from urllib.parse import urlparse, quote
from pathlib import Path
import os.path
import os
import configparser
import subprocess
import datetime
import time
import sys

def read_config():
    config = configparser.RawConfigParser()
    config.read("config.ini")
    return config

def get_mixes(mixes_dir):
    mixes = []
    for path in Path(mixes_dir).rglob('url.txt'):
        with open(path, "r") as fd:
            first_line = fd.readline()
            first_line = first_line.strip()
            url = quote(urlparse(first_line).geturl(), safe=":/") # do a sanity url parse and quote
        mixes.append((path.parent, url))
    return mixes

def download_channel(target_directory, channel_url, options="", update_mpd=False, mpd_root=""):
    mpd_update_options = []
    if update_mpd:
        mpd_update_options = ["--exec", "mpc update \"{}\"".format(str(target_directory).replace(mpd_root, "", 1).lstrip("/"))]
    p = subprocess.Popen(["youtube-dl", *options.split(" "), *mpd_update_options, channel_url], cwd=target_directory)
    p.wait()

def lock_downloader():
    if os.path.isfile("lockfile"):
        return False
    else:
        with open("lockfile", "w") as fd:
            print("Creating lockfile")
            timestamp = int(datetime.datetime.now().timestamp())
            fd.write(str(timestamp) + "\n")
        return True

def unlock_downloader():
    os.remove("lockfile")


lock_success = lock_downloader()
if not lock_success:
    with open("lockfile", "r") as fd:
        timestamp = fd.readline().strip()
    time = datetime.datetime.fromtimestamp(int(timestamp))
    print("Downloader already running. It was started at {}".format(time))
    sys.exit(1)

config = read_config()
mixes = get_mixes(config["general"]["mixes_dir"])
for folder,url in mixes:
    download_channel(folder, url, config["youtube-dl"]["options"], update_mpd=config["mpd"]["update"], mpd_root=config["mpd"]["mpd_root"])
print("Download operation finished. Releasing lockfile now.")
unlock_downloader()