#!/bin/sh
event=$1
# check event is defined or return
[[ -z "$event" ]] && exit 0
# check we run as post-install event or return
[[ "$event" == "post-install" ]] || exit 0
# check mariadb is not running or return
/usr/bin/pgrep  mariadbd && exit 0
# ONLY delete the mysql data dirictory if it is initial state
# we assume if only mysql, test, sys and performance_schema this is the case
validdirs="/var/lib/mysql/mysql/ /var/lib/mysql/performance_schema/ /var/lib/mysql/sys/ /var/lib/mysql/test/"
for dir in $(ls -d /var/lib/mysql/*/) ; do
    [[ $(echo ${validdirs} | grep ${dir}) ]] || exit 0
done

# we should be safe to reset dir content
# we use find as glob will ignore dot starting filename
# rm -rf /var/lib/mysql/*
find /var/lib/mysql -mindepth 1 -maxdepth 1 -print0 | xargs -0 rm -rf
exit 0