#!/bin/bash

# Source helper script.
ABSOLUTE_PATH=$(dirname "$(readlink -e "$0")") # using readlink, because somone might be calling
                                               # this script using a symlink

if [ -e "${ABSOLUTE_PATH}/../lib/beeond-lib" ]
then
   BEEOND_LIB="${ABSOLUTE_PATH}/../lib/beeond-lib"
else
   BEEOND_LIB="${ABSOLUTE_PATH}/../scripts/lib/beeond-lib"
fi

#shellcheck source=scripts/lib/beeond-lib
source "${BEEOND_LIB}"
PARALLEL="${ABSOLUTE_PATH}/../thirdparty/parallel/parallel"

# Print usage.
print_usage_and_exit()
{
   echo ""
   echo "BeeOND copy (http://www.beegfs.com)"
   echo ""
   echo "DESCRIPTION:"
   echo "   BeeGFS OnDemand copying/staging system."
   echo ""
   echo "USAGE: $(basename "$0") <mode> <options>"
   echo ""
   echo "ACTIONS:"
   echo "   The first argument to $(basename "$0") is considered to be an action that the script"
   echo "   should perform."
   echo ""
   echo "   The following actions are available:"
   echo ""
   echo "   stagein: (EXPERIMENTAL)"
   echo "      Stage a complete directory from the global storage in to BeeOND."
   echo ""
   echo "      Mandatory arguments:"
   echo "         -n FILENAME  => File containing the list of nodes where the parallel"
   echo "                         copy should be performed. All nodes must have access to"
   echo "                         the global and local directories."
   echo "         -g PATH      => Directory on global storage. (*)"
   echo "         -l PATH      => Directory on local (BeeOND) storage. (*)"
   echo ""
   echo "      Notes:"
   echo "         (*) Global and local directories have to be specified in form of an"
   echo "             absolute path."
   echo ""
   echo "   stageout: (EXPERIMENTAL)"
   echo "      Stage a complete directory out from BeeOND to the global storage."
   echo "      Only changes will be staged out of the local directory and committed to"
   echo "      the global directory."
   echo ""
   echo "      Mandatory arguments:"
   echo "         -l PATH      => Local directory."
   echo ""
   echo "      Notes:"
   echo "         The contents will be completely synchronized, i.e. deleted files on "
   echo "         BeeOND will get deleted on global storage, too."
   echo ""
   echo "   copy:"
   echo "      Perform a parallel copy of a set of files or folders."
   echo "      Files will be copied into the target directory, folders will be copied"
   echo "      recursively. The copy process is parallelized across the set of nodes"
   echo "      specified in the nodefile."
   echo ""
   echo "      Mandatory arguments:"
   echo "         -n FILENAME  => File containing the list of nodes where the parallel"
   echo "                         copy should be performed. All nodes must have access to"
   echo "                         the sources and the target directory."
   echo ""
   echo "      Notes:"
   echo "         Further command line arguments are consdiered source directory or file"
   echo "         names. The last command line argument specifies the target directory"
   echo ""
   echo "EXAMPLES:"
   echo "   Stage data from /mnt/beegfs-global/dataset in to BeeOND mounted at /mnt/beeond,"
   echo "   using the nodes given in /tmp/nodefile:"
   echo "      beeond-cp stagein -n /tmp/nodefile -g /mnt/beegfs-global/dataset -l /mnt/beeond"
   echo ""
   echo "   Stage out modified data from BeeOND mounted at /mnt/beeond to the global "
   echo "   storage:"
   echo "      beeond-cp stageout -n /tmp/nodefile -g /mnt/beegfs-global/dataset -l /mnt/beeond"
   echo "" 
   echo "   Recursively copy the directories dir_1 and dir_2 to /mnt/beegfs, using the nodes"
   echo "   in /tmp/nodefile:"
   echo "      beeond-cp copy -n /tmp/nodefile dir_1 dir_2 /mnt/beegfs"
   echo ""
   echo "NOTE:"
   echo "   BeeOND copy uses GNU Parallel -"
   echo "   When using programs that use GNU Parallel to process data for publication"
   echo "   please cite:"
   echo "     O. Tange (2011): GNU Parallel - The Command-Line Power Tool,"
   echo "     ;login: The USENIX Magazine, February 2011:42-47."
   echo ""
   echo "   SSH is used to log into the nodes specified in the nodefile. Please make"
   echo "   sure your SSH configuration allows for enough concurrent sessions and pending"
   echo "   logins. You might have to (ask your admin to) raise the MaxSessions and"
   echo "   MaxStartups settings in the sshd_config file."
   echo ""
   echo "   Also please make sure you have the access rights needed to write to the"
   echo "   global store. Otherwise the stage-out might fail. Note that the access rights"
   echo "   in the BeeOND local store do not necessarily reflect those in the global"
   echo "   store."

   exit 1
}

### main functions
do_start()
{
   local NODEFILE="${1}"
   local GLOBAL_PATH="${2}"
   local LOCAL_PATH="${3}"

   beeond_print_info "BeeOND startup..."

   beeond_print_info "nodefile: ${NODEFILE}"
   beeond_print_info "global path: ${GLOBAL_PATH}"
   beeond_print_info "local path: ${LOCAL_PATH}"

   MISSING_PARAM=0
   if [ "${NODEFILE}" = "" ]
   then
      beeond_print_error "No nodefile specified."
      MISSING_PARAM=1
   fi
   if [ "${GLOBAL_PATH}" = "" ]
   then
      beeond_print_error "Global path not specified."
      MISSING_PARAM=1
   fi
   if [ "${LOCAL_PATH}" = "" ]
   then
      beeond_print_error "Local path not specified."
      MISSING_PARAM=1
   fi

   # Expand relative path to nodefile.
   if [ ! "${NODEFILE:0:1}" = "/" ]
   then
      NODEFILE="${PWD}/${NODEFILE}"
   fi

   if [ ! -e "${NODEFILE}" ]
   then
      beeond_print_error_and_exit "Node file does not exist."
   fi

   # The paths to the global and local directory have to be specified as absolute paths to prevent
   # user errors (like copying a lot of files to ~/mnt/beeond).
   if [ ! "${GLOBAL_PATH:0:1}" = "/" ] || [ ! "${LOCAL_PATH:0:1}" = "/" ]
   then
      beeond_print_error_and_exit "Global path and local path have to be absolute."
   fi

   [ "${MISSING_PARAM}" = "1" ] && exit 1

   # Make sure target directory is empty before starting.
   if [ -e "${LOCAL_PATH}" ]
   then
      [ -d "${LOCAL_PATH}" ] \
         || beeond_print_error_and_exit "Target path is not a directory."

      find "${LOCAL_PATH}" -maxdepth 0 -type d -empty | read -r _ \
         || beeond_print_error_and_exit "Target directory is not empty."
   else
      mkdir -p "${LOCAL_PATH}" \
         || beeond_print_error_and_exit "Cannot create target directory."
   fi

   local CONCURRENCY=$(( $(wc -l < "${NODEFILE}") ))
   beeond_print_info "Concurrency: ${CONCURRENCY}"

   beeond_print_info "Writing session information."
   beeond_save_session_info "${NODEFILE}" "${GLOBAL_PATH}"

   beeond_print_info "Starting stage-in..."
   NODES=( $(grep -v '^$' "${NODEFILE}" | uniq) ) # Store as array and ignore empty lines.
   NODELIST=$(IFS=,; echo "${NODES[*]}") # turn argument list into comma-separated string for PDSH

   beeond_stage_in "${GLOBAL_PATH}" "${LOCAL_PATH}" "${NODELIST}" ${CONCURRENCY}

   beeond_print_info "Done."
}

do_stop()
{
   local LOCAL_PATH="${1}"

   if [ "${LOCAL_PATH}" = "" ]
   then
      beeond_print_error_and_exit "No path specified."
   fi

   # Expand relative local path.
   # Note: Don't have to ensure that it's an absolute path here: We confirm it's a BeeOND instance
   #       by looking for the session info file.
   if [ ! "${LOCAL_PATH:0:1}" = "/" ]
   then
      LOCAL_PATH="${PWD}/${LOCAL_PATH}"
   fi

   # Read parameters from session info file.
   NODEFILE=$(grep NodeFile "${LOCAL_PATH}/${BEEOND_SESSION_FILE}" | cut -d = -f 2-)
   GLOBAL_PATH=$(grep GlobalPath "${LOCAL_PATH}/${BEEOND_SESSION_FILE}" | cut -d = -f 2-)

   if [ "${NODEFILE}" = "" ]
   then
      beeond_print_error "Error reading node file name from session file."
      MISSING_PARAM=1
   fi
   if [ "${GLOBAL_PATH}" = "" ]
   then
      beeond_print_error "Error reading global path from session file."
      MISSING_PARAM=1
   fi

   [ "${MISSING_PARAM}" = "1" ] && exit 1

   if [ ! -e "${NODEFILE}" ]
   then
      beeond_print_error_and_exit "Node file does not exist."
   fi

   beeond_print_info "BeeOND shutdown..."

   beeond_print_info "nodefile: ${NODEFILE}"
   beeond_print_info "global path: ${GLOBAL_PATH}"
   beeond_print_info "local path: ${LOCAL_PATH}"

   NODES=( $(grep -v '^$' "${NODEFILE}" | uniq) ) # Store as array and ignore empty lines.
   NODELIST=$(IFS=,; echo "${NODES[*]}")

   local CONCURRENCY=$(( $(wc -l < "${NODEFILE}") ))
   beeond_print_info "Concurrency: ${CONCURRENCY}"

   beeond_stage_out "${GLOBAL_PATH}" "${LOCAL_PATH}" "${NODELIST}" ${CONCURRENCY}

   beeond_print_info "Done."
}

do_copy()
{
   local NODEFILE="${1}"
   shift

   beeond_print_info "BeeOND copy..."

   if [ "${NODEFILE}" = "" ]
   then
      beeond_print_error "No nodefile specified."
   fi

   # Expand relative path to nodefile.
   if [ ! "${NODEFILE:0:1}" = "/" ]
   then
      NODEFILE="${PWD}/${NODEFILE}"
   fi

   if [ ! -e "${NODEFILE}" ]
   then
      beeond_print_error_and_exit "Node file does not exist."
   fi

   NODES=( $(grep -v '^$' "${NODEFILE}" | uniq) ) # Store as array and ignore empty lines.
   NODELIST=$(IFS=,; echo "${NODES[*]}")

   local CONCURRENCY=$(( $(wc -l < "${NODEFILE}") ))
   beeond_print_info "Concurrency: ${CONCURRENCY}"

   beeond_copy "${NODELIST}" "${CONCURRENCY}" "$@"
}

# Print help if no arguments given.
if [ $# -eq 0 ] ; then
   print_usage_and_exit
fi

# Do it.
ACTION="${1}"

if [ "${ACTION}" = "stagein" ]
then
   shift
   while getopts ":n:g:l:" opt; do
      case $opt in
         n)
            NODEFILE="${OPTARG}"
         ;;
         g)
            GLOBAL_PATH="${OPTARG}"
         ;;
         l)
            LOCAL_PATH="${OPTARG}"
         ;;
         \?)
            beeond_print_error_and_exit "Invalid option: -${OPTARG}."
         ;;
         :)
            beeond_print_error_and_exit "Option -${OPTARG} requires an argument."
         ;;
      esac
   done

   do_start "${NODEFILE}" "${GLOBAL_PATH}" "${LOCAL_PATH}"
elif [ "${ACTION}" = "stageout" ]
then
   shift
   while getopts ":l:" opt; do
      case $opt in
         l)
            LOCAL_PATH="${OPTARG}"
         ;;
         \?)
            beeond_print_error_and_exit "Invalid option: -${OPTARG}."
         ;;
         :)
            beeond_print_error_and_exit "Option -${OPTARG} requires an argument."
         ;;
      esac
   done

   do_stop "${LOCAL_PATH}"
elif [ "${ACTION}" = "copy" ]
then
   shift

   # Nodefile has to be given as the only command line argument.
   if getopts ":n:" opt
   then
      if [ "$opt" = "n" ]
      then
         NODEFILE="${OPTARG}"
      else
         beeond_print_error_and_exit "Invalid option: -${opt}"
      fi

   else
      beeond_print_error_and_exit "No nodefile specified."
   fi

   # All following command line arguments are file or directory names, specifying the sources and
   # the target of the copy ancion
   shift # shift out -n parameter
   shift # shift out name of node file

   do_copy "${NODEFILE}" "$@"
elif [ "${ACTION}" = "info" ]
then
   do_print_info
else
   print_usage_and_exit
fi