# Part of JoeyLib, Copyright (c) 2026 Scott Duensing, under the MIT License.
# See LICENSE.md for license information.
# SPDX-License-Identifier: MIT
#
# Shared by the Win16 gates (scripts/bench-win16.sh, scripts/verify-win16-*.sh)
# and joey-run: run a Win16 program (make win16) on Windows for Workgroups
# 3.11 under DOSBox Staging (scripts/dosbox-win16.conf), headless on a
# private Xvfb display (or, WIN16_HEADLESS=0, in a window on $DISPLAY).
# Windows is a copy of the installer's (component win311, WIN16_C) made for
# the run, so a run never changes it; the program's folder is drive D:, so
# what it writes lands there, and it is Windows' shell, so Windows ends (and
# DOSBox with it) when the program does. The copy runs JoeyLib's own drivers:
# KPJOY.DRV (component kpjoy, KPJOY_DRV), the joystick driver Windows 3.1
# lacks, and KPCOMM.DRV (component kpcomm, KPCOMM_DRV) in place of its
# COMM.DRV. Source after joeyEnv.sh.
#
#   win16Need                   exit 2 unless Windows, its drivers and DOSBox
#                               are installed
#   win16Stage WORK FOLDER EXE [ARGS...]
#                               WORK/c: a copy of Windows whose shell is EXE
#                               in FOLDER (drive D:), given ARGS (WIN.COM
#                               hands its command line to the shell; a shell=
#                               line with arguments is not loaded at all),
#                               with JoeyLib's drivers
#   win16Start WORK [NAME=VALUE...]
#                               boot it in the background, the NAME=VALUEs in
#                               the DOS environment Windows starts from (the
#                               port's JOEYLIB_SCALE and the like); sets
#                               WIN16_DISPLAY, WIN16_GUARD (the timeout
#                               wrapper, which is DOSBox itself when
#                               WIN16_WALL=0: no cap) and WIN16_PID (DOSBox).
#                               Sound is off unless WIN16_SOUND=1 (then SDL
#                               plays it, through SDL_AUDIODRIVER if set);
#                               WIN16_DOSBOX_ARGS are more DOSBox arguments
#                               (--set serial1=...)
#   win16Log FOLDER             print the program's joeylog in FOLDER, if any
#                               (a DOS program makes it JOEYLOG.TXT)
#   win16Window                 print DOSBox's X window
#   win16Stop                   stop DOSBox and the display
#
# Win16 code only ever runs on DOSBox's emulated CPU: running it natively
# (the 32-bit Wine's winevdm) crashed the host's kernel.

WIN16_DISPLAY=""
WIN16_GUARD=""
WIN16_PID=""
WIN16_XVFB_PID=""
WIN16_FOLDER=""
WIN16_ARGS=""
WIN16_HEADLESS="${WIN16_HEADLESS:-1}"
WIN16_SOUND="${WIN16_SOUND:-0}"
WIN16_DOSBOX_ARGS=()
# A hard cap on DOSBox in seconds, whatever happens to the script that
# started it; 0 for none.
WIN16_WALL="${WIN16_WALL:-900}"


win16Need() {
    joeyNeed DOSBOX dosbox
    joeyNeed WIN16_C emulator:win16
    joeyNeed KPJOY_DRV kpjoy
    joeyNeed KPCOMM_DRV kpcomm
}


win16Stage() {
    local work="$1"
    WIN16_FOLDER="$2"
    WIN16_ARGS="${*:4}"
    rm -rf "${work:?}/c"
    mkdir -p "$work"
    cp -r "$WIN16_C" "$work/c"
    cp "$KPJOY_DRV" "$work/c/WINDOWS/SYSTEM/KPJOY.DRV"
    cp "$KPCOMM_DRV" "$work/c/WINDOWS/SYSTEM/KPCOMM.DRV"
    python3 "$JOEY_REPO/tools/winIni.py" "$work/c/WINDOWS/SYSTEM.INI" \
        set boot    shell    "D:\\$3" \
        set boot    comm.drv kpcomm.drv \
        set drivers joystick kpjoy.drv
}


win16Start() {
    local work="$1"
    local assign
    local envArgs=()
    local soundArgs=(--set "nosound=true")
    local procEnv=(XDG_CONFIG_HOME="$work/xdg" SDL_AUDIODRIVER=dummy)
    local wrapper=()
    shift
    for assign in "$@"; do
        envArgs+=(-c "SET $assign")
    done
    if [ "$WIN16_SOUND" = "1" ]; then
        soundArgs=()
        procEnv=(XDG_CONFIG_HOME="$work/xdg")
    fi
    [ "$WIN16_WALL" = "0" ] || wrapper=(timeout -s KILL "$WIN16_WALL")
    mkdir -p "$work/xdg"
    if [ "$WIN16_HEADLESS" = "1" ]; then
        # A second boot in the same WORK (the save gate's) must not read the
        # last display's number before the new Xvfb has written its own.
        rm -f "$work/display"
        Xvfb -displayfd 3 -screen 0 1024x768x24 -nolisten tcp 3> "$work/display" > /dev/null 2>&1 &
        WIN16_XVFB_PID=$!
        for _ in 1 2 3 4 5 6 7 8 9 10; do
            [ -s "$work/display" ] && break
            sleep 0.5
        done
        WIN16_DISPLAY=":$(cat "$work/display")"
    else
        WIN16_DISPLAY="$DISPLAY"
    fi
    env "${procEnv[@]}" DISPLAY="$WIN16_DISPLAY" "${wrapper[@]}" "$DOSBOX" "${JOEY_DOSBOX_ISOLATE[@]}" \
        --conf "$JOEY_REPO/scripts/dosbox-win16.conf" "${soundArgs[@]}" "${WIN16_DOSBOX_ARGS[@]}" \
        -c "MOUNT C \"$work/c\"" -c "MOUNT D \"$WIN16_FOLDER\"" "${envArgs[@]}" \
        -c "C:" -c 'CD \WINDOWS' -c "WIN${WIN16_ARGS:+ $WIN16_ARGS}" -c "EXIT" > "$work/dosbox.log" 2>&1 &
    WIN16_GUARD=$!
    if [ ${#wrapper[@]} -eq 0 ]; then
        WIN16_PID=$WIN16_GUARD
    else
        WIN16_PID="$(joeyChild "$WIN16_GUARD")"
    fi
}


win16Log() {
    find "$1" -maxdepth 1 -iname joeylog.txt -print -quit 2> /dev/null
}


win16Window() {
    joeyFindWindow "$WIN16_DISPLAY" "$WIN16_PID"
}


win16Stop() {
    joeyStop "$WIN16_PID" "$WIN16_GUARD" "$WIN16_XVFB_PID" 2> /dev/null
    WIN16_PID=""
    WIN16_GUARD=""
    WIN16_XVFB_PID=""
}