Mitter/mitterlib/network/__init__.py

#!/usr/bin/env python
# -*- 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 logging
import os.path

from mitterlib.network.networkbase import NetworkData
from mitterlib import module_search

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

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

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

def _import_name(module):
    """Based on the name of the module, return the proper "import"
    statement."""
    (name, _) = os.path.splitext(module)
    return 'mitterlib.network.%s' % (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 module_search(__file__, SKIPPABLES):
            import_name = _import_name(module_name)
            module = __import__(import_name, fromlist=[import_name])
            connection = module.Connection(self._options)
            self._networks[connection.SHORTCUT] = connection

        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

        results = []
        for shortcut in self._targets(network):
            results.append(self.networks[shortcut].update(status, reply_to))
        return results

    def reply_prefix(self, message):
        """Return the prefix to be used in the reply for that message."""
        return self.networks[message.network].reply_prefix(message)

    def repost(self, message):
        """Repost a message in the user's timeline. The network used is
        the same in the message."""
        self.networks[message.network].repost(message)
        return

    def favourite(self, message):
        """Change the favourite status of the message."""
        self.networks[message.network].favourite(message)
        return

    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."""
        # TODO: This should probably be named parent() and receive a
        # NetworkData. Still returns a single NetworkData object.
        if not network in self.networks:
            raise NetworksNoSuchNetworkError(network)

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

    def link(self, message):
        """Returns a link directly to the message."""
        return self.networks[message.network].link(message)

    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 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

    def can_delete(self, message):
        """Return True if the message can be deleted; False otherwise."""
        return self.networks[message.network].can_delete(message)

    def can_reply(self, message):
        """Return True if the message can be replied; False otherwise."""
        return self.networks[message.network].can_reply(message)

    def can_repost(self, message):
        """Return True if the message can be resposted; False otherwise."""
        return self.networks[message.network].can_repost(message)

    def can_favourite(self, message):
        """Return True if the message can be favourited/unfavourited; False
        otherwise."""
        return self.networks[message.network].can_favourite(message)

    # TODO: Function to return a regexp for usernames
    # TODO: Function to return a pre-message for replies (how to handle
    #   dynamic content, like usernames?)