$tabSize = 2
$tabStr = " "

# indent regexp tests

$indentExp = [
  /^module\b/,
  /(=\s*|^)if\b/,
  /(=\s*|^)until\b/,
  /(=\s*|^)for\b/,
  /(=\s*|^)unless\b/,
  /(=\s*|^)while\b/,
  /(=\s*|^)begin\b/,
  /(=\s*|^)case\b/,
  /\bthen\b/,
  /^class\b/,
  /^rescue\b/,
  /^def\b/,
  /\bdo\b/,
  /^else\b/,
  /^elsif\b/,
  /^ensure\b/,
  /\bwhen\b/,
  /\{[^\}]*$/,
  /\[[^\]]*$/
]

# outdent regexp tests

$outdentExp = [
  /^rescue\b/,
  /^ensure\b/,
  /^elsif\b/,
  /^end\b/,
  /^else\b/,
  /\bwhen\b/,
  /^[^\{]*\}/,
  /^[^\[]*\]/
]

def makeTab(tab)
  return (tab < 0)?"":$tabStr * $tabSize * tab
end

def addLine(line,tab)
  line.strip!
  line = makeTab(tab)+line if line.length > 0
  return line + "\n"
end

def format_ruby
  commentBlock = false
  multiLineArray = Array.new
  multiLineStr = ""
  tab = 0
  ############
  #filename entered on command line as argument gets passed in Ruby's
  #special argument array ARGV. The ARGV[0] zeroth element has the filename
  ############
  filename = ARGV[0]
  source = File.new(filename,'r').read
  dest = ""
  source.split("\n").each do |line|
    # combine continuing lines
    if(!(line =~ /^\s*#/) && line =~ /[^\\]\\\s*$/)
      puts "hereeeeer"
      #multiLineArray.push line
      #multiLineStr += line.sub(/^(.*)\\\s*$/,"\\1")
      next
    end

    # add final line
    if(multiLineStr.length > 0)
      puts "HERLKJHLJKEHR"
      #multiLineArray.push line
      #multiLineStr += line.sub(/^(.*)\\\s*$/,"\\1")
    end

    tline = ((multiLineStr.length > 0)?multiLineStr:line).strip
    if(tline =~ /^=begin/)
      commentBlock = true
    end
    if(commentBlock)
      # add the line unchanged
      dest += line + "\n"
    else
      commentLine = (tline =~ /^#/)
      if(!commentLine)
        # throw out sequences that will
        # only sow confusion
        tline.gsub!(/\/.*?\//,"")
        tline.gsub!(/%r\{.*?\}/,"")
        tline.gsub!(/%r(.).*?\1/,"")
        tline.gsub!(/\\\"/,"'")
        tline.gsub!(/".*?"/,"\"\"")
        tline.gsub!(/'.*?'/,"''")
        tline.gsub!(/#\{.*?\}/,"")
        $outdentExp.each do |re|
          if(tline =~ re)
            tab -= 1
            break
          end
        end
      end
      if (multiLineArray.length > 0)
        multiLineArray.each do |ml|
          dest += addLine(ml,tab)
        end
        multiLineArray.clear
        multiLineStr = ""
      else
        dest += addLine(line,tab)
      end
      if(!commentLine)
        $indentExp.each do |re|
          if(tline =~ re && !(tline =~ /\s+end\s*$/))
            tab += 1
            break
          end
        end
      end
    end
    if(tline =~ /^=end/)
      commentBlock = false
    end
  end
  #STDOUT.write(dest)
  #File.open(filename, 'w') {|fw| fw.write(dest)}
  puts "File #{ARGV[0]} has been formatted."
  # uncomment this to complain about mismatched blocks
  if(tab != 0)
    STDERR.puts "Indentation error: #{tab}"
  end
end

format_ruby