#!/bin/sh
# SPDX-FileCopyrightText: 2026 Alexander Bates <alex@bates64.com>
#
# SPDX-License-Identifier: 0BSD

# Builds the macOS disk image without macOS, which electron-builder can't:
# an HFS+ volume holding the app, an Applications shortcut, and the
# background, laid out by dmg-layout.py and compressed with LZFSE, like
# electron-builder.yml's ULMO. Run from the cross devshell.
#
#   scripts/make-dmg.sh dist/mac-universal/Diorama64.app dist/Diorama64.dmg

set -eu

here=$(cd "$(dirname "$0")" && pwd)
app=$1
out=$2
name=$(basename "$app" .app)

work=$(mktemp -d)
trap 'rm -rf "$work"' EXIT

mkdir -p "$work/stage/.background"
# One TIFF holding both resolutions, which is how Finder picks the Retina
# one. Each needs its own DPI, or Finder draws the 1x one at half size.
magick "$here/../build/background.png" -units PixelsPerInch -set density 72 \
  \( "$here/../build/background@2x.png" -units PixelsPerInch -set density 144 \) \
  -compress lzw "$work/stage/.background/background.tiff"
cp -a "$app" "$work/stage/"
ln -s /Applications "$work/stage/Applications"

# The volume is fixed-size, so leave room for the filesystem's own data.
size=$(($(du -sm "$work/stage" | cut -f1) * 115 / 100 + 20))
truncate -s "${size}M" "$work/volume.hfs"
mkfs.hfsplus -v "$name" "$work/volume.hfs" >/dev/null
hfsplus "$work/volume.hfs" addall "$work/stage" -s clone_link >/dev/null
python3 "$here/dmg-layout.py" "$work/DS_Store" "$name" "$name.app"
hfsplus "$work/volume.hfs" add "$work/DS_Store" /.DS_Store
dmg build "$work/volume.hfs" "$out" -c lzfse >/dev/null