Fix various issues with domain block import

- stop using Paperclip for processing domain allow/block imports
- stop leaving temporary files
- better error handling
- assume CSV files are UTF-8-encoded

app/controllers/admin/export_domain_allows_controller.rb

@@ -8,8 +8,6 @@ module Admin
 
     before_action :set_dummy_import!, only: [:new]
 
-    ROWS_PROCESSING_LIMIT = 20_000
-
     def new
       authorize :domain_allow, :create?
     end
@@ -23,9 +21,11 @@ module Admin
       authorize :domain_allow, :create?
       begin
         @import = Admin::Import.new(import_params)
+        return render :new unless @import.validate
+
         parse_import_data!(export_headers)
 
-        @data.take(ROWS_PROCESSING_LIMIT).each do |row|
+        @data.take(Admin::Import::ROWS_PROCESSING_LIMIT).each do |row|
           domain = row['#domain'].strip
           next if DomainAllow.allowed?(domain)
 

app/controllers/admin/export_domain_blocks_controller.rb

@@ -8,8 +8,6 @@ module Admin
 
     before_action :set_dummy_import!, only: [:new]
 
-    ROWS_PROCESSING_LIMIT = 20_000
-
     def new
       authorize :domain_block, :create?
     end
@@ -23,12 +21,14 @@ module Admin
       authorize :domain_block, :create?
 
       @import = Admin::Import.new(import_params)
+      return render :new unless @import.validate
+
       parse_import_data!(export_headers)
 
       @global_private_comment = I18n.t('admin.export_domain_blocks.import.private_comment_template', source: @import.data_file_name, date: I18n.l(Time.now.utc))
 
       @form = Form::DomainBlockBatch.new
-      @domain_blocks = @data.take(ROWS_PROCESSING_LIMIT).filter_map do |row|
+      @domain_blocks = @data.take(Admin::Import::ROWS_PROCESSING_LIMIT).filter_map do |row|
         domain = row['#domain'].strip
         next if DomainBlock.rule_for(domain).present?
 

app/controllers/concerns/admin_export_controller_concern.rb

@@ -27,13 +27,13 @@ module AdminExportControllerConcern
     params.require(:admin_import).permit(:data)
   end
 
-  def import_data
-    Paperclip.io_adapters.for(@import.data).read
+  def import_data_path
+    params[:admin_import][:data].path
   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 = CSV.read(import_data_path, headers: true, encoding: 'UTF-8')
+    data = CSV.read(import_data_path, headers: default_headers, encoding: 'UTF-8') unless data.headers&.first&.strip&.include?(default_headers[0])
     @data = data.reject(&:blank?)
   end
 end

app/models/admin/import.rb

@@ -2,28 +2,31 @@
 
 # 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
+  ROWS_PROCESSING_LIMIT = 20_000
 
-  # Paperclip required callbacks
-  define_model_callbacks :save, only: [:after]
-  define_model_callbacks :destroy, only: [:before, :after]
+  attr_accessor :data
 
-  attr_accessor :data_file_name, :data_content_type
+  validates :data, presence: true
+  validate :validate_data
 
-  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
+  def data_file_name
+    data.original_filename
   end
 
-  def destroy
-    run_callbacks :destroy
+  private
+
+  def validate_data
+    return if data.blank?
+
+    csv_data = CSV.read(data.path, encoding: 'UTF-8')
+
+    row_count  = csv_data.size
+    row_count -= 1 if csv_data.first&.first == '#domain'
+
+    errors.add(:data, I18n.t('imports.errors.over_rows_processing_limit', count: ROWS_PROCESSING_LIMIT)) if row_count > ROWS_PROCESSING_LIMIT
+  rescue CSV::MalformedCSVError => e
+    errors.add(:data, I18n.t('imports.errors.invalid_csv_file', error: e.message))
   end
 end

app/validators/admin_import_validator.rb

@@ -1,19 +0,0 @@
-# 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

config/locales/en.yml

@@ -1159,6 +1159,7 @@ en:
     invalid_markup: 'contains invalid HTML markup: %{error}'
   imports:
     errors:
+      invalid_csv_file: 'Invalid CSV file. Error: %{error}'
       over_rows_processing_limit: contains more than %{count} rows
     modes:
       merge: Merge