#!/bin/bash
# Copyright 2021 Luca Paris
#This file is part of masync.

#masync is free software: you can redistribute it and/or modify
#it under the terms of the GNU General Public License as published by
#the Free Software Foundation, either version 3 of the License, or
#(at your option) any later version.

#masync is distributed in the hope that it will be useful,
#but WITHOUT ANY WARRANTY; without even the implied warranty of
#MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#GNU General Public License for more details.

#You should have received a copy of the GNU General Public License
#along with masync.  If not, see <http://www.gnu.org/licenses/>.

## REQUIREMENT
# apt-get install inotify-tools
# @1   hash to retrieve sync
# @2   local path to sync
# @3   remote path to sync
#echo "$1, $2, $3"
source ~/bin/.synccmd.sh
TMPQUEUEFILE=~/.syncdir_$1.queue
TMPQUEUEDELETES=~/.syncdir_$1.deletes

LOCALPATH_HASH=$1
LOCALPATH=$2
REMOTEPATH=$3

REMOTEHOST=$(echo "$REMOTEPATH" | cut -d : -f 1 | cut -d @ -f 2)
REMOTERELATIVEPATH=$(echo "$REMOTEPATH" | cut -d : -f 2)

synccycle() {
  lastsynctime="$(date -u +%s.%N)"
  ### max waiting time for pull (seconds) 
  maxpulllimit=30
  while :
  do
    if [ -f "$TMPQUEUEFILE" ]; then 
      nqueue=$(wc -l < ${TMPQUEUEFILE})
      if [ $nqueue -gt 0 ]; then
        echo "${TMPQUEUEFILE} not empty syncing ${nqueue} actions from queue"
        ## FIRST STEP push deletion if there are
        if [ -f "$TMPQUEUEDELETES" ]; then 
          ndeletes=$(wc -l < ${TMPQUEUEDELETES})
          echo "delete queue $ndeletes"
          cat "${TMPQUEUEDELETES}"
          if [ $ndeletes -gt 0 ]; then
            ssh $REMOTEHOST "rm -rf $(head -n $ndeletes ${TMPQUEUEDELETES} | tr '\n', ' ')"
            # remove the first ndeletes lines
            tail -n +$(expr ${ndeletes} + 1) < ${TMPQUEUEDELETES} > ${TMPQUEUEDELETES}
          fi
        fi
        ## end push deletion if there are
        sync $LOCALPATH_HASH $LOCALPATH $REMOTEPATH 
        # remove the first nqueue lines from queue
        tail -n +$(expr ${nqueue} + 1) < ${TMPQUEUEFILE} > ${TMPQUEUEFILE}
        lastsynctime="$(date -u +%s.%N)"
        ## step to next iteration
        continue
      fi
    fi
    now="$(date -u +%s.%N)"
    elapsed="$(bc <<<"$now-$lastsynctime")"
    ## if elapsed is greater than maxpulllimit sync from remote with delete option
    if [ 1 -eq $(echo "$elapsed>$maxpulllimit" | bc) ]; then
      echo 'maxpulllimit reached: sync from remote with --delete option'
      sync $LOCALPATH_HASH $REMOTEPATH $LOCALPATH '--delete' 
      lastsynctime="$(date -u +%s.%N)"
    fi
  done
}

synccycle &

# exclude swp,swpx and 4913 files created by vim
# inotifywait -m -r -e close_write -e move -e delete --exclude "\.swp|\.swx|4913|.txt~" ~/googleDrive/Copy/Appunti/
inotifywait -m -r -e close_write -e move -e delete --exclude "\.swp|\.swx|4913|.txt~" $LOCALPATH | while read dir action file; do
    if [ $action = 'DELETE' ] || [ $action = 'DELETE,ISDIR' ]; then
      echo "Enqueue delete: $dir$file"
      echo $dir$file | sed -e "s~$LOCALPATH~$REMOTERELATIVEPATH~g" | tee -a ${TMPQUEUEDELETES}
    fi
    echo "Add notify to queue: file '$file' in directory '$dir' for '$action'" | tee -a ${TMPQUEUEFILE}
  done