_GUIDE_MAPPING = {
+      'Managing_Configurations_Ansible' => 'managing_configurations_using_ansible_integration',
+    }.freeze
+
+    # An upstream chapter mapping, in case downstream another chapter should be
+    # used. The top level key is the upstream guide name where the value is a
+    # mapping of upstream chapter to downstream mapping
+    DOCS_GUIDE_CHAPTER_MAPPING = {
       'Managing_Hosts' => {
-        'registering-a-host_managing-hosts' => "#{ForemanThemeSatellite.documentation_root}/managing_hosts/registering_hosts_to_server_managing-hosts#Registering_Hosts_by_Using_Global_Registration_managing-hosts",
-      }
+        'registering-a-host_managing-hosts' => 'Registering_Hosts_by_Using_Global_Registration_managing-hosts',
+      },
     }.freeze
 
-    def self.flat_docs_guides_links
-      nested_to_flat_k_v(nil, DOCS_GUIDES_LINKS).to_h
+    DOCS_GUIDE_PAGES = JSON.load_file(File.join(__dir__, 'documentation-toc.json'))
+
+    # @param guide [String]
+    #   The downstream guide name
+    # @param chapter [String]
+    #   The downstream chapter name
+    # @return [String]
+    #   The page where the chapter is located
+    # @return nil
+    #   If no chapter was found
+    def self.find_page_for_guide_chapter(guide, chapter)
+      DOCS_GUIDE_PAGES[guide]&.find { |_page, chapters| chapters.include?(chapter) }&.first
     end
 
-    private_class_method def self.nested_to_flat_k_v(prefix, source)
-      key_values = []
-      source.map do |k, v|
-        key = "#{prefix}/#{k}"
-        if v.is_a?(Hash)
-          key_values.append(*nested_to_flat_k_v(key, v))
+    def self.docs_url(guide, chapter)
+      root = ForemanThemeSatellite.documentation_root
+      downstream_guide = DOCS_GUIDE_MAPPING.fetch(guide) { guide.downstream }
+
+      if chapter
+        downstream_chapter = DOCS_GUIDE_CHAPTER_MAPPING.fetch(guide, chapter) || chapter
+        page = find_page_for_guide_chapter(downstream_guide, downstream_chapter)
+
+        if page
+          "#{root}/#{downstream_guide}/#{page}##{downstream_chapter}"
         else
-          key_values.append([key, v])
+          logger.warning("Could not find page for chapter '#{downstream_chapter}' in guide '#{downstream_guide}'")
+          "#{root}-single/#{downstream_guide}/index##{downstream_chapter}"
         end
+      else
+        "#{root}/#{downstream_guide}"
+      end
+    end
+
+    def self.flat_docs_guides_links
+      DOCS_GUIDE_CHAPTER_MAPPING.inject({}) do |hash, guide, chapters|
+        hash.update(chapters.keys.to_h { |chapter| ["/#{guide}/#{chapter}", docs_url(guide, chapter)] })
       end
     end
   end

test/integration/documentation_controller_branding_test.rb

@@ -7,6 +7,24 @@ def test_docs_redirect_branded
     assert_redirected_to "https://docs.redhat.com/documentation/en-us/red_hat_satellite/#{ForemanThemeSatellite.documentation_version}/html/managing_hosts/registering_hosts_to_server_managing-hosts#Registering_Hosts_by_Using_Global_Registration_managing-hosts"
   end
 
+  def test_docs_dynamically_generated
+    get "/links/docs/Managing_Content?chapter=Products_and_Repositories_content-management"
+
+    assert_redirected_to "https://docs.redhat.com/documentation/en-us/red_hat_satellite/#{ForemanThemeSatellite.documentation_version}/html/managing_content/importing_content_content-management#Products_and_Repositories_content-management"
+  end
+
+  def test_docs_with_mapped_guide
+    get "/links/docs/Managing_Configurations_Ansible?chapter=Importing_Ansible_Roles_and_Variables_ansible"
+
+    assert_redirected_to "https://docs.redhat.com/documentation/en-us/red_hat_satellite/#{ForemanThemeSatellite.documentation_version}/html/managing_configurations_using_ansible/getting_started_with_ansible_in_satellite_ansible_integration#Importing_Ansible_Roles_and_Variables_ansible"
+  end
+
+  def test_docs_chapter_does_not_exist
+    get "/links/docs/Managing_Content?chapter=does-not-exist"
+
+    assert_redirected_to "https://docs.redhat.com/documentation/en-us/red_hat_satellite/#{ForemanThemeSatellite.documentation_version}/html-single/managing_content/index#does-not-exist"
+  end
+
   def test_docs_redirect_unknown_chapter
     get "/links/docs/Managing_Hosts"