#!/usr/bin/env python3

import struct
import itertools
import binascii
import string
import serial
import time
import zlib

from cobs import cobs

if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser()
    parser.add_argument('port')
    parser.add_argument('-b', '--baudrate', type=int, default=115200)
    args = parser.parse_args()

    ser = serial.Serial(args.port, args.baudrate, timeout=0)

    byte_count = 0
    line = b''
    packet = b''
    start_time = time.time()
    seq = 0

    make_color = lambda x: f'\033[38;5;{x}m'
    field_colors = [ make_color(x) for x in [ 48, 48, 48, 48, 220, 220, 220, 220, 207, 207, 207, 207 ] ]
    last_tx = time.time()
    lastc = -10000
    while True:
        data = ser.read()
        for c in data:
            #if byte_count == 0:
                #print(f'\033[38;5;244m{time.time() - start_time: 8.3f} \033[0m', end='')

            col = '\033[91m' if c == 0 else '\033[0m' # if c == (lastc - 1) % 256 else '\033[92m')
            #print(f'{col}{c:02x}', end=' ')
            line += bytes([c])
            byte_count += 1
            if c == 0:
                #print('   ' * (16 - byte_count), end='\033[0m\n')
                byte_count =  16
                try:
                    payload = cobs.decode(packet)
                    if len(payload) > 4:
                        crc = zlib.crc32(payload[:-4])
                        ref_crc = struct.pack('<I', crc)
                        crc_ok = (crc,) == struct.unpack('<I', payload[-4:])
                    else:
                        crc_ok = False
                        ref_crc = ''
                    if len(payload) == 12:
                        print(' '.join(f'{col if col else ""}{c if c else 0:02x}' for col, c in itertools.zip_longest(field_colors,
                        payload)), 'OK' if crc_ok else f'WRONG')
                except cobs.DecodeError:
                    print('COBS framing error')
                packet = b''
            else:
                packet += bytes([c])
            isprint = lambda c: c in b'0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~ '
            if byte_count == 16:
                printable = ''.join( chr(c) if isprint(c) else '.' for c in line )
                #print(f'\033[93m | {printable}\033[0m')
                byte_count = 0
                line = b''
            lastc = c


        if time.time() - last_tx > 0.01:
            seq = int((time.time() - start_time) * 10)
            data = struct.pack('<I', seq)
            #seq += 1
            #ser.write(bytes(list(range(255, -1, -1))))
            ser.write(cobs.encode(data + struct.pack('<I', zlib.crc32(data))) + b'\0')
            last_tx = time.time()
        #time.sleep(0.01)