#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
#     ||          ____  _ __
#  +------+      / __ )(_) /_______________ _____  ___
#  | 0xBC |     / __  / / __/ ___/ ___/ __ `/_  / / _ \
#  +------+    / /_/ / / /_/ /__/ /  / /_/ / / /_/  __/
#   ||  ||    /_____/_/\__/\___/_/   \__,_/ /___/\___/
#
#  Copyright (C) 2011-2013 Bitcraze AB
#
#  Crazyflie Nano Quadcopter Client
#
#  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 2
#  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, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA  02110-1301, USA.

""" CRTP UDP Driver. Work either with the UDP server or with an UDP device
See udpserver.py for the protocol"""

__author__ = 'Bitcraze AB'
__all__ = ['UdpDriver']


from .crtpdriver import CRTPDriver
from .crtpstack import CRTPPacket
from .exceptions import WrongUriType
import Queue
import re
import struct
from socket import socket


class UdpDriver(CRTPDriver):
    def __init__(self):
        None

    def connect(self, uri, linkQualityCallback, linkErrorCallback):
        #check if the URI is a radio URI
        if not re.search("^udp://", uri):
            raise WrongUriType("Not an UDP URI")

        self.queue = Queue.Queue()
        self.socket = socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.addr = ("localhost", 7777)
        self.socket.connect(self.addr)

        #Add this to the server clients list
        self.socket.sendto("\xFF\x01\x01\x01", self.addr)

    def receive_packet(self, time=0):
        data, addr = self.socket.recvfrom(1024)

        if data:
            data = struct.unpack('b' * (len(data) - 1), data[0:len(data) - 1])
            pk = CRTPPacket()
            pk.port = data[0]
            pk.data = data[1:]
            return pk

        try:
            if time == 0:
                return self.rxqueue.get(False)
            elif time < 0:
                while True:
                    return self.rxqueue.get(True, 10)
            else:
                return self.rxqueue.get(True, time)
        except Queue.Empty:
            return None

    def send_packet(self, pk):
        raw = (pk.port,) + struct.unpack("B"* len(pk.data), pk.data)

        cksum = 0
        for i in raw:
            cksum += i

        cksum %= 256

        data = ''.join(chr(v) for v in (raw + (cksum,)))

        #print tuple(data)
        self.socket.sendto(data, self.addr)

    def close(self):
        #Remove this from the server clients list
        self.socket.sendto("\xFF\x01\x02\x02", self.addr)

    def get_name(self):
        return "udp"

    def scan_interface(self, address):
        return []
