#!/usr/bin/env python3
"""Фоновый логгер ЧСС с BLE HR-датчика (стандарт 0x180D / 0x2A37, напр. Coospo H808S).
Пишет строки 'epoch,bpm' в указанный файл, пока процесс не убьют. Авто-переподключение
при обрыве. Спаривание не требуется.

Использование: python3 tools/hr_log.py <BLE-addr> <logfile>
"""
import asyncio, sys, time
from bleak import BleakClient, BleakScanner

ADDR = sys.argv[1]
LOG = sys.argv[2]
HR_CHR = "00002a37-0000-1000-8000-00805f9b34fb"


def make_cb(logf):
    def cb(_, data: bytearray):
        flags = data[0]
        bpm = int.from_bytes(data[1:3], "little") if flags & 1 else data[1]
        logf.write(f"{time.time():.1f},{bpm}\n")
        logf.flush()
    return cb


async def main():
    logf = open(LOG, "a")
    logf.write(f"# {time.time():.1f} start addr={ADDR}\n")
    logf.flush()
    while True:
        try:
            dev = await BleakScanner.find_device_by_address(ADDR, timeout=15.0)
            if dev is None:
                logf.write(f"# {time.time():.1f} not_found, retry\n")
                logf.flush()
                await asyncio.sleep(3)
                continue
            async with BleakClient(dev) as cli:
                logf.write(f"# {time.time():.1f} connected\n")
                logf.flush()
                await cli.start_notify(HR_CHR, make_cb(logf))
                while cli.is_connected:
                    await asyncio.sleep(1)
            logf.write(f"# {time.time():.1f} disconnected, reconnect\n")
            logf.flush()
        except Exception as e:
            logf.write(f"# {time.time():.1f} err {e}\n")
            logf.flush()
            await asyncio.sleep(3)


asyncio.run(main())