#!/bin/bash

#
# Backup script.
# The backups are stored in /var/backups/local and the log
# in /var/logs/backup.log
#
# Parameters:
# $1 - File where all the references are stored.
#
# Not tested with folders with spaces.
#
{
	CACHE_REFERENCES="";

	# Log
	BACKUP_LOG="/var/log/backup.log";
	#BACKUP_LOG="backup.log";

	# Fichero por defecto.
	#REFERENCES_FILE="/etc/default/references.backup";
	REFERENCES_FILE="references.backup";

	# Directorio de backups.
	BACKUP_DIR="/var/backups/local";

	# Fecha de ejecucion
	NOW=`date '+%Y%m%d%H%M'`;

	#
	# Backup del directorio/fichero.
	# Param: Directorios o ficheros. Con secuencias de escape.
	#
	function backup_files() {

		tar cpfz "$BACKUP_DIR$NOW.backup.tar.gz" $1 1> /dev/null 2>> "$BACKUP_LOG";

		return $?;

	}

	#
	# Lectura del fichero de referencias.
	# Param: Fichero de referencias.
	# Return: 0 si se ha leido correctamente. 1 otherwhise.
	#
	function read_references() {

		if [ ! -f "$1" ]; then {
			echo "[$NOW] File $1 not found. Backup failed." >> "$BACKUP_LOG";
			return 1;
		} fi;

		COUNT=0;
		ERRORS=0;

		while read LINE; do {

			FILE=`echo "$LINE" | grep '^\ *[^#].*$'`;
			if [ "$FILE" == "" ]; then {
				continue;
			} elif [ -e "$FILE" ]; then {
				if [ "$CACHE_REFERENCES" != "" ]; then {
					CACHE_REFERENCES="$CACHE_REFERENCES $FILE";
				} else {
					CACHE_REFERENCES="$FILE";
				} fi;

				[ $? -eq 0 ] && echo "[$NOW] Added file $FILE to backup." >> "$BACKUP_LOG";
			} else {
				echo "[$NOW] File $FILE not found. Not added." >> "$BACKUP_LOG";
				let "ERRORS=$ERRORS+1";
			} fi;

			let "COUNT=$COUNT+1";

		} done < "$1";

		echo "[$NOW] Read $COUNT files/directories." >> "$BACKUP_LOG";
		[ $ERRORS -ne 0 ] && echo "[$NOW] Found $ERRORS errors." >> "$BACKUP_LOG";

		[ $COUNT -ne $ERRORS ] && return 0;
		return 1;
	}

	#
	# Main
	#
	{

		if [ ! -f "$BACKUP_LOG" ]; then {
			touch "$BACKUP_LOG";
		} fi;

		if [ "$1" != "" ]; then {
			REFERENCES_FILE="$1";
		} fi;

		echo "[$NOW] Init backup with the references in $REFERENCES_FILE" >> "$BACKUP_LOG";

		read_references "$REFERENCES_FILE";

		[ $? -eq 0 ] && backup_files "$CACHE_REFERENCES";

		if [ $? -ne 0 ]; then {
			echo "[$NOW] Backup failed." >> "$BACKUP_LOG";
			exit 1;
		} fi;

		echo "[$NOW] Backup successful." >> "$BACKUP_LOG";
		exit 0;

	}

}