#!/usr/bin/ruby

require 'webrick/httprequest'
require 'webrick/httpresponse'
require 'webrick/config'
require 'stringio'

module WEBrick
  class CGISocket
    private

    def initialize(env = ENV, stdin = $stdin, stdout = $stdout)
      @env = env
      @header_part = StringIO.new
      @body_part = stdin
      @out_port = stdout

      @server_addr = '0.0.0.0'
      @server_host = @env['SERVER_HOST'] || @server_addr
      @server_port = @env['SERVER_PORT'] || nil
      @remote_addr = @env['REMOTE_ADDR']
      @remote_host = @env['REMOTE_HOST'] || @remote_addr

      begin
	setup_header
      rescue Exception
	raise Errno::EPIPE, 'invalid CGI environment'
      end
      @header_part << LF
      @header_part.rewind
    end

    def setup_header
      request_line = @env['REQUEST_METHOD'] + ' ' + @env['SCRIPT_NAME']
      request_line << '?' + @env['QUERY_STRING'] if @env['QUERY_STRING']
      request_line << ' ' + @env['SERVER_PROTOCOL'] if @env['SERVER_PROTOCOL']
      @header_part << request_line + LF

      add_header('CONTENT_LENGTH', 'Content-Length')
      add_header('CONTENT_TYPE', 'Content-Type')
      add_header('SERVER_SOFTWARE', 'Server')
      if @env['AUTH_TYPE'] && !@env['AUTH_TYPE'].empty?
	@header_part << 'Authorization: ' + @env['AUTH_TYPE'] + ' ' + LF
      end

      ENV.each_key do |name|
	if /^HTTP_/ =~ name
	  add_header(name, name.gsub(/_/, '-'))
	end
      end
    end

    def add_header(envname, hdrname)
      if @env[envname] && !@env[envname].empty?
	@header_part << hdrname + ': ' + @env[envname] + LF
      end
    end

    public

    def peeraddr
      [nil, nil, @remote_host, @remote_addr]
    end

    def addr
      [nil, @server_port, @server_host, @server_addr]
    end

    def gets(eol = LF)
      unless @header_part.eof?
	@header_part.gets(eol)
      else
	@body_part.gets(eol)
      end
    end

    def read(size = nil)
      unless @header_part.eof?
	@header_part.read(size)
      else
	@body_part.read(size)
      end
    end

    def <<(data)
      @out_port << data
    end

    def self.wrap(config = Config::HTTP, env = ENV, stdin = $stdin)
      cgisock = self.new(env, stdin)
      req = HTTPRequest.new(config)

      req.parse(cgisock)
      req.script_name = (ENV['SCRIPT_NAME'] || "").dup
      if ENV['PATH_INFO']
	unless ENV['PATH_INFO'].empty?
	  req.path_info = ENV['PATH_INFO'].dup
	else
	  req.path_info = ''
	end
      else
	req.path_info = nil
      end

      config = config.dup
      config[:ServerSoftware] = req['server'] # XXX:
      res = HTTPResponse.new(config)
      class << res
	def status_line
	  ""
	end
      end
      res.request_method = req.request_method
      res.request_uri = req.request_uri
      res.request_http_version = req.http_version
      res.keep_alive = req.keep_alive?

      if block_given?
	yield(cgisock, req, res)
	req.fixup
	nil
      else
	[cgisock, req, res]
      end
    end
  end
end

if __FILE__ == $0
  begin
    require 'logger'
    config = WEBrick::Config::HTTP.dup
    config[:Logger] = Logger.new(STDERR)
    WEBrick::CGISocket.wrap(config) do |sock, req, res|
      res['content-type'] = 'text/plain; charset=iso-8859-1'
      res.chunked = true if req.http_version > '1.0'

      res.body << "BEGIN: CGI environment -> HTTP request:\n"
      res.body << req.to_s
      res.body << "END\n\n"

      res.body << "BEGIN: WEBrick::HTTPRequest:\n"
      res.body << req.inspect
      res.body << "\nEND\n\n"

      t = ''
      res.setup_header # XXX: this is only for self-test.
      res.send_header(t)
      res.body << "BEGIN: WEBrick::HTTPResponse header:\n"
      res.body << t
      res.body << "\nEND\n\n"

      res.send_response(sock)
    end
  rescue Exception
    puts "Content-Type: text/plain; charset=iso-8859-1"
    puts
    puts "BEGIN: excpetion:"
    puts $!
    puts $@
    puts "END"
  end

end