require_relative '../test_helper'
require 'open3'

# in a fresh process: plugins and their gems are loaded only when used
class LazyLoadingTest < PipelineTest
  def loaded_after code
    script = <<~RUBY
      require 'bundler/setup'
      require #{File.join(ROOT, 'lib/datapipeline').inspect}
      #{code}
      features = $LOADED_FEATURES.join(' ')
      puts %w[pg sqlite3 roo caxlsx http].select { |gem| features.match?(%r{/gems/\#{gem}-\\d}) }.join(',')
    RUBY
    out, err, status = Open3.capture3({ 'BUNDLE_GEMFILE' => File.join(ROOT, 'Gemfile') }, RbConfig.ruby, '-e', script)
    assert status.success?, err
    out.strip.split(',')
  end

  def test_nothing_loaded_at_start
    assert_empty loaded_after('')
  end

  def test_json_and_csv_need_no_gem
    with_tmpdir do |dir|
      code = "DataPipeline.new { logger Logger.new(IO::NULL); read container(:json, file: '#{dir}/x.json').tap { File.write('#{dir}/x.json', '[]') }; write container(:csv, file: '#{dir}/y.csv') }.run"
      assert_empty loaded_after(code)
    end
  end

  def test_each_plugin_loads_only_its_gem
    with_tmpdir do |dir|
      assert_equal %w[sqlite3], loaded_after("DataPipeline::SqliteStorage.new(database: ':memory:').close")
      assert_equal %w[caxlsx], loaded_after("DataPipeline::ExcelStorage.new(file: '#{dir}/a.xlsx').write([{ 'a' => 1 }])")
      assert_equal %w[roo caxlsx].sort, loaded_after("DataPipeline::ExcelStorage.new(file: '#{dir}/b.xlsx').write([{ 'a' => 1 }]); DataPipeline::ExcelStorage.new(file: '#{dir}/b.xlsx').read").sort
      assert_equal %w[http], loaded_after("DataPipeline::RestStorage.new(url: 'http://localhost')")
    end
  end

  def test_missing_gem_message
    plugin = Class.new(DataPipeline::StoragePlugin) { def initialize(**) = self.class.require_gem('gibtsnicht_gem') }
    Object.const_set(:GibtsNichtStorage, plugin) unless defined?(GibtsNichtStorage)
    error = assert_raises(LoadError) { GibtsNichtStorage.new }
    assert_includes error.message, "gem 'gibtsnicht_gem'"
  end
end