#!/usr/bin/env bash
# Launch the built Apple IIgs examples in GSplus. GSplus is booted from
# a GS/OS 6.0.4 System disk (toolchains/emulators/support/gsos-system.po)
# with joey.2mg mounted as the data disk on slot 5 drive 2. GS/OS drops
# to Finder; the user navigates to the JOEYLIB volume and double-clicks
# whichever example they want to run.
#
# No argument: GSplus has no way to dispatch a specific binary on boot
# (Finder is interactive), so this script just stages the disk and
# launches the emulator.

set -euo pipefail

if [[ $# -ne 0 ]]; then
    echo "usage: $0" >&2
    echo "       (no arguments -- launch GSplus, pick the demo in Finder)" >&2
    exit 2
fi

repo=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)

gsplus=$repo/toolchains/emulators/gsplus/bin/gsplus
rom=$repo/toolchains/emulators/support/apple-iigs.rom
sys_disk=$repo/toolchains/emulators/support/gsos-system.po
data_disk=$repo/build/iigs/bin/joey.2mg
null_c600=$repo/toolchains/emulators/support/iigs-null-c600.rom

for f in "$gsplus" "$rom" "$sys_disk" "$data_disk" "$null_c600"; do
    if [[ ! -f $f ]]; then
        echo "missing: $f" >&2
        if [[ $f == "$data_disk" ]]; then
            echo "run 'make iigs-disk' to build it." >&2
        else
            echo "run ./toolchains/install.sh (support files should have been staged)." >&2
        fi
        exit 1
    fi
done

# GSplus writes back to disk images during the session; stage writable
# copies so repeated runs do not mutate the originals.
work=$(mktemp -d -t joeylib-iigs.XXXXXX)

cleanup() {
    # Stash the post-run disk image for manual inspection.
    if [[ -f $work/joey.2mg ]]; then
        cp "$work/joey.2mg" "$repo/build/iigs/bin/joey-after-run.2mg"
        echo "run-iigs: saved post-run disk -> $repo/build/iigs/bin/joey-after-run.2mg" >&2
    fi
    rm -rf "$work"
}
trap cleanup EXIT

cp "$sys_disk"  "$work/boot.po"
cp "$data_disk" "$work/joey.2mg"

# Stage the null slot-6 PROM as c600.rom in the work dir. GSplus loads
# any file named c600.rom in its search path (cwd first) as the slot 6
# ROM card, overriding the built-in Disk II firmware. The staged image
# is 256 bytes with a leading RTS and no Pascal 1.1 firmware signature,
# so the IIgs boot ROM's slot scan skips slot 6 and the two empty 5.25
# drives never get probed. Source: toolchains/install.sh's
# install_support_iigs_null_c600.
cp "$null_c600" "$work/c600.rom"

cat <<EOF
GSplus launching GS/OS 6.0.4.
Once Finder is up:
  1. Open the JOEYLIB disk on the desktop.
  2. Double-click whichever demo you want to run.
EOF

# GSplus auto-creates config.kegs in its cwd on first run. cd into
# the scratch dir so that file lands there and gets cleaned up with
# the rest of the temp state, rather than polluting the directory
# the user invoked the script from.
cd "$work"
# GSplus accepts any config.kegs key as a CLI override via "-<key>
# <value>". g_limit_speed=2 caps emulation at the IIgs's native
# 2.8 MHz; without this override GSplus boots at 8 MHz and our
# performance characteristics don't match real hardware. The other
# settings (0=unlimited, 1=1.024 MHz, 3=8 MHz) are reachable through
# the in-emulator speed-cycle key if needed.
#
# No exec: let the bash EXIT trap fire so the scratch dir (and the
# config.kegs GSplus auto-creates) gets cleaned up.
"$gsplus" -rom "$rom" \
    -s5d1 "$work/boot.po" \
    -s5d2 "$work/joey.2mg" \
    -g_limit_speed 2