# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
Exceptions and errors for use in twisted.internet modules.
"""

from __future__ import division, absolute_import

import socket

from twisted.python import deprecate
from twisted.python.versions import Version



class BindError(Exception):
"""An error occurred binding to an interface"""

def __str__(self):
s = self.__doc__
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class CannotListenError(BindError):
"""
This gets raised by a call to startListening, when the object cannotstart
listening.

@ivar interface: the interface I tried to listen on
@ivar port: the port I tried to listen on
@ivar socketError: the exception I got when I tried to listen
@type socketError: L{socket.error}
"""
def __init__(self, interface, port, socketError):
BindError.__init__(self, interface, port, socketError)
self.interface = interface
self.port = port
self.socketError = socketError

def __str__(self):
iface = self.interface or 'any'
return "Couldn't listen on %s:%s: %s." % (iface, self.port,
self.socketError)



class MulticastJoinError(Exception):
"""
An attempt to join a multicast group failed.
"""



class MessageLengthError(Exception):
"""Message is too long to send"""

def __str__(self):
s = self.__doc__
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class DNSLookupError(IOError):
"""DNS lookup failed"""

def __str__(self):
s = self.__doc__
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class ConnectInProgressError(Exception):
"""A connect operation was started and isn't done yet."""


# connection errors

class ConnectError(Exception):
"""An error occurred while connecting"""

def __init__(self, osError=None, string=""):
self.osError = osError
Exception.__init__(self, string)

def __str__(self):
s = self.__doc__ or self.__class__.__name__
if self.osError:
s = '%s: %s' % (s, self.osError)
if self.args[0]:
s = '%s: %s' % (s, self.args[0])
s = '%s.' % s
return s



class ConnectBindError(ConnectError):
"""Couldn't bind"""



class UnknownHostError(ConnectError):
"""Hostname couldn't be looked up"""



class NoRouteError(ConnectError):
"""No route to host"""



class ConnectionRefusedError(ConnectError):
"""Connection was refused by other side"""



class TCPTimedOutError(ConnectError):
"""TCP connection timed out"""



class BadFileError(ConnectError):
"""File used for UNIX socket is no good"""



class ServiceNameUnknownError(ConnectError):
"""Service name given as port is unknown"""



class UserError(ConnectError):
"""User aborted connection"""



class TimeoutError(UserError):
"""User timeout caused connection failure"""



class SSLError(ConnectError):
"""An SSL error occurred"""



class VerifyError(Exception):
"""Could not verify something that was supposed to be signed.
"""



class PeerVerifyError(VerifyError):
"""The peer rejected our verify error.
"""



class CertificateError(Exception):
"""
We did not find a certificate where we expected to find one.
"""



try:
import errno
errnoMapping = {
errno.ENETUNREACH: NoRouteError,
errno.ECONNREFUSED: ConnectionRefusedError,
errno.ETIMEDOUT: TCPTimedOutError,
}
if hasattr(errno, "WSAECONNREFUSED"):
errnoMapping[errno.WSAECONNREFUSED] = ConnectionRefusedError
errnoMapping[errno.WSAENETUNREACH] = NoRouteError
except ImportError:
errnoMapping = {}



def getConnectError(e):
"""Given a socket exception, return connection error."""
if isinstance(e, Exception):
args = e.args
else:
args = e
try:
number, string = args
except ValueError:
return ConnectError(string=e)

if hasattr(socket, 'gaierror') and isinstance(e, socket.gaierror):
# Only works in 2.2 in newer. Really that means always; #5978 covers
# this and other wierdnesses in this function.
klass = UnknownHostError
else:
klass = errnoMapping.get(number, ConnectError)
return klass(number, string)



class ConnectionClosed(Exception):
"""
Connection was closed, whether cleanly or non-cleanly.
"""



class ConnectionLost(ConnectionClosed):
"""Connection to the other side was lost in a non-clean fashion"""

def __str__(self):
s = self.__doc__.strip().splitlines()[0]
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class ConnectionAborted(ConnectionLost):
"""
Connection was aborted locally, using
L{twisted.internet.interfaces.ITCPTransport.abortConnection}.

@since: 11.1
"""



class ConnectionDone(ConnectionClosed):
"""Connection was closed cleanly"""

def __str__(self):
s = self.__doc__
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class FileDescriptorOverrun(ConnectionLost):
"""
A mis-use of L{IUNIXTransport.sendFileDescriptor} caused the connection to
be closed.

Each file descriptor sent using C{sendFileDescriptor} must be associated
with at least one byte sent using L{ITransport.write}. If at any point
fewer bytes have been written than file descriptors have been sent, the
connection is closed with this exception.
"""



class ConnectionFdescWentAway(ConnectionLost):
"""Uh""" #TODO



class AlreadyCalled(ValueError):
"""Tried to cancel an already-called event"""

def __str__(self):
s = self.__doc__
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class AlreadyCancelled(ValueError):
"""Tried to cancel an already-cancelled event"""

def __str__(self):
s = self.__doc__
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class PotentialZombieWarning(Warning):
"""
Emitted when L{IReactorProcess.spawnProcess} is called in a way which may
result in termination of the created child process not being reported.

Deprecated in Twisted 10.0.
"""
MESSAGE = (
"spawnProcess called, but the SIGCHLD handler is not "
"installed. This probably means you have not yet "
"called reactor.run, or called "
"reactor.run(installSignalHandler=0). You will probably "
"never see this process finish, and it may become a "
"zombie process.")

deprecate.deprecatedModuleAttribute(
Version("Twisted", 10, 0, 0),
"There is no longer any potential for zombie process.",
__name__,
"PotentialZombieWarning")



class ProcessDone(ConnectionDone):
"""A process has ended without apparent errors"""

def __init__(self, status):
Exception.__init__(self, "process finished with exit code 0")
self.exitCode = 0
self.signal = None
self.status = status



class ProcessTerminated(ConnectionLost):
"""
A process has ended with a probable error condition

@ivar exitCode: See L{__init__}
@ivar signal: See L{__init__}
@ivar status: See L{__init__}
"""
def __init__(self, exitCode=None, signal=None, status=None):
"""
@param exitCode: The exit status of the process. This is roughly like
the value you might pass to L{os.exit}. This is L{None} if the
process exited due to a signal.
@type exitCode: L{int} or L{types.NoneType}

@param signal: The exit signal of the process. This is L{None} if the
process did not exit due to a signal.
@type signal: L{int} or L{types.NoneType}

@param status: The exit code of the process. This is a platform
specific combination of the exit code and the exit signal. See
L{os.WIFEXITED} and related functions.
@type status: L{int}
"""
self.exitCode = exitCode
self.signal = signal
self.status = status
s = "process ended"
if exitCode is not None: s = s + " with exit code %s" % exitCode
if signal is not None: s = s + " by signal %s" % signal
Exception.__init__(self, s)



class ProcessExitedAlready(Exception):
"""
The process has already exited and the operation requested can no longer
be performed.
"""



class NotConnectingError(RuntimeError):
"""The Connector was not connecting when it was asked to stop connecting"""

def __str__(self):
s = self.__doc__
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class NotListeningError(RuntimeError):
"""The Port was not listening when it was asked to stop listening"""

def __str__(self):
s = self.__doc__
if self.args:
s = '%s: %s' % (s, ' '.join(self.args))
s = '%s.' % s
return s



class ReactorNotRunning(RuntimeError):
"""
Error raised when trying to stop a reactor which is not running.
"""


class ReactorNotRestartable(RuntimeError):
"""
Error raised when trying to run a reactor which was stopped.
"""



class ReactorAlreadyRunning(RuntimeError):
"""
Error raised when trying to start the reactor multiple times.
"""


class ReactorAlreadyInstalledError(AssertionError):
"""
Could not install reactor because one is already installed.
"""



class ConnectingCancelledError(Exception):
"""
An C{Exception} that will be raised when an L{IStreamClientEndpoint} is
cancelled before it connects.

@ivar address: The L{IAddress} that is the destination of the
cancelled L{IStreamClientEndpoint}.
"""

def __init__(self, address):
"""
@param address: The L{IAddress} that is the destination of the
L{IStreamClientEndpoint} that was cancelled.
"""
Exception.__init__(self, address)
self.address = address



class UnsupportedAddressFamily(Exception):
"""
An attempt was made to use a socket with an address family (eg I{AF_INET},
I{AF_INET6}, etc) which is not supported by the reactor.
"""



class UnsupportedSocketType(Exception):
"""
An attempt was made to use a socket of a type (eg I{SOCK_STREAM},
I{SOCK_DGRAM}, etc) which is not supported by the reactor.
"""


class AlreadyListened(Exception):
"""
An attempt was made to listen on a file descriptor which can only be
listened on once.
"""


__all__ = [
'BindError', 'CannotListenError', 'MulticastJoinError',
'MessageLengthError', 'DNSLookupError', 'ConnectInProgressError',
'ConnectError', 'ConnectBindError', 'UnknownHostError', 'NoRouteError',
'ConnectionRefusedError', 'TCPTimedOutError', 'BadFileError',
'ServiceNameUnknownError', 'UserError', 'TimeoutError', 'SSLError',
'VerifyError', 'PeerVerifyError', 'CertificateError',
'getConnectError', 'ConnectionClosed', 'ConnectionLost',
'ConnectionDone', 'ConnectionFdescWentAway', 'AlreadyCalled',
'AlreadyCancelled', 'PotentialZombieWarning', 'ProcessDone',
'ProcessTerminated', 'ProcessExitedAlready', 'NotConnectingError',
'NotListeningError', 'ReactorNotRunning', 'ReactorAlreadyRunning',
'ReactorAlreadyInstalledError', 'ConnectingCancelledError',
'UnsupportedAddressFamily', 'UnsupportedSocketType']