#! /bin/sh
#
# Copyright 2015-2020. Quantum Corporation. All Rights Reserved.
# StorNext is either a trademark or registered trademark of
# Quantum Corporation in the US and/or other countries.
#

# uncomment for debugging
# set -x

# just in case the user doesn't have EDITOR defined...
EDITOR=${EDITOR:=vi}

# Set the correct binary, config dir paths and commands for macOS
OSNAME=`uname`
if [ "$OSNAME" == "Darwin" ]; then
    PATH=${PATH}:/System/Library/Filesystems/acfs.fs/Contents/bin
    CONFIG_DIR=/Library/Preferences/Xsan
    STAT_CMD="stat -f %m"
    MD5_CMD=md5
else
    PATH=${PATH}:/usr/cvfs/bin
    CONFIG_DIR=/usr/cvfs/config
    STAT_CMD="stat -c %Y"
    MD5_CMD=md5sum
fi


usage()
{
    echo "Usage: $0 -n <fsname> [-f <tmpfile>]"
    echo "  -n    Name of file system to edit"
    echo "  -f    Location of temporary file (in case of failed edit)"
    echo "  -h    This usage"
}

while getopts "n:f:h" c; do
  case $c in
      "n")
	  fsname=$OPTARG
	  ;;
      "f")
	  TMPFILE=$OPTARG
	  # We don't want to delete the tmpfile if it's specified
	  NODELTMP=1
	  CWD=`pwd`
	  DIRNAME=`dirname "$TMPFILE"`
	  if [[ "$DIRNAME" =~ "^/" ]]; then
	      if [ "$DIRNAME" = "$CONFIG_DIR" ]; then
		  INPLACE=1
	      fi
	  elif [ "$CWD/$DIRNAME/" = "$CONFIG_DIR/" ]; then
	      INPLACE=1
	  fi
	 
	  if [ "$INPLACE" = "1" ]; then
	      echo "You cannot edit a config file in-place with sncfgedit."
	      echo "To edit the exiting config, simply specify the fsname."
	      exit 1
	  fi
	  ;;
      "h")
	  usage
	  exit 0
	  ;;
  esac
done

if [ -z "$fsname" ]; then
    usage
    exit 1
fi

if [ -z "$TMPFILE" ]; then    

    TMPFILE=`mktemp -t tmp_${fsname}_cfg-XXXXX` || exit 1

    echo "Attempting to get ${fsname}'s config file"
    sncfgquery -n ${fsname} -d > $TMPFILE
    ret=$?
    # we don't exit on ENOENT either
    if [ $ret -ne 0 -a $ret -ne 2 ]; then
        # relying on stderr output from sncfgquery for message
	exit $ret
    fi

    if [ $ret -eq 2 ]; then
        createnew=0
        while true
        do
            /bin/echo -n "No config file for ${fsname} exists. Do you want to create one? (y/n) "
            read line
            firstchar=`echo $line | cut -b1`
            if [ "$firstchar" = "n" ]; then
                break;
            fi
            if [ "$firstchar" = "y" ]; then
                createnew=1;
                break;
            fi
        done
        if [ $createnew -eq 0 ]; then
            if [ -z "$NODELTMP" ]; then
                rm -f $TMPFILE
            fi
            echo "Exiting." 1>&2
            exit 1
        fi
	sncfgtemplate -n $fsname > $TMPFILE || exit $ret
	NEW_FILE=1
    fi
fi

TMPMTIME1=`${STAT_CMD} $TMPFILE` || exit 1
MD5SUM1=`${MD5_CMD} $TMPFILE`

while true
do
    $EDITOR $TMPFILE || exit 1

    TMPMTIME2=`${STAT_CMD} $TMPFILE` || exit 1
    MD5SUM2=`${MD5_CMD} $TMPFILE`

    if [ "${TMPMTIME1}" = "${TMPMTIME2}" -a "${MD5SUM1}" = "${MD5SUM2}" ]; then
        if [ -n "$NEW_FILE" ]; then
            echo "File unchanged - not installing"
        else
            echo "New config not installed"
        fi
        if [ -z "$NODELTMP" ]; then
            rm -f $TMPFILE
        fi
        exit 0
    fi

    if ! sncfgvalidate -f $TMPFILE -n $fsname; then
        echo "Error validating new config." 1>&2

        editagain=0
        while true
        do
            /bin/echo -n "Do you want to (q)uit and leave behind temporary file or (r)e-enter editor? "
            read line
            firstchar=`echo $line | cut -b1`
            if [ "$firstchar" = "q" ]; then
                break;
            fi
            if [ "$firstchar" = "r" ]; then
                editagain=1;
                break;
            fi
        done
        if [ $editagain -eq 0 ]; then
            echo "Leaving temporary file at $TMPFILE" 1>&2
            exit 1
        fi
    else
        break
    fi
done

# sncfginstall automatically backs up the original file if it exits
echo "Installing new config for $fsname"
if ! sncfginstall -f $TMPFILE -n $fsname; then
    echo "Error writing out new config - leaving temporary file at $TMPFILE" 1>&2
    exit 1
fi

echo "File successfully updated"