#!/bin/bash

function join {
	local d=$1;
	shift;
	local p=$1;
	shift;
	echo -n "$p$1";
	shift;
	printf "%s" "${@/#/$d$p}";
}

if ! lockfile-create -p -r 2 $0; then
	echo "Another backup is running, aborting"
	exit 49
fi

### Program arguments ###

# Backup target directory
BACKUP_TARGET=$1

# Backup local directory
BACKUP_DIRECTORY=$2

# Exclusions
BACKUP_EXCLUSIONS=$(join " " "--exclude=" $3)
echo "Exclusions: $BACKUP_EXCLUSIONS"

# Script executed before starting the backup
BEFORE_SCRIPT=$4

# Script executed after finishing the backup
AFTER_SCRIPT=$5

# Backup root path, change it to create a new backup
BACKUP_ROOT=$6

# Backup archive path, change it for each backup
BACKUP_ARCHIVE=$7

# Backup additional arguments
BACKUP_ARGS=$8

### Backup automatic properties ###
BACKUP_ROOT_PATH="$(cat /etc/hostname)"
BACKUP_BASE_PATH="$BACKUP_ROOT_PATH/$BACKUP_ROOT"
BACKUP_CONTENTS_PATH="$BACKUP_BASE_PATH/_backup/"


RSYNC_BASE_CMD=(rsync --timeout=120 -avzzhP)
RSYNC_BASE_CMD+=("$BACKUP_ARGS")

RSYNC_STRUCTURE_CMD=${RSYNC_BASE_CMD[*]}
RSYNC_STRUCTURE_CMD+=(--relative $BACKUP_CONTENTS_PATH $BACKUP_TARGET)

RSYNC_DATA_CMD=${RSYNC_BASE_CMD[*]}
RSYNC_DATA_CMD+=(--delete --inplace $BACKUP_EXCLUSIONS)
if [ ! -z "$BACKUP_ARCHIVE" ]; then
	RSYNC_DATA_CMD+=(--backup --backup-dir=../$BACKUP_ARCHIVE)
fi
RSYNC_DATA_CMD+=($BACKUP_DIRECTORY $BACKUP_TARGET/$BACKUP_CONTENTS_PATH)

echo "Starting backup. Target: $BACKUP_BASE_PATH. Archive: $BACKUP_ARCHIVE"

### Before Script ###
echo "Before script ..."
eval "$BEFORE_SCRIPT"
echo "Done"

### Create local model of the remote's backup directory tree and send it ###
echo "Directory structure..."
cd ~/
mkdir -p "$BACKUP_CONTENTS_PATH"
eval ${RSYNC_STRUCTURE_CMD[*]} || exit 1
echo "Done"

### Backup home directory except some unwanted files ###
echo "Backup data..."
eval ${RSYNC_DATA_CMD[*]} || exit 1
echo "Done"

### Remove local model of the backup directory tree ###
rm -R "$BACKUP_ROOT_PATH"

### After Script ###
eval "$AFTER_SCRIPT"


# Remove lock
echo "Backup finished. Removing lock..."
lockfile-remove $0