#!/usr/bin/env nix-shell
#!nix-shell -i bash -p bash ffmpeg
#shellcheck shell=bash
set -euo pipefail

if [[ $# -ne 2 ]]; then
	echo "usage: $0 /path/to/necrodancer /path/to/output"
	exit 1
fi

# Original songs named zone<zone>_<level>.ogg
# Remixes named zone<zone>_<level>_<remix>.ogg
# I think remix IDs are:
# (none): Danny Baranowsky
# 1: A_Rival
# 2: Jules Conroy
# 3: virt
# 4: Girlfriend Records
# 5: OverClocked
# 6: Masafumi Takada
# chp: Chipzel

music="$1/data/music"
sounds="$1/data/sounds_streaming"

for zone in {1..4}; do
	if [[ $zone -eq 3 ]]; then
		suffixes=( "c" "h" )
	else
		suffixes=( "" )
	fi
	for level in {1..3}; do
		for remix in "" _1 _2 _3 _4 _6 _chp; do
			for suffix in "${suffixes[@]}"; do
				ffmpeg -y \
					-i "$music/zone${zone}_${level}${remix}${suffix}.ogg" \
					-i "$sounds/zone${zone}_${level}${suffix}_shopkeeper.ogg" \
					-filter_complex amix=inputs=2:duration=longest \
					-b:a 128k \
					"$2/zone${zone}_${level}${remix}${suffix}_complete.opus"
			done
		done
	done
done