Add profile directory (#9427)

Fix #5578

app/controllers/directories_controller.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+class DirectoriesController < ApplicationController
+  layout 'public'
+
+  before_action :set_instance_presenter
+  before_action :set_tag, only: :show
+  before_action :set_tags
+  before_action :set_accounts
+
+  def index
+    render :index
+  end
+
+  def show
+    render :index
+  end
+
+  private
+
+  def set_tag
+    @tag = Tag.discoverable.find_by!(name: params[:id].downcase)
+  end
+
+  def set_tags
+    @tags = Tag.discoverable.limit(30)
+  end
+
+  def set_accounts
+    @accounts = Account.searchable.discoverable.page(params[:page]).per(50).tap do |query|
+      query.merge!(Account.tagged_with(@tag.id)) if @tag
+
+      if popular_requested?
+        query.merge!(Account.popular)
+      else
+        query.merge!(Account.by_recent_status)
+      end
+    end
+  end
+
+  def set_instance_presenter
+    @instance_presenter = InstancePresenter.new
+  end
+
+  def popular_requested?
+    request.path.ends_with?('/popular')
+  end
+end