#!/usr/bin/env python3
# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

"""
radiorec.py – Recording internet radio streams
Copyright (C) 2013  Martin Brodbeck <martin@brodbeck-online.de>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

import argparse
import configparser
import datetime
import os
import stat
import sys
import threading
import urllib.request

def check_duration(value):
    try:
        value = int(value)
    except ValueError:
        raise argparse.ArgumentTypeError('Duration must be a positive integer.')

    if value < 1:
        raise argparse.ArgumentTypeError('Duration must be a positive integer.')
    else:
        return value

def read_settings():
    settings_base_dir = ''
    if sys.platform == 'linux':
        settings_base_dir = os.getenv('HOME') + os.sep + '.config' + os.sep + 'radiorec'
    elif sys.platform == 'win32':
        settings_base_dir = os.getenv('LOCALAPPDATA') + os.sep + 'radiorec'
    settings_base_dir += os.sep
    config = configparser.ConfigParser()
    config.read(settings_base_dir + 'settings.ini')
    return dict(config.items())

def record_worker(stoprec, streamurl, target_dir, args):
    conn = urllib.request.urlopen(streamurl)
    cur_dt_string = datetime.datetime.now().strftime('%Y-%m-%dT%H_%M_%S')
    filename = target_dir + os.sep + cur_dt_string + "_" + args.station
    if args.name:
        filename += '_' + args.name
    content_type = conn.getheader('Content-Type')
    if(content_type == 'audio/mpeg'):
        filename += '.mp3'
    elif(content_type == 'application/ogg' or content_type == 'audio/ogg'):
        filename += '.ogg'
    elif(content_type == 'audio/x-mpegurl'):
        print('Sorry, M3U playlists are currently not supported')
        sys.exit()
    else:
        print('Unknown content type "' + content_type + '". Assuming mp3.')
        filename += 'mp3'

    with open(filename, "wb") as target:
        if args.public:
            verboseprint('Apply public write permissions (Linux only)')
            os.chmod(filename, stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IWGRP |
                     stat.S_IROTH | stat.S_IWOTH)
        verboseprint('Recording ' + args.station + '...')
        while(not stoprec.is_set() and not conn.closed):
            target.write(conn.read(1024))

def record(args):
    settings = read_settings()
    streamurl = ''
    global verboseprint
    verboseprint = print if args.verbose else lambda *a, **k: None

    try:
        streamurl = settings['STATIONS'][args.station]
    except KeyError:
        print('Unkown station name: ' + args.station)
        sys.exit()
    if streamurl.endswith('.m3u'):
        verboseprint('Seems to be an M3U playlist. Trying to parse...')
        with urllib.request.urlopen(streamurl) as remotefile:
            for line in remotefile:
                if not line.decode('utf-8').startswith('#'):
                    tmpstr = line.decode('utf-8')
                    break
        streamurl = tmpstr
    verboseprint('stream url: ' + streamurl)
    target_dir = os.path.expandvars(settings['GLOBAL']['target_dir'])
    stoprec = threading.Event()

    recthread = threading.Thread(target = record_worker, 
                        args = (stoprec, streamurl, target_dir, args), daemon = True)
    recthread.start()
    recthread.join(args.duration * 60)

    if(recthread.is_alive):
        stoprec.set()

def list(args):
    settings = read_settings()
    for key in sorted(settings['STATIONS']):
        print(key)

def main():
    parser = argparse.ArgumentParser(description='This program records internet radio streams. '
                                    'It is free software and comes with ABSOLUTELY NO WARRANTY.')
    subparsers = parser.add_subparsers(help='sub-command help')
    parser_record = subparsers.add_parser('record', help='Record a station')
    parser_record.add_argument('station', type=str, help='Name of the radio station '
                                               '(see config file for a list)')
    parser_record.add_argument('duration', type=check_duration, 
                        help='Recording time in minutes')
    parser_record.add_argument('name', nargs='?', type=str, 
                        help='A name for the recording')
    parser_record.add_argument('-p', '--public', action='store_true', help="Public write permissions (Linux only)")
    parser_record.add_argument('-v', '--verbose', action='store_true', help="Verbose output")
    parser_record.set_defaults(func=record)
    parser_list = subparsers.add_parser('list', help='List all known stations')
    parser_list.set_defaults(func=list)

    args = parser.parse_args()
    args.func(args)

if __name__ == '__main__':
    main()