require 'chunks/chunk'

# These are basic chunks that have a pattern and can be protected.
# They are used by rendering process to prevent wiki rendering
# occuring within literal areas such as <code> and <pre> blocks
# and within HTML tags.
module Literal

  class AbstractLiteral < Chunk::Abstract

    def initialize(match_data, content)
      super
      @unmask_text = @text
    end

  end

  # A literal chunk that protects 'code' and 'pre' tags from wiki rendering.
  class Pre < AbstractLiteral
    PRE_BLOCKS = "a|pre|code|math"
    PRE_PATTERN = Regexp.new('<('+PRE_BLOCKS+')\b[^>]*?>.*?</\1>', Regexp::MULTILINE)
    def self.pattern() PRE_PATTERN end
  end 

  # A literal chunk that protects HTML tags from wiki rendering.
  class Tags < AbstractLiteral
    TAGS_PATTERN = Regexp.new('<[-a-zA-Z]+[^>]*?>', Regexp::MULTILINE) 
    def self.pattern() TAGS_PATTERN  end
  end

  # A literal chunk that protects equations from wiki rendering.
  class Math < AbstractLiteral
    MATH_START = '(\${1,2}|' + Regexp.escape('\[') + '|\\begin\{equation\})'
    MATH_END =   '(\${1,2}|' + Regexp.escape('\]') + '|\\end\{equation\})'
    MATH_PATTERN = Regexp.new(MATH_START + '([^$]|\\\$)+?' + MATH_END, Regexp::MULTILINE)
    def self.pattern() MATH_PATTERN  end
  end

end