#!/usr/bin/env sh

# Usage:
# postgres_backup.sh [man]		//Manual backup
# postgres_backup.sh auto		//Auto backup (separate backup location)
# postgres_backup.sh [auto|man] debug	//Outputs status messages to STDOUT

# CONFIG
### Example Config File ############
###
### PORT=5432
### DIR=/var/lib/pgsql/backup
### COMPRESSION=zstd
### COMP_LEVEL=14
### THREADS=2
###
####################################

source ${HOME}/.postgres_backup.conf
# END CONFIG


## Check if debug mode is called, and define debug message function
[ "$2" = "debug" ] && DEBUG="true" || DEBUG="false"
msg_debug() {
	[ "$DEBUG" = "true" ] && echo -e "$1"
}


## Check if automated, set appropriate directory
[ "$1" = "auto" ] && DIR=${DIR}/auto || DIR=${DIR}/manual
msg_debug "Backup directory set to $(tput bold)${DIR}$(tput sgr0)"

## Set date for timestamp
DATE=$(date +%Y%m%d-%H%M)
msg_debug "Date set to $(tput bold)${DATE}$(tput sgr0)"

## Get list of DBs
list_db=$(psql -p${PORT} -U postgres -t -c 'select datname from pg_database;' | grep -v 'template0\|template1\|postgres' | sed '/^$/d')

case $COMPRESSION in
	xz)
		compress="xz -T${THREADS} -${COMP_LEVEL} -"
		comp_ext="xz"
		msg_debug "Compression set to $(tput bold)${COMPRESSION}$(tput sgr0)"
		;;
	zstd)
		compress="zstd -T${THREADS} -${COMP_LEVEL} -z -"
		comp_ext="zst"
		msg_debug "Compression set to $(tput bold)${COMPRESSION}$(tput sgr0)"
		;;
	*)
		echo "ERROR 11: Compression not configured correctly!" >2
		exit 11
		;;
esac

msg_debug "\nStarting backup procedures...\n"

## Backup globals
pg_dumpall -p${PORT} -g | eval $compress > ${DIR}/globals_${DATE}.dmp.${comp_ext}
msg_debug "Backed up $(tput setaf 2)$(tput bold)globals$(tput sgr0) as '$(tput setaf 3)${DIR}/globals_${DATE}.dmp.${comp_ext}$(tput sgr0)' using '$(tput bold)${compress}$(tput sgr0)'"

msg_debug "Starting DB dump loop..."
for db in $list_db; do
	target="${DIR}/${db}_${DATE}.dmp.${comp_ext}"
	pg_dump -O $db | eval $compress > $target
	msg_debug "Backed up '$(tput setaf 2)$(tput bold)${db}$(tput sgr0)' as '$(tput setaf 3)${target}$(tput sgr0)' using '$(tput bold)${compress}$(tput sgr0)'"
done

exit 0