#!/bin/bash
#set -x

# get path to all needed tools
# /bin
echo=$(which echo)
gzip=$(which gzip)
grep=$(which grep)
mktemp=$(which mktemp)
mv=$(which mv)
pwd=$(which pwd)
rm=$(which rm)
umount=$(which umount)
# /usr/bin
cut=$(which cut)
dirname=$(which dirname)
expr=$(which expr)
head=$(which head)
mysql=$(which mysql)
mysqldump=$(which mysqldump)
nice=$(which nice)
rsync=$(which rsync)
seq=$(which seq)
ssh=$(which ssh)
sshfs=$(which sshfs)
tail=$(which tail)

# check if all needed tools are installed (only the ones not installed under /bin/)
alltoolsinstalled="yes"
test "$cut" = "" && echo "'cut' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$dirname" = "" && echo "'dirname' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$expr" = "" && echo "'expr' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$head" = "" && echo "'head' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$mysql" = "" && echo "'mysql' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$mysqldump" = "" && echo "'mysqldump' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$nice" = "" && echo "'nice' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$rsync" = "" && echo "'rsync' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$ssh" = "" && echo "'ssh' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$sshfs" = "" && echo "'sshfs' not installed or not found by 'which'" && alltoolsinstalled="no"
test "$tail" = "" && echo "'tail' not installed or not found by 'which'" && alltoolsinstalled="no"

if [ "$alltoolsinstalled" = "no" ]
then
   exit 1
fi

# main configuration
script_dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
config_file="$script_dir/main.cfg"

# remote and local directories
db_dir="$script_dir/db"
backupdirsingle=db

# source a specified section from a specified config
function source_section {
   config_name="$1"
   section_name="$2"
   section_start="^\[$section_name\]$"
   section_end="^\[/$section_name\]$"

   line_start=$($grep -n "$section_start" "$config_name" | $cut -d: -f1)
   line_end=$($expr $($grep -n "$section_end" "$config_name" | $cut -d: -f1) - 1)
   line_diff=$($expr $line_end - $line_start)

   tmp_file=$($mktemp)
   $head -n $line_end "$config_name" | $tail -n $line_diff > "$tmp_file"
   source "$tmp_file"
   $rm -f "$tmp_file"
}

# copy file with rsync to server
function rsync_server {
   filefrom="$1"
   dirto="$2"
   #nice -n 19 rsync -rle "ssh -i $keyfile" "$filefrom" "$userserver:$dirto"
   # limit the bandwith
   $nice -n 19 $rsync --bwlimit=100000 -rle "$ssh -i $keyfile" "$filefrom" "$userserver:$dirto"
   ret=$?
   if [ $ret -ne 0 ]
   then
      $echo "problem in rsync: $filefrom"
   fi
}

# general section from main config
source_section "$config_file" "general"

# change folder for temporary storage
cd "$db_dir"

# get all databases
databases=$($nice -n 19 $mysql -u root -N -e "show databases;" | $grep -v "^information_schema$" | $grep -v "^mysql$" | $grep -v "^performance_schema$")

# handle each database
for database in $databases
do
   # dump and gzip database
   $nice -n 19 $mysqldump -u root "$database" > "$database.sql"
   $nice -n 19 $gzip "$database.sql"

   # mount for renaming
   $sshfs $userserver:$backupdir $backupdir_local -o IdentityFile=$keyfile -o IdentitiesOnly=yes

   # rotate old backups
   for count in `seq 7 -1 2`
   do
      count_last=$($expr $count - 1)
      $rm -f "$backupdir_local/$backupdirsingle/$database.sql.gz.$count"
      $mv -f "$backupdir_local/$backupdirsingle/$database.sql.gz.$count_last" "$backupdir_local/$backupdirsingle/$database.sql.gz.$count" > /dev/null 2>&1
   done
   $rm -f "$backupdir_local/$backupdirsingle/$database.sql.gz.1"
   $mv -f "$backupdir_local/$backupdirsingle/$database.sql.gz" "$backupdir_local/$backupdirsingle/$database.sql.gz.1" > /dev/null 2>&1

   # unmount
   $umount $backupdir_local

   rsync_server "$database.sql.gz" "$backupdir/$backupdirsingle/"

   # delete temporary file
   $rm -f "$database.sql.gz"
done # for database in $databases