#!/usr/bin/python

from __future__ import with_statement

import sys
import wave
import alsaaudio

def pcm(wav, card='default', period=320):
    pcm = alsaaudio.PCM(card=card)
    pcm.setchannels(wav.getnchannels())
    pcm.setrate(wav.getframerate())
    pcm.setformat([
        None,
        alsaaudio.PCM_FORMAT_U8,
        alsaaudio.PCM_FORMAT_S16_LE,
        alsaaudio.PCM_FORMAT_S24_LE,
        alsaaudio.PCM_FORMAT_S32_LE,
        ][wav.getsampwidth()])

    pcm.setperiodsize(period)
    return pcm

def play(dev, wav, n=1, period=320):
    data = wav.readframes(period)
    if not data:
        wav.rewind()
        data = wav.readframes(period)

    c = 0
    while data:
        dev.write(data)
        data = wav.readframes(period)
        c = c + 1
        if c > n: break

def narg(n, default):
    try:
        return sys.argv[n]
    except IndexError:
        return default

def main():
    '''
    Usage:
        sudo typewriter.py <wavfile> <eventdev> <alsacard>

    Example:
        sudo typewriter.py ./rain.wav /dev/input/event11 default

    Defaults:
        <eventdev> = /dev/console
        <alsacard> = default
    '''
    wavfile = sys.argv[1]
    eventdev = narg(2, '/dev/console')
    alsacard = narg(3, 'default')

    wav = wave.open(wavfile, 'r')
    dev = pcm(wav, alsacard)
    with open(eventdev, 'r') as kbd:
        while True:
            kbd.read(30)
            play(dev, wav, 2)
            #print "hit!"

if __name__ == '__main__':
    main()