catprint/cheshire.py

import argparse
import asyncio
import os
import socket
import sys
import time


import bleak

CAT_NAME = 'GB03'
CAT_SERVICE = '0000ae30-0000-1000-8000-00805f9b34fb'
CAT_CHARAC = '0000ae01-0000-1000-8000-00805f9b34fb'

DEFAULT_SOCKET = '/tmp/catprint.s'


async def getcat():
    devices = await bleak.BleakScanner.discover()
    for d in devices:
        print(f'- {d.name}')
        if d.name == CAT_NAME:
            return d
    return None


async def getcharac(client):
    await client.get_services()
    for service in client.services:
        if service.uuid != CAT_SERVICE:
            continue
        for charac in service.characteristics:
            if charac.uuid != CAT_CHARAC:
                continue
            return charac
    return None
    

async def endprint(client):
    pass


CHECKSUM_TABLE = [0, 7, 14, 9, 28, 27, 18, 21, 56, 63, 54, 49, 36, 35, 42, 45,
        112, 119, 126, 121, 108, 107, 98, 101, 72, 79, 70, 65, 84, 83, 90, 93,
        224, 231, 238, 233, 252, 251, 242, 245, 216, 223, 214, 209, 196, 195,
        202, 205, 144, 151, 158, 153, 140, 139, 130, 133, 168, 175, 166, 161,
        180, 179, 186, 189, 199, 192, 201, 206, 219, 220, 213, 210, 255, 248,
        241, 246, 227, 228, 237, 234, 183, 176, 185, 190, 171, 172, 165, 162,
        143, 136, 129, 134, 147, 148, 157, 154, 39, 32, 41, 46, 59, 60, 53, 50,
        31, 24, 17, 22, 3, 4, 13, 10, 87, 80, 89, 94, 75, 76, 69, 66, 111, 104,
        97, 102, 115, 116, 125, 122, 137, 142, 135, 128, 149, 146, 155, 156,
        177, 182, 191, 184, 173, 170, 163, 164, 249, 254, 247, 240, 229, 226,
        235, 236, 193, 198, 207, 200, 221, 218, 211, 212, 105, 110, 103, 96,
        117, 114, 123, 124, 81, 86, 95, 88, 77, 74, 67, 68, 25, 30, 23, 16, 5,
        2, 11, 12, 33, 38, 47, 40, 61, 58, 51, 52, 78, 73, 64, 71, 82, 85, 92,
        91, 118, 113, 120, 127, 106, 109, 100, 99, 62, 57, 48, 55, 34, 37, 44,
        43, 6, 1, 8, 15, 26, 29, 20, 19, 174, 169, 160, 167, 178, 181, 188,
        187, 150, 145, 152, 159, 138, 141, 132, 131, 222, 217, 208, 215, 194,
        197, 204, 203, 230, 225, 232, 239, 250, 253, 244, 243]


def checksum(data):
    cs = 0
    for d in data:
        cs = CHECKSUM_TABLE[cs ^ d]
    return cs


def packet(command, payload):
    return bytes([
        0x51, 0x78,  # magic
        command,
        0,  # always 0
        len(payload),
        0,  # always 0
        ]) + bytes(payload) + bytes([checksum(payload), 0xff])


async def startprint(client):
    await client.write_gatt_char(CAT_CHARAC, packet(0xbe, [0]))
    await asyncio.sleep(0.05)
    await client.write_gatt_char(CAT_CHARAC, packet(0xaf, [0xff, 0xff]))
    await asyncio.sleep(0.05)


sent = [0]


async def scanline(client, data):
    if sent[0] == 15:
        sent[0] = 0
        response = True
    else:
        sent[0] += 1
        response = False
    response = False
    await client.write_gatt_char(CAT_CHARAC, packet(0xa2, data), response)
    #await client.write_gatt_char(CAT_CHARAC, packet(0xa1, [1, 0]))
    await asyncio.sleep(0.05)


async def feedpaper(client, lines=120):
    await client.write_gatt_char(CAT_CHARAC, packet(0xa1, [lines, 0]))
    await asyncio.sleep(0.02 * lines)


def parse_args():
    parser = argparse.ArgumentParser(description='Print stuff on a cat.')
    parser.add_argument('--address', help='address of the printer')
    parser.add_argument('--socket', dest='socket_path',
            help='socket of the daemon',
            default=DEFAULT_SOCKET)

    return parser.parse_args()


async def main(address=None, socket_path=None):
    if address is None:
        while True:
            device = await getcat()
            if device is None:
                print('No cat printer found :(')
                time.sleep(1)
                continue
            print('Cat printer found!')
            print(f'{device.address}')
            address = device.address
            break

    while True:
        client = bleak.BleakClient(address)
        await client.connect()
        if client is not None:
            print('connected!')
            break
        else:
            print('could not connect')
            time.sleep(1)

    await startprint(client)

    if os.path.exists(socket_path):
        os.remove(socket_path)

    server = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
    server.bind(socket_path)
    while True:
        datagram, addr = server.recvfrom(1024)
        cmd = datagram[0]
        print(f'got stuff from {addr}: {cmd}')
        start = time.time()
        if cmd == ord('f'):  # feed
            await feedpaper(client)
        elif cmd == ord('s'):  # scan
            data = datagram[1:]
            await scanline(client, data)
        else:
            continue
        print(f'done in {time.time() - start} s')
        server.sendto(b'done', addr)


if __name__ == "__main__":
    asyncio.run(main(**vars(parse_args())))