asterisk-misc/ring_mon/apply-state

#!/usr/bin/env python3
"""
This script handles phone ringing and provide led notifications, blinking with different patterns.

It will handle multiple devices.

For maximum configurability without writing crazy configuration file, most things can be "plugged" as
commands.
To get the status of a device, it will just invoke a program. Write your code there (a simple SQL query?
reading a file? rasterisk?) and return one of ring/up/onair/off

The state is then applied running another command. Write your script, and make it do HTTP requests, mqtt set,
directly control a GPIO... you know it.

It does not provide any integration with inotify. However, it will behave nicely if you send it a SIGHUP, so
you can just run your favourite inotify-like tool (entr, watchman, you name it) and send it a SIGHUP every
time you need it.
"""

import logging
import os
import signal
import sys
import time
from argparse import ArgumentParser
from multiprocessing import Pipe, Process
from pathlib import Path
from subprocess import CalledProcessError, Popen, check_output


def rotate(lst: list, n: int) -> list:
    return lst[n:] + lst[:n]


# all waveforms must have the same length
WAVEFORMS = {
    "ring": ([True] * 4 + [False] * 4) * 5,
    "up": ([True] * 1 + [False] * 9) * 4,
    "onair": [True] * 40,
    "off": [False] * 40,
}
assert len({len(waveform) for waveform in WAVEFORMS.values()}) == 1
for wf_name in list(WAVEFORMS.keys()):
    WAVEFORMS[wf_name] = rotate(WAVEFORMS[wf_name], -2)


class LightManager:
    """Handles a single light."""

    def __init__(self, args, tick_duration_s=0.1, device_name="1", device_number=0):
        self.args = args
        self.waveforms = WAVEFORMS
        self.tick_duration_s = tick_duration_s
        self.device_name = device_name
        self.device_number = device_number

        self.log = logging.getLogger(
            "%s-%s" % (self.__class__.__name__, self.device_name)
        )

        self.stop_pipe_r, self.stop_pipe_w = Pipe(False)

    def set_light(self, on: bool):
        self.log.debug("set %s", on)
        env = os.environ.copy()
        env["DEVICE_NUMBER"] = str(self.device_number)

        p = Popen(
            [str(self.args.bin_set_light.resolve()), "on" if on else "off"], env=env
        )
        p.communicate()

    def do_waveform(self, status) -> tuple:
        last_set = None
        self.log.debug("status=%s", status)
        sys.stderr.flush()
        waveform = self.waveforms[status]
        for i, elem in enumerate(waveform):
            # if i % 10 == 0:
            #     print("  ", i, end="")
            #     sys.stdout.flush()
            if last_set != elem:
                self.set_light(elem)
                last_set = elem
            if self.stop_pipe_r.poll():
                reason = self.stop_pipe_r.recv()
                return reason
            time.sleep(self.tick_duration_s)
        return ("ok", None)

    def get_status(self) -> str:
        try:
            status = check_output(
                [str(self.args.bin_state.resolve()), self.device_name]
            )
        except CalledProcessError:
            status = "off"

        status = status.lower().strip()
        if status not in self.waveforms:
            return "off"
        return status

    def run(self):
        status = self.get_status()
        while True:
            # this will do a complete waveform, unless data is written to stop_pipe_w; in which case, it will
            # return early
            reason, _ = self.do_waveform(status)
            if self.args.enable_polling or reason != "ok":
                status = self.get_status()

    def refresh(self, reason=("refresh", None)):
        self.stop_pipe_w.send(reason)


EXE_DIR = Path(sys.argv[0]).parent

MANAGERS = {}
DEVICES = []


def on_sighup(signal, *args):
    global MANAGERS
    for dev in MANAGERS:
        print("refreshing", dev)
        MANAGERS[dev]["manager"].refresh(("signal", signal))


def parse_devices(s: str) -> list:
    return s.split(",")


def main():
    global MANAGERS
    global DEVICES

    p = ArgumentParser()
    p.add_argument("--devices", type=parse_devices, default="1")
    p.add_argument("--bin-state", type=Path, default=(EXE_DIR / "get-status"))
    p.add_argument("--bin-set-light", type=Path, default=(EXE_DIR / "set-light"))
    p.add_argument(
        "--disable-polling", dest="enable_polling", default=True, action="store_false"
    )
    p.add_argument(
        "--log-level",
        choices=["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"],
        default="INFO",
    )
    args = p.parse_args()

    logging.basicConfig(level=args.log_level)

    DEVICES += args.devices
    signal.signal(signal.SIGHUP, on_sighup)
    for i, dev in enumerate(DEVICES):
        m = LightManager(args, device_name=dev, device_number=i)
        MANAGERS[dev] = {"manager": m}
        Process(target=m.run).start()


if __name__ == "__main__":
    main()