"""Response classes used by urllib.

The base class, addbase, defines a minimal file-like interface,
including read() and readline(). The typical response object is an
addinfourl instance, which defines an info() method that returns
headers and a geturl() method that returns the url.
"""

import tempfile

__all__ = ['addbase', 'addclosehook', 'addinfo', 'addinfourl']


class addbase(tempfile._TemporaryFileWrapper):
 """Base class for addinfo and addclosehook. Is a good idea for garbage collection."""

 # XXX Add a method to expose the timeout on the underlying socket?

 def __init__(self, fp):
 super(addbase, self).__init__(fp, '<urllib response>', delete=False)
 # Keep reference around as this was part of the original API.
 self.fp = fp

 def __repr__(self):
 return '<%s at %r whose fp = %r>' % (self.__class__.__name__,
 id(self), self.file)

 def __enter__(self):
 if self.fp.closed:
 raise ValueError("I/O operation on closed file")
 return self

 def __exit__(self, type, value, traceback):
 self.close()


class addclosehook(addbase):
 """Class to add a close hook to an open file."""

 def __init__(self, fp, closehook, *hookargs):
 super(addclosehook, self).__init__(fp)
 self.closehook = closehook
 self.hookargs = hookargs

 def close(self):
 try:
 closehook = self.closehook
 hookargs = self.hookargs
 if closehook:
 self.closehook = None
 self.hookargs = None
 closehook(*hookargs)
 finally:
 super(addclosehook, self).close()


class addinfo(addbase):
 """class to add an info() method to an open file."""

 def __init__(self, fp, headers):
 super(addinfo, self).__init__(fp)
 self.headers = headers

 def info(self):
 return self.headers


class addinfourl(addinfo):
 """class to add info() and geturl() methods to an open file."""

 def __init__(self, fp, headers, url, code=None):
 super(addinfourl, self).__init__(fp, headers)
 self.url = url
 self.code = code

 def getcode(self):
 return self.code

 def geturl(self):
 return self.url