#!/usr/bin/env bash
set -euo pipefail

SSH_PORT=2222
MEMORY=8G
CPUS=4
MOUNTS=()
CLAUDE=false
IMAGE=""

usage() {
  cat <<EOF
Usage: ephvm-run.sh <image.qcow2> [options]

Options:
  --mount <path>       Mount host directory into VM (repeatable)
  --claude             Mount claude config dir (auto-detects from CLAUDE_CONFIG_DIR or ~/.claude)
  --memory <size>      VM memory (default: 8G)
  --cpus <n>         VM CPUs (default: 4)
  --ssh-port <port>  SSH port forward (default: 2222)
EOF
  exit 1
}

[ "${1:-}" ] || usage

IMAGE="$1"
shift

while [ $# -gt 0 ]; do
  case "$1" in
    --mount)      MOUNTS+=("$2"); shift 2 ;;
    --claude)     CLAUDE=true; shift ;;
    --memory)     MEMORY="$2"; shift 2 ;;
    --cpus)     CPUS="$2"; shift 2 ;;
    --ssh-port) SSH_PORT="$2"; shift 2 ;;
    *)          echo "unknown option: $1"; usage ;;
  esac
done

if [ ! -f "$IMAGE" ]; then
  echo "error: image not found: $IMAGE"
  exit 1
fi

ACCEL="tcg"
[ -r /dev/kvm ] && ACCEL="kvm"

QEMU_ARGS=(
  qemu-system-x86_64
  -accel "$ACCEL"
  -m "$MEMORY"
  -smp "$CPUS"
  -drive "file=$IMAGE,format=qcow2,snapshot=on"
  -nic "user,hostfwd=tcp::${SSH_PORT}-:22"
  -nographic
)

if [ "$ACCEL" != "tcg" ]; then
  QEMU_ARGS+=(-cpu host)
fi

FS_ID=0
for mount_path in "${MOUNTS[@]}"; do
  mount_path=$(realpath "$mount_path")
  name=$(basename "$mount_path")
  QEMU_ARGS+=(
    -virtfs "local,path=$mount_path,mount_tag=mount_$name,security_model=none,id=fs${FS_ID}"
  )
  FS_ID=$((FS_ID + 1))
done

if [ "$CLAUDE" = true ]; then
  if [ -z "${CLAUDE_CONFIG_DIR:-}" ]; then
    echo "error: --claude requires CLAUDE_CONFIG_DIR to be set"
    exit 1
  fi
  mkdir -p "$CLAUDE_CONFIG_DIR"
  claude_dir=$(realpath "$CLAUDE_CONFIG_DIR")

  QEMU_ARGS+=(
    -virtfs "local,path=$claude_dir,mount_tag=claude,security_model=none,id=fs${FS_ID}"
  )
fi

exec "${QEMU_ARGS[@]}"