Mitter/mitterlib/network/__init__.py

#!/usr/bin/python2.5
# -*- coding: utf-8 -*-

# Mitter, a simple client for Twitter
# Copyright (C) 2007, 2008  The Mitter Contributors
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os.path
import glob
import logging

from mitterlib.network.networkbase import NetworkData

_log = logging.getLogger('mitterlib.network.Networks')

# List of files that are not networks
SKIPPABLES = ('__init__.py', 'networkbase.py')

#--------------------------------------------------------------------
# Helper functions
#--------------------------------------------------------------------


def _import_name(module):
    (name, _) = os.path.splitext(module)
    return 'mitterlib.network.%s' % (name)


def _networks():
    network_dir = os.path.dirname(__file__)

    networks = glob.glob(os.path.join(network_dir, '*.py'))
    for network in networks:
        network_name = os.path.basename(network)
        if network_name in SKIPPABLES:
            # not a real network
            continue

        module_name = _import_name(network_name)
        yield module_name

#--------------------------------------------------------------------
# Exceptions
#--------------------------------------------------------------------


class NetworksError(Exception):
    """Basic Networks exception."""
    pass


class NetworksNoSuchNetworkError(NetworksError):
    """The request network does not exists."""

    def __init__(self, network):
        self._network = network

    def __str__(self):
        return 'Unknown network %s' % (self._network)
    pass


class NetworksNoNetworkSetupError(NetworksError):
    """There are no networks set up."""
    pass


class NetworksErrorLoadingNetwork(NetworksError):
    """Error loadig one of the networks."""

    def __init__(self, network, exception):
        self._network = network
        self._exception = str(exception)

    def __str__(self):
        return "Couldn't load %s (%s)" % (self._network, self._exception)


class Networks(object):
    """Network transparency layer: Keeps a list of available networks and send
    requests to all those who have been setup."""

    def __init__(self, options):
        self._networks = {}
        self._options = options
        self.options()

    @property
    def networks(self):
        if self._networks:
            return self._networks

        for module_name in _networks():
            try:
                module = __import__(module_name, fromlist=[module_name])
                connection = module.Connection(self._options)
                self._networks[connection.SHORTCUT] = connection
            except ImportError, ex:
                raise NetworksErrorLoadingNetwork(module_name, ex)

        return self._networks

    def _targets(self, shortcut):
        """Select a network based on the shortcut. If the shortcut is None,
        returns all available network shortcuts."""
        if shortcut:
            if not shortcut in self.networks:
                raise NetworksNoSuchNetworkError(shortcut)
            else:
                targets = [shortcut]
        else:
            targets = self.networks

        setup = False
        for target in targets:
            if self.networks[target].is_setup():
                setup = True
                yield target

        if not setup:
            raise NetworksNoNetworkSetupError

    def settings(self):
        """Return a dictionary with the options that the interfaces need to
        setup."""
        result = []
        for shortcut in self.networks:
            settings = {
                'shortcut': shortcut,
                'name': self.networks[shortcut].NAMESPACE,
                'options': self.networks[shortcut].AUTH,
            }
            result.append(settings)
        return result

    def options(self):
        """Request all networks to add their options."""
        for shortcut in self.networks:
            conn = self.networks[shortcut]
            conn.options(self._options)

        return

    def name(self, shortcut):
        """Return the name of a network based on the shortcut."""
        try:
            name = self.networks[shortcut].NAMESPACE
        except KeyError:
            raise NetworksNoSuchNetworkError(shortcut)
        return name

    # This is basically a copy of all methods available in NetworkBase, with
    # the additional parameter "network" (to request data from just one
    # source)

    def messages(self, network=None):
        """Return a list of NetworkData objects for the main "timeline" (the
        default list presented to the user.)"""
        result = []
        for shortcut in self._targets(network):
            for message in self.networks[shortcut].messages():
                message.network = shortcut
                result.append(message)
        return result

    def update(self, status, reply_to=None, network=None):
        """Update the user status. Must return the id for the new status."""
        if reply_to and isinstance(reply_to, NetworkData):
            # If you pass a NetworkData object, we get the proper network
            network = reply_to.network

        for shortcut in self._targets(network):
            self.networks[shortcut].update(status, reply_to)
        return None

    def delete_message(self, message, network=None):
        """Delete an update. Message can be a NetworkData object, in which
        case network is not necessary; otherwise a network must be
        provided."""
        if isinstance(message, NetworkData):
            network = message.network

        self.networks[network].delete_message(message)
        return

    def message(self, message_id, network):
        """Return a single NetworkData object for a specified message."""
        if not network in self.networks:
            raise NetworksNoSuchNetworkError(network)

        data = self.networks[network].message(message_id)
        data.network = network
        return data

    def replies(self, network=None):
        """Return a list of NetworkData objects for the replies for the user
        messages."""
        result = []
        for shortcut in self._targets(network):
            for message in self.networks[shortcut].replies():
                message.network = shortcut
                result.append(message)
        return result

    def inbox(self, network=None):
        """Return a list of NetworkData objects for the direct messages/inbox
        of the user."""
        return []

    def available_requests(self, network=None):
        """Return a dictionary with the available requests the user can
        make to each network before getting capped."""
        result = {}
        for shortcut in self._targets(network):
            requests = self.networks[shortcut].available_requests()
            result[shortcut] = requests
        return result