#!/usr/bin/env bash
# Full USB stack validation harness for Red Bear OS in QEMU.
#
# Boots a Red Bear image with xHCI, USB keyboard, USB tablet, and USB mass storage
# attached, then checks boot logs for successful USB device enumeration and driver spawn.

set -euo pipefail

find_uefi_firmware() {
    local candidates=(
        "/usr/share/ovmf/x64/OVMF.4m.fd"
        "/usr/share/OVMF/x64/OVMF.4m.fd"
        "/usr/share/ovmf/x64/OVMF_CODE.4m.fd"
        "/usr/share/OVMF/x64/OVMF_CODE.4m.fd"
        "/usr/share/ovmf/OVMF.fd"
        "/usr/share/OVMF/OVMF_CODE.fd"
        "/usr/share/qemu/edk2-x86_64-code.fd"
    )
    local path
    for path in "${candidates[@]}"; do
        if [[ -f "$path" ]]; then
            printf '%s\n' "$path"
            return 0
        fi
    done
    return 1
}

usage() {
    cat <<'USAGE'
Usage: test-usb-qemu.sh [--check] [config]

Boot or validate the full USB stack on a Red Bear image in QEMU.
Defaults to redbear-desktop.

Checks performed:
  1. xHCI controller initializes and reports interrupt mode
  2. USB HID driver spawns for keyboard/tablet
  3. USB SCSI driver spawns for mass storage
  4. BOS descriptor fetched (or gracefully skipped for USB 2)
  5. No panics or crash-class errors in USB daemons
USAGE
}

check_mode=0
config="redbear-desktop"
for arg in "$@"; do
    case "$arg" in
        --help|-h|help)
            usage
            exit 0
            ;;
        --check)
            check_mode=1
            ;;
        redbear-*)
            config="$arg"
            ;;
    esac
done

firmware="$(find_uefi_firmware)" || {
    echo "ERROR: no usable x86_64 UEFI firmware found" >&2
    exit 1
}

arch="${ARCH:-$(uname -m)}"
image="build/$arch/$config/harddrive.img"
extra="build/$arch/$config/extra.img"
usb_img="build/$arch/$config/usb-test-storage.img"
log_file="build/$arch/$config/usb-stack-check.log"

if [[ ! -f "$image" ]]; then
    echo "ERROR: missing image $image" >&2
    echo "Build it first with: ./local/scripts/build-redbear.sh $config" >&2
    exit 1
fi

if [[ ! -f "$extra" ]]; then
    truncate -s 1g "$extra"
fi

if [[ ! -f "$usb_img" ]]; then
    truncate -s 64M "$usb_img"
fi

pkill -f "qemu-system-x86_64.*$image" 2>/dev/null || true
sleep 1

rm -f "$log_file"

set +e
timeout 120s qemu-system-x86_64 \
  -name "Red Bear OS USB Test" \
  -device qemu-xhci,id=xhci \
  -smp 4 \
  -m 2048 \
  -bios "$firmware" \
  -chardev stdio,id=debug,signal=off,mux=on \
  -serial chardev:debug \
  -mon chardev=debug \
  -machine q35 \
  -device ich9-intel-hda -device hda-output \
  -device virtio-net,netdev=net0 \
  -netdev user,id=net0 \
  -nographic -vga none \
  -drive file="$image",format=raw,if=none,id=drv0 \
  -device nvme,drive=drv0,serial=NVME_SERIAL \
  -drive file="$extra",format=raw,if=none,id=drv1 \
  -device nvme,drive=drv1,serial=NVME_EXTRA \
  -drive file="$usb_img",format=raw,if=none,id=usbdisk \
  -device usb-storage,bus=xhci.0,drive=usbdisk \
  -device usb-kbd,bus=xhci.0 \
  -device usb-tablet,bus=xhci.0 \
  -enable-kvm -cpu host \
  > "$log_file" 2>&1
set -e

failures=0

echo "--- USB Stack Validation: $config ---"

# Check 1: xHCI interrupt mode
if grep -q "xhcid: using MSI/MSI-X interrupt delivery\|xhcid: using legacy INTx interrupt delivery" "$log_file"; then
    echo "  [PASS] xHCI interrupt-driven mode detected"
else
    echo "  [FAIL] xHCI did not report interrupt-driven mode" >&2
    failures=$((failures + 1))
fi

# Check 2: USB HID driver spawn
if grep -q "USB HID driver spawned" "$log_file"; then
    echo "  [PASS] USB HID driver spawned"
else
    echo "  [FAIL] USB HID driver did not spawn" >&2
    failures=$((failures + 1))
fi

# Check 3: USB SCSI driver spawn
if grep -q "USB SCSI driver spawned" "$log_file"; then
    echo "  [PASS] USB SCSI driver spawned"
else
    echo "  [FAIL] USB SCSI driver did not spawn" >&2
    failures=$((failures + 1))
fi

# Check 4: BOS descriptor handling (info or debug log)
if grep -q "BOS:" "$log_file"; then
    echo "  [PASS] BOS descriptor processing active"
elif grep -q "BOS descriptor not available" "$log_file"; then
    echo "  [PASS] BOS descriptor gracefully skipped (USB 2 device)"
else
    echo "  [WARN] No BOS descriptor log output found"
fi

# Check 5: No panics or crash-class errors (stall recovery messages are expected)
if grep -qi "panic\|usbscsid: .*IO ERROR\|usbscsid: startup failed\|usbhidd: .*IO ERROR" "$log_file"; then
    echo "  [FAIL] USB stack hit crash-class errors" >&2
    failures=$((failures + 1))
else
    echo "  [PASS] No crash-class errors detected"
fi

# Check 6: Hub driver (if hub detected)
if grep -q "USB HUB driver spawned" "$log_file"; then
    echo "  [PASS] USB hub driver spawned"
else
    echo "  [INFO] No hub driver spawn (expected for direct-attached devices)"
fi

echo "--- Results: $failures failure(s), log: $log_file ---"

if [[ "$failures" -gt 0 ]]; then
    exit 1
fi

exit 0