#!/usr/bin/env bash
# Part of JoeyLib, Copyright (c) 2026 Scott Duensing, under the MIT License.
# See LICENSE.md for license information.
# SPDX-License-Identifier: MIT
#
# verify-dos-input.sh - Headless typed-character acceptance gate for the
# DOS port. Runs KEYS.EXE in DOSBox Staging under Xvfb, types the
# RetroNet definition-of-done string with xdotool (real X key events,
# shift and all, so ':' exercises the INT 9 shift path), takes a RAW
# native-resolution screenshot, and decodes the example's verification
# scanline (row 198) from the exact VGA DAC colors. KEYS gives all 16
# palette entries distinct colors precisely so this decode is exact.
# Then the named keys a second key gives (scripts/lib/keysGate.sh): the
# keypad's arrows and Enter, and the right Ctrl and Alt (the INT 9
# handler's 0xE0-prefixed codes). A mapper file binds just these keys and
# puts the screenshot on F11 (scripts/lib/dosboxKeys.sh): DOSBox's Ctrl+F5
# would hand KEYS a Ctrl press.
#
# Usage:   scripts/verify-dos-input.sh
# Requires: DOSBox Staging (install.sh install emulator:dos), Xvfb, xdotool, python3 + PIL;
#           build/dos/bin/KEYS.EXE (make dos).
set -euo pipefail

repo=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
source "$repo/scripts/lib/joeyEnv.sh"
source "$repo/scripts/lib/dosboxKeys.sh"
source "$repo/scripts/lib/keysGate.sh"
joeyNeed DOSBOX dosbox
bin_dir=$repo/build/dos/bin
conf=$repo/scripts/dosbox-386sx16.conf

target="192.168.1.10:6510"

[ -f "$bin_dir/KEYS.EXE" ] || { echo "verify-dos-input: build KEYS.EXE first (make dos)" >&2; exit 2; }

work=$(mktemp -d -t joeylib-dos-input.XXXXXX)
display_num=$((RANDOM % 500 + 300))
cleanup() {
    joeyStop "${dosbox_pid:-}"
    [ -n "${xvfb_pid:-}" ]   && kill "$xvfb_pid" 2>/dev/null
    rm -rf "$work"
}
trap cleanup EXIT

mkdir -p "$work/shots"
dosboxKeysMapper "$work/mapper.txt" "${DOSBOX_KEYS_TYPING[@]}" "${DOSBOX_KEYS_NAMED[@]}"

Xvfb ":$display_num" -screen 0 1024x768x24 >/dev/null 2>&1 &
xvfb_pid=$!
sleep 1

XDG_CONFIG_HOME="$work/xdg" DISPLAY=":$display_num" "$DOSBOX" "${JOEY_DOSBOX_ISOLATE[@]}" \
    --conf "$conf" \
    --set "capture_dir=$work/shots" \
    --set "mapperfile=$work/mapper.txt" \
    -c "MOUNT C $bin_dir" -c "C:" -c "KEYS.EXE" \
    >"$work/dosbox.log" 2>&1 &
dosbox_pid=$!

# Let DOS boot and KEYS reach its poll loop on the simulated 386SX-16.
sleep 12

# Staging titles its window "<PROG> - <n> cycles/ms"; it is the only
# client on this private display, so match any named window.
win=$(joeyFindWindow ":$display_num" "$dosbox_pid")
if [ -z "$win" ]; then
    echo "verify-dos-input: FAIL - DOSBox window not found" >&2
    exit 1
fi
DISPLAY=":$display_num" xdotool windowactivate --sync "$win" 2>/dev/null || true
DISPLAY=":$display_num" xdotool type --window "$win" --delay 150 -- "$target"
sleep 2
png="$work/typed.png"
if ! dosboxShot ":$display_num" "$win" "$work/shots" "$png"; then
    echo "verify-dos-input: FAIL - no screenshot captured" >&2
    exit 1
fi

python3 - "$png" "$target" <<'PY'
import sys
from PIL import Image

png, target = sys.argv[1], sys.argv[2]
img = Image.open(png).convert("RGB")
w, h = img.size
# Raw capture is native 320x200; tolerate an integer upscale.
sx, sy = w // 320, h // 200
if sx < 1 or sy < 1 or w % 320 or h % 200:
    print(f"verify-dos-input: FAIL - unexpected screenshot size {w}x{h}")
    sys.exit(1)

def dac8(c4):
    v6 = ((c4 << 2) | (c4 >> 2)) & 0x3F
    return (v6 << 2) | (v6 >> 4)

# KEYS palette 0 (see buildPalette): gray ramp with the four demo
# colors and red at 15. 12-bit 0x0RGB -> exact 8-bit via the port's
# 6-bit DAC expansion.
pal12 = [(i << 8) | (i << 4) | i for i in range(16)]
pal12[0], pal12[1], pal12[2], pal12[3] = 0x000, 0x333, 0x0F0, 0xFFF
pal12[15] = 0xF00
# Nearest-color match: emulators differ in how they scale the 6-bit
# DAC to 8-bit (bit-replication vs rounding), but the palette entries
# sit ~17 units apart per channel, so nearest is unambiguous.
palRgb = [(dac8((v >> 8) & 0xF), dac8((v >> 4) & 0xF), dac8(v & 0xF)) for v in pal12]

def pix(px):
    r, g, b = img.getpixel((px * sx, 198 * sy))
    best, bestDist = 0, 1 << 30
    for n, (pr, pg, pb) in enumerate(palRgb):
        d = (r - pr) ** 2 + (g - pg) ** 2 + (b - pb) ** 2
        if d < bestDist:
            best, bestDist = n, d
    if bestDist > 3 * 8 ** 2:
        print(f"verify-dos-input: FAIL - pixel {px} color {(r, g, b)} too far from any palette entry")
        sys.exit(1)
    return best

row = bytes((pix(2 * i) << 4) | pix(2 * i + 1) for i in range(40))
expect = bytes([0xA5, 0xA5, len(target), 0x00]) + target.encode("ascii")
got = row[: len(expect)]
print("VERIFY-DOS-INPUT row=" + row.hex().upper())
if got != expect:
    print(f"verify-dos-input: FAIL\n  expected: {expect.hex().upper()}\n  got:      {got.hex().upper()}")
    sys.exit(1)
PY

# The stage in the raw screenshot: KEYS's row 198 found where it is.
found=$(python3 "$repo/scripts/lib/keysRow.py" "$png" "$target") || true
if [[ ! "$found" =~ row\ at\ \(([0-9]+),([0-9]+)\)\ at\ ([0-9]+)x ]]; then
    echo "verify-dos-input: FAIL - KEYS's stage is not in the screenshot: $found" >&2
    exit 1
fi
scale=${BASH_REMATCH[3]}
stageAt="${BASH_REMATCH[1]},$((BASH_REMATCH[2] - 198 * scale))"
# X's names for the keys (scripts/lib/keysGate.sh's).
declare -A xKey=([up]=Up [kp8]=KP_Up [kp2]=KP_Down [kp4]=KP_Left [kp6]=KP_Right [kpenter]=KP_Enter [rctrl]=Control_R [ralt]=Alt_R)
KEYS_LABEL=verify-dos-input
keysPress() {
    DISPLAY=":$display_num" xdotool keydown --window "$win" "${xKey[$1]}"
}
keysRelease() {
    DISPLAY=":$display_num" xdotool keyup --window "$win" "${xKey[$1]}"
}
keysRead() {
    if dosboxShot ":$display_num" "$win" "$work/shots" "$work/cells.png"; then
        python3 "$repo/scripts/lib/keysCells.py" "$work/cells.png" --at "$stageAt" --scale "$scale"
    else
        echo "no screenshot"
    fi
}
keysRunSteps kp8 kp2 kp4 kp6 kpenter rctrl ralt
if [ -n "$KEYS_FAILS" ]; then
    echo "verify-dos-input: FAIL - $KEYS_FAILS" >&2
    exit 1
fi
echo "verify-dos-input: PASS (typed \"$target\", all ${#target} chars arrived via jlInputGetChar; $KEYS_STEPS named-key steps: the keypad's arrows and Enter, right Ctrl and Alt, Up held with its second key)"