#!/usr/bin/perl
use v5.14;

my ($name, $format);

sub pick_one {
    my $x=1;
    chomp @_;
    map {say "$x. $_[$x-1]"; $x++} @_;
    my $answer;
    while ($answer !~ /^\d+$/) {
        print "? ";
        $answer = <STDIN>;
    }
    return $answer;
}

sub usage {
    my @path = split '/', $0;
    say "$path[-1] <twitch-username>";
    exit(1);
}

sub get_format {
    my @formats = `twitch-formats $name`;
    say "Pick a format: ";
    return @formats[pick_one(@formats)-1];
}
$name = $ARGV[0];
not $name and $name = $ENV{"TWITCH_LOGIN"};
not $name and usage();

my $format = $ARGV[1];
not $format and $format = get_format();
say $format;

my $url = "https://twitch.tv/$name";
exec "mpv --ytdl-format=\"$format\" \"$url\""