1 files changed, 158 insertions, 0 deletions
diff --git a/lib/search/navigation.rb b/lib/search/navigation.rb
new file mode 100644
index 00000000000..3594ac0dc30
--- /dev/null
+++ b/lib/search/navigation.rb
@@ -0,0 +1,158 @@
+# frozen_string_literal: true
+
+module Search
+  class Navigation
+    include Gitlab::Allowable
+
+    def initialize(user:, project: nil, group: nil, options: {})
+      @user = user
+      @project = project
+      @group = group
+      @options = options
+    end
+
+    def tab_enabled_for_project?(tab)
+      return false unless project.present?
+
+      abilities = Array(search_tab_ability_map[tab])
+      Array.wrap(project).any? { |p| abilities.any? { |ability| can?(user, ability, p) } }
+    end
+
+    def tabs
+      {
+        projects: {
+          sort: 1,
+          label: _("Projects"),
+          data: { qa_selector: 'projects_tab' },
+          condition: project.nil?
+        },
+        blobs: {
+          sort: 2,
+          label: _("Code"),
+          data: { qa_selector: 'code_tab' },
+          condition: show_code_search_tab?
+        },
+        #  sort: 3 is reserved for EE items
+        issues: {
+          sort: 4,
+          label: _("Issues"),
+          condition: show_issues_search_tab?
+        },
+        merge_requests: {
+          sort: 5,
+          label: _("Merge requests"),
+          condition: show_merge_requests_search_tab?
+        },
+        wiki_blobs: {
+          sort: 6,
+          label: _("Wiki"),
+          condition: show_wiki_search_tab?
+        },
+        commits: {
+          sort: 7,
+          label: _("Commits"),
+          condition: show_commits_search_tab?
+        },
+        notes: {
+          sort: 8,
+          label: _("Comments"),
+          condition: show_comments_search_tab?
+        },
+        milestones: {
+          sort: 9, label: _("Milestones"),
+          condition: show_milestones_search_tab?
+        },
+        users: {
+          sort: 10,
+          label: _("Users"),
+          condition: show_user_search_tab?
+        },
+        snippet_titles: {
+          sort: 11,
+          label: _("Snippets"),
+          search: { snippets: true, group_id: nil, project_id: nil },
+          condition: show_snippets_search_tab?
+        }
+      }
+    end
+
+    private
+
+    attr_reader :user, :project, :group, :options
+
+    def show_elasticsearch_tabs?
+      !!options[:show_elasticsearch_tabs]
+    end
+
+    def search_tab_ability_map
+      {
+        milestones: :read_milestone,
+        snippets: :read_snippet,
+        issues: :read_issue,
+        blobs: :read_code,
+        commits: :read_code,
+        merge_requests: :read_merge_request,
+        notes: [:read_merge_request, :read_code, :read_issue, :read_snippet],
+        users: :read_project_member,
+        wiki_blobs: :read_wiki
+      }
+    end
+
+    def show_user_search_tab?
+      return true if tab_enabled_for_project?(:users)
+      return false unless can?(user, :read_users_list)
+
+      project.nil? && feature_flag_tab_enabled?(:global_search_users_tab)
+    end
+
+    def show_code_search_tab?
+      return true if tab_enabled_for_project?(:blobs)
+
+      project.nil? && show_elasticsearch_tabs? && feature_flag_tab_enabled?(:global_search_code_tab)
+    end
+
+    def show_wiki_search_tab?
+      return true if tab_enabled_for_project?(:wiki_blobs)
+
+      project.nil? && show_elasticsearch_tabs? && feature_flag_tab_enabled?(:global_search_wiki_tab)
+    end
+
+    def show_commits_search_tab?
+      return true if tab_enabled_for_project?(:commits)
+
+      project.nil? && show_elasticsearch_tabs? && feature_flag_tab_enabled?(:global_search_commits_tab)
+    end
+
+    def show_issues_search_tab?
+      return true if tab_enabled_for_project?(:issues)
+
+      project.nil? && feature_flag_tab_enabled?(:global_search_issues_tab)
+    end
+
+    def show_merge_requests_search_tab?
+      return true if tab_enabled_for_project?(:merge_requests)
+
+      project.nil? && feature_flag_tab_enabled?(:global_search_merge_requests_tab)
+    end
+
+    def show_comments_search_tab?
+      return true if tab_enabled_for_project?(:notes)
+
+      project.nil? && show_elasticsearch_tabs?
+    end
+
+    def show_snippets_search_tab?
+      !!options[:show_snippets] && project.nil? && feature_flag_tab_enabled?(:global_search_snippet_titles_tab)
+    end
+
+    def show_milestones_search_tab?
+      project.nil? || tab_enabled_for_project?(:milestones)
+    end
+
+    def feature_flag_tab_enabled?(flag)
+      group.present? || Feature.enabled?(flag, user, type: :ops)
+    end
+  end
+end
+
+Search::Navigation.prepend_mod