#!/bin/sh
# Nico Schottelius
# Initially written for SyGroup (www.sygroup.ch)
# Date: Mon Nov 14 11:45:11 CET 2005
# Last Modified: (See ls -l or git)

#
# where to find our configuration and temporary file
#
CCOLLECT_CONF=${CCOLLECT_CONF:-/etc/ccollect}
CSOURCES=${CCOLLECT_CONF}/sources
CDEFAULTS=${CCOLLECT_CONF}/defaults
CPREEXEC="${CDEFAULTS}/pre_exec"
CPOSTEXEC="${CDEFAULTS}/post_exec"

TMP=$(mktemp "/tmp/$(basename $0).XXXXXX")
VERSION=0.6
RELEASE="2007-08-16/17"
HALF_VERSION="ccollect ${VERSION}"
FULL_VERSION="ccollect ${VERSION} (${RELEASE})"

#
# CDATE: how we use it for naming of the archives
# DDATE: how the user should see it in our output (DISPLAY)
#
CDATE="date +%Y%m%d-%H%M"
DDATE="date +%Y-%m-%d-%H:%M:%S"

#
# unset parallel execution
#
PARALLEL=""

#
# catch signals
#
trap "rm -f \"${TMP}\"" 1 2 15

#
# Functions
#

# time displaying echo
_techo()
{
   echo "$(${DDATE}): $@"
}

# exit on error
_exit_err()
{
   _techo "$@"
   rm -f "${TMP}"
   exit 1
}

add_name()
{
   sed "s:^:\[${name}\] :"
}

#
# Tell how to use us
#
usage()
{
   echo "$(basename $0): <interval name> [args] <sources to backup>"
   echo ""
   echo "   ccollect creates (pseudo) incremental backups"
   echo ""
   echo "   -h, --help:          Show this help screen"
   echo "   -p, --parallel:      Parallelise backup processes"
   echo "   -a, --all:           Backup all sources specified in ${CSOURCES}"
   echo "   -v, --verbose:       Be very verbose (uses set -x)"
   echo ""
   echo "   This is version ${VERSION}, released on ${RELEASE}"
   echo "   (the first version was written on 2005-12-05 by Nico Schottelius)."
   echo ""
   echo "   Retrieve latest ccollect at http://unix.schottelius.org/ccollect/"
   exit 0
}

#
# need at least interval and one source or --all
#
if [ $# -lt 2 ]; then
   usage
fi

#
# check for configuraton directory
#
[ -d "${CCOLLECT_CONF}" ] || _exit_err "No configuration found in " \
   "\"${CCOLLECT_CONF}\" (is \$CCOLLECT_CONF properly set?)"

#
# Filter arguments
#
export INTERVAL="$1"; shift
i=1
no_sources=0

#
# Create source "array"
#
while [ "$#" -ge 1 ]; do
   eval arg=\"\$1\"; shift

   if [ "${NO_MORE_ARGS}" = 1 ]; then
        eval source_${no_sources}=\"${arg}\"
        no_sources=$((${no_sources}+1))
        
        # make variable available for subscripts
        eval export source_${no_sources}
   else
      case "${arg}" in
         -a|--all)
            ALL=1
            ;;
         -v|--verbose)
            VERBOSE=1
            ;;
         -p|--parallel)
            PARALLEL=1
            ;;
         -h|--help)
            usage
            ;;
         --)
            NO_MORE_ARGS=1
            ;;
         *)
            eval source_${no_sources}=\"$arg\"
            no_sources=$(($no_sources+1))
            ;;
      esac
   fi

   i=$(($i+1))
done

# also export number of sources
export no_sources

#
# be really, really, really verbose
#
if [ "${VERBOSE}" = 1 ]; then
   set -x
fi

#
# Look, if we should take ALL sources
#
if [ "${ALL}" = 1 ]; then
   # reset everything specified before
   no_sources=0

   #
   # get entries from sources
   #
   cwd=$(pwd -P)
   ( cd "${CSOURCES}" && ls > "${TMP}" ); ret=$?

   [ "${ret}" -eq 0 ] || _exit_err "Listing of sources failed. Aborting."

   while read tmp; do
      eval source_${no_sources}=\"${tmp}\"
      no_sources=$((${no_sources}+1))
   done < "${TMP}"
fi

#
# Need at least ONE source to backup
#
if [ "${no_sources}" -lt 1 ]; then
   usage
else
   _techo "${HALF_VERSION}: Beginning backup using interval ${INTERVAL}"
fi

#
# Look for pre-exec command (general)
#
if [ -x "${CPREEXEC}" ]; then
   _techo "Executing ${CPREEXEC} ..."
   "${CPREEXEC}"; ret=$?
   _techo "Finished ${CPREEXEC}."

   [ "${ret}" -eq 0 ] || _exit_err "${CPREEXEC} exited with return code ${ret}" \
      ", aborting backup."
fi

#
# check default configuration
#

D_FILE_INTERVAL="${CDEFAULTS}/intervals/${INTERVAL}"
D_INTERVAL=$(cat "${D_FILE_INTERVAL}" 2>/dev/null)


#
# Let's do the backup
#
i=0
while [ "${i}" -lt "${no_sources}" ]; do

   #
   # Get current source
   #
   eval name=\"\$source_${i}\"
   i=$((${i}+1))

   export name

   #
   # start ourself, if we want parallel execution
   #
   if [ "${PARALLEL}" ]; then
      "$0" "${INTERVAL}" "${name}" &
      continue
   fi

#
# Start subshell for easy log editing
#
(
   #
   # Stderr to stdout, so we can produce nice logs
   #
   exec 2>&1

   #
   # Configuration
   #
   backup="${CSOURCES}/${name}"
   c_source="${backup}/source"
   c_dest="${backup}/destination"
   c_exclude="${backup}/exclude"
   c_verbose="${backup}/verbose"
   c_vverbose="${backup}/very_verbose"
   c_rsync_extra="${backup}/rsync_options"
   c_summary="${backup}/summary"
   c_pre_exec="${backup}/pre_exec"
   c_post_exec="${backup}/post_exec"
   c_incomplete="${backup}/delete_incomplete"

   #
   # Marking backups: If we abort it's not removed => Backup is broken
   #
   c_marker=".ccollect-marker"

   #
   # Times
   #
   begin_s=$(date +%s)

   #
   # unset possible options
   #
   EXCLUDE=""
   RSYNC_EXTRA=""
   SUMMARY=""
   VERBOSE=""
   VVERBOSE=""
   DELETE_INCOMPLETE=""

   _techo "Beginning to backup"

   #
   # Standard configuration checks
   #
   if [ ! -e "${backup}" ]; then
      _exit_err "Source does not exist."
   fi

   #
   # configuration _must_ be a directory
   #
   if [ ! -d "${backup}" ]; then
      _exit_err "\"${name}\" is not a cconfig-directory. Skipping."
   fi

   #
   # first execute pre_exec, which may generate destination or other
   # parameters
   #
   if [ -x "${c_pre_exec}" ]; then
      _techo "Executing ${c_pre_exec} ..."
      "${c_pre_exec}"; ret="$?"
      _techo "Finished ${c_pre_exec} (return code ${ret})."

      if [ "${ret}" -ne 0 ]; then
         _exit_err "${c_pre_exec} failed. Skipping."
      fi
   fi

   #
   # interval definition: First try source specific, fallback to default
   #
   c_interval="$(cat "${backup}/intervals/${INTERVAL}" 2>/dev/null)"

   if [ -z "${c_interval}" ]; then
      c_interval="${D_INTERVAL}"

      if [ -z "${c_interval}" ]; then
         _exit_err "No definition for interval \"${INTERVAL}\" found. Skipping."
      fi
   fi

   #
   # Source checks
   #
   if [ ! -f "${c_source}" ]; then
      _exit_err "Source description \"${c_source}\" is not a file. Skipping."
   else
      source=$(cat "${c_source}"); ret=$?
      if [ ${ret} -ne 0 ]; then
         _exit_err "Source ${c_source} is not readable. Skipping."
      fi
   fi

   #
   # destination _must_ be a directory
   #
   if [ ! -d "${c_dest}" ]; then
      _exit_err "Destination ${c_dest} is not a directory. Skipping."
   fi

   #
   # Check whether to delete incomplete backups
   #
   if [ -f "${c_incomplete}" ]; then
      DELETE_INCOMPLETE="yes"
   fi

   #
   # Verbosity for rsync

   # NEW method as of 0.6:
   # - insert ccollect default parameters
   # - insert options
   # - insert user options
   
   #
   # rsync standard options
   #

   set -- "$@" "--archive" "--delete" "--numeric-ids" "--relative"   \
                "--delete-excluded" "--sparse" 

   #
   # exclude list
   #
   if [ -f "${c_exclude}" ]; then
      set -- "$@" "--exclude-from=${c_exclude}"
   fi

   #
   # Output a summary
   #
   if [ -f "${c_summary}" ]; then
      set -- "$@" "--stats"
   fi

   #
   # Verbosity for rsync
   #
   if [ -f "${c_vverbose}" ]; then
      set -- "$@" "-vv"
   elif [ -f "${c_verbose}" ]; then
      set -- "$@" "-v"
   fi

   #
   # extra options for rsync provided by the user
   #
   if [ -f "${c_rsync_extra}" ]; then
      while read line; do
         set -- "$@" "$line"
      done < "${c_rsync_extra}"
   fi

   #
   # Check for incomplete backups
   #
   (
      set -e
      # FIXME: debug
      set -x
      cd "${c_dest}"
      # one column output to ${TMP}
      ls -1 "${INTERVAL}"*/${c_marker} > "${TMP}"

      # FIXME: debug
      cat "${TMP}"

      while read incomplete; do
         realincomplete=$(echo ${incomplete} | sed "s/${c_marker}\$//")
         _techo "Incomplete backup: ${realincomplete}"
         if [ "$DELETE_INCOMPLETE" = "yes" ]; then
            _techo "Deleting ${realincomplete}"
            echo rm $VVERBOSE -rf "${realincomplete}"
         fi
      done < "${TMP}"
   ) || _exit_err "Searching for incomplete backups failed."

   #
   # check if maximum number of backups is reached, if so remove
   #

   # use grep and ls -p so we only look at directories
   count=$(cd "${c_dest}" && ls -p1 | grep "^${INTERVAL}\..*/\$" | wc -l \
      | sed 's/^ *//g')  || _exit_err "Counting backups failed"

   _techo "Existing backups: ${count} Total keeping backups: ${c_interval}"
   
   if [ "${count}" -ge "${c_interval}" ]; then
      substract=$((${c_interval} - 1))
      remove=$((${count} - ${substract}))
      echo "Removing ${remove} backup(s)..."

      (
         set -e
         cd "${c_dest}"
         ls -p1 | grep "^${INTERVAL}\..*/\$" | sort -n | head -n "${remove}" > "${TMP}"

         while read to_remove; do
            _techo "Removing ${to_remove} ..."
            rm $VVERBOSE -rf "$to_remove"
         done < "${TMP}"
      ) || _exit_err "
   fi

   #last_dir=$(ls -d "${c_dest}/${INTERVAL}."?* 2>/dev/null | sort -n | tail -n 1)
   #
   # Check for backup directory to clone from
   #
   found_old=0
   (
      # can we use ls? or will it produce broken results?
      #cd "${c_dest}" && ls -dp1 | grep "^${INTERVAL}\..*/\$" | wc -l | sed 's/^ *//g')
      cd "${c_dest}" && ls -dp1 "${INTERVAL}".* > "${TMP}"
   )
   while read old; do
      echo "Found ${old}"
   done < "${TMP}"

   #
   # Check for backups on other intervals, if we did not find any
   #

   #
   # clone the old directory with hardlinks
   #

   destination_date=$($CDATE)
   destination_dir="$c_dest/${INTERVAL}.${destination_date}.$$"

   #
   # FIXME: In 0.6 add search for the latest available backup!
   #
   last_dir=$(ls -d "$c_dest/${INTERVAL}."?* 2>/dev/null | sort -n | tail -n 1)

   # give some info
   echo "Beginning to backup, this may take some time..."

   echo "Creating $destination_dir ..."
   mkdir $VVERBOSE "$destination_dir" || \
      _exit_err "Creating $destination_dir failed. Skipping."

   #
   # make an absolute path, perhaps $CCOLLECT_CONF is relative!
   #
   abs_destination_dir="$(cd "$destination_dir" && pwd -P)"

   #
   # added mark in 0.6 (and remove it, if successful later)
   #
   touch "${abs_destination_dir}/${c_marker}"

   #
   # the rsync part
   # options partly stolen from rsnapshot
   #

   _techo "Transferring files..."


   #
   # FIXME:useropts / rsync extra: one parameter per line!
   # 0.5.3!
   #

   set -x
   rsync "$@" "$source" "$abs_destination_dir"; ret=$?
   #   abs_last_dir="$(cd "$last_dir" && pwd -P)"
  #    if [ -z "$abs_last_dir" ]; then
  #       echo "Changing to the last backup directory failed. Skipping."
  #       exit 1
  #    fi
  #    rsync_hardlink="--link-dest=$abs_last_dir"

   set +x
   if [ "$ret" -ne 0 ]; then
      echo "Warning: rsync exited non-zero, the backup may be broken (see rsync errors)."
   fi

   #
   # remove marking here
   #
   rm -f "${abs_destination_dir}/${c_marker}"

   _techo "Finished backup (rsync return code: $ret)."


   #
   # post_exec
   #
   if [ -x "${c_post_exec}" ]; then
      _techo "Executing ${c_post_exec} ..."
      "${c_post_exec}"; ret=$?
      _techo "Finished ${c_post_exec}."

      if [ ${ret} -ne 0 ]; then
         _exit_err "${c_post_exec} failed."
      fi
   fi

   # Calculation
   end_s=$(date +%s)

   full_seconds=$((${end_s} - ${begin_s}))
   hours=$(($full_seconds / 3600))
   seconds=$(($full_seconds - ($hours * 3600)))
   minutes=$(($seconds / 60))
   seconds=$((${seconds} - (${minutes} * 60)))

   _techo "Backup lasted: ${hours}:${minutes}:${seconds} (h:m:s)"

) | add_name
done

#
# Be a good parent and wait for our children, if they are running wild parallel
#
if [ "${PARALLEL}" ]; then
   _techo "Waiting for child jobs to complete..."
   wait
fi

#
# Look for post-exec command (general)
#
if [ -x "${CPOSTEXEC}" ]; then
   _techo "Executing ${CPOSTEXEC} ..."
   "${CPOSTEXEC}"
   ret=$?
   _techo "Finished ${CPOSTEXEC}."

   if [ ${ret} -ne 0 ]; then
      echo "${CPOSTEXEC} failed."
   fi
fi

rm -f "${TMP}"
_techo "Finished ${WE}"