prolefeeder/config.py.example

import os
import random
import string
from datetime import datetime, timedelta


def random_choices(population, k):
    """Emulate random.choices for Python < 3.6"""
    return [random.choice(population) for _ in range(k)]


def mp3_sources(data_dir, pattern, kbits):
    def start_time_for_source_fn(fn):
        return datetime.strptime(fn, pattern)

    def length_for_source_fn(fn):
        size = os.stat(os.path.join(data_dir, fn)).st_size
        length = timedelta(minutes=size / (1000*kbits/8) / 60)
        return length

    def get_sources():
        # Get a sorted list of all source files with start time and length
        sources = []
        for fn in os.listdir(data_dir):
            try:
                start_time = start_time_for_source_fn(fn)
                length = length_for_source_fn(fn)
                sources.append({'fn': os.path.join(data_dir, fn), 'start_time': start_time, 'length': length})
            except ValueError:
                pass
        return sources

    return get_sources


class Config:
    SECRET_KEY = os.environ.get('SECRET_KEY') or \
            ''.join(random_choices(string.ascii_letters, k=20))
    OUT_DIR    = os.environ.get('OUT_DIR') or '/var/tmp/prolefeeder-test-out'
    MAX_LENGTH = os.environ.get('MAX_LENGTH') or 180

    DEBUG      = False

    if not os.path.exists(OUT_DIR):
        raise RuntimeError("OUT_DIR does not exist")

    # Here's the interesting part: configuring the source.
    #
    # We need to return a function that returns a list of dicts of source files with metadata, e.g.
    # [ {"fn": "/path/to/foo-20:01.mp3", "start_time": datetime(...), "length": timedelta(hours=1)} ]

    data_dir   = os.environ.get('DATA_DIR') or '/var/tmp/prolefeeder-test-data'
    kbits      = os.environ.get('KBITS') or 128
    pattern    = 'qfhi-%Y%m%d-%H%M.mp3'

    if not os.path.exists(data_dir):
        raise RuntimeError("DATA_DIR does not exist")

    SOURCES = mp3_sources(data_dir, pattern, kbits)