Record account suspend/silence time and keep track of domain blocks (#10660)

* Record account suspend/silence time and keep track of domain blocks

* Also unblock users who were suspended/silenced before dates were recorded

* Add tests

* Keep track of suspending date for users suspended through the CLI

* Show accurate number of accounts that would be affected by unsuspending an instance

* Change migration to set silenced_at and suspended_at

* Revert "Also unblock users who were suspended/silenced before dates were recorded"

This reverts commit a015c65d2d1e28c7b7cfab8b3f8cd5fb48b8b71c.

* Switch from using suspended and silenced to suspended_at and silenced_at

* Add post-deployment migration script to remove `suspended` and `silenced` columns

* Use Account#silence! and Account#suspend! instead of updating the underlying property

* Add silenced_at and suspended_at migration to post-migration

* Change account fabricator to translate suspended and silenced attributes

* Minor fixes

* Make unblocking domains always retroactive

db/post_migrate/20190511152737_remove_suspended_silenced_account_fields.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+class RemoveSuspendedSilencedAccountFields < ActiveRecord::Migration[5.2]
+  class Account < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+  end
+
+  class DomainBlock < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+    enum severity: [:silence, :suspend, :noop]
+
+    has_many :accounts, foreign_key: :domain, primary_key: :domain
+  end
+
+  disable_ddl_transaction!
+
+  def up
+    # Record suspend date of blocks and silences for users whose limitations match
+    # a domain block
+    DomainBlock.where(severity: [:silence, :suspend]).find_each do |block|
+      scope = block.accounts
+      if block.suspend?
+        block.accounts.where(suspended: true).in_batches.update_all(suspended_at: block.created_at)
+      else
+        block.accounts.where(silenced: true).in_batches.update_all(silenced_at: block.created_at)
+      end
+    end
+
+    # Set dates for accounts which have limitations not related to a domain block
+    Account.where(suspended: true, suspended_at: nil).in_batches.update_all(suspended_at: Time.now.utc)
+    Account.where(silenced: true, silenced_at: nil).in_batches.update_all(silenced_at: Time.now.utc)
+
+    safety_assured do
+      remove_column :accounts, :suspended, :boolean, null: false, default: false
+      remove_column :accounts, :silenced, :boolean, null: false, default: false
+    end
+  end
+
+  def down
+    safety_assured do
+      add_column :accounts, :suspended, :boolean, null: false, default: false
+      add_column :accounts, :silenced, :boolean, null: false, default: false
+    end
+  end
+end