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

import ssl
import time
import socket
import select
import logging
from sjrpc.core import RpcConnection, ConnectionManager

class SimpleRpcServer(ConnectionManager):
    '''
    A simple RPC Server that wait for new connections and dispatch messages
    from thoses are already established.
    
    :param sock: the :class:`socket` object to bind to the server connection
    :param default_handler: the default handler to bind to the new client 
        connections
    '''
    
    def __init__(self, sock, default_handler=None, on_disconnect=None):
        super(SimpleRpcServer, self).__init__()
        sock.setblocking(False)
        self._listening_sock = sock
        self._poll.register(sock)
        self._clients = {}
        self._default_handler = default_handler
        self._on_disconnect = on_disconnect

    def _accept_connection(self):
        return self._listening_sock.accept()
        
    def register(self, connection):
        super(SimpleRpcServer, self).register(connection)
        self._clients[connection.get_fd()] = connection
    
    def shutdown(self):
        super(SimpleRpcServer, self).shutdown()
        time.sleep(ConnectionManager.POLL_TIMEOUT)
        for connection in self._clients.values():
            connection.shutdown(self._on_disconnect)
        self._listening_sock.close()

    def shutdown_client(self, fd):
        conn = self._clients.get(fd)
        try:
            self._poll.unregister(fd)
        except IOError:
            pass
        if fd is not None:
            try:
                del self._clients[fd]
            except KeyError:
                pass
            if conn is not None:
                conn.shutdown(callback=self._on_disconnect)

    def all_connections(self):
        return set(self._clients.values())

    def handle_event(self, fd, event):
        if fd == self._listening_sock.fileno():
            # Event concerns the listening socket:
            if event & select.EPOLLIN:
                accepted = self._accept_connection()
                if accepted is not None:
                    sock, address = accepted
                    sock.setblocking(False)
                    connection = RpcConnection(sock, self, 
                                               handler=self._default_handler)
                    self.register(connection)
        else:
            # Event concerns a client socket:
            connection = self._clients[fd]
            
            if event & select.EPOLLIN:
                # Data are ready to be readed on socket
                try:
                    connection.receive()
                except socket.error as err:
                    logging.error('Socket error while receiving from client '
                                  'fd/%s: %s' % (fd, err))
                    self.shutdown_client(fd)
                except Exception as err:
                    logging.error('Unknown error while receiving from client '
                                  'fd/%s: %s' % (fd, err))
                    self.shutdown_client(fd)
                
            if event & select.EPOLLOUT:
                # Data are ready to be written on socket
                try:
                    connection.send()
                except socket.error as err:
                    logging.error('Socket error while sending to the client '
                                  'fd/%s: %s' % (fd, err))
                    self.shutdown_client(fd)
                except Exception as err:
                    logging.error('Unknown error while sending to the client '
                                  'fd/%s: %s' % (fd, err))
                    self.shutdown_client(fd)

            if event & select.EPOLLHUP:
                logging.error('Socket HUP fd/%s: %s' % (fd, err))
                self.shutdown_client(fd)


class SimpleSslRpcServer(SimpleRpcServer):
    '''
    A simple RPC Server that wait for new connections and dispatch messages
    from thoses are already established. This server version enable SSL on
    client sockets.
    
    :param sock: the :class:`socket` object to bind to the server connection
    :param default_handler: the default handler to bind to the new client 
        connections
    '''

    def __init__(self, sock, certfile=None, keyfile=None, **kwargs):
        self._certfile = certfile
        self._keyfile = keyfile
        super(SimpleSslRpcServer, self).__init__(sock, **kwargs)

    def _accept_connection(self):
        sock, address = self._listening_sock.accept()
        try:
            sslsock = ssl.wrap_socket(sock, server_side=True,
                                      keyfile=self._keyfile,
                                      certfile=self._certfile,
                                      ssl_version=ssl.PROTOCOL_TLSv1,
                                      do_handshake_on_connect=True)
        except ssl.SSLError as err:
            logging.error('Error when accepting ssl connection: %s' % err)
        else:
            return sslsock, address