Added pro feed

• Added:
- pro feed

app/controllers/api/v1/timelines/pro_controller.rb

@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+class Api::V1::Timelines::ProController < Api::BaseController
+  before_action :require_user!, only: [:show]
+  after_action :insert_pagination_headers, unless: -> { @statuses.empty? }
+
+  respond_to :json
+
+  def show
+    @statuses = load_statuses
+    render json: @statuses, each_serializer: REST::StatusSerializer, relationships: StatusRelationshipsPresenter.new(@statuses, current_user&.account_id)
+  end
+
+  private
+
+  def load_statuses
+    cached_pro_statuses
+  end
+
+  def cached_pro_statuses
+    cache_collection pro_statuses, Status
+  end
+
+  def pro_statuses
+    statuses = pro_timeline_statuses.paginate_by_id(
+      limit_param(DEFAULT_STATUSES_LIMIT),
+      params_slice(:max_id, :since_id, :min_id)
+    )
+
+    if truthy_param?(:only_media)
+      # `SELECT DISTINCT id, updated_at` is too slow, so pluck ids at first, and then select id, updated_at with ids.
+      status_ids = statuses.joins(:media_attachments).distinct(:id).pluck(:id)
+      statuses.where(id: status_ids)
+    else
+      statuses
+    end
+  end
+
+  def pro_timeline_statuses
+    Status.as_pro_timeline(current_account)
+  end
+
+  def insert_pagination_headers
+    set_pagination_headers(next_path, prev_path)
+  end
+
+  def pagination_params(core_params)
+    params.slice(:limit, :only_media).permit(:limit, :only_media).merge(core_params)
+  end
+
+  def next_path
+    api_v1_timelines_pro_url pagination_params(max_id: pagination_max_id)
+  end
+
+  def prev_path
+    api_v1_timelines_pro_url pagination_params(min_id: pagination_since_id)
+  end
+
+  def pagination_max_id
+    @statuses.last.id
+  end
+
+  def pagination_since_id
+    @statuses.first.id
+  end
+end