"""Display for manual WSPR transmission."""

from encode import wspr_encode

import datetime
import time

def display(symbols, output=False):
    assert len(symbols) == 162, len(symbols)
    baud = 1.4648
    while True:
        dt = datetime.datetime.utcnow()
        # t is the offset from the start of the message
        t = (dt.minute % 2) * 60 + dt.second + 1e-6*dt.microsecond - 1
        n = int(t * baud)
        current = '_' if n < 0 or n >= 162 else symbols[n]
        bit0 = int(isinstance(current, int) and current % 2 == 1)
        bit1 = int(isinstance(current, int) and current >= 2)
        # Display a # if the resistors coming from the VCO voltage should be
        # grounded. Left = bit0, right = bit1.
        display = (' ' if bit0 else '#') + '    ' + (' ' if bit1 else '#')
        print(f"\033[H\033[J{n:3d}     {display}", flush=True)
        delay = (n+1)/baud - t
        time.sleep(delay)


if __name__ == '__main__':
    import sys
    if len(sys.argv) != 4:
        print('Usage: %s callsign locator dbm' % sys.argv[0])
        sys.exit(1)
    callsign = sys.argv[1]
    locator = sys.argv[2]
    dbm = int(sys.argv[3])
    symbols = wspr_encode(callsign, locator, dbm)
    display(symbols, output=True)