#!/bin/bash
# ---------------------------------------------------------------
# Company:		University of Rostock
# Engineer:		Tim Brockmann
# Create Date:  17.10.2023
# Project Name:	APU-testbed
# File Name:    start_backup.sh
# Target OS:	Tiny Core Linux 14.0
# Dependencies: - rsync v3.1.1
# Task:
# This script is part of the pre-configured tiny core and
# initializes the backup process. Therefore it fetches the
# ----------------------------------------------------------------
# 1. create logfile and prepare local and remote paths
# ----------------------------------------------------------------
# define timezone and update time
export TZ=Europe/Berlin
sudo ntpd -q
sh /etc/init.d/settime.sh
sleep 10 # wait to set the correct ntp time

# define the control pc as the central testbed instance
export CTRLPC=192.168.0.1

# get execution time of the script
export EXEC_TIME=$(date "+%Y-%m-%d_%T")

# Get my current IP address (eth0)
export IP_ADDRESS=$(ifconfig eth0 | grep -o -E 'inet addr:([0-9]{1,3}\.){3}[0-9]{1,3}' | awk -F ':' '{print $2}')

# Perform the nslookup and store the result in a variable
export NSLOOKUP_RESULT=$(nslookup $IP_ADDRESS)

# Extract the hostname and path's from the nslookup result using awk
export APU_HOSTNAME=$(echo "$NSLOOKUP_RESULT" | awk '/Name:/{getline; print}' | awk '{print $4}')
export LOG_FILE_NAME="${EXEC_TIME}_${APU_HOSTNAME}_backup.log"
export LOCAL_LOG_FILE="/home/tc/${LOG_FILE_NAME}"

# create empty log file
touch $LOCAL_LOG_FILE
echo "Start -----------------------------------------------------------------" | tee -a ${LOCAL_LOG_FILE}
time_to_wait=$((0 + $RANDOM % 15))
echo "Waiting random time ($time_to_wait seconds) to avoid a simultaneous access to the rsync server" | tee -a ${LOCAL_LOG_FILE}
sleep $time_to_wait

# log path on cotrol pc
export REMOTE_PATH="/home/tftproot/"
export REMOTE_LOG_PATH="${REMOTE_PATH}backup_logs/${APU_HOSTNAME}/"
export BACKUP_SCRIPT_NAME="apu_backup_plan.sh"
export PART_SCRIPT_NAME="partitioning_ssd.sh"

get_backup_instructions() {
	# gets apu_backup_plan.sh from control pc
	echo "Start getting backup plan....." | tee -a ${LOCAL_LOG_FILE}
	rsync -ahxL --stats --delete -e 'ssh -o StrictHostKeyChecking=no' apu@"${CTRLPC}":${REMOTE_PATH}${BACKUP_SCRIPT_NAME} /home/tc/ | tee -a ${LOCAL_LOG_FILE}
	rsync -ahxL --stats --delete -e 'ssh -o StrictHostKeyChecking=no' apu@"${CTRLPC}":${REMOTE_PATH}${PART_SCRIPT_NAME} /home/tc/ | tee -a ${LOCAL_LOG_FILE}
	echo "Getting backupplan done ............." | tee -a ${LOCAL_LOG_FILE}
}

run_backup() {
	bash /home/tc/${BACKUP_SCRIPT_NAME} | /opt/scripts/predate.sh | tee -a ${LOCAL_LOG_FILE}
}

transfer_logfile() {
	# create directory
	rsync -ahx --inplace --stats --delete -e 'ssh -o StrictHostKeyChecking=no' /home/tc/*.log apu@"${CTRLPC}":"${REMOTE_LOG_PATH}"
	# rsync log file
}

# create remote directory (-p .. make parent directories as needed)
ssh apu@${CTRLPC} "mkdir -p "${REMOTE_LOG_PATH}""

# ------------------------------------------------------------------------------------------------
# 2. copy the backup script from the ctrlpc
# ------------------------------------------------------------------------------------------------
get_backup_instructions

# ------------------------------------------------------------------------------------------------
# 3. run the backup script
# ------------------------------------------------------------------------------------------------
run_backup

# ------------------------------------------------------------------------------------------------
# 4. copy the logfile to the ctrlpc
# ------------------------------------------------------------------------------------------------
echo "Done ------------------------------------------------------------------" | tee -a ${LOCAL_LOG_FILE}
transfer_logfile

# ------------------------------------------------------------------------------------------------


# on node side the bootlocal-script starts the run-script:
## run script
#   1. the run script creates an empty logfile with the hostname in the identifier (e.g. apu84_tc.log)
#   2. get backup script and backup plan file (backup_plan.conf) from ctrl pc
#   3. if there is no one, write it to the logfile and stop this run
#   -> otherwise
#   4. if both files are loaded, run the backup script
#
## stop run (part of run script)
#   1. close log file
#   2. rsync the logfile to the control pc (specific location is nedded -> node_logs)
#   3. reboot (or wait for reboot -> still not clear -> leave configurable)