#!/usr/bin/bash

# This creates a "power hour" playlist.
#
# It expects an ordered playlist as a directory of 60 mp3 files. (If you're
# still using PowerAmp, you can get this by exporting a PowerAmp backup that
# includes playlists, and then running `poweramp-extract-playlist` on it.)
#
# This will then slice off the first minute of each of those 60 songs and
# concatenate it with LMFAO's "Shots Shots Shots" chorus. (This actually makes
# the power hour 7-8 minutes longer than 60 minutes... This probably matters.
# But I'm old. I'll take the extra breather.) It will write the resulting mp3
# to the destination directory given. Finally, this will also copy the victory
# song from Tecmo Super Bowl as the final 61st song to the destination
# directory.
#
# Back in the old days, I used to use an Android app for this. But I've long
# since been able to find any such app. I'd guess the lawyers at Google decided
# adults shouldn't be playing drinking games. Fuck that.

set -e

usage() {
  echo "Usage: $(basename "$0") <source-playlist-dir> <dest-directory>"
}

src="$1"
dst="$2"
tecmo="/m/media/music/active/powerhour/tecmo/tecmo.mp3"
shots="/m/media/music/active/powerhour/shots/shots.mp3"
log="/m/log/powerhour-ffmpeg.log"
trunc="$(mktemp -d)"
for mp3 in "$src"/*.mp3; do
  base="$(basename "$mp3")"
  if [ -f "$dst/$base" ]; then
    echo "skipping $mp3" >&2
    continue
  fi
  video-slice --accurate 00:00:00 00:01:00 "$mp3" "$trunc/$base" &> "$log"
  ffmpeg -i "concat:$trunc/$base|$shots" -acodec copy "$dst/$base" &> "$log"
  echo "finished $base" >&2
done
cp -a "$tecmo" "$dst/61 - tecmo.mp3"