#!/bin/bash
 
###########################
####### LOAD CONFIG #######
###########################
 
SCRIPTPATH=$(cd ${0%/*} && pwd -P)
source $SCRIPTPATH/pg_backup.config
 
 
###########################
#### PRE-BACKUP CHECKS ####
###########################
 
# Make sure we're running as the required backup user
if [ $BACKUP_USER != "" -a "$(id -un)" != "$BACKUP_USER" ]; then
	echo "This script must be run as $BACKUP_USER. Exiting."
	exit 1;
fi;
 
 
###########################
### INITIALISE DEFAULTS ###
###########################
 
if [ ! $HOSTNAME ]; then
	HOSTNAME="localhost"
fi;
 
if [ ! $USERNAME ]; then
	USERNAME="postgres"
fi;
 
 
###########################
#### START THE BACKUPS ####
###########################
 
 
FINAL_BACKUP_DIR=$BACKUP_DIR"`date +\%Y-\%m-\%d`/"
 
echo "Making backup directory in $FINAL_BACKUP_DIR"
 
if ! mkdir -p $FINAL_BACKUP_DIR; then
	echo "Cannot create backup directory in $FINAL_BACKUP_DIR. Go and fix it!"
	exit 1;
fi;
 
 
###########################
### SCHEMA-ONLY BACKUPS ###
###########################
 
for SCHEMA_ONLY_DB in ${SCHEMA_ONLY_LIST//,/ }
do
	SCHEMA_ONLY_CLAUSE="$SCHEMA_ONLY_CLAUSE or datname ~ '$SCHEMA_ONLY_DB'"
done
 
SCHEMA_ONLY_QUERY="select datname from pg_database where false $SCHEMA_ONLY_CLAUSE order by datname;"
 
echo -e "\n\nPerforming schema-only backups"
echo -e "--------------------------------------------\n"
 
SCHEMA_ONLY_DB_LIST=`psql -h "$HOSTNAME" -U "$USERNAME" -At -c "$SCHEMA_ONLY_QUERY" postgres`
 
echo -e "The following databases were matched for schema-only backup:\n${SCHEMA_ONLY_DB_LIST}\n"
 
for DATABASE in $SCHEMA_ONLY_DB_LIST
do
	echo "Schema-only backup of $DATABASE"
 
	if ! pg_dump -Fp -s -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" | gzip > $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz.in_progress; then
		echo "[!!ERROR!!] Failed to backup database schema of $DATABASE"
	else
		mv $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE"_SCHEMA.sql.gz
	fi
done
 
 
###########################
###### FULL BACKUPS #######
###########################
 
for SCHEMA_ONLY_DB in ${SCHEMA_ONLY_LIST//,/ }
do
	EXCLUDE_SCHEMA_ONLY_CLAUSE="$EXCLUDE_SCHEMA_ONLY_CLAUSE and datname !~ '$SCHEMA_ONLY_DB'"
done
 
FULL_BACKUP_QUERY="select datname from pg_database where not datistemplate and datallowconn $EXCLUDE_SCHEMA_ONLY_CLAUSE order by datname;"
 
echo -e "\n\nPerforming full backups"
echo -e "--------------------------------------------\n"
 
for DATABASE in `psql -h "$HOSTNAME" -U "$USERNAME" -At -c "$FULL_BACKUP_QUERY" postgres`
do
	if [ $ENABLE_PLAIN_BACKUPS = "yes" ]
	then
		echo "Plain backup of $DATABASE"
 
		if ! pg_dump -Fp -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" | gzip > $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress; then
			echo "[!!ERROR!!] Failed to produce plain backup database $DATABASE"
		else
			mv $FINAL_BACKUP_DIR"$DATABASE".sql.gz.in_progress $FINAL_BACKUP_DIR"$DATABASE".sql.gz
		fi
	fi
 
	if [ $ENABLE_CUSTOM_BACKUPS = "yes" ]
	then
		echo "Custom backup of $DATABASE"
 
		if ! pg_dump -Fc -h "$HOSTNAME" -U "$USERNAME" "$DATABASE" -f $FINAL_BACKUP_DIR"$DATABASE".custom.in_progress; then
			echo "[!!ERROR!!] Failed to produce custom backup database $DATABASE"
		else
			mv $FINAL_BACKUP_DIR"$DATABASE".custom.in_progress $FINAL_BACKUP_DIR"$DATABASE".custom
		fi
	fi
 
done
 
echo -e "\nAll database backups complete!"