#!/usr/bin/env bash
# Run a test script inside a throwaway overlay of the golden image, injecting a
# fresh nina binary so we test the latest build without rebaking the golden.
# The script's serial output is captured (this command's stdout); the overlay is
# discarded afterward, leaving the golden untouched.
#
# Usage: run-in-vm.sh <golden.qcow2> <nina-linux-binary> <test-script.sh>
# Tunables via env: MEM_MB (2048), SMP (2), RUN_TIMEOUT (1800)
set -euo pipefail

GOLDEN="${1:?usage: run-in-vm.sh <golden.qcow2> <nina-bin> <test-script>}"
NINA="${2:?need nina binary}"
SCRIPT="${3:?need test script}"
MEM_MB="${MEM_MB:-2048}"
SMP="${SMP:-2}"
RUN_TIMEOUT="${RUN_TIMEOUT:-1800}"
for f in "$GOLDEN" "$NINA" "$SCRIPT"; do [ -f "$f" ] || { echo "missing: $f" >&2; exit 1; }; done

work="$(mktemp -d)"
trap 'rm -rf "$work"' EXIT
seed="$work/seed"; mkdir -p "$seed"
cp "$NINA" "$seed/nina"
cp "$SCRIPT" "$seed/runtest.sh"
SEED_ISO="$work/seed.iso"
hdiutil makehybrid -quiet -iso -joliet -default-volume-name NINASEED -o "$SEED_ISO" "$seed"

overlay="$work/overlay.qcow2"
qemu-img create -f qcow2 -b "$(cd "$(dirname "$GOLDEN")" && pwd)/$(basename "$GOLDEN")" -F qcow2 "$overlay" >/dev/null
echo "throwaway overlay: $overlay  (backing: $GOLDEN)"

export RV_OVERLAY="$overlay" RV_SEED="$SEED_ISO" RV_MEM="$MEM_MB" RV_SMP="$SMP" RV_TIMEOUT="$RUN_TIMEOUT"

expect -c '
  set timeout 600
  set overlay $env(RV_OVERLAY)
  set seed    $env(RV_SEED)
  set mem     $env(RV_MEM)
  set smp     $env(RV_SMP)
  set runto   $env(RV_TIMEOUT)

  spawn qemu-system-x86_64 \
    -machine q35 -accel tcg -cpu max -smp $smp -m $mem \
    -drive file=$overlay,if=virtio,format=qcow2 \
    -drive file=$seed,media=cdrom,readonly=on \
    -netdev user,id=n0 -device virtio-net-pci,netdev=n0 \
    -nographic

  expect {
    timeout { puts "\n!! no autologin on serial"; exit 2 }
    "automatic login" {}
  }
  sleep 6
  send "mkdir -p /mnt-seed && mount /dev/sr0 /mnt-seed && install -m755 /mnt-seed/nina /root/nina && echo KILN_RUN_BEGIN\r"
  expect { timeout { puts "\n!! seed/nina setup failed"; exit 3 } "KILN_RUN_BEGIN" {} }
  send "sh /mnt-seed/runtest.sh; echo KILN_RUN_END_RC=\$?\r"
  set timeout $runto
  expect {
    timeout { puts "\n!! test script timed out"; exit 4 }
    -re {KILN_RUN_END_RC=[0-9]+} {}
  }
  send "poweroff\r"
  set timeout 120
  expect eof
'
echo "=== overlay discarded; golden unchanged ==="