=begin

= net/http.rb

maintained by Minero Aoki <aamine@dp.u-netsurf.ne.jp>
This file is derived from http-access.rb

=end

require 'net/session'


module Net


class HTTPError < ProtocolError; end
class HTTPBadResponse < HTTPError; end


class HTTPSession < Session

  Version = '1.1.0'

  session_setvar :port,         '80'
  session_setvar :command_type, 'HTTPCommand'


  def get( path = '/', header = nil, ret = '' )
    confirm_connection
    @proto.get path, header, ret
  end

  def head( path = '/', header = nil )
    confirm_connection
    @proto.head path, header
  end


  private


  def confirm_connection
    if @socket.closed? then
      @socket.reopen
    end
  end

end

HTTP = HTTPSession



class HTTPCommand < Command

  HTTPVersion = '1.1'

  def initialize( sock )
    @http_version = HTTPVersion

    @in_header = {}
    @in_header[ 'Host' ]       = sock.addr
    #@in_header[ 'User-Agent' ] = "Ruby http version #{HTTPSession::Version}"
    #@in_header[ 'Connection' ] = 'Keep-Alive'
    #@in_header[ 'Accept' ]     = '*/*'

    super sock
  end


  attr :http_version

  def get( path, u_header = nil, ret = '' )
    @socket.writeline sprintf( 'GET %s HTTP/%s', path, HTTPVersion )
    write_header u_header
    check_reply SuccessCode
    header = read_header
    @socket.read content_length( header ), ret
    @socket.close unless keep_alive? header

    return header, ret
  end


  def head( path, u_header = nil )
    @socket.writeline sprintf( 'HEAD %s HTTP/%s', path, HTTPVersion )
    write_header u_header
    check_reply SuccessCode
    header = read_header
    @socket.close unless keep_alive? header

    header
  end


  # def put

  # def delete

  # def trace

  # def options


  private


  def do_quit
    unless @socket.closed? then
      head '/', { 'Connection' => 'Close' }
    end
  end


  def get_reply
    str = @socket.readline
    /\AHTTP\/(\d+\.\d+)?\s+(\d\d\d)\s+(.*)\z/i === str
    @http_version = $1
    status  = $2
    discrip = $3
    
    klass = case status[0]
            when ?1 then
              case status[2]
              when ?0 then ContinueCode
              when ?1 then SuccessCode
              else         UnknownCode
              end
            when ?2 then SuccessCode
            when ?3 then RetryCode
            when ?4 then ServerBusyCode
            when ?5 then FatalErrorCode
            else UnknownCode
            end
    klass.new( status, discrip )
  end

  
  def content_length( header )
    unless str = header[ 'content-length' ] then
      raise HTTPBadResponce, "content-length not given"
    end
    unless /content-length:\s*(\d+)/i === str then
      raise HTTPBadResponce, "content-length format error"
    end
    $1.to_i
  end

  def keep_alive?( header )
    if str = header[ 'connection' ] then
      if /connection:\s*keep-alive/i === str then
        return true
      end
    else
      if @http_version == '1.1' then
        return true
      end
    end

    false
  end


  def read_header
    header = {}
    while true do
      line = @socket.readline
      break if line.empty?
      /\A[^:]+/ === line
      nm = $&
      nm.strip!
      nm.downcase!
      header[ nm ] = line
    end

    header
  end

  def write_header( user )
    if user then
      header = @in_header.dup.update user
    else
      header = @in_header
    end
    header.each do |n,v|
      @socket.writeline n + ': ' + v
    end
    @socket.writeline ''

    if tmp = header['Connection'] then
      /close/i === tmp
    else
      false
    end
  end

end


end   # module Net