#!/usr/bin/python3
"""Gradual alarm clock, without daylight savings time support.

This alarm wakes you up gradually, ramping up the volume from 0% to
103% over the course of several minutes, then up to 130% after that.
It spawns off mpv to actually play the music as many times as is
necessary to wake you up.

Quitting mpv will not stop the alarm; you will have to kill it with ^C
in the window where you launched it or something similar.

"""
import argparse
import contextlib
import os
import subprocess
import socket
import sys
import time

# I was going to port this to Python 2, but the lack of things like
# FileExistsError made me decide it wasn’t worth it.


def parse_args():
    formatter = argparse.RawDescriptionHelpFormatter
    p = argparse.ArgumentParser(description=__doc__, formatter_class=formatter)
    p.add_argument('-d', '--duration', type=float, default=10*60,
                   help='duration of gradual wakeup in seconds (default %(default)s)')
    p.add_argument('-m', '--max-post-time', type=float, default=10*60,
                   help=('maximum time to keep playing at full volume or above ' +
                         'before giving up (default %(default)s)'))
    default_time = '10:00'
    p.add_argument('-t', '--time', type=time_of_day,
                   default=time_of_day(default_time),
                   help='time of day for the alarm (default {})'.format(default_time))
    p.add_argument('music', nargs='+', type=song_filename,
                   help='filenames of music to play for the alarm')
    return p.parse_args()


def song_filename(s):
    if not os.path.exists(s):
        raise ValueError(s)
    return s


def time_of_day(s):
    hh, mm = map(int, s.split(':'))
    if not 0 <= hh <= 23 or not 0 <= mm <= 59:
        raise ValueError(s)
    return (hh * 60 + mm) * 60


def wait_until(desired_tod):
    now = time.localtime(time.time())
    tod = (now.tm_hour * 60 + now.tm_min) * 60 + now.tm_sec
    delay = desired_tod - tod
    if -660 < delay <= 0:  # XXX this will screw up on times just after midnight
        return
    # XXX note that this is the wrong thing in time zones with
    # daylight savings time
    delay %= 86400
    print('Alarm will begin sounding in {}h{}m'.format(int(delay // 3600),
                                                       int(delay // 60 % 60)))
    time.sleep(delay)


def play_music(music, quit, volume_func, sockname):
    kid = subprocess.Popen(['mpv',
                            '--volume=0',
                            '--input-ipc-server={}'.format(sockname)]
                           + music)
    cmd = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    while True:
        try:
            cmd.connect(sockname)
            break
        except (ConnectionRefusedError, FileNotFoundError):
            time.sleep(0.2)

    def do(line):
        cmd.send((line + '\n').encode('utf-8'))

    do('set volume 0')

    while True:
        if kid.poll() is None:
            if quit():
                # Time to quit!
                do('quit')      # Hope this works!
                sys.exit(0)

            # We used to do a whole dance with the `volume` audio
            # filter here, sending `af set volume=10` and the like to
            # raise the volume by 10dB, with a limit of 60.  More
            # recent versions of mpv (I’m using 0.35.1) have changed
            # the interface in two ways:
            #
            # 1. The volume setting is now, like, a multiplier applied
            # to the standard volume, or something?  Instead of
            # decibels.  DANGEROUS!  Fortunately I didn’t blow any
            # speakers this time.
            #
            # 2. The normal volume now goes up to 130, which is
            # probably plenty to wake me up.
            vol = min(130, volume_func())

            # Sending on a closed socket raises BrokenPipeError.
            with contextlib.suppress(BrokenPipeError):
                do('set volume {}'.format(vol))

            time.sleep(0.2)
        else:
            with contextlib.suppress(BrokenPipeError):
                cmd.close()
            break


def main():
    args = parse_args()
    subprocess.check_output(['mpv', '-help'])  # Verify mpv is installed
    wait_until(args.time - args.duration)

    start = time.time()
    vol = lambda: round((time.time() - start)/args.duration * 100)
    quit = lambda: time.time() - start > args.max_post_time + args.duration
    try:
        while True:
            play_music(args.music, quit, vol, 'tmp.sock')
    finally:
        os.system('stty sane')
        os.unlink('tmp.sock')


if __name__ == '__main__':
    main()