class Excon::Response

def self.parse(socket, datum)
  # this will discard any trailing lines from the previous response if any.
  begin
    line = socket.readline
  end until status = line[9, 3].to_i
  reason_phrase = line[13..-3] # -3 strips the trailing "\r\n"
  datum[:response] = {
    :body          => String.new,
    :cookies       => [],
    :host          => datum[:host],
    :headers       => Excon::Headers.new,
    :path          => datum[:path],
    :port          => datum[:port],
    :status        => status,
    :status_line   => line,
    :reason_phrase => reason_phrase
  }
  unix_proxy = datum[:proxy] ? datum[:proxy][:scheme] == UNIX : false
  unless datum[:scheme] == UNIX || unix_proxy
    datum[:response].merge!(
      :remote_ip     => socket.remote_ip,
      :local_port    => socket.local_port,
      :local_address => socket.local_address
    )
  end
  parse_headers(socket, datum)
  unless (['HEAD', 'CONNECT'].include?(datum[:method].to_s.upcase)) || NO_ENTITY.include?(datum[:response][:status])
    if key = datum[:response][:headers].keys.detect {|k| k.casecmp('Transfer-Encoding') == 0 }
      encodings = Utils.split_header_value(datum[:response][:headers][key])
      if (encoding = encodings.last) && encoding.casecmp('chunked') == 0
        transfer_encoding_chunked = true
        if encodings.length == 1
          datum[:response][:headers].delete(key)
        else
          datum[:response][:headers][key] = encodings[0...-1].join(', ')
        end
      end
    end
    # use :response_block unless :expects would fail
    if response_block = datum[:response_block]
      if datum[:middlewares].include?(Excon::Middleware::Expects) && datum[:expects] &&
                            !Array(datum[:expects]).include?(datum[:response][:status])
        response_block = nil
      end
    end
    if transfer_encoding_chunked
      if response_block
        while (chunk_size = socket.readline.chomp!.to_i(16)) > 0
          while chunk_size > 0
            chunk = socket.read(chunk_size) || raise(EOFError)
            chunk_size -= chunk.bytesize
            response_block.call(chunk, nil, nil)
          end
          new_line_size = 2 # 2 == "\r\n".length
          while new_line_size > 0
            chunk = socket.read(new_line_size) || raise(EOFError)
            new_line_size -= chunk.length
          end
        end
      else
        while (chunk_size = socket.readline.chomp!.to_i(16)) > 0
          while chunk_size > 0
            chunk = socket.read(chunk_size) || raise(EOFError)
            chunk_size -= chunk.bytesize
            datum[:response][:body] << chunk
          end
          new_line_size = 2 # 2 == "\r\n".length
          while new_line_size > 0
            chunk = socket.read(new_line_size) || raise(EOFError)
            new_line_size -= chunk.length
          end
        end
      end
      parse_headers(socket, datum) # merge trailers into headers
    else
      if key = datum[:response][:headers].keys.detect {|k| k.casecmp('Content-Length') == 0 }
        content_length = datum[:response][:headers][key].to_i
      end
      if remaining = content_length
        if response_block
          while remaining > 0
            chunk = socket.read([datum[:chunk_size], remaining].min) || raise(EOFError)
            response_block.call(chunk, [remaining - chunk.bytesize, 0].max, content_length)
            remaining -= chunk.bytesize
          end
        else
          while remaining > 0
            chunk = socket.read([datum[:chunk_size], remaining].min) || raise(EOFError)
            datum[:response][:body] << chunk
            remaining -= chunk.bytesize
          end
        end
      else
        if response_block
          while chunk = socket.read(datum[:chunk_size])
            response_block.call(chunk, nil, nil)
          end
        else
          while chunk = socket.read(datum[:chunk_size])
            datum[:response][:body] << chunk
          end
        end
      end
    end
  end
  datum
end