#
# Get CGI String
#
# EXAMPLE:
# require "cgi-lib.rb"
# foo = CGI.new
# foo['field']   <== value of 'field'
# foo.keys       <== array of fields
# and foo has Hash class methods
#
# foo.cookie['name']  <== cookie value of 'name'
# foo.cookie.keys     <== all cookie names
# and foo.cookie has Hash class methods
#
# make raw cookie string
# cookie1 = CGI.cookie({'name'    => 'name',
#                       'value'   => 'value',
#                       'path'    => 'path',   # optional
#                       'domain'  => 'domain', # optional
#                       'expires' => Time.now, # optional
#                       'secure'  => true      # optional
#                      })
#
# print CGI.header("Content-Type: text/html", cookie1, cookie2)
#
# print CGI.header("HTTP/1.0 200 OK", "Content-Type: text/html")
# print CGI.header # == print CGI.header("Content-Type: text/html")
#
# make HTML tag string
# CGI.tag("element", {"attribute_name"=>"attribute_value"}){"content"}
#
# print CGI.tag("HTML"){
#         CGI.tag("HEAD"){ CGI.tag("TITLE"){"TITLE"} } +
#         CGI.tag("BODY"){
#           CGI.tag("FORM", {"ACTION"=>"test.rb", "METHOD"=>"POST"}){
#             CGI.tag("INPUT", {"TYPE"=>"submit", "VALUE"=>"submit"})
#           } +
#           CGI.tag("HR")
#         }
#       }
#
# print HTTP header and strings to STDOUT
# CGI.print{ "string" } # add HTTP header "Content-Type: text/html"
# CGI.print("Content-Type: text/plain"){ "string" }
# CGI.print("HTTP/1.0 200 OK", "Content-Type: text/html"){ "string" }


# if running on Windows(IIS or PWS) then change cwd.
if ENV['SERVER_SOFTWARE'] =~ /^Microsoft-/ then
  Dir.chdir ENV['PATH_TRANSLATED'].sub(/[^\\]+$/, '')
end

require "delegate"

class CGI < SimpleDelegator

  CR  = "\015"
  LF  = "\012"
  EOL = CR + LF

  attr("inputs")
  attr("cookie")

  # original is CGI.pm
  def read_from_cmdline
    require "shellwords.rb"
    words = Shellwords.shellwords(if not ARGV.empty? then
                         ARGV.join(' ')
                       else
                         STDERR.print "(offline mode: enter name=value pairs on standard input)\n" if STDIN.tty?
                         readlines.join(' ').gsub(/\n/, '')
                       end.gsub(/\\=/, '%3D').gsub(/\\&/, '%26'))

    if words.find{|x| x =~ /=/} then words.join('&') else words.join('+') end
  end
  
  # escape url encode
  def escape(str)
    str.gsub!(/[^a-zA-Z0-9_\-.]/n){ sprintf("%%%02X", $&.unpack("C")[0]) }
    str
  end

  # unescape url encoded
  def unescape(str)
    str.gsub!(/\+/, ' ')
    str.gsub!(/%([0-9a-fA-F]{2})/){ [$1.hex].pack("c") }
    str
  end

  # escape HTML
  def escapeHTML(str)
    str.gsub(/&/, "&amp;").gsub(/\"/, "&quot;").gsub(/>/, "&gt;").gsub(/</, "&lt;")
  end

  module_function :escape, :unescape, :escapeHTML

  def initialize(input = $stdin)

    @inputs = {}
    case ENV['REQUEST_METHOD']
    when "GET"
      # exception messages should be printed to stdout.
      STDERR.reopen(STDOUT)
      ENV['QUERY_STRING'] or ""
    when "POST"
      # exception messages should be printed to stdout.
      STDERR.reopen(STDOUT)
      input.read Integer(ENV['CONTENT_LENGTH'])
    else
      read_from_cmdline
    end.split(/&/).each do |x|
      key, val = x.split(/=/,2).collect{|x|unescape(x)}
      if @inputs.include?(key)
        @inputs[key] += "\0" + (val or "")
      else
        @inputs[key] = (val or "")
      end
    end

    super(@inputs)

    if ENV.has_key?('HTTP_COOKIE')
      @cookie = {}
      ENV['HTTP_COOKIE'].split("; ").each do |x|
        key, val = x.split(/=/,2).collect{|x|unescape(x)}
        if @cookie.include?(key)
          @cookie[key] += "\0" + (val or "")
        else
          @cookie[key] = (val or "")
        end
      end
    end
  end

  def CGI.header(*options)
    options.push("Content-Type: text/html") if options.empty?
    if options.find{|item| /^Expires: |^Set-Cookie: /i === item}
      options.push("Date: " + Time.now.gmtime.strftime("%a, %d %b %Y %X %Z"))
    end
    options.join(EOL) + EOL + EOL
  end

  def CGI.cookie(options)
    "Set-Cookie: " + options['name'] + '=' + escape(options['value']) +
    (options['domain']  ? '; domain='  + options['domain'] : '') +
    (options['path']    ? '; path='    + options['path']   : '') +
    (options['expires'] ? '; expires=' + options['expires'].strftime("%a, %d %b %Y %X %Z") : '') +
    (options['secure']  ? '; secure' : '')
  end

  def CGI.tag(element, attributes = {})
    "<" + escapeHTML(element) + attributes.collect{|name, value|
      " " + escapeHTML(name) + '="' + escapeHTML(value) + '"'
    }.to_s + ">" +
    (iterator? ? yield.to_s + "</" + escapeHTML(element) + ">" : "")
  end

  def CGI.print(*header)
    header.push("Content-Type: text/html") if header.empty?
    STDOUT.print CGI.header(*header) + yield.to_s
  end

  def CGI.message(message, title = "", header = ["Content-Type: text/html"])
    if message.kind_of?(Hash)
      title   = message['title']
      header  = message['header']
      message = message['body']
    end
    CGI.print(*header){
      CGI.tag("HTML"){
        CGI.tag("HEAD"){ CGI.tag("TITLE"){ title } } +
        CGI.tag("BODY"){ message }
      }
    }
    TRUE
  end

  def CGI.error
    CGI.message({'title'=>'ERROR', 'body'=>
      CGI.tag("PRE"){
        "ERROR: " + CGI.tag("STRONG"){ escapeHTML($!.to_s) } + "\n" +
        escapeHTML($@.join("\n"))
      }
    })
    exit
  end
end