#!/bin/bash

set -e

user="root"
passwd_file="/root/.my.cnf"
passwd=""
timeout=0
mysql_running=0
mysql_status=""
mysqlsafe_running=0
sqltest="$(mktemp /tmp/lliurex-sgbdXXXX)"

echo "quit" > $sqltest

do_check_user(){

	local uid=$(id -u)
	[ $uid -ne 0 ] && return 1
	return 0

}

do_create_passwd(){

	passwd="`pwgen --capitalize --numerals 7 1`"

}

do_get_passwd(){

	passwd=$(sed -ne "/^\[mysql\]/,/^\[/s%^password[^=]\+=[[:space:]]\+%%p" "$passwd_file") 

}

is_mycnf_present(){

	if [ ! -e "$passwd_file" ] ; then
		# root my.cnf file does not exists
		# generate password for root
		return 1
	fi
	return 0

}

do_write_mycnf(){

cat << EOF
[mysql]
user            = $user
password        = $passwd

[mysqladmin]
user            = $user
password        = $passwd

[mysqldump]
user            = $user
password        = $passwd
EOF

return 0

}

do_fix_permission(){

   chmod 600 $passwd_file 

}

do_write_passsql() {

cat << EOF
use mysql
update user set password=password('$passwd') where user='$user';
flush privileges;
exit
EOF

return 0

}

is_mysql_alive(){

	local ret
	local pid
	
	ret=0
        pid=$(pidof mysqld) || ret=1
	mysql_status="$(LC_ALL=C service mysql status 2>&1)"

        [ $ret -eq 0 ] && return 0
	return 1

}

#------
# main
#-----

if ! do_check_user ; then
	echo "You must be root to execute this utility"
	exit 1
fi

# If mysql is running we activate this flag

if [ "$1" = "is-mysql-live" ]; then
	if is_mysql_alive && [ "$mysql_status" != "status: Unknown job: mysql" ]; then
		exit 0
	else
		exit 1
	fi
fi

if is_mysql_alive ; then
	mysql_running=1
fi

if is_mycnf_present && [ "$1" != "force-upgrade" ]; then
	# If my.cnf file exists then sync in mysql
	do_get_passwd
else
	# If not present my.cnf then we create a passwd
	# and a my.cnf file
	do_create_passwd
	do_write_mycnf > "$passwd_file"
fi

do_fix_permission 

if [ $mysql_running -eq 1 ] ; then
	if ! mysql -u $user -p$passwd < $sqltest 2>/dev/null; then
		rm -f $sqltest
		echo " * Mysql database server running, setting Safe Mode"
		[ "$mysql_status" != "mysql stop/waiting" ] && service mysql stop 2>/dev/null >/dev/null
	else
		rm -f $sqltest
		exit 0
	fi
else
	echo " * Mysql database server is not running"
	exit 0
fi

# Mysql is started in safe mode
/usr/bin/mysqld_safe --skip-grant-tables 2>/dev/null >/dev/null &

while [ $timeout -lt 3 -a $mysqlsafe_running -eq 0 ] ; do

	sleep 1

	if is_mysql_alive ; then
        	mysqlsafe_running=1
	fi

	timeout=$(($timeout+1))

done

if [ $mysqlsafe_running -eq 1 ] ; then
	# Sql statement to set password created
	sqltemp="$(mktemp /tmp/lliurex-sgbdXXXX)"
	do_write_passsql > $sqltemp 
	# Password is assigned in mysql 
	/usr/bin/mysql < $sqltemp
	echo " * Mysql root password assigned"
	# tempfile deleted
	rm -f $sqltemp
else
	echo " * Mysql root password cannot be assigned"
	echo " * Root password assigment deferred to next execution of this utility"
	echo "   or next reboot of the machine"
	exit 1
fi

# If mysql was running when the utility is invoked then restart mysql
# else stop mysql because for changing the password it was started 
# in safe mode
if [ $mysql_running -eq 1 ] || [ $mysqlsafe_running -eq 1 ]; then
	echo " * Mysql database server was running, so restarting"
	killall mysqld
	service mysql start 2>/dev/null >/dev/null
else
	echo " * Mysql database server was stopped, so stopping"
	service mysql stop 2>/dev/null >/dev/null
fi

exit 0