"""Device-side ESP-NOW sender (MicroPython, channel 5)."""

import espnow
import network
import ubinascii


CHANNEL = 5
DEST_HEX = "ffffffffffff"
PAYLOAD_HEX = "4c0501000000"


def _set_channel(channel):
    sta = network.WLAN(network.STA_IF)
    sta.active(True)
    sta.config(pm=network.WLAN.PM_NONE)
    sta.config(channel=channel)


def _add_peer(esp, dest, channel):
    try:
        esp.add_peer(dest, channel=channel)
    except TypeError:
        esp.add_peer(dest)
    except OSError:
        pass


def send_once(dest_hex=DEST_HEX, payload_hex=PAYLOAD_HEX, channel=CHANNEL):
    dest = ubinascii.unhexlify(dest_hex)
    pkt = ubinascii.unhexlify(payload_hex)
    _set_channel(channel)
    e = espnow.ESPNow()
    e.active(True)
    _add_peer(e, dest, channel)
    ok = e.send(dest, pkt, True)
    print("sent", ok, "ch", channel, "dest", dest_hex, "len", len(pkt))
    return ok


if __name__ == "__main__":
    send_once()