#!/bin/bash
# SPDX-License-Identifier: BSD-3-Clause
# Copyright (c) 2026 Open-IOV contributors
# gzdoom_pbuf_run.sh - in-guest GZDoom run recipe for the offscreen SDL2
# GLX-pbuffer harness.  Run this inside the guest after push_gl_tools.sh has
# placed the shims in /tmp.  It prints the exact command line, runs GZDoom
# under timeout, and leaves the output in $GZLOG.
#
# Environment (all overridable):
#   GZDOOM_BIN  default /opt/gzdoom/gzdoom
#   WAD         default /usr/share/games/doom/freedoom2.wad
#   GZCAP       default /tmp/gzframes.bin  (sdl_cap.so capture file)
#   GZPBUF_W/H  default 640/480            (gz_pbuf.so pbuffer size)
#   GZLOG       default /tmp/gzdoom-pbuf.log
#   TIMEOUT     default 300 seconds
#   GZ_ARGS     extra GZDoom args appended after the base set
#   GZ_DETACH   default 0; set 1 to setsid/nohup the run and return
#   DISPLAY     default :0
#
# The base args are windowed GL: +set vid_fullscreen 0, 640x480, OpenGL
# backend 0, +vid_rendermode 4 (GL mode), MAP01.  The preload order matters:
# sdl_cap.so first (captures SDL_GL_SwapWindow), gz_pbuf.so second (turns the
# SDL GL context into a GLX pbuffer and the swap into glFinish).
set -u

GZDOOM_BIN="${GZDOOM_BIN:-/opt/gzdoom/gzdoom}"
WAD="${WAD:-/usr/share/games/doom/freedoom2.wad}"
GZCAP="${GZCAP:-/tmp/gzframes.bin}"
GZPBUF_W="${GZPBUF_W:-640}"
GZPBUF_H="${GZPBUF_H:-480}"
GZLOG="${GZLOG:-/tmp/gzdoom-pbuf.log}"
TIMEOUT="${TIMEOUT:-300}"
GZ_ARGS="${GZ_ARGS:-}"
GZ_DETACH="${GZ_DETACH:-0}"
DISPLAY="${DISPLAY:-:0}"
SDL_VIDEODRIVER="${SDL_VIDEODRIVER:-offscreen}"
LD_PRELOAD="${LD_PRELOAD:-/tmp/sdl_cap.so /tmp/gz_pbuf.so}"

export DISPLAY SDL_VIDEODRIVER LD_PRELOAD GZCAP GZPBUF_W GZPBUF_H

if [ ! -x "$GZDOOM_BIN" ]; then
    echo "gzdoom_pbuf_run: GZDOOM_BIN not executable: $GZDOOM_BIN" >&2
    exit 2
fi
if [ ! -f "$WAD" ]; then
    echo "gzdoom_pbuf_run: WAD not found: $WAD" >&2
    exit 2
fi
for so in /tmp/sdl_cap.so /tmp/gz_pbuf.so; do
    if [ ! -f "$so" ]; then
        echo "gzdoom_pbuf_run: shim missing: $so" >&2
        exit 2
    fi
done

CMD=(
    "$GZDOOM_BIN"
    -iwad "$WAD"
    +set vid_fullscreen 0
    +set vid_defwidth "$GZPBUF_W"
    +set vid_defheight "$GZPBUF_H"
    +set vid_preferbackend 0
    +vid_rendermode 4
    -nosound
    -nomusic
    +vid_activeinbackground 1
    +vid_maxfps 60
    +map MAP01
)
if [ -n "$GZ_ARGS" ]; then
    read -r -a GZ_EXTRA <<< "$GZ_ARGS"
    CMD+=("${GZ_EXTRA[@]}")
fi

echo "gzdoom_pbuf_run: DISPLAY=$DISPLAY SDL_VIDEODRIVER=$SDL_VIDEODRIVER"
echo "gzdoom_pbuf_run: LD_PRELOAD=$LD_PRELOAD"
echo "gzdoom_pbuf_run: GZCAP=$GZCAP GZPBUF_W=$GZPBUF_W GZPBUF_H=$GZPBUF_H"
echo "gzdoom_pbuf_run: LOG=$GZLOG TIMEOUT=$TIMEOUT DETACH=$GZ_DETACH"
printf 'CMD:'
printf ' %q' "${CMD[@]}"
echo

if [ "$GZ_DETACH" = "1" ]; then
    setsid nohup timeout "$TIMEOUT" "${CMD[@]}" > "$GZLOG" 2>&1 < /dev/null &
    echo "PID=$!"
    echo "LOG=$GZLOG"
    exit 0
fi

timeout "$TIMEOUT" "${CMD[@]}" > "$GZLOG" 2>&1
rc=$?
echo "RC=$rc"
echo "LOG=$GZLOG"
exit "$rc"