#!/bin/bash
#
# Title: YTDL List Downloader
# Author: TheOuterLinux (https://theouterlinux.gitlab.io)
# Purpose: To make it easier to download a bunch of videos from 
#          youtube-dl supported websites 
#          (https://ytdl-org.github.io/youtube-dl/supportedsites.html).
# License: GPLv3 or newer
# Last updated: 2021/02/15
if [ "$1" = "" ] || [ "$1" = "--help" ] || [ "$1" = "-h" ] || [ "$1" = "/?" ] || [ ! -f "$1" ]
then
    echo '''
Usage:
    
    ytlist "/path/to/existing/list.txt" [number of connections, ex: 10]
    
    **Please make sure to change to the directory you would like to
      download your videos to before running. If axel is not installed
      and/or no [number of connections] is supplied, just youtube-dl is
      used to grab videos.
         '''
else
    if [ "$2" = "" ] || [ "$2" = "1" ] || [ "$2" = "0" ]
    then
        echo ""
        echo "Using youtube-dl to grab videos..."
        echo ""
        while read URL; do
            youtube-dl "$URL"
        done <"$1"
    else
        if ! [[ $2 == ?(-)+([0-9]) ]]
        then
             echo '''
Usage:
    
ytlist "/path/to/list.txt" [number of connections, ex: 10]
    
    **The second argument you supplied, aka [number of connections],
      must be an integer such as "10" without quotations, for example.
         '''
        else
            if [ -f "/usr/bin/axel" ]
            then
                echo ""
                echo "Using youtube-dl and axel -n $2 to grab videos..."
                echo ""
                while read URL; do
                    youtube-dl --external-downloader /usr/bin/axel --external-downloader-args '-n 10' "$URL"
                done <"$1"
            else
                echo ""
                echo "Using youtube-dl to grab videos..."
                echo ""
                while read URL; do
                    youtube-dl "$URL"
                done <"$1"
            fi
        fi
    fi
fi