module Erubis::CGenerator

def self.supported_properties()  # :nodoc:
  return [
          [:indent, '',       "indent spaces (ex. '  ')"],
          [:out,    'stdout', "output file pointer name"],
        ]
end

def add_expr_debug(src, code)
  code.strip!
  s = nil
  if code =~ /\A\".*?\"\s*,\s*(.*)/
    s = $1.gsub(/[%"]/, '\\\1') + '='
  end
  src << @indent if src.empty? || src[-1] == ?\n
  src << " fprintf(stderr, \"*** debug: #{s}\" #{code});"
end

def add_expr_escaped(src, code)
  src << @indent if src.empty? || src[-1] == ?\n
  src << ' ' << escaped_expr(code) << ';'
end

def add_expr_literal(src, code)
  src << @indent if src.empty? || src[-1] == ?\n
  src << " fprintf(#{@out}, " << code.strip << ');'
end

def add_postamble(src)
  # empty
end

def add_preamble(src)
  src << "#line 1 \"#{self.filename}\"\n" if self.filename
end

def add_stmt(src, code)
  src << code
end

def add_text(src, text)
  return if text.empty?
  src << (src.empty? || src[-1] == ?\n ? @indent : ' ')
  src << "fputs("
  i = 0
  text.each_line do |line|
    src << "\n" << @indent << '      ' if i > 0
    i += 1
    src << '"' << escape_text(line) << '"'
  end
  src << ", #{@out});"   #<< (text[-1] == ?\n ? "\n" : "")
  src << "\n" if text[-1] == ?\n
end

def escape_text(text)
  @@table_ ||= { "\r"=>"\\r", "\n"=>"\\n", "\t"=>"\\t", '"'=>'\\"', "\\"=>"\\\\" }
  text.gsub!(/[\r\n\t"\\]/) { |m| @@table_[m] }
  return text
end

def escaped_expr(code)
  return "#{@escapefunc}(#{code.strip}, #{@out})"
end

def init_generator(properties={})
  super
  @escapefunc ||= "escape"
  @indent = properties[:indent] || ''
  @out = properties[:out] || 'stdout'
end