#!/bin/bash

################################################################################
# Global variables
################################################################################
MODE="find"
ATIME_SEARCH=0


################################################################################
# Functions
################################################################################

die() {
  printf '%s\n' "$1" >&2
  exit 1
}

show_help() {
cat << HELP

Helper script to search and manage atime and retention settings.
Script must be executed on a Special Delete Mount, to bypass the WORM xlator.

Usage: $1 [OPTION]
Mandatory:
  -d|--directory DIRECTORY      search this directory, can also be a single file

Optional:
  -m|--mode MODE                show, find or set (default: ${MODE})

Options for search mode:
  -a|--atime ATIME              search for files with an atime (seconds since
                                epoch) higher than this value
  -r|--retention RETENTION      which retention time to search for. Only works
                                with special delete mounts
Options for set mode
  -n|--new-retention            set the new retention/atime. atime will be
                                calculated: trusted.archive_time+new-retention

HELP
}

get_atime_of_file() {
  stat --format=%X "${1}" 2> /dev/null
}

get_xattr_of_file() {
  getfattr --absolute-names --only-values -m "${2}" "${1}" | tr -d '\0'
}

find_files_with_atime() {
  while read -r FILE; do
    ATIME_FILE=$(get_atime_of_file "${FILE}")
    if [ "${ATIME_FILE}" == "" ]; then
      continue
    fi
    if [ ${ATIME_FILE} -ge ${ATIME_SEARCH} ]; then
      echo "${FILE}"
    fi
  done <<< $(find "${DIRECTORY}" -type f)
}


find_files_with_retention() {
  while read -r FILE; do
    RETENTION_FILE=$(get_xattr_of_file "${FILE}" "trusted.worm.attr" | grep -o '[0-9]\+$')
    if [ "${RETENTION_FILE}" == "" ]; then
      continue
    fi

    if [ ${RETENTION_FILE} -eq ${RETENTION_SEARCH} ]; then
      echo "${FILE}"
    fi
  done <<< $(find "${DIRECTORY}" -type f)
}


set_atime() {
  for FILE in $(find_files_with_retention "${DIRECTORY}" "${RETENTION_SEARCH}"); do
    if [ -f "${FILE}" ]; then
      ARCHIVE_TIME=$(get_xattr_of_file "${FILE}" "trusted.archive_time")
      NEW_ATIME=$((ARCHIVE_TIME+NEW_RETENTION))
      #echo touch -a --date=@${NEW_ATIME} "${FILE}"
      touch -a --date=@${NEW_ATIME} "${FILE}"
    fi
  done
}


show_atime_retention() {
  while read -r FILE; do
    ATIME=$(get_atime_of_file "${FILE}")
    if [ "${ATIME}" == "" ]; then
      continue
    fi
    TRUSTED_WORM_ATTR=$(get_xattr_of_file "${FILE}" "trusted.worm.attr" | grep -o '[0-9]\+$')
    echo "${FILE}"
    echo "  atime:             $(date --date=@${ATIME}) || ${ATIME}"
    echo "  trusted.worm.attr: ${TRUSTED_WORM_ATTR}"
  done <<< $(find "${DIRECTORY}" -type f)
}

################################################################################
# Argument parser
################################################################################
while :; do
  case $1 in
    -h|-\?|--help)
        show_help    # Display a usage synopsis.
        exit
        ;;
    -a|--atime)  # Takes an option argument; ensure it has been specified.
        if [ "$2" ]; then
            ATIME_SEARCH=$2
            shift
        else
            die 'ERROR: "-a|--atime" requires a non-empty option argument.'
        fi
        ;;
    -d|--directory)  # Takes an option argument; ensure it has been specified.
        if [ "$2" ]; then
            DIRECTORY=$2
            shift
        else
            die 'ERROR: "-d|--directory" requires a non-empty option argument.'
        fi
        ;;
    -r|--retention)  # Takes an option argument; ensure it has been specified.
        if [ "$2" ]; then
            RETENTION_SEARCH=$2
            shift
        else
            die 'ERROR: "-r|--retention" requires a non-empty option argument.'
        fi
        ;;
    -m|--mode)  # Takes an option argument; ensure it has been specified.
        if [ "$2" ]; then
            MODE=$2
            shift
        else
            die 'ERROR: "-m|--mode" requires a non-empty option argument.'
        fi
        ;;
    -n|--new-retention)  # Takes an option argument; ensure it has been specified.
        if [ "$2" ]; then
            NEW_RETENTION=$2
            shift
        else
            die 'ERROR: "-n|--new-retention" requires a non-empty option argument.'
        fi
        ;;
    --)              # End of all options.
        shift
        break
        ;;
    *)               # Default case: No more options, so break out of the loop.
        break
  esac

  shift
done



################################################################################
# Main, main, main
################################################################################
if [ "${DIRECTORY}" == "" ]; then
  show_help
  exit 0
fi

OPER_MODE="${MODE}"

if  [ "${OPER_MODE}" == "show" ]; then
  show_atime_retention "${DIRECTORY}"
elif [ "${OPER_MODE}" == "find" ]; then
  if [ "${RETENTION_SEARCH}" != "" ]; then
    find_files_with_retention
  else
    find_files_with_atime
  fi
elif  [ "${OPER_MODE}" == "set" ]; then
  # Some panic checks..
  if [ ! -e "${DIRECTORY}" ]; then
    echo "${DIRECTORY} is not existent. Will exit now..."
    exit 1
  fi
  if [ "${RETENTION_SEARCH}" == "" ]; then
    echo "RETENTION_SEARCH is not set. Cowardly refusing to continue..."
    exit 1
  fi
  if [ "${NEW_RETENTION}" == "" ]; then
    echo "NEW_RETENTION is not set. Cowardly refusing to continue..."
    exit 1
  fi

  # Finally set the new atime
  set_atime "${DIRECTORY}" "${RETENTION_SEARCH}"
fi