# 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 that run in DOSBox Staging (DOS, DVX,
# Win16): how a stick is moved and how JOY is photographed there. DOSBox's
# joysticktype 4axis puts four axes and four buttons on the game port with
# no host joystick, which a two-stick reader takes as sticks A (axes 0-1,
# buttons 0-1) and B (axes 2-3, buttons 2-3), as a Y cable gives them. A
# mapper file binds a host key to each line and xdotool holds the keys; the
# raw screenshot is on a key of its own (F11), so no Ctrl reaches the
# program. The mapper replaces every DOSBox binding: only these keys and
# Escape reach the machine. Source after joyGate.sh.
#
#   dosboxJoyMapper FILE        write the mapper file
#   dosboxJoyTap NAME           press and let go of a key of the table
#                               (escape, shot)
#   joyPress / joyRelease       joyGate.sh's: hold the controls' keys
#   joyShot PNG                 joyGate.sh's: the raw screenshot as PNG
#
# The gate sets DOSBOX_JOY_DISPLAY and DOSBOX_JOY_WINDOW (DOSBox's X
# display and window) and DOSBOX_JOY_SHOTS (its capture_dir).

DOSBOX_JOY_DISPLAY=""
DOSBOX_JOY_WINDOW=""
DOSBOX_JOY_SHOTS=""
DOSBOX_JOY_SHOT_SECONDS=5       # the screenshot key until DOSBox has written the file
DOSBOX_JOY_TAP_SECONDS=0.3

# Control or name, its host key (xdotool's name), the key's SDL scancode and
# the DOSBox mapper event it drives.
DOSBOX_JOY_KEYS=(
    "A-left j 13 jaxis_0_0-"     "A-right l 15 jaxis_0_0+"
    "A-up i 12 jaxis_0_1-"       "A-down k 14 jaxis_0_1+"
    "A-button0 a 4 jbutton_0_0"  "A-button1 s 22 jbutton_0_1"
    "B-left f 9 jaxis_0_2-"      "B-right h 11 jaxis_0_2+"
    "B-up t 23 jaxis_0_3-"       "B-down g 10 jaxis_0_3+"
    "B-button0 q 20 jbutton_0_2" "B-button1 w 26 jbutton_0_3"
    "shot F11 68 hand_rawshot"
    "escape Escape 41 key_esc"
)


# dosboxJoyKey NAME -- the host key for a control or name of the table.
dosboxJoyKey() {
    local entry
    local name
    local key
    for entry in "${DOSBOX_JOY_KEYS[@]}"; do
        read -r name key _ <<< "$entry"
        if [ "$name" = "$1" ]; then
            printf '%s\n' "$key"
            return 0
        fi
    done
    return 1
}


dosboxJoyMapper() {
    local entry
    local key
    local code
    local event
    for entry in "${DOSBOX_JOY_KEYS[@]}"; do
        read -r _ key code event <<< "$entry"
        printf '%s "key %s"\n' "$event" "$code"
    done > "$1"
}


dosboxJoyTap() {
    local key
    key=$(dosboxJoyKey "$1") || return 1
    DISPLAY="$DOSBOX_JOY_DISPLAY" xdotool keydown --window "$DOSBOX_JOY_WINDOW" "$key"
    sleep "$DOSBOX_JOY_TAP_SECONDS"
    # A key that ends the program (escape) can take DOSBox's window with it.
    DISPLAY="$DOSBOX_JOY_DISPLAY" xdotool keyup --window "$DOSBOX_JOY_WINDOW" "$key" 2> /dev/null || true
}


# dosboxJoyHold keydown|keyup CONTROL...
dosboxJoyHold() {
    local action="$1"
    local control
    local key
    shift
    for control in "$@"; do
        key=$(dosboxJoyKey "$control") || { joyFail "no key for $control"; continue; }
        DISPLAY="$DOSBOX_JOY_DISPLAY" xdotool "$action" --window "$DOSBOX_JOY_WINDOW" "$key"
    done
}


joyPress() {
    dosboxJoyHold keydown "$@"
}


joyRelease() {
    dosboxJoyHold keyup "$@"
}


# DOSBox makes the file before it writes it: it is done when it has bytes
# and one more poll adds none.
joyShot() {
    local before
    local found
    local size=""
    local deadline
    before=$(find "$DOSBOX_JOY_SHOTS" -name '*.png' | wc -l)
    dosboxJoyTap shot
    deadline=$((SECONDS + DOSBOX_JOY_SHOT_SECONDS))
    while [ "$SECONDS" -lt "$deadline" ]; do
        sleep 0.2
        [ "$(find "$DOSBOX_JOY_SHOTS" -name '*.png' | wc -l)" -gt "$before" ] || continue
        found=$(ls -t "$DOSBOX_JOY_SHOTS"/*.png | head -1)
        [ -s "$found" ] || continue
        if [ "$(stat -c %s "$found")" = "$size" ]; then
            mv "$found" "$1"
            return 0
        fi
        size=$(stat -c %s "$found")
    done
    return 1
}