Allow import/export of instance-level domain blocks/allows (#1754)

* Allow import/export of instance-level domain blocks/allows.
Fixes #15095

* Pacify circleci

* Address simple code review feedback

* Add headers to exported CSV

* Extract common import/export functionality to
AdminExportControllerConcern

* Add additional fields to instance-blocked domain export

* Address review feedback

* Split instance domain block/allow import/export into separate pages/controllers

* Address code review feedback

* Pacify DeepSource

* Work around Paperclip::HasAttachmentFile for Rails 6

* Fix deprecated API warning in export tests

* Remove after_commit workaround

16 files changed, 414 insertions, 1 deletions

diff --git a/app/controllers/admin/export_domain_allows_controller.rb b/app/controllers/admin/export_domain_allows_controller.rb
new file mode 100644
index 000000000..eb2955ac3
--- /dev/null
+++ b/app/controllers/admin/export_domain_allows_controller.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+require 'csv'
+
+module Admin
+  class ExportDomainAllowsController < BaseController
+    include AdminExportControllerConcern
+
+    before_action :set_dummy_import!, only: [:new]
+
+    ROWS_PROCESSING_LIMIT = 20_000
+
+    def new
+      authorize :domain_allow, :create?
+    end
+
+    def export
+      authorize :instance, :index?
+      send_export_file
+    end
+
+    def import
+      authorize :domain_allow, :create?
+      begin
+        @import = Admin::Import.new(import_params)
+        parse_import_data!(export_headers)
+
+        @data.take(ROWS_PROCESSING_LIMIT).each do |row|
+          domain = row['#domain'].strip
+          next if DomainAllow.allowed?(domain)
+
+          domain_allow = DomainAllow.new(domain: domain)
+          log_action :create, domain_allow if domain_allow.save
+        end
+        flash[:notice] = I18n.t('admin.domain_allows.created_msg')
+      rescue ActionController::ParameterMissing
+        flash[:error] = I18n.t('admin.export_domain_allows.no_file')
+      end
+      redirect_to admin_instances_path
+    end
+
+    private
+
+    def export_filename
+      'domain_allows.csv'
+    end
+
+    def export_headers
+      %w(#domain)
+    end
+
+    def export_data
+      CSV.generate(headers: export_headers, write_headers: true) do |content|
+        DomainAllow.allowed_domains.each do |instance|
+          content << [instance.domain]
+        end
+      end
+    end
+  end
+end
diff --git a/app/controllers/admin/export_domain_blocks_controller.rb b/app/controllers/admin/export_domain_blocks_controller.rb
new file mode 100644
index 000000000..0ad5b92b5
--- /dev/null
+++ b/app/controllers/admin/export_domain_blocks_controller.rb
@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+require 'csv'
+
+module Admin
+  class ExportDomainBlocksController < BaseController
+    include AdminExportControllerConcern
+
+    before_action :set_dummy_import!, only: [:new]
+
+    ROWS_PROCESSING_LIMIT = 20_000
+
+    def new
+      authorize :domain_block, :create?
+    end
+
+    def export
+      authorize :instance, :index?
+      send_export_file
+    end
+
+    def import
+      authorize :domain_block, :create?
+      begin
+        @import = Admin::Import.new(import_params)
+        parse_import_data!(export_headers)
+
+        @data.take(ROWS_PROCESSING_LIMIT).each do |row|
+          domain = row['#domain'].strip
+          next if DomainBlock.rule_for(domain).present?
+
+          domain_block = DomainBlock.new(domain: domain,
+                                         severity: row['#severity'].strip,
+                                         reject_media: row['#reject_media'].strip,
+                                         reject_reports: row['#reject_reports'].strip,
+                                         public_comment: row['#public_comment'].strip,
+                                         obfuscate: row['#obfuscate'].strip)
+          if domain_block.save
+            DomainBlockWorker.perform_async(domain_block.id)
+            log_action :create, domain_block
+          end
+        end
+        flash[:notice] = I18n.t('admin.domain_blocks.created_msg')
+      rescue ActionController::ParameterMissing
+        flash[:error] = I18n.t('admin.export_domain_blocks.no_file')
+      end
+      redirect_to admin_instances_path(limited: '1')
+    end
+
+    private
+
+    def export_filename
+      'domain_blocks.csv'
+    end
+
+    def export_headers
+      %w(#domain #severity #reject_media #reject_reports #public_comment #obfuscate)
+    end
+
+    def export_data
+      CSV.generate(headers: export_headers, write_headers: true) do |content|
+        DomainBlock.with_user_facing_limitations.each do |instance|
+          content << [instance.domain, instance.severity, instance.reject_media, instance.reject_reports, instance.public_comment, instance.obfuscate]
+        end
+      end
+    end
+  end
+end
diff --git a/app/controllers/concerns/admin_export_controller_concern.rb b/app/controllers/concerns/admin_export_controller_concern.rb
new file mode 100644
index 000000000..013915d02
--- /dev/null
+++ b/app/controllers/concerns/admin_export_controller_concern.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+module AdminExportControllerConcern
+  extend ActiveSupport::Concern
+
+  private
+
+  def send_export_file
+    respond_to do |format|
+      format.csv { send_data export_data, filename: export_filename }
+    end
+  end
+
+  def export_data
+    raise 'Override in controller'
+  end
+
+  def export_filename
+    raise 'Override in controller'
+  end
+
+  def set_dummy_import!
+    @import = Admin::Import.new
+  end
+
+  def import_params
+    params.require(:admin_import).permit(:data)
+  end
+
+  def import_data
+    Paperclip.io_adapters.for(@import.data).read
+  end
+
+  def parse_import_data!(default_headers)
+    data = CSV.parse(import_data, headers: true)
+    data = CSV.parse(import_data, headers: default_headers) unless data.headers&.first&.strip&.include?(default_headers[0])
+    @data = data.reject(&:blank?)
+  end
+end
diff --git a/app/models/admin/import.rb b/app/models/admin/import.rb
new file mode 100644
index 000000000..c305be237
--- /dev/null
+++ b/app/models/admin/import.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+# A non-activerecord helper class for csv upload
+class Admin::Import
+  extend ActiveModel::Callbacks
+  include ActiveModel::Model
+  include Paperclip::Glue
+
+  FILE_TYPES = %w(text/plain text/csv application/csv).freeze
+
+  # Paperclip required callbacks
+  define_model_callbacks :save, only: [:after]
+  define_model_callbacks :destroy, only: [:before, :after]
+
+  attr_accessor :data_file_name, :data_content_type
+
+  has_attached_file :data
+  validates_attachment_content_type :data, content_type: FILE_TYPES
+  validates_attachment_presence :data
+  validates_with AdminImportValidator, on: :create
+
+  def save
+    run_callbacks :save
+  end
+
+  def destroy
+    run_callbacks :destroy
+  end
+end
diff --git a/app/models/domain_allow.rb b/app/models/domain_allow.rb
index 4b0a89c18..2e14fce25 100644
--- a/app/models/domain_allow.rb
+++ b/app/models/domain_allow.rb
@@ -23,6 +23,10 @@ class DomainAllow < ApplicationRecord
       !rule_for(domain).nil?
     end
 
+    def allowed_domains
+      select(:domain)
+    end
+
     def rule_for(domain)
       return if domain.blank?
 
diff --git a/app/validators/admin_import_validator.rb b/app/validators/admin_import_validator.rb
new file mode 100644
index 000000000..338ceb3a7
--- /dev/null
+++ b/app/validators/admin_import_validator.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class AdminImportValidator < ActiveModel::Validator
+  FIRST_HEADER = '#domain'
+
+  def validate(import)
+    return if import.type.blank? || import.data.blank?
+
+    # We parse because newlines could be part of individual rows. This
+    # runs on create so we should be reading the local file here before
+    # it is uploaded to object storage or moved anywhere...
+    csv_data = CSV.parse(import.data.queued_for_write[:original].read)
+
+    row_count  = csv_data.size
+    row_count -= 1 if csv_data.first&.first == FIRST_HEADER
+
+    import.errors.add(:data, I18n.t('imports.errors.over_rows_processing_limit', count: Admin::DomainBlocksController::ROWS_PROCESSING_LIMIT)) if row_count > Admin::DomainBlocksController::ROWS_PROCESSING_LIMIT
+  end
+end
diff --git a/app/views/admin/export_domain_allows/new.html.haml b/app/views/admin/export_domain_allows/new.html.haml
new file mode 100644
index 000000000..dc0cf8c52
--- /dev/null
+++ b/app/views/admin/export_domain_allows/new.html.haml
@@ -0,0 +1,10 @@
+- content_for :page_title do
+  = t('.title')
+
+= simple_form_for @import, url: import_admin_export_domain_allows_path, html: { multipart: true } do |f|
+  .fields-row
+    .fields-group.fields-row__column.fields-row__column-6
+      = f.input :data, wrapper: :with_block_label, hint: t('simple_form.hints.imports.data'), as: :file
+
+  .actions
+    = f.button :button, t('imports.upload'), type: :submit
diff --git a/app/views/admin/export_domain_blocks/new.html.haml b/app/views/admin/export_domain_blocks/new.html.haml
new file mode 100644
index 000000000..0291aeed7
--- /dev/null
+++ b/app/views/admin/export_domain_blocks/new.html.haml
@@ -0,0 +1,10 @@
+- content_for :page_title do
+  = t('.title')
+
+= simple_form_for @import, url: import_admin_export_domain_blocks_path, html: { multipart: true } do |f|
+  .fields-row
+    .fields-group.fields-row__column.fields-row__column-6
+      = f.input :data, wrapper: :with_block_label, hint: t('simple_form.hints.imports.data'), as: :file
+
+  .actions
+    = f.button :button, t('imports.upload'), type: :submit
diff --git a/app/views/admin/instances/index.html.haml b/app/views/admin/instances/index.html.haml
index ee1b3d0ce..abb2d8c0e 100644
--- a/app/views/admin/instances/index.html.haml
+++ b/app/views/admin/instances/index.html.haml
@@ -4,8 +4,12 @@
 - content_for :heading_actions do
   - if whitelist_mode?
     = link_to t('admin.domain_allows.add_new'), new_admin_domain_allow_path, class: 'button', id: 'add-instance-button'
+    = link_to t('admin.domain_allows.export'), export_admin_export_domain_allows_path(format: :csv), class: 'button'
+    = link_to t('admin.domain_allows.import'), new_admin_export_domain_allow_path, class: 'button'
   - else
     = link_to t('admin.domain_blocks.add_new'), new_admin_domain_block_path, class: 'button', id: 'add-instance-button'
+    = link_to t('admin.domain_blocks.export'), export_admin_export_domain_blocks_path(format: :csv), class: 'button'
+    = link_to t('admin.domain_blocks.import'), new_admin_export_domain_block_path, class: 'button'
 
 .filters
   .filter-subset
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 50e762db7..583683bff 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -421,6 +421,8 @@ en:
       add_new: Allow federation with domain
       created_msg: Domain has been successfully allowed for federation
       destroyed_msg: Domain has been disallowed from federation
+      export: Export
+      import: Import
       undo: Disallow federation with domain
     domain_blocks:
       add_new: Add new domain block
@@ -429,6 +431,8 @@ en:
       domain: Domain
       edit: Edit domain block
       existing_domain_block_html: You have already imposed stricter limits on %{name}, you need to <a href="%{unblock_url}">unblock it</a> first.
+      export: Export
+      import: Import
       new:
         create: Create block
         hint: The domain block will not prevent creation of account entries in the database, but will retroactively and automatically apply specific moderation methods on those accounts.
@@ -469,6 +473,14 @@ en:
       resolved_dns_records_hint_html: The domain name resolves to the following MX domains, which are ultimately responsible for accepting e-mail. Blocking an MX domain will block sign-ups from any e-mail address which uses the same MX domain, even if the visible domain name is different. <strong>Be careful not to block major e-mail providers.</strong>
       resolved_through_html: Resolved through %{domain}
       title: Blocked e-mail domains
+    export_domain_allows:
+      new:
+        title: Import domain allows
+      no_file: No file selected
+    export_domain_blocks:
+      new:
+        title: Import domain blocks
+      no_file: No file selected
     follow_recommendations:
       description_html: "<strong>Follow recommendations help new users quickly find interesting content</strong>. When a user has not interacted with others enough to form personalized follow recommendations, these accounts are recommended instead. They are re-calculated on a daily basis from a mix of accounts with the highest recent engagements and highest local follower counts for a given language."
       language: For language
diff --git a/config/routes.rb b/config/routes.rb
index 574715705..787665192 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -194,7 +194,21 @@ Rails.application.routes.draw do
     get '/dashboard', to: 'dashboard#index'
 
     resources :domain_allows, only: [:new, :create, :show, :destroy]
-    resources :domain_blocks, only: [:new, :create, :destroy, :update, :edit]
+    resources :domain_blocks, only: [:new, :create, :show, :destroy, :update, :edit]
+
+    resources :export_domain_allows, only: [:new] do
+      collection do
+        get :export, constraints: { format: :csv }
+        post :import
+      end
+    end
+
+    resources :export_domain_blocks, only: [:new] do
+      collection do
+        get :export, constraints: { format: :csv }
+        post :import
+      end
+    end
 
     resources :email_domain_blocks, only: [:index, :new, :create] do
       collection do
diff --git a/spec/controllers/admin/domain_allows_controller_spec.rb b/spec/controllers/admin/domain_allows_controller_spec.rb
new file mode 100644
index 000000000..8bacdd3e4
--- /dev/null
+++ b/spec/controllers/admin/domain_allows_controller_spec.rb
@@ -0,0 +1,48 @@
+require 'rails_helper'
+
+RSpec.describe Admin::DomainAllowsController, type: :controller do
+  render_views
+
+  before do
+    sign_in Fabricate(:user, admin: true), scope: :user
+  end
+
+  describe 'GET #new' do
+    it 'assigns a new domain allow' do
+      get :new
+
+      expect(assigns(:domain_allow)).to be_instance_of(DomainAllow)
+      expect(response).to have_http_status(200)
+    end
+  end
+
+  describe 'POST #create' do
+    it 'blocks the domain when succeeded to save' do
+      post :create, params: { domain_allow: { domain: 'example.com' } }
+
+      expect(flash[:notice]).to eq I18n.t('admin.domain_allows.created_msg')
+      expect(response).to redirect_to(admin_instances_path)
+    end
+
+    it 'renders new when failed to save' do
+      Fabricate(:domain_allow, domain: 'example.com')
+
+      post :create, params: { domain_allow: { domain: 'example.com' } }
+
+      expect(response).to render_template :new
+    end
+  end
+
+  describe 'DELETE #destroy' do
+    it 'disallows the domain' do
+      service = double(call: true)
+      allow(UnallowDomainService).to receive(:new).and_return(service)
+      domain_allow = Fabricate(:domain_allow)
+      delete :destroy, params: { id: domain_allow.id }
+
+      expect(service).to have_received(:call).with(domain_allow)
+      expect(flash[:notice]).to eq I18n.t('admin.domain_allows.destroyed_msg')
+      expect(response).to redirect_to(admin_instances_path)
+    end
+  end
+end
diff --git a/spec/controllers/admin/export_domain_allows_controller_spec.rb b/spec/controllers/admin/export_domain_allows_controller_spec.rb
new file mode 100644
index 000000000..f6275c2d6
--- /dev/null
+++ b/spec/controllers/admin/export_domain_allows_controller_spec.rb
@@ -0,0 +1,42 @@
+require 'rails_helper'
+
+RSpec.describe Admin::ExportDomainAllowsController, type: :controller do
+  render_views
+
+  before do
+    sign_in Fabricate(:user, admin: true), scope: :user
+  end
+
+  describe 'GET #export' do
+    it 'renders instances' do
+      Fabricate(:domain_allow, domain: 'good.domain')
+      Fabricate(:domain_allow, domain: 'better.domain')
+
+      get :export, params: { format: :csv }
+      expect(response).to have_http_status(200)
+      expect(response.body).to eq(IO.read(File.join(file_fixture_path, 'domain_allows.csv')))
+    end
+  end
+
+  describe 'POST #import' do
+    it 'allows imported domains' do
+      post :import, params: { admin_import: { data: fixture_file_upload('domain_allows.csv') } }
+
+      expect(response).to redirect_to(admin_instances_path)
+
+      # Header should not be imported
+      expect(DomainAllow.where(domain: '#domain').present?).to eq(false)
+
+      # Domains should now be added
+      get :export, params: { format: :csv }
+      expect(response).to have_http_status(200)
+      expect(response.body).to eq(IO.read(File.join(file_fixture_path, 'domain_allows.csv')))
+    end
+
+    it 'displays error on no file selected' do
+      post :import, params: { admin_import: {} }
+      expect(response).to redirect_to(admin_instances_path)
+      expect(flash[:error]).to eq(I18n.t('admin.export_domain_allows.no_file'))
+    end
+  end
+end
diff --git a/spec/controllers/admin/export_domain_blocks_controller_spec.rb b/spec/controllers/admin/export_domain_blocks_controller_spec.rb
new file mode 100644
index 000000000..0cb221972
--- /dev/null
+++ b/spec/controllers/admin/export_domain_blocks_controller_spec.rb
@@ -0,0 +1,47 @@
+require 'rails_helper'
+
+RSpec.describe Admin::ExportDomainBlocksController, type: :controller do
+  render_views
+
+  before do
+    sign_in Fabricate(:user, admin: true), scope: :user
+  end
+
+  describe 'GET #export' do
+    it 'renders instances' do
+      Fabricate(:domain_block, domain: 'bad.domain', severity: 'silence', public_comment: 'bad')
+      Fabricate(:domain_block, domain: 'worse.domain', severity: 'suspend', reject_media: true, reject_reports: true, public_comment: 'worse', obfuscate: true)
+      Fabricate(:domain_block, domain: 'reject.media', severity: 'noop', reject_media: true, public_comment: 'reject media')
+      Fabricate(:domain_block, domain: 'no.op', severity: 'noop', public_comment: 'noop')
+
+      get :export, params: { format: :csv }
+      expect(response).to have_http_status(200)
+      expect(response.body).to eq(IO.read(File.join(file_fixture_path, 'domain_blocks.csv')))
+    end
+  end
+
+  describe 'POST #import' do
+    it 'blocks imported domains' do
+      allow(DomainBlockWorker).to receive(:perform_async).and_return(true)
+
+      post :import, params: { admin_import: { data: fixture_file_upload('domain_blocks.csv') } }
+
+      expect(response).to redirect_to(admin_instances_path(limited: '1'))
+      expect(DomainBlockWorker).to have_received(:perform_async).exactly(3).times
+
+      # Header should not be imported
+      expect(DomainBlock.where(domain: '#domain').present?).to eq(false)
+
+      # Domains should now be added
+      get :export, params: { format: :csv }
+      expect(response).to have_http_status(200)
+      expect(response.body).to eq(IO.read(File.join(file_fixture_path, 'domain_blocks.csv')))
+    end
+  end
+
+  it 'displays error on no file selected' do
+    post :import, params: { admin_import: {} }
+    expect(response).to redirect_to(admin_instances_path(limited: '1'))
+    expect(flash[:error]).to eq(I18n.t('admin.export_domain_blocks.no_file'))
+  end
+end
diff --git a/spec/fixtures/files/domain_allows.csv b/spec/fixtures/files/domain_allows.csv
new file mode 100644
index 000000000..4200ac3f5
--- /dev/null
+++ b/spec/fixtures/files/domain_allows.csv
@@ -0,0 +1,3 @@
+#domain
+good.domain
+better.domain
diff --git a/spec/fixtures/files/domain_blocks.csv b/spec/fixtures/files/domain_blocks.csv
new file mode 100644
index 000000000..28ffb9175
--- /dev/null
+++ b/spec/fixtures/files/domain_blocks.csv
@@ -0,0 +1,4 @@
+#domain,#severity,#reject_media,#reject_reports,#public_comment,#obfuscate
+bad.domain,silence,false,false,bad,false
+worse.domain,suspend,true,true,worse,true
+reject.media,noop,true,false,reject media,false