#!/bin/bash

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#                                                                               
# 1. set exec perms
# chmod +x pg_backup.sh   
# 2. run .pg_backup db_01 db_02 ... db_n
#

set -e

# CONTAINER="database"
CONTAINER="postgres"
# DB_USER="odoo"
DB_USER="postgres"
DATE=$(date +%Y%m%d)
TIME=$(date +%H%M%S)
DAYS_TO_KEEP=7
# BACKUP_PATH="/mnt/backup/local"
# CLONE_PATH="/mnt/backup/nfs"
BKP_PATH="/home/robert/test_pg_backup"
SYNC_PATH="/home/robert/test_sync_backup"
TMP_PATH="." 

# perform database backup if docker exist
perform_backups()
{
    if [ ! -x "$(command -v docker)" ]; then
        echo "cannot perform backup"
        exit 1
    fi

    local BKP_TODAY_PATH=$(printf "%s/backup_%s" "$BKP_PATH" "$DATE")

    if [ ! -d "$BKP_TODAY_PATH" ]; then
        mkdir "$BKP_TODAY_PATH"
    fi

    for DB_NAME in $@; do
        local TMP_FILE=$(printf "%s/%s_%s.tar" "$TMP_PATH" "$DB_NAME" "$TIME")

        docker exec $CONTAINER pg_dump -U $DB_USER -d $DB_NAME -F tar -C -b -c -f $TMP_FILE
        docker cp $CONTAINER:$TMP_FILE $BKP_TODAY_PATH
        docker exec $CONTAINER rm $TMP_FILE
    done
}

# delete old backups
delete_old_backups() 
{
    find $1 -maxdepth 1 -type d -name "backup_*" -mtime +$2 -exec rm -rf '{}' ';'
}

# sync two backup paths
local_sync_backups_path() 
{
    if [ ! -x "$(command -v rsync)" ]; then
        echo "cannot sync backups path"
        exit 1
    fi

    rsync -arz $1 $2
}

# sync two backup paths remotely
remote_sync_backups_path()
{
    if [ ! -x "$(command -v rsync)" ]; then
        echo "cannot sync backups path"
        exit 1
    fi

    rsync -arz "ssh -p $1" "$2@$3:$4" $5
}

perform_backups $@
delete_old_backups $BKP_PATH $DAYS_TO_KEEP
sync_local_backups_path $BKP_PATH $SYNC_PATH

exit 0