import numpy as np

from gnuradio import gr, gr_unittest, blocks
import pmt


class signal_sink(gr.sync_block):
    def __init__(self):
        gr.sync_block.__init__(self, name="sink", in_sig=[np.float32], out_sig=None)

        self.signal = pmt.from_bool(False)
        self.port_name = pmt.intern("sig")
        self.message_port_register_out(self.port_name)

    def work(self, input_items, output_items):
        #self.message_port_pub(self.port_name, self.signal)
        return len(input_items[0])


class qa_msg_passing(gr_unittest.TestCase):
    def setUp(self):
        self.tb = gr.top_block()

    def tearDown(self):
        self.tb = None

    def test_copy(self):
        src_data = np.arange(1000)
        src = blocks.vector_source_f(src_data)
        copy = blocks.copy(gr.sizeof_float)
        msg_debug = blocks.message_debug()
        sig_sink = signal_sink()

        self.tb.connect(src, copy, sig_sink)
        self.tb.msg_connect(sig_sink, "sig", copy, "en")           # This causes problems
        #self.tb.msg_connect(sig_sink, "sig", msg_debug, "print")  # This does not

        # Run once (this run is successful)

        self.tb.run()

        # Run again (this run hangs)

        src.rewind()
        self.tb.start()
        print("Debug: 2nd top_block run started...")
        self.tb.wait()
        print("Debug: 2nd top_block run exited...")


if __name__ == '__main__':
    #import os
    #print("Blocked waiting for GDB attach (pid = {})".format(os.getpid()))
    #raw_input("Press Enter to continue...")
    gr_unittest.run(qa_msg_passing)