# frozen_string_literal: true

require 'spec_helper'

RSpec.describe 'cross-database foreign keys' do
  # Since we don't expect to have any cross-database foreign keys
  # this is empty. If we will have an entry like
  # `ci_daily_build_group_report_results.project_id`
  # should be added.
  let(:allowed_cross_database_foreign_keys) do
    %w[].freeze
  end

  def foreign_keys_for(table_name)
    ApplicationRecord.connection.foreign_keys(table_name)
  end

  def is_cross_db?(fk_record)
    Gitlab::Database::GitlabSchema.table_schemas([fk_record.from_table, fk_record.to_table]).many?
  end

  it 'onlies have allowed list of cross-database foreign keys', :aggregate_failures do
    all_tables = ApplicationRecord.connection.data_sources

    all_tables.each do |table|
      foreign_keys_for(table).each do |fk|
        if is_cross_db?(fk)
          column = "#{fk.from_table}.#{fk.column}"
          expect(allowed_cross_database_foreign_keys).to include(column), "Found extra cross-database foreign key #{column} referencing #{fk.to_table} with constraint name #{fk.name}. When a foreign key references another database you must use a Loose Foreign Key instead https://docs.gitlab.com/ee/development/database/loose_foreign_keys.html ."
        end
      end
    end
  end
end