#!/bin/bash

set -e

# Environment variables
#
# CONTAINER - name of the container where the database is running
# NOTIFY_URL - optional, URL to send notification to
# TARGET_DIR - directory where to store the backup
# HISTORY - number of backups to keep (default: 3)

if [ -z "$CONTAINER" ]; then
    echo "CONTAINER environment variable is not set."
    exit 1
fi

if [ -z "$TARGET_DIR" ]; then
    echo "TARGET_DIR environment variable is not set."
    exit 1
fi

if [ -z "$HISTORY" ]; then
    HISTORY=3
fi

docker info > /dev/null 2>&1
if [ ! $? -eq 0 ]; then
    echo "Docker is not available."
    exit 1
fi

if [ ! -d "$TARGET_DIR" ]; then
    echo "TARGET_DIR does not exist. Creating it..."
    exit 2
fi


echo "Starting backup for container: $CONTAINER"
if [ `docker exec -i $CONTAINER test -e /usr/bin/mariadb-dump && echo "yes" || echo "no"` = "yes" ]; then
    DBTYPE="mariadb"
    FILENAME=`date +"%Y%m%d_%H%M%S"`_$DBTYPE_$CONTAINER.sql.zst
    docker exec -i $CONTAINER mariadb-dump \
        --all-databases \
        --user=root \
        --password=$MARIADB_ROOT_PASSWORD \
        --add-drop-trigger \
        --add-drop-table \
        --add-drop-database \
        --hex-blob \
        --compress \
        --events \
        --routines \
        --single-transaction \
        --triggers | zstd -1 > $TARGET_DIR/$FILENAME.tmp
        mv $TARGET_DIR/$FILENAME.tmp $TARGET_DIR/$FILENAME
elif [ `docker exec -i $CONTAINER test -e /usr/bin/pg_dump && echo "yes" || echo "no"` = "yes" ]; then
    DBTYPE="pgsql"
    FILENAME=`date +"%Y%m%d_%H%M%S"`_$DBTYPE_$CONTAINER.sql.zst
    docker exec -i $CONTAINER pg_dumpall --username=$DB_USER --password=$PGPASSWORD | zstd -1 > $TARGET_DIR/$FILENAME.tmp
    mv $TARGET_DIR/$FILENAME.tmp $TARGET_DIR/$FILENAME
else
    echo "Unsupported database type or database client not found in the container."
    exit 1
fi

echo "Backup completed successfully."

# Remove old backups
echo "Removing old backups, keeping last $HISTORY backups..."
cd $TARGET_DIR
ls -1t *_$DBTYPE_$CONTAINER.sql.zst | tail -n +$((HISTORY + 1)) | xargs -r rm --
cd -
echo "Old backups removed."


if [ -n "$NOTIFY_URL" ]; then
    curl $NOTIFY_URL
fi