#!/bin/bash

#Enable pipefail to receive the error code of rsync and not only tee
set -Eeuo pipefail

trap 'on_error $LINENO' ERR

on_error() {
    local line=$1
    echo "ERROR: Script failed at line $line" >&2

    if [ -f "$tmpLogFilePath" ]; then
        mailContent=$(cat "$tmpLogFilePath")
    else
        mailContent="Log file not available"
    fi

    {
        echo "To: $mailTo"
        echo "From: $mailFrom"
        echo "Subject: Backup FAILED (CRASH) on $(date +'%c')"
        echo ""
        echo "Script crashed at line $line"
        echo ""
        echo "$mailContent"
    } | sendmail -t

    exit 1
}

#Check if path to the config file was provided
if [ -z "$1" ]
then
    echo "Please call this script with the path to the config file!"
    exit
fi


#Read the backup folders and configuration variables from the config script
. $1

#Local variables
globalErrors=0
logFilePath="${logPath}${logFileName}"

#Rotate logs
find $logPath -type f -mtime +$rotationDays -name '*.log' -execdir rm -- '{}' \;

touch $tmpLogFilePath
touch $logFilePath

echo $logFilePath

#Terminate if the last backup has not finished yet
if pidof -o %PPID -x "$0" > /dev/null; then
	echo "Backup job already running. Exiting..."
	exit
fi

#Run the backup jobs as defined in the backup_folders array from the config
echo "Starting backup job(s)" | tee $tmpLogFilePath
for sourceFolder in "${!backup_folders[@]}"
do
	#Exclude files
	IFS=';' read -ra split <<< "${backup_folders[$sourceFolder]}"
	#check if exclude file is not zero and file exists. Set to zero if not existing.
	excludeDIRs=${split[1]-}
	if [[ -n ${excludeDIRs} ]] && ! [ -f ${excludeDIRs} ]; then
		echo "Error: Could not find exclude file ${excludeDIRs}. Ignoring it." | tee -a $tmpLogFilePath
		excludeDIRs=""
	fi

	destinationFolder=${split[0]}
	mkdir -p ${destinationFolder}


	while [ "$retryAttempts" -ge "0" ]
	do
		echo "Starting Job" | tee -a $tmpLogFilePath
		echo "SRC: ${sourceFolder}" | tee -a $tmpLogFilePath
		echo "DEST: ${destinationFolder}" | tee -a $tmpLogFilePath
		echo "Exclude file: ${excludeDIRs}" | tee -a $tmpLogFilePath
		date | tee -a $tmpLogFilePath
		#SSH Host settings need to be set in the ssh client config!
		rsync --delete --out-format="%t %f %''b" -avz ${excludeDIRs:+"--exclude-from=$excludeDIRs"} ${sourceFolder} ${destinationFolder} 2>&1 | tee -a $tmpLogFilePath 2>&1
		rsyncExitCode=$?
		echo "Ending backup job" | tee -a $tmpLogFilePath
		date | tee -a $tmpLogFilePath
		echo "" | tee -a $tmpLogFilePath

		if [ $rsyncExitCode -eq 0 ]; then
			break
		else
			echo "Error: rsync exited with code $rsyncExitCode. Retrying..." | tee -a $tmpLogFilePath
			retryAttempts=$((retryAttempts-1))
			globalErrors=$((globalErrors+1))
		fi
	done
done

#copy over
cat $tmpLogFilePath > $logFilePath

#Mail Notifications
if [ $globalErrors -eq 0 ]; then
	#send mail for success
	echo -e "To:$mailTo\nFrom:$mailFrom\nSubject:Backup SUCCESSFUL on $(date +'%c')\n\n$(cat $tmpLogFilePath)" | sendmail $mailTo
else
	#send mail for failure
	echo -e "To:$mailTo\nFrom:$mailFrom\nSubject:Backup FAILED on $(date +'%c')\n\n$(cat $tmpLogFilePath)" | sendmail $mailTo
fi

#delete tmp file
rm $tmpLogFilePath