#

# Copyright 2005,2006 Free Software Foundation, Inc.

# 

# This file is part of GNU Radio

# 

# GNU Radio 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, or (at your option)

# any later version.

# 

# GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to

# the Free Software Foundation, Inc., 51 Franklin Street,

# Boston, MA 02110-1301, USA.

# 

from math import pi

import Numeric

from gnuradio import gr, packet_utils

import gnuradio.gr.gr_threading as _threading

# /////////////////////////////////////////////////////////////////////////////

#                   mod/demod with packets as i/o

# /////////////////////////////////////////////////////////////////////////////

class mod_pkts(gr.hier_block):

    """

    Wrap an arbitrary digital modulator in our packet handling framework.

    Send packets by calling send_pkt

    """

    def __init__(self, fg, modulator, access_code=None, msgq_limit=2, pad_for_usrp=True):

        """

        Hierarchical block for sending packets

        Packets to be sent are enqueued by calling send_pkt.

        The output is the complex modulated signal at baseband.

        @param fg: flow graph

        @type fg: flow graph

        @param modulator: instance of modulator class (gr_block or hier_block)

        @type modulator: complex baseband out

        @param access_code: AKA sync vector

        @type access_code: string of 1's and 0's between 1 and 64 long

        @param msgq_limit: maximum number of messages in message queue

        @type msgq_limit: int

        @param pad_for_usrp: If true, packets are padded such that they end up a multiple of 128 samples

        See gmsk_mod for remaining parameters

        """

        self._modulator = modulator

        self._pad_for_usrp = pad_for_usrp

        if access_code is None:

            access_code = packet_utils.default_access_code

        if not packet_utils.is_1_0_string(access_code):

            raise ValueError, "Invalid access_code %r. Must be string of 1's and 0's" % (access_code,)

        self._access_code = access_code

        # accepts messages from the outside world

        self._pkt_input = gr.message_source(gr.sizeof_char, msgq_limit)

        fg.connect(self._pkt_input, self._modulator)

        gr.hier_block.__init__(self, fg, None, self._modulator)

    def send_pkt(self, payload='', eof=False):

        """

        Send the payload.

        @param payload: data to send

        @type payload: string

        """

        if eof:

            msg = gr.message(1) # tell self._pkt_input we're not sending any more packets

        else:

            # print "original_payload =", string_to_hex_list(payload)

            pkt = packet_utils.make_packet(payload,

                                           self._modulator.samples_per_symbol(),

                                           self._modulator.bits_per_symbol(),

                                           self._access_code,

                                           self._pad_for_usrp)

            #print "pkt =", string_to_hex_list(pkt)

            msg = gr.message_from_string(pkt)

        self._pkt_input.msgq().insert_tail(msg)

class demod_pkts(gr.hier_block):

    """

    Wrap an arbitrary digital demodulator in our packet handling framework.

    The input is complex baseband.  When packets are demodulated, they are passed to the

    app via the callback.

    """

    def __init__(self, fg, demodulator, access_code=None, callback=None, threshold=-1):

        """

        Hierarchical block for demodulating and deframing packets.

        The input is the complex modulated signal at baseband.

        Demodulated packets are sent to the handler.

        @param fg: flow graph

        @type fg: flow graph

        @param demodulator: instance of demodulator class (gr_block or hier_block)

        @type demodulator: complex baseband in

        @param access_code: AKA sync vector

        @type access_code: string of 1's and 0's

        @param callback:  function of two args: ok, payload

        @type callback: ok: bool; payload: string

        @param threshold: detect access_code with up to threshold bits wrong (-1 -> use default)

        @type threshold: int

        """

        self._demodulator = demodulator

        if access_code is None:

            access_code = packet_utils.default_access_code

        if not packet_utils.is_1_0_string(access_code):

            raise ValueError, "Invalid access_code %r. Must be string of 1's and 0's" % (access_code,)

        self._access_code = access_code

        if threshold == -1:

            threshold = 12              # FIXME raise exception

        self._rcvd_pktq = gr.msg_queue()          # holds packets from the PHY

        self.correlator = gr.correlate_access_code_bb(access_code, threshold)

        self.framer_sink = gr.framer_sink_1(self._rcvd_pktq)

        fg.connect(self._demodulator, self.correlator, self.framer_sink)

        gr.hier_block.__init__(self, fg, self._demodulator, None)

        self._watcher = _queue_watcher_thread(self._rcvd_pktq, callback)

class _queue_watcher_thread(_threading.Thread):

    def __init__(self, rcvd_pktq, callback):

        _threading.Thread.__init__(self)

        self.setDaemon(1)

        self.rcvd_pktq = rcvd_pktq

        self.callback = callback

        self.keep_running = True

        self.start()

    def run(self):

        while self.keep_running:

            msg = self.rcvd_pktq.delete_head()

            ok, payload = packet_utils.unmake_packet(msg.to_string())

            if self.callback:

                self.callback(ok, payload)