#!/usr/bin/env python
#coding=utf8

import logging
import socket
from copy import copy
from sjrpc.server import SimpleSslRpcServer
from handlers import WelcomeHandler
from conf import CCConf
from client import CCClient
from exceptions import AlreadyRegistered, NotConnectedAccountError
from orderedset import OrderedSet
from tql import TqlParser, TqlObject
from objectsdb import ObjectsDB


class CCServer(object):
    '''
    CloudControl server main class.

    :param conf_dir: the directory that store the client configuration
    :param certfile: the path to the ssl certificate
    :param keyfile: the path to the ssl key
    :param address: the interface to bind
    :param port: the port to bind
    '''

    LISTEN_BACKLOG = 5

    # These tags are reserved and cannot be setted by an user:
    RESERVED_TAGS = ('id', 'a', 'r', 'close', 'con', 'ip')

    def __init__(self, conf_dir, certfile=None, keyfile=None,
                 address='0.0.0.0', port=1984):

        # Dict containing all connected accounts, the key is the login of
        # the account and the value the :class:`RpcConnection` of the peer:
        self._connected = {}

        # The interface object to the configuration directory:
        self.conf = CCConf(conf_dir)

        # Create the server socket
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        sock.bind((address, port))
        sock.listen(CCServer.LISTEN_BACKLOG)

        if certfile:
            logging.info('SSL Certificate: %s' % certfile)
        if keyfile:
            logging.info('SSL Key: %s' % certfile)

        logging.info('Started to listen on %s port %s' % (address, port))

        self.objects = ObjectsDB(self)

        # Create the connection manager:
        self.manager = SimpleSslRpcServer(sock, certfile=certfile,
                                          keyfile=keyfile,
                                          default_handler=WelcomeHandler(self),
                                          on_disconnect='on_disconnect')

        # Register accounts on the database:
        self._update_accounts()

    def _update_accounts(self):
        '''
        Update the database with accounts.
        '''

        db_accounts = self.objects.get_ids()
        accounts = set(self.conf.list_accounts())

        to_register = accounts - db_accounts
        to_unregister = db_accounts - accounts

        for login in to_register:
            conf = self.conf.show(login)
            obj = TqlObject(id=login, r=conf['role'], a=login)
            self.objects.register(obj)

        for login in to_unregister:
            self.objects.unregister(login)

    def iter_connected_role(self, role=None):
        '''
        Generator to iter on each connected client with specified role. If role
        is None, return all connected clients.

        :param role: role to filter
        '''

        for login, client in self._connected.iteritems():
            if role is None or client.role == role:
                yield client

    def register(self, login, role, connection):
        '''
        Register a new connected account on the server.

        :param login: login of the account
        :param connection: connection to register
        :param tags: tags to add for the client
        '''

        if login in self._connected:
            raise AlreadyRegistered('A client is already connected with this '
                                    'account.')
        else:
            self._connected[login] = CCClient(login, role, self, connection)

    def unregister(self, connection):
        '''
        Unregister an already connected account.

        :param connection: the connection of the client to unregister
        '''
        
        client = self.search_client_by_connection(connection)
        if client.login in self._connected:
            del self._connected[client.login]
        self.objects.unregister_children(client.login)

    def sub_register(self, parent, name, role):
        '''
        Register a new node supervised by a parent.

        :param parent: the parent login of the subnode
        :param login: the name of the subnode
        :param role: the role of the subnode
        '''

        obj_parent = self.objects.get_by_id(parent)
        oid = '%s.%s' % (parent, name)
        obj = TqlObject(id=oid, r=role, __parent=obj_parent)
        self.objects.register(obj)

    def sub_unregister(self, parent, name):
        '''
        Unregister a node supervised by a parent.

        :param parent: the parent of the subnode
        :param login: the name of the subnode
        '''

        oid = '%s.%s' % (parent, name)
        self.objects.unregister(oid)

    def search_client_by_connection(self, connection):
        '''
        Search a connected client by it connection. If no client is found,
        return None.

        :param connection: the connection of the client to search
        :return: the found client or None
        '''

        for client in self._connected.values():
            if client.connection is connection:
                return client
        else:
            return None

    def run(self):
        '''
        Run the server mainloop.
        '''

        logging.info('Running manager mainloop')
        self.manager.run()

    def get_connection(self, login):
        '''
        Get the connection of a connecter account login.

        :param login: login of the connection to get
        :return: :class:`RpcConnection` instance of the peer connection
        '''

        return self._connected[login]

    def kill(self, login):
        '''
        Disconnect from the server the client identified by provided login.

        :param login: the login of the user to disconnect
        :throws NotConnectedAccount: when provided account is not connected (or
            if account doesn't exists).
        '''

        client = self._connected.get(login)
        if client is None:
            raise NotConnectedAccountError('The account %s is not '
                                           'connected' % login)
        client.shutdown()

    def list(self, query, show=set()):
        '''
        List objects on the server.

        :param query: the TQL to use to selection objects on list.
        '''

        self._update_accounts()

        parser = TqlParser(query)
        ast, to_show, to_get = parser.parse()

        to_show += show
        to_check = set()

        # Calculate the tags to get/check/show:
        if '*' in to_show:
            to_get = None

        deny = set()

        for tag in copy(to_show):
            if tag == '*':
                to_show = None
                deny.clear()
            elif tag.startswith('-'):
                tag = tag[1:]
                if to_show is None:
                    deny.add(tag)
                elif tag in to_show:
                    to_show.remove(tag)

        if to_get is not None:
            to_get -= set(self.RESERVED_TAGS)
            to_check = to_get & deny
            to_get -= to_check

        objects = OrderedSet(self.objects.all(to_get, to_check))
        if ast is not None:
            objects, _ = ast.eval(objects, objects)
        objects_dicts = []
        for obj in objects:
            objects_dicts.append(obj.to_dict(to_show, deny=deny))

        return objects_dicts