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

import logging
import socket
from sjrpc.server import SimpleSslRpcServer
from handlers import WelcomeHandler
from conf import CCConf
from client import CCClient

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

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

    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
        '''
        
        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]

    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 resolve_tags(self, login, requested_tags=None):
        '''
        Try to resolve all provided tags for the specified account.
        '''

        tags = {}
        conf = self.conf.show(login)
        tags['a'] = login
        tags['id'] = login
        tags['role'] = conf['role']

        if login in self._connected:
            client = self._connected[login]
            try:
                tags.update(client.connection.call('get_tags',
                                                   tuple(requested_tags)))
            except Exception as err:
                logging.error('Error while calling get_tags on '
                              '%s: %s' % (client.login, err))
            else:
                tags['status'] = 'online'
        else:
            tags['status'] = 'offline'

        # Apply all user specified tags:
        tags.update(conf['tags'])

        # Also add user specified tags in a special field for vm inheritance
        # (only useful for hypervisors)
        tags['__static_user'] = conf['tags']

        return tags