require File.expand_path(File.dirname(__FILE__) + '/spec_helper')

describe Quarto::Transformer do
	include Quarto::REXMLMatchers
	
	context '#transform' do
		before :each do
			@xml = %q(
				<doc>
					<div>
						<p>Foo</p>
						<p>Bar</p>
						
						<book>
							<title>Foobar</title>
							<author>Baz</author>
							<cover_url>http://example.com/foobar.jpeg</cover_url>
						</book>
					</div>
				</doc>
			)
			@doc = REXML::Document.new(@xml)
			
			class TestTransformer < Quarto::Transformer
				def literal?(element)
					['doc', 'div', 'p'].include?(element.name)
				end
			end
			
			@t = TestTransformer.new
		end
		
		after :each do
			Object.class_eval do
				remove_const :TestTransformer
			end
		end
		
		it 'should return a string' do
			@t.transform(@doc).should be_a(String)
			@t.transform(@doc.root).should be_a(String)
			@t.transform(REXML::Document.new('')).should be_a(String)
		end
		
		it 'should raise if passed anything other than a REXML::Element' do
			lambda { @t.transform(nil) }.should raise_error(ArgumentError, 'Expected REXML::Element but got nil')
			lambda { @t.transform('foo') }.should raise_error(ArgumentError, 'Expected REXML::Element but got "foo"')
		end
		
		it 'should not transform elements that lack custom transform methods and for which literal? returns true' do
			result = REXML::Document.new(@t.transform(@doc))
			result.should have_element('doc')
			result.should have_element('div')
			result.should have_element('p', :text => 'Foo')
			result.should have_element('p', :text => 'Bar')
		end
		
		it 'should ignore elements that lack custom transform methods and for which literal? returns false' do
			result = REXML::Document.new(@t.transform(@doc))
			['book', 'title', 'author' 'cover_url'].each do |el|
				result.should_not have_element(el)
			end
		end
		
		it 'should use custom transform methods' do
			begin
				class CustomizedTestTransformer < TestTransformer
					def transform_book(book_element, raise_on_unrecognized_element)
						%Q(
							<div class="book">
								<h1 class="title">#{book_element.elements['title'].text}</h1>
								<h2 class="author">#{book_element.elements['author'].text}</h2>
								<img src="#{book_element.elements['cover_url'].text}"/>
							</div>
						)
					end
				end
			
				t = CustomizedTestTransformer.new
				result = REXML::Document.new(t.transform(@doc))
				result.should have_element('div', :attributes => {'class' => 'book'})
				result.should have_element('h1', :attributes => {'class' => 'title'}, :text => 'Foobar')
				result.should have_element('h2', :attributes => {'class' => 'author'}, :text => 'Baz')
				result.should have_element('img', :attributes => {'src' => 'http://example.com/foobar.jpeg'})
			ensure
				Object.class_eval do
					remove_const :CustomizedTestTransformer
				end
			end
		end
		
		it 'should give precedence to custom transform methods over literal?' do
			begin
				class CustomizedTestTransformer < TestTransformer
					def transform_p(p_element, raise_on_unrecognized_element)
						%Q(<div class="paragraph">#{p_element.text}</div>)
					end
				end
			
				t = CustomizedTestTransformer.new
				result = REXML::Document.new(t.transform(@doc))
				result.should have_element('div', :attributes => {'class' => 'paragraph'}, :text => 'Foo')
				result.should have_element('div', :attributes => {'class' => 'paragraph'}, :text => 'Bar')
			ensure
				Object.class_eval do
					remove_const :CustomizedTestTransformer
				end
			end				
		end
	end
	
	context '.literals' do
		before :each do
			class TestTransformer < Quarto::Transformer
				literals :doc, :div, 'p'
			end
		end
		
		after :each do
			Object.class_eval do
				remove_const :TestTransformer
			end
		end
		
		it 'should define literal? so that it returns true for any element on the list and false for any other' do
			t = TestTransformer.new
			['doc', 'div', 'p'].each do |el_name|
				t.send(:literal?, REXML::Element.new(el_name)).should == true
			end
			['foo', 'bar', 'baz'].each do |el_name|
				t.send(:literal?, REXML::Element.new(el_name)).should == false
			end
		end
		
		it 'should have no effect if literal? is subsequently defined' do
			class TestTransformer < Quarto::Transformer
				def literal?(element)
					false
				end
			end
			
			t = TestTransformer.new
			['doc', 'div', 'p'].each do |el_name|
				t.send(:literal?, REXML::Element.new(el_name)).should == false
			end
		end
	end
end