require "ev/tree"

class SGMLObject < TreeObject
  def to_s
    res	= ""

    parsetree("prechildren_to_s", "postchildren_to_s", res)

    res
  end

  def to_h
    res	= ""

    parsetree("prechildren_to_sgml", "postchildren_to_sgml", res)

    res
  end
end

class Text < SGMLObject
  def initialize(text)
    super()
    @text = text
  end

  def prechildren_to_s(res)
    #res << "#{CGI.unescapeHTML(@text)} "
    res << @text
  end

  def prechildren_to_sgml(res)
    #res << "#{CGI.unescapeHTML(@text)}"
    res << @text
  end
end

class Comment < SGMLObject
  def initialize(text)
    super()
    @text = text
  end

  def prechildren_to_sgml(res)
    res << "#{@text}"
  end
end

class Special < SGMLObject
  def initialize(text)
    super()
    @text = text
  end

  def prechildren_to_sgml(res)
    res << "#{@text}"
  end
end

class Instruction < SGMLObject
  def initialize(text)
    super()
    @text = text
  end

  def prechildren_to_sgml(res)
    res << "#{@text}"
  end
end

class Tag < SGMLObject
  attr_reader :args
  attr_writer :args

  def initialize(subtype, args={})
    super(subtype)
    @args = args
    @text = ""
  end
end

class OpenTag < Tag
  def initialize(*args)
    super
    @upordown = Down
  end

  def prechildren_to_sgml(res)
    a	= [@subtype]

    @args.each do |k, v|
      if not v.include?("'")
        a << "#{k}='#{v}'"
      else
        if not v.include?('"')
          a << "#{k}=\"#{v}\""
        else
          a << "#{k}='#{v.gsub(/\'/, '"')}'"
        end
      end
    end

    res << "<#{a.join(" ")}>" + @text
  end

  def postchildren_to_sgml(res)
    res << "</#{@subtype}>"	if @closed
  end
end

class CloseTag < Tag
  def initialize(*args)
    super
    @upordown = Dummy
  end
end

class SGML < Tree
  def initialize(*args)
    @tagcache	= {}

    super
  end

  def buildobjects(string)
    @objects = []

    verwerk3	=
    lambda do |string|
      a	= []
  
      string[1..-2].splitblocks(["'", "'"], ['"', '"']).collect do |type, s|
        case type
        when 0
          if self.class.to_s == "HTML"
            s.splitwords.each do |w|
              d	= w.split("=", 2)
  
              if d.length == 1
                a << d[0]
              else
                a << d[0]	if not d[0].nil? and not d[0].empty?
                a << "="
                a << d[1]	if not d[1].nil? and not d[1].empty?
              end
            end
          else
            a.concat s.splitwords(["/", "="])
          end
        when 1, 2	then a << s
        end
      end
  
      open	= false
      close	= false
  
      a = a[0].splitwords("/") + a[1..-1]
  
      if a[0] == "/"
        close	= true
        a.shift
      else
        open	= true
      end
  
      if a[-1] == "/"
        close	= true
        a.pop
      end
  
      tag	= a.shift.downcase
      args	= {}
  
      while not a.length.zero?
        if a.length >= 3 and a[1] == "="
          key	= a.shift.downcase
          dummy	= a.shift
          value	= a.shift.noquotes
          args[key]	= value
        else
          key	= a.shift.downcase
          args[key]	= ""
        end
      end
  
      [tag, args, open, close]
    end

    verwerk2	=
    lambda do |string|
      if @tagcache.include? string
        res	= @tagcache[string]
      else
        res	= verwerk3.call(string)

        @tagcache[string] = res
      end

      res
    end

    verwerk1 =
    lambda do |string|
      tag, args, open, close	= verwerk2.call(string)

      @objects << OpenTag.new(tag.dup, args.dup)	if open
      @objects << CloseTag.new(tag.dup, args.dup)	if close
    end

    string.splitblocks(["<!--", "-->"], ["<!", ">"], ["<?", "?>"], ["<", ">"]).each do |type, s|
      case type
      when 0		then @objects << Text.new(s)
      when 1		then @objects << Comment.new(s)
      when 2		then @objects << Special.new(s)
      when 3		then @objects << Instruction.new(s)
      when 4		then verwerk1.call(s)
      end
    end
  end

  def to_s
    res	= ""

    parsetree("prechildren_to_s", "postchildren_to_s", res)

    res
  end

  def to_h
    res	= ""

    parsetree("prechildren_to_sgml", "postchildren_to_sgml", res)

    res
  end
end