require_relative '../../spec_helper'
require 'stringio'

require_relative '../support/grammar_abc_helper'
require_relative '../../../lib/rley/parser/token'
require_relative '../../../lib/rley/parser/earley_parser'
require_relative '../../../lib/rley/ptree/parse_tree'
require_relative '../../../lib/rley/parse_tree_visitor'
# Load the class under test
require_relative '../../../lib/rley/formatter/debug'

module Rley # Re-open the module to get rid of qualified names
  module Formatter
    describe Debug do
      include GrammarABCHelper # Mix-in module for grammar abc

      # Factory method. Build a production with the given sequence
      # of symbols as its rhs.
      let(:grammar_abc) do
        builder = grammar_abc_builder
        builder.grammar
      end
      
      # Variables for the terminal symbols
      let(:a_) { grammar_abc.name2symbol['a'] }
      let(:b_) { grammar_abc.name2symbol['b'] }
      let(:c_) { grammar_abc.name2symbol['c'] }
      
      # Helper method that mimicks the output of a tokenizer
      # for the language specified by gramma_abc
      let(:grm_abc_tokens1) do
        [
          Parser::Token.new('a', a_),
          Parser::Token.new('a', a_),
          Parser::Token.new('b', b_),
          Parser::Token.new('c', c_),
          Parser::Token.new('c', c_)
        ]
      end

      # Factory method that builds a sample parse tree.
      # Generated tree has the following structure:
      # S[0,5]
      # +- A[0,5]
      #    +- a[0,0]
      #    +- A[1,4]
      #    |  +- a[1,1]
      #    |  +- A[2,3]
      #    |  |  +- b[2,3]
      #    |  +- c[3,4]
      #    +- c[4,5]
      # Capital letters represent non-terminal nodes
      let(:grm_abc_ptree1) do
        parser = Parser::EarleyParser.new(grammar_abc)
        parse_result = parser.parse(grm_abc_tokens1)
        parse_result.parse_tree
      end
  
      let(:destination) { StringIO.new('', 'w') }

      context 'Standard creation & initialization:' do
        it 'should be initialized with an IO argument' do
          expect { Debug.new(StringIO.new('', 'w')) }.not_to raise_error
        end
        
        it 'should know its output destination' do
          instance = Debug.new(destination)
          expect(instance.output).to eq(destination)
        end
      end # context
  

 
      context 'Formatting events:' do   
        it 'should support visit events of a parse tree' do
          instance = Debug.new(destination)
          visitor = Rley::ParseTreeVisitor.new(grm_abc_ptree1)
          instance.render(visitor)
          expectations = <<-SNIPPET
before_ptree
  before_non_terminal
    before_children
      before_non_terminal
        before_children
          before_terminal
          after_terminal
          before_non_terminal
            before_children
              before_terminal
              after_terminal
              before_non_terminal
                before_children
                  before_terminal
                  after_terminal
                after_children
              after_non_terminal
              before_terminal
              after_terminal
            after_children
          after_non_terminal
          before_terminal
          after_terminal
        after_children
      after_non_terminal
    after_children
  after_non_terminal
after_ptree
SNIPPET
          expect(destination.string).to eq(expectations)
        end
      end # context
    end # describe
  end # module
end # module

# End of file