#! /bin/sh

#
# MariaDB Backup
# Do backup of one or all databases of a given MariaDB server
#

#
# List Databases
#

# only argument is a database url
DB_URL="$1";

# load database values as environment variables while checking URL validity
#
# will populate variables
# - $DB_USERNAME
# - $DB_PASSWORD
# - $DB_HOST
# - $DB_PORT
# - $DB_NAME
# - any query var as a prefixed variable $db_arg_${name}=${value}
dburl-parser.sh ${DB_URL} > /tmp/ofelia.dotenv;
source /tmp/ofelia.dotenv;
rm /tmp/ofelia.dotenv;

# set backup destination
if test -z "${BACKUP_DATABASES_PATH}"; then
    echo "failed initializing backup -- \$BACKUP_DATABASES_PATH is empty";
    exit 1;
fi
## set subdirectory
backup_path="/$(
    echo "/${BACKUP_DATABASES_PATH}/${db_arg_directory:-\/}/"\
    | sed 's/\/\{1,\}/\//g'\
    | sed 's/^\/\(.*\)\/$/\1/'
    )/"

## directory path
mkdir -p ${backup_path};
## file name
backup_prefix="${db_arg_prefix:-backup-}";
backup_extension="${db_arg_file_extension:-SQL}";

# set databases list
if test "${DB_NAME}" = '*'; then
    ## build a list with every database name if * is informed
    databases=$(mysql\
        --user=${DB_USERNAME}\
        --password=${DB_PASSWORD}\
        --host="${DB_HOST}"\
        --execute="SHOW DATABASES;"\
        --vertical\
        --column-names=false\
        | grep -ve ^\*\
        | xargs
    );
else
    ## use the database informed or force using --all-databases param
    databases="${DB_NAME:-::ALL_DATABASES::}";
fi

# proccess each database
for database_item in ${databases}; do
    if test -z "${database_item}"; then
        ## skip empty lines
        continue;
    elif test "${database_item}" = "::ALL_DATABASES::"; then
        # backup everything in a single file if no database was set
        database="--all-databases";
        filename_database="all-databases";
    else
        # backup each database name to its own file
        database="--databases ${database_item}";
        filename_database="${database_item}";
    fi
    cat | xargs mariadb-dump << HEREDOC
$(test -n ${DB_USERNAME} && echo "--user=${DB_USERNAME}")
$(test -n ${DB_PASSWORD} && echo "--password=${DB_PASSWORD}")
$(test -n ${DB_HOST} && echo "--host=${DB_HOST}")
$(test -n ${DB_PORT} && echo "--port=${DB_PORT}")
--result-file=$(
    printf '%s/%s%s-%s_%s.%s'\
    ${backup_path}\
    ${backup_prefix}\
    ${DB_HOST}\
    ${filename_database}\
    $(date +%s)\
    ${backup_extension}
)
${database}
HEREDOC
done