# Copyright (c) 2003-2006 Ralph Meijer
# See LICENSE for details.

import sha
import time
import uuid
from twisted.words.protocols.jabber import jid
from twisted.words.xish import utility
from twisted.application import service
from twisted.internet import defer
from zope.interface import implements
import backend, storage

def _get_affiliation(node, entity):
    d = node.get_affiliation(entity)
    d.addCallback(lambda affiliation: (node, affiliation))
    return d

class BackendService(service.MultiService, utility.EventDispatcher):

    implements(backend.IBackendService)

    options = {"pubsub#persist_items":
                  {"type": "boolean",
                   "label": "Persist items to storage"},
               "pubsub#deliver_payloads":
                  {"type": "boolean",
                   "label": "Deliver payloads with event notifications"},
              }

    default_config = {"pubsub#persist_items": True,
                      "pubsub#deliver_payloads": True,
                     }

    def __init__(self, storage):
        service.MultiService.__init__(self)
        utility.EventDispatcher.__init__(self)
        self.storage = storage

    def supports_publisher_affiliation(self):
        return True

    def supports_outcast_affiliation(self):
        return True

    def supports_persistent_items(self):
        return True

    def get_node_type(self, node_id):
        d = self.storage.get_node(node_id)
        d.addCallback(lambda node: node.get_type())
        return d

    def get_nodes(self):
        return self.storage.get_node_ids()

    def get_node_meta_data(self, node_id):
        d = self.storage.get_node(node_id)
        d.addCallback(lambda node: node.get_meta_data())
        d.addCallback(self._make_meta_data)
        return d

    def _make_meta_data(self, meta_data):
        options = []
        for key, value in meta_data.iteritems():
            if self.options.has_key(key):
                option = {"var": key}
                option.update(self.options[key])
                option["value"] = value
                options.append(option)

        return options

class PublishService(service.Service):
    
    implements(backend.IPublishService)

    def _check_auth(self, node, requestor):
        def check(affiliation, node):
            if affiliation not in ['owner', 'publisher']:
                raise backend.Forbidden
            return node

        d = node.get_affiliation(requestor)
        d.addCallback(check, node)
        return d

    def publish(self, node_id, items, requestor):
        d = self.parent.storage.get_node(node_id)
        d.addCallback(self._check_auth, requestor)
        d.addCallback(self._do_publish, items, requestor)
        return d

    def _do_publish(self, node, items, requestor):
        configuration = node.get_configuration()
        persist_items = configuration["pubsub#persist_items"]
        deliver_payloads = configuration["pubsub#deliver_payloads"]
        
        if items and not persist_items and not deliver_payloads:
            raise backend.ItemForbidden
        elif not items and (persist_items or deliver_payloads):
            raise backend.ItemRequired

        if persist_items or deliver_payloads:
            for item in items:
                if not item.getAttribute("id"):
                    item["id"] = uuid.generate() 

        if persist_items:
            d = node.store_items(items, requestor)
        else:
            d = defer.succeed(None)

        d.addCallback(self._do_notify, node.id, items, deliver_payloads)
        return d

    def _do_notify(self, result, node_id, items, deliver_payloads):
        if items and not deliver_payloads:
            for item in items:
                item.children = []

        self.parent.dispatch({ 'items': items, 'node_id': node_id },
                             '//event/pubsub/notify')

class NotificationService(service.Service):

    implements(backend.INotificationService)

    def get_notification_list(self, node_id, items):
        d = self.parent.storage.get_node(node_id)
        d.addCallback(lambda node: node.get_subscribers())
        d.addCallback(self._magic_filter, node_id, items)
        return d

    def _magic_filter(self, subscribers, node_id, items):
        list = []
        for subscriber in subscribers:
            list.append((subscriber, items))
        return list

    def register_notifier(self, observerfn, *args, **kwargs):
        self.parent.addObserver('//event/pubsub/notify', observerfn,
                                *args, **kwargs)

class SubscriptionService(service.Service):

    implements(backend.ISubscriptionService)

    def subscribe(self, node_id, subscriber, requestor):
        subscriber_entity = subscriber.userhostJID()
        if subscriber_entity != requestor:
            return defer.fail(backend.Forbidden())

        d = self.parent.storage.get_node(node_id)
        d.addCallback(_get_affiliation, subscriber_entity)
        d.addCallback(self._do_subscribe, subscriber)
        return d

    def _do_subscribe(self, result, subscriber):
        node, affiliation = result

        if affiliation == 'outcast':
            raise backend.Forbidden

        d = node.add_subscription(subscriber, 'subscribed')
        d.addCallback(lambda _: 'subscribed')
        d.addErrback(self._get_subscription, node, subscriber)
        d.addCallback(self._return_subscription, node.id)
        return d

    def _get_subscription(self, failure, node, subscriber):
        failure.trap(storage.SubscriptionExists)
        return node.get_subscription(subscriber)

    def _return_subscription(self, result, node_id):
        return node_id, result

    def unsubscribe(self, node_id, subscriber, requestor):
        if subscriber.userhostJID() != requestor:
            return defer.fail(backend.Forbidden())

        d = self.parent.storage.get_node(node_id)
        d.addCallback(lambda node: node.remove_subscription(subscriber))
        return d

    def get_subscriptions(self, entity):
        return self.parent.storage.get_subscriptions(entity)

class NodeCreationService(service.Service):

    implements(backend.INodeCreationService)

    def supports_instant_nodes(self):
        return True

    def create_node(self, node_id, requestor):
        if not node_id:
            node_id = 'generic/%s' % uuid.generate() 
        d = self.parent.storage.create_node(node_id, requestor)
        d.addCallback(lambda _: node_id)
        return d

    def get_default_configuration(self):
        d = defer.succeed(self.parent.default_config)
        d.addCallback(self._make_config)
        return d

    def get_node_configuration(self, node_id):
        if not node_id:
            raise backend.NoRootNode

        d = self.parent.storage.get_node(node_id)
        d.addCallback(lambda node: node.get_configuration())

        d.addCallback(self._make_config)
        return d

    def _make_config(self, config):
        options = []
        for key, value in self.parent.options.iteritems():
            option = {"var": key}
            option.update(value)
            if config.has_key(key):
                option["value"] = config[key]
            options.append(option)

        return options

    def set_node_configuration(self, node_id, options, requestor):
        if not node_id:
            raise backend.NoRootNode

        for key, value in options.iteritems():
            if not self.parent.options.has_key(key):
                raise backend.InvalidConfigurationOption
            if self.parent.options[key]["type"] == 'boolean':
                try:
                    options[key] = bool(int(value))
                except ValueError:
                    raise backend.InvalidConfigurationValue

        d = self.parent.storage.get_node(node_id)
        d.addCallback(_get_affiliation, requestor)
        d.addCallback(self._do_set_node_configuration, options)
        return d

    def _do_set_node_configuration(self, result, options):
        node, affiliation = result

        if affiliation != 'owner':
            raise backend.Forbidden

        return node.set_configuration(options)

class AffiliationsService(service.Service):

    implements(backend.IAffiliationsService)

    def get_affiliations(self, entity):
        return self.parent.storage.get_affiliations(entity)

class ItemRetrievalService(service.Service):

    implements(backend.IItemRetrievalService)

    def get_items(self, node_id, requestor, max_items=None, item_ids=[]):
        d = self.parent.storage.get_node(node_id)
        d.addCallback(_get_affiliation, requestor)
        d.addCallback(self._do_get_items, max_items, item_ids)
        return d

    def _do_get_items(self, result, max_items, item_ids):
        node, affiliation = result

        if affiliation == 'outcast':
            raise backend.Forbidden

        if item_ids:
            return node.get_items_by_id(item_ids)
        else:
            return node.get_items(max_items)

class RetractionService(service.Service):

    implements(backend.IRetractionService)
                                                                                
    def retract_item(self, node_id, item_ids, requestor):
        d = self.parent.storage.get_node(node_id)
        d.addCallback(_get_affiliation, requestor)
        d.addCallback(self._do_retract, item_ids)
        return d
                                                                                
    def _do_retract(self, result, item_ids):
        node, affiliation = result
        persist_items = node.get_configuration()["pubsub#persist_items"]
                                                                                
        if affiliation not in ['owner', 'publisher']:
            raise backend.Forbidden
                                                                                
        if not persist_items:
            raise backend.NodeNotPersistent
                                                                                
        d = node.remove_items(item_ids)
        d.addCallback(self._do_notify_retraction, node.id)
        return d
                                                                                
    def _do_notify_retraction(self, item_ids, node_id):
        self.parent.dispatch({ 'item_ids': item_ids, 'node_id': node_id },
                             '//event/pubsub/retract')
                                                                                
    def purge_node(self, node_id, requestor):
        d = self.parent.storage.get_node(node_id)
        d.addCallback(_get_affiliation, requestor)
        d.addCallback(self._do_purge)
        return d
    
    def _do_purge(self, result):
        node, affiliation = result
        persist_items = node.get_configuration()["pubsub#persist_items"]
                                                                                
        if affiliation != 'owner':
            raise backend.Forbidden
                                                                                
        if not persist_items:
            raise backend.NodeNotPersistent
                                                                                
        d = node.purge()
        d.addCallback(self._do_notify_purge, node.id)
        return d
    
    def _do_notify_purge(self, result, node_id):
        self.parent.dispatch(node_id, '//event/pubsub/purge')

class NodeDeletionService(service.Service):

    implements(backend.INodeDeletionService)

    def __init__(self):
        self._callback_list = []

    def register_pre_delete(self, pre_delete_fn):
        self._callback_list.append(pre_delete_fn)

    def get_subscribers(self, node_id):
        d = self.parent.storage.get_node(node_id)
        d.addCallback(lambda node: node.get_subscribers())
        return d

    def delete_node(self, node_id, requestor):
        d = self.parent.storage.get_node(node_id)
        d.addCallback(_get_affiliation, requestor)
        d.addCallback(self._do_pre_delete)
        return d
    
    def _do_pre_delete(self, result):
        node, affiliation = result
                                                                                
        if affiliation != 'owner':
            raise backend.Forbidden

        d = defer.DeferredList([cb(node.id) for cb in self._callback_list],
                               consumeErrors=1)
        d.addCallback(self._do_delete, node.id)

    def _do_delete(self, result, node_id):
        dl = []
        for succeeded, r in result:
            if succeeded and r:
                dl.extend(r)

        d = self.parent.storage.delete_node(node_id)
        d.addCallback(self._do_notify_delete, dl)

        return d
    
    def _do_notify_delete(self, result, dl):
        for d in dl:
            d.callback(None)