#!/bin/bash
# Author: geaaru@sabayonlinux.org
# Description: Scripting tool for simplify dracut sabayon images creation.

set -e

# Permit to override default options to users.
# ZFS integration needs systemd stuff.
if [ -f "/etc/sabayon-dracut.conf" ] ; then
  source /etc/sabayon-dracut.conf
fi

SABAYON_DRACUT_COMMON_ARGS="${SABAYON_DRACUT_COMMON_ARGS:--H -q -f -o systemd -o systemd-initrd -o systemd-networkd -o dracut-systemd}"
SABAYON_INITRD_DIR="${SABAYON_INITRD_DIR:-/boot}"
# Current initrd naming is: initramfs-genkernel-${ARCH}-${KVER}.0-sabayon
SABAYON_INITRD_PREFIX="${SABAYON_INITRD_PREFIX:-initramfs-genkernel}"
SAB_ARCH=${SAB_ARCH:-$(uname -m)}

_error () {
  echo "$@"
  exit 1
}

_help () {
  echo "
------------------------------------
Sabayon Dracut Script
Copyright (s) 2018-2020 Sabayon
------------------------------------

Usage:

[--rebuild-all]         Rebuild all Sabayon kernel initrd images.
                        Based on naming convention
                        ${SABAYON_INITRD_PREFIX}-${SAB_ARCH}-VERSION-sabayon.
[--rebuild|-r vesion]   Rebuild image for a specific version.
[--list-available|-L]   List available Sabayon initrd available.
[--dry-run]             Doesn't execute final rebuild. Only print command
                        execute.
[--force]               Force creation if doesn't exist.
[--help|-h]             Help message.


Examples:

\$# sabayon-dracut --rebuild 4.18

\$# sabayon-dracut --list-available
"
  return 1
}

_get_images () {
  local n=$(ls ${SABAYON_INITRD_DIR}/${SABAYON_INITRD_PREFIX}*-sabayon 2>/dev/null | wc -l)

  if [ $n = 0 ] ; then
    SAB_INITRD_IMAGES=()
  else
    SAB_INITRD_IMAGES=( $(ls ${SABAYON_INITRD_DIR}/${SABAYON_INITRD_PREFIX}*-sabayon 2>/dev/null) )
  fi
  export SAB_INITRD_IMAGES
}

_list () {
  local i=0
  local n_images=${#SAB_INITRD_IMAGES[@]}
  local file
  local version

  if [ "$n_images" = 0 ] ; then
    echo "No images found."
  else
    echo "======================================================"
    echo " Initrd Images ${n_images}"
    echo "======================================================"
    echo " Version   Image"
    echo "======================================================"
    for i in ${SAB_INITRD_IMAGES[@]} ; do
      file=$(basename $i)
      v=${file/${SABAYON_INITRD_PREFIX}-${SAB_ARCH}-} ; v=${v/.0-sabayon/}
      echo " $v      $file"
    done
    echo "======================================================"
  fi
}

_rebuild_all () {
  # Check if version is available
  for i in ${SAB_INITRD_IMAGES[@]} ; do
    file=$(basename $i)
    v=${file/${SABAYON_INITRD_PREFIX}-${SAB_ARCH}-} ; v=${v/.0-sabayon/}
    _rebuild "$v" || {
      echo "Something is wrong with kernel $v but I go ahead."
    }
  done
}

_rebuild () {
  local i
  local found=0
  local version=$1

  if [ "$(id -u)" != "0" ]; then
    echo "This script must be run as root" 1>&2
    exit 1
  fi

  # Check if version is available
  for i in ${SAB_INITRD_IMAGES[@]} ; do
    file=$(basename $i)
    v=${file/${SABAYON_INITRD_PREFIX}-${SAB_ARCH}-} ; v=${v/.0-sabayon/}
    if [ "$version" = "$v" ] ; then
      found=1
      break
    fi
  done

  if [[ "$found" = 0 && "${SAB_REBUILD_FORCE}" != 1 ]] ; then
    echo "No image with version $version found."
  fi

  local image_name="${SABAYON_INITRD_PREFIX}-${SAB_ARCH}-${version}.0-sabayon"
  local kver="${version}.0-sabayon"

  echo "Building ${SABAYON_INITRD_DIR}/${image_name}"

  if [ "${SAB_DRYRUN}" = 1 ] ; then
    echo "dracut ${SABAYON_DRACUT_COMMON_ARGS} --kver=${kver} ${SABAYON_INITRD_DIR}/${image_name}"
  else
    dracut ${SABAYON_DRACUT_COMMON_ARGS} --kver=${kver} ${SABAYON_INITRD_DIR}/${image_name}
  fi
}

main () {
  _parse_args() {
    if [ $# -lt 1 ] ; then
      _help
      return 1
    fi

    SAB_REBUILD_ALL=0
    SAB_REBUILD_VERSION=""
    SAB_REBUILD_FORCE=0
    SAB_INITRD_LIST=0
    SAB_DRYRUN=0

    while [ $# -gt 0 ] ; do
      case "$1" in
        --help|-h)
          _help || return 1
          ;;
        --rebuild-all)
          SAB_REBUILD_ALL=1
          ;;
        --rebuild|-r)
          SAB_REBUILD_VERSION=$2
          shift
          ;;
        --list-available|-L)
          SAB_INITRD_LIST=1
          ;;
        --dry-run)
          SAB_DRYRUN=1
          ;;
        --force)
          SAB_REBUILD_FORCE=1
          ;;
        *|--)
          _error "Invalid parameter $1"
          ;;
      esac
      shift
    done

    if [[ "${SAB_REBUILD_ALL}" = 1 && -n "${SAB_REBUILD_VERSION}" ]] ; then
      _error "Both --rebuild-all and --rebuild options used."
    fi

    export SAB_REBUILD_ALL SAB_REBUILD_VERSION SAB_INITRD_LIST SAB_DRYRUN SAB_REBUILD_FORCE
    return 0
  }

  _parse_args "$@"

  _get_images

  [ "${SAB_INITRD_LIST}" = 1 ] && _list
  [ -n "${SAB_REBUILD_VERSION}" ] && _rebuild "${SAB_REBUILD_VERSION}"
  [ "${SAB_REBUILD_ALL}" = 1 ] && _rebuild_all

  unset -f _parse_args

  return 0
}

main $@
exit $?