module Hermes
  # A few assertions built on top of Capybara.
  module Assertions

    METHODS = {
      'xpath' => 'no_xpath',
      'css' => 'no_css',
      'link' => 'no_link',
      'select' => 'no_select',
      'field' => 'no_field',
      'button' => 'no_button',
      'checked_field' => 'unchecked_field',
      'selector' => 'no_selector',
      'table' => 'no_table'
    }.freeze

    def assert_current_path(expected)
      assert_equal expected, current_path
    end

    def assert_difference_on_click_button(button, *args)
      assert_difference(*args) do
        click_button button
      end
    end

    def assert_difference_on_click_link(link, *args)
      assert_difference(*args) do
        click_link link
      end
    end

    def assert_content(content)
      if has_content?(content)
        assert_block("assert_content") { true }
      else
        assert_block("#{body_inner_text}\nExpected to have #{content}"){ false }
      end
    end

    def assert_no_content(content)
      boolean = has_content?(content)
      if boolean
        assert_block("#{body_inner_text}\nExpected to have no content #{content}"){ false }
      else
        assert_block("assert_no_content") { true }
      end
    end

    METHODS.each do |inclusion_method, rejection_method|
      class_eval <<-RUBY, __FILE__, __LINE__ + 1
        def assert_#{inclusion_method}(*args, &block)
          match = has_#{inclusion_method}?(*args, &block)
          if match
            assert_block("assert_#{inclusion_method}") { true }
          else
            assert_block("\#{page.body}\nExpected to have #{inclusion_method.gsub('_', ' ')} \#{args.inspect}"){ false }
          end
        end

        def assert_#{rejection_method}(*args, &block)
          match = has_#{rejection_method}?(*args, &block)
          if match
            assert_block("assert_#{rejection_method}") { true }
          else
            assert_block("\#{page.body}\Expected to have #{rejection_method.gsub('_', ' ')} \#{args.inspect}"){ false }
          end
        end
      RUBY
    end

    def assert_mail_deliveries(many=1)
      assert_difference("ActionMailer::Base.deliveries.size", many){ yield }
    end

    def assert_link_to(url, options={})
      msg = "#{page.body}\nExpected to have link to #{url}"
      assert_block(msg) do
        has_css? "a[href*='%s']" % url, options
      end
    end

    protected

    def body_inner_text
      Nokogiri::HTML(page.body).inner_text.gsub(/^\s*$/, "").squeeze("\n")
    end
  end
end