#!/usr/bin/env python3
# Copyright 2018 Mycroft AI Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from select import select
from sys import stdin
from termios import tcsetattr, tcgetattr, TCSADRAIN

import pyaudio
import tty
import wave
from os.path import isfile
from prettyparse import create_parser

usage = '''
    Record audio samples for use with precise
    
    :-w --width int 2
        Sample width of audio
    
    :-r --rate int 16000
        Sample rate of audio
    
    :-c --channels int 1
        Number of audio channels
'''


def key_pressed():
    return select([stdin], [], [], 0) == ([stdin], [], [])


def termios_wrapper(main):
    global orig_settings
    orig_settings = tcgetattr(stdin)
    try:
        hide_input()
        main()
    finally:
        tcsetattr(stdin, TCSADRAIN, orig_settings)


def show_input():
    tcsetattr(stdin, TCSADRAIN, orig_settings)


def hide_input():
    tty.setcbreak(stdin.fileno())


orig_settings = None

RECORD_KEY = ' '
EXIT_KEY_CODE = 27


def record_until(p, should_return, args):
    chunk_size = 1024
    stream = p.open(format=p.get_format_from_width(args.width), channels=args.channels,
                    rate=args.rate, input=True, frames_per_buffer=chunk_size)

    frames = []
    while not should_return():
        frames.append(stream.read(chunk_size))

    stream.stop_stream()
    stream.close()

    return b''.join(frames)


def save_audio(name, data, args):
    wf = wave.open(name, 'wb')
    wf.setnchannels(args.channels)
    wf.setsampwidth(args.width)
    wf.setframerate(args.rate)
    wf.writeframes(data)
    wf.close()


def next_name(name):
    name += '.wav'
    pos, num_digits = None, None
    try:
        pos = name.index('#')
        num_digits = name.count('#')
    except ValueError:
        print("Name must contain at least one # to indicate where to put the number.")
        raise

    def get_name(i):
        nonlocal name, pos
        return name[:pos] + str(i).zfill(num_digits) + name[pos + num_digits:]

    i = 0
    while True:
        if not isfile(get_name(i)):
            break
        i += 1

    return get_name(i)


def wait_to_continue():
    while True:
        c = stdin.read(1)
        if c == RECORD_KEY:
            return True
        elif ord(c) == EXIT_KEY_CODE:
            return False


def record_until_key(p, args):
    def should_return():
        return key_pressed() and stdin.read(1) == RECORD_KEY

    return record_until(p, should_return, args)


def _main():
    parser = create_parser(usage)
    parser.add_argument('file_label', nargs='?', help='File label (Ex. recording-##)')
    args = parser.parse_args()
    show_input()
    args.file_label = args.file_label or input("File label (Ex. recording-##): ")
    args.file_label = args.file_label + ('' if '#' in args.file_label else '-##')
    hide_input()

    p = pyaudio.PyAudio()

    while True:
        print('Press space to record (esc to exit)...')

        if not wait_to_continue():
            break

        print('Recording...')
        d = record_until_key(p, args)
        name = next_name(args.file_label)
        save_audio(name, d, args)
        print('Saved as ' + name)

    p.terminate()


def main():
    termios_wrapper(_main)


if __name__ == '__main__':
    main()