=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 = '1.1.2'

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


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

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


  private


  def confirm_connection
    if @socket.closed? then
      @socket.reopen
    end
  end
  
  def do_finish
    unless @proto.error_occured or @socket.closed? then
      head '/', { 'Connection' => 'Close' }
    end
  end


  def edit_path( path )
    path
  end

  class << self
    def Proxy( addr, port )
      klass = super
      klass.module_eval %-
        def edit_path( path )
          'http://' + address + (port == self.port ? '' : ":\#{port}") + path
        end
      -
      klass
    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 = '' )
    header = get_response(
      sprintf( 'GET %s HTTP/%s', path, HTTPVersion ), u_header )
    
    if chunked? header then
      clen = read_chunked_body( ret )
      header.delete 'transfer-encoding'
      header[ 'content-length' ] = "Content-Length: #{clen}"
    else
      @socket.read content_length( header ), ret
    end
    @socket.close unless keep_alive? header

    return header, ret
  end


  def head( path, u_header = nil )
    header = get_response(
      sprintf( 'HEAD %s HTTP/%s', path, HTTPVersion ), u_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
      @socket.close
    end
  end

  def get_response( line, u_header )
    @socket.writeline line
    write_header u_header
    rep = get_reply
    header = read_header
    reply_must rep, SuccessCode

    header
  end

  def get_reply
    str = @socket.readline
    unless /\AHTTP\/(\d+\.\d+)?\s+(\d\d\d)\s*(.*)\z/i === str then
      raise HTTPBadResponse, "wrong status line format: #{str}"
    end
    @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 /\Acontent-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 /\Aconnection:\s*keep-alive/i === str then
        return true
      end
    else
      if @http_version == '1.1' then
        return true
      end
    end

    false
  end

  def chunked?( header )
    if str = header[ 'transfer-encoding' ] then
      if /\Atransfer-encoding:\s*chunked/i === str 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

  def read_chunked_body( ret )
    line = nil
    len = nil
    total = 0

    while true do
      line = @socket.readline
      unless /[0-9a-hA-H]+/ === line then
        raise HTTPBadResponce, "chunk size not given"
      end
      len = $&.hex
      break if len == 0
      @socket.read( len, ret ); total += len
      @socket.read 2   # \r\n
    end
    while true do
      line = @socket.readline
      break if line.empty?
    end

    total
  end

end


end   # module Net