Add notifications of severed relationships (#27511)

app/controllers/severed_relationships_controller.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+class SeveredRelationshipsController < ApplicationController
+  layout 'admin'
+
+  before_action :authenticate_user!
+  before_action :set_body_classes
+  before_action :set_cache_headers
+
+  before_action :set_event, only: [:following, :followers]
+
+  def index
+    @events = AccountRelationshipSeveranceEvent.where(account: current_account)
+  end
+
+  def following
+    respond_to do |format|
+      format.csv { send_data following_data, filename: "following-#{@event.target_name}-#{@event.created_at.to_date.iso8601}.csv" }
+    end
+  end
+
+  def followers
+    respond_to do |format|
+      format.csv { send_data followers_data, filename: "followers-#{@event.target_name}-#{@event.created_at.to_date.iso8601}.csv" }
+    end
+  end
+
+  private
+
+  def set_event
+    @event = AccountRelationshipSeveranceEvent.find(params[:id])
+  end
+
+  def following_data
+    CSV.generate(headers: ['Account address', 'Show boosts', 'Notify on new posts', 'Languages'], write_headers: true) do |csv|
+      @event.severed_relationships.active.where(local_account: current_account).includes(:remote_account).reorder(id: :desc).each do |follow|
+        csv << [acct(follow.target_account), follow.show_reblogs, follow.notify, follow.languages&.join(', ')]
+      end
+    end
+  end
+
+  def followers_data
+    CSV.generate(headers: ['Account address'], write_headers: true) do |csv|
+      @event.severed_relationships.passive.where(local_account: current_account).includes(:remote_account).reorder(id: :desc).each do |follow|
+        csv << [acct(follow.account)]
+      end
+    end
+  end
+
+  def acct(account)
+    account.local? ? account.local_username_and_domain : account.acct
+  end
+
+  def set_body_classes
+    @body_classes = 'admin'
+  end
+
+  def set_cache_headers
+    response.cache_control.replace(private: true, no_store: true)
+  end
+end