import re
import select
import sys

import evdev # https://github.com/gvalkov/python-evdev
import pulsectl # https://github.com/mk-fg/python-pulse-control


# NOTE: adapted from evdev/evtest.py
def select_mouse(key_code:int = -1) -> evdev.InputDevice:
    def devicenum(device_path):
        digits = re.findall(r"\d+$", device_path)
        return [int(i) for i in digits]

    devices = sorted(evdev.list_devices('/dev/input'), key=devicenum)
    devices = [evdev.InputDevice(path) for path in devices]
    if not devices:
        msg = "error: no input devices found (do you have rw permission on %s/*?)"
        print(msg % device_dir, file=sys.stderr)
        return None

    for i, dev in enumerate(devices):
        print("{}: {}".format(i, dev.name))

    selection = input("select mouse device: ")
    try:
        if int(selection) > len(devices):
            return None
    except (TypeError, ValueError):
        print("invalid comparison")
        return None

    dev_caps = devices[int(selection)].capabilities()

    if (evdev.ecodes.EV_KEY not in dev_caps or
        key_code not in dev_caps[evdev.ecodes.EV_KEY]):
        print("this device doesn't have a BTN_SIDE")
        return None

    return devices[int(selection)]

def parse_event(e:evdev.InputEvent, listen_key:int) -> int:
    if e.type == evdev.ecodes.EV_KEY:
        if e.code == listen_key:
            return e.value

    return -1

def select_source() -> pulsectl.PulseSourceInfo:
    with pulsectl.Pulse() as pulse:
        source_list = pulse.source_list()

        for i, source in enumerate(source_list):
            print("{}: {}".format(i, source.description))

        selection = input("select sount input device: ")
        try:
            if int(selection) > i:
                return None
        except (TypeError, ValueError):
            print("invalid comparison")
            return None

    return source_list[int(selection)]


if __name__ == '__main__':
    # TODO: capture initial mute state

    # TODO: select other devices/buttons
    key_code = evdev.ecodes.BTN_SIDE
    device = select_mouse(key_code)

    if device == None:
        print("error selecting device")
        # FIXME: restore initial mute state here too
        sys.exit(1)

    source = select_source()

    if source is None:
        print("error selecting pulse source")
        # FIXME: restore initial mute state here too
        sys.exit(1)

    pulse = pulsectl.Pulse()

    # NOTE: listen for the BTN_SIDE event
    # TODO: an option to play a sound on mute/unmute here would be nice too:
    #   https://github.com/hamiltron/py-simple-audio

    try:
        print("Listening for events (press ctrl-c to exit) ...")
        pulse = pulsectl.Pulse()
        pulse.source_list()

        while True:
            for event in device.read_loop():
                ret = parse_event(event, key_code)
                if ret == 0:
                    pulse.mute(source, True)
                elif ret == 1:
                    pulse.mute(source, False)
                else:
                    pass
    except (KeyboardInterrupt, EOFError):
        pass

    # TODO: restore initial mute state


    sys.exit(0)