# shellcheck shell=bash
# 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 joystick gates of the ports that read the host's gamepads
# (SDL3, Win32 under Wine): two virtual Xbox 360 pads
# (tests/gate/virtualPad.c) as sticks A and B, or two generic joysticks
# no gamepad mapping knows. The pads are the whole machine's while they
# exist, so a real pad plugged in here would be seen too: PAD_ONLY_ENV is
# the environment that hides every other pad from SDL, as a gamepad and as
# a raw joystick both (and from Wine's SDL-backed bus driver). Source after
# joyGate.sh.
#
#   padStart WORK [generic]  make the pads, Xbox 360 pads or generic
#                        joysticks, and set PAD_ONLY_ENV to their ids (exit
#                        2 when /dev/uinput cannot be written); again after
#                        padStop for another set
#   padOrder             the host numbers two identical pads in its own
#                        order (Wine does B first): move pad A once with JOY
#                        up, and if JOY shows it as stick B, swap the pads'
#                        roles from then on
#   padStop              remove them
#   joyPress / joyRelease  joyGate.sh's: hold or let go of the controls

PAD_PID=""
PAD_FD=""
PAD_OUT=""
PAD_SENT=0
PAD_SWAP=0
PAD_READY_SECONDS=10
PAD_REPLY_SECONDS=5
# The virtual pads' USB vendor/product (virtualPad's), by kind.
PAD_IDS_XBOX360=0x045e/0x028e
PAD_IDS_GENERIC=0x1209/0x0001
PAD_ONLY_ENV=(SDL_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT=$PAD_IDS_XBOX360)


# padWait COUNT SECONDS -- wait until the pad helper has printed COUNT
# lines of "ok" (or, COUNT 0, "ready").
padWait() {
    local deadline=$((SECONDS + $2))
    while [ "$SECONDS" -lt "$deadline" ]; do
        if [ "$1" = 0 ]; then
            grep -qx ready "$PAD_OUT" 2> /dev/null && return 0
        elif [ "$(grep -cx ok "$PAD_OUT" 2> /dev/null)" -ge "$1" ]; then
            return 0
        fi
        joeyAlive "$PAD_PID" || return 1
        sleep 0.1
    done
    return 1
}


padOrder() {
    local got
    padSend press A-left
    sleep "$JOY_PRESS_SECONDS"
    joyShot "$JOY_WORK/order.png"
    got=$("$(joeyTool joyScreen)" "$JOY_WORK/order.png" "${JOY_SCREEN_ARGS[@]}")
    padSend release A-left
    sleep "$JOY_PRESS_SECONDS"
    case "$got" in
        *"A=1-000"*) PAD_SWAP=0 ;;
        *"B=1-000"*) PAD_SWAP=1 ;;
        *)           joyFail "pad A moved neither stick: $got" ;;
    esac
}


# padSend WORD CONTROL... -- with the pads' roles swapped (PAD_SWAP), stick
# A's controls go to pad B and B's to pad A.
padSend() {
    local words=("$1")
    local control
    shift
    for control in "$@"; do
        if [ "$PAD_SWAP" = 1 ]; then
            case "$control" in
                A-*) control="B-${control#A-}" ;;
                B-*) control="A-${control#B-}" ;;
            esac
        fi
        words+=("$control")
    done
    printf '%s\n' "${words[*]}" >&"$PAD_FD"
    PAD_SENT=$((PAD_SENT + 1))
    padWait "$PAD_SENT" "$PAD_REPLY_SECONDS" || joyFail "the virtual pads did not take: $*"
}


padStart() {
    local fifo="$1/pad.in"
    local kind=()
    local pad
    if [ ! -w /dev/uinput ]; then
        echo "$JOY_LABEL: cannot write /dev/uinput, which the virtual gamepads need (a desktop session's user usually can)" >&2
        exit 2
    fi
    PAD_ONLY_ENV=(SDL_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT=$PAD_IDS_XBOX360)
    if [ "${2:-}" = generic ]; then
        kind=(--generic)
        PAD_ONLY_ENV=(SDL_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT=$PAD_IDS_GENERIC)
    fi
    PAD_OUT="$1/pad.out"
    PAD_SENT=0
    PAD_SWAP=0
    rm -f "$fifo" "$PAD_OUT"
    mkfifo "$fifo"
    pad=$(joeyTool virtualPad) || exit 1
    "$pad" "${kind[@]}" "JoeyLib gate" < "$fifo" > "$PAD_OUT" 2>&1 &
    PAD_PID=$!
    exec {PAD_FD}> "$fifo"
    if ! padWait 0 "$PAD_READY_SECONDS"; then
        echo "$JOY_LABEL: FAIL - the virtual gamepads did not come up: $(cat "$PAD_OUT")" >&2
        exit 1
    fi
}


padStop() {
    [ -n "$PAD_PID" ] || return 0
    { printf 'quit\n' >&"$PAD_FD"; } 2> /dev/null
    exec {PAD_FD}>&-
    wait "$PAD_PID" 2> /dev/null
    PAD_PID=""
}


joyPress() {
    padSend press "$@"
}


joyRelease() {
    padSend release "$@"
}