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

log() {
  printf '[make-rootfs] %s\n' "$*"
}

usage() {
  cat <<'EOF'
Usage: ./scripts/make-rootfs.sh --kernel <path> [--initrd <path>] [--modules <dir>] [--size <size>] [--base-rootfs <path>]

Builds build/manual/rootfs-docker.ext4 using scripts/customize.sh. If
--base-rootfs is omitted, the first existing file is used:
  ./build/manual/rootfs-base.ext4
  ./ubuntu-noble-rootfs/rootfs.ext4
  ./ubuntu-lts/rootfs.ext4
EOF
}

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
MANUAL_DIR="${BANGER_MANUAL_DIR:-$REPO_ROOT/build/manual}"
OUT_ROOTFS="$MANUAL_DIR/rootfs-docker.ext4"
SIZE_SPEC="6G"
BASE_ROOTFS=""
KERNEL_PATH=""
INITRD_PATH=""
MODULES_DIR=""

while [[ $# -gt 0 ]]; do
  case "$1" in
    --size)
      SIZE_SPEC="${2:-}"
      shift 2
      ;;
    --base-rootfs)
      BASE_ROOTFS="${2:-}"
      shift 2
      ;;
    --kernel)
      KERNEL_PATH="${2:-}"
      shift 2
      ;;
    --initrd)
      INITRD_PATH="${2:-}"
      shift 2
      ;;
    --modules)
      MODULES_DIR="${2:-}"
      shift 2
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      log "unknown option: $1"
      usage
      exit 1
      ;;
  esac
done

if [[ -z "$BASE_ROOTFS" ]]; then
  if [[ -f "$MANUAL_DIR/rootfs-base.ext4" ]]; then
    BASE_ROOTFS="$MANUAL_DIR/rootfs-base.ext4"
  elif [[ -f "$REPO_ROOT/ubuntu-noble-rootfs/rootfs.ext4" ]]; then
    BASE_ROOTFS="$REPO_ROOT/ubuntu-noble-rootfs/rootfs.ext4"
  elif [[ -f "$REPO_ROOT/ubuntu-lts/rootfs.ext4" ]]; then
    BASE_ROOTFS="$REPO_ROOT/ubuntu-lts/rootfs.ext4"
  else
    log "no base rootfs found; pass --base-rootfs"
    exit 1
  fi
fi

if [[ -z "$KERNEL_PATH" ]]; then
  log "kernel path is required; pass --kernel"
  exit 1
fi

mkdir -p "$MANUAL_DIR"

log "building $OUT_ROOTFS from $BASE_ROOTFS"
args=(
  "$SCRIPT_DIR/customize.sh"
  "$BASE_ROOTFS"
  --out "$OUT_ROOTFS"
  --size "$SIZE_SPEC"
  --kernel "$KERNEL_PATH"
  --docker
)
if [[ -n "$INITRD_PATH" ]]; then
  args+=(--initrd "$INITRD_PATH")
fi
if [[ -n "$MODULES_DIR" ]]; then
  args+=(--modules "$MODULES_DIR")
fi
exec "${args[@]}"