#!/bin/bash

set -e

user="root"
passwd_file="/root/.my.cnf"
utf8_cnf="/etc/mysql/conf.d/utf8_charset.cnf"
mysqlSock="/var/run/mysqld/mysqld.sock"
passwd="null"
sqltest="$(mktemp /tmp/lliurex-sgbdXXXX)"
debug=0
limit=10
alive=2
type_db=""

mysql_version_upper(){
    local ret=1;
    ver=$(mysqld --version 2>&1|perl -nE '/(\d+\.\d+\.\d+)/ && print $1')
    is_maria=$(mysqld --version 2>&1|grep -io 'mariadb'|wc -l)
    if [ $is_maria -gt 0 ]; then
	type_db='maria';
    else
	type_db='mysql';
    fi
    
    if [ "$type_db" = "maria" ]; then 
	ret=0
    else
	if dpkg --compare-versions $ver gt "5.7.6"; then ret=0; fi;
    fi


    if [ $debug -eq 1 ]; then
	if [ $ret -eq 0 ]; then
    	    echo "Compare versions: Detected $type_db version $ver (mysql > 5.7.6 new user tables)"
	else
	    echo "Compare versions: Detected $type_db version $ver (mysql < 5.7.6)"
	fi
    fi

    return $ret
}

is_mysql_alive(){
	local ret=1
	alive=1
	tst=$(ps ax|grep mysqld|grep -v grep|wc -l)
	if [ -e $mysqlSock ] && [ $tst -gt 0 ]; then
		ret=0
		alive=0
	fi
	if [ $debug -eq 1 ] ; then
	    if [ $ret -eq 0 ]; then
		echo "mysqld esta vivo!"
	    else
		echo "mysqld esta muerto!"
	    fi
	fi
	return $ret
}

do_create_passwd(){
	passwd="`pwgen --capitalize --numerals 7 1`"
	do_write_mycnf > "$passwd_file"
	chmod 600 $passwd_file

	return 0
}

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

	if [ $debug -eq 1 ] ; then
		echo "pass root Mysql:"$passwd
	fi

	return 0	
}

do_write_passSql() {
	local sqlQuery
	
	if mysql_version_upper; then
	    sqlQuery="UPDATE mysql.user SET authentication_string=PASSWORD('$passwd'),plugin='mysql_native_password',password_expired='N' WHERE User='root'; "
	    # NEED TO CHANGE AUTH PLUGIN abobe fails when --skip-grant-tables
	    #sqlQuery="ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '$passwd'; "
	    
	else
	    sqlQuery="UPDATE mysql.user SET Password=PASSWORD('$passwd') WHERE User='root'; "
	fi
        SQLQUERY_UPDATE=$sqlQuery"FLUSH PRIVILEGES;"

	return 0
}

do_write_mycnf(){
	echo -e "[mysql]"
	echo -e "user       = "$user
	echo -e "password   = "$passwd
	echo -e ""
	echo -e "[mysqladmin]"
	echo -e "user       = "$user
	echo -e "password   = "$passwd
	echo -e ""
	echo -e "[mysqldump]"
	echo -e "user       = "$user
	echo -e "password   = "$passwd

	return 0
}

do_write_utf8_cnf(){
	echo -e "[mysqld]"
	echo -e "character-set-server=utf8"
	echo -e "collation-server=utf8_general_ci"
	echo -e "init-connect='SET NAMES utf8'"
	echo -e ""
	echo -e "[client]"
	echo -e "default-character-set=utf8"
	echo -e ""
	
	return 0
}

do_create_utf8_cnf(){
	
	do_write_utf8_cnf > "$utf8_cnf"
	return 0
	
}

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

	return 0
}

is_utf8_present(){
	if [ ! -e "$utf8_cnf" ] ; then
		return 1
	fi

	return 0
}

on_systemd(){
    local ret=1

    tst=$(which systemd)
    if [ -n $tst ]; then 
	ret=0
    fi
    if [ $debug -eq 1 ]; then 
	if [ $ret -eq 0 ]; then
	    echo "I'm on a systemd system"
	else
	    echo "I'm not on a systemd system"
	fi
    fi
    
    return $ret
}
mysql_process(){
	local timeout

	if [ $debug -eq 1 ] ; then
		echo "************************entering mysql mode "$1
	fi 	

	case "$1" in
		"start")
			if [ $debug -eq 1 ] ; then
				echo "arrancando"
			fi
			if on_systemd; then
			    #sometimes when isn't fully systemd service fails if not is stopped before 
			    systemctl stop mysql >/dev/null 2>/dev/null || true
			    systemctl $1 mysql >/dev/null 2>/dev/null || true
			else
			    service mysql stop >/dev/null 2>/dev/null || true
			    service mysql $1 >/dev/null 2>/dev/null || true
			fi
			timeout=0
			while  true  ; do
				is_mysql_alive || true 
				if [ $alive -eq 0 ] ; then break ; fi
				if [ $timeout -eq $limit ] ; then
					echo "Error al arrancar"
					exit 1
				fi
				timeout=$(($timeout+1))
				sleep 1
				if [ $debug -eq 1 ] ; then
					echo "time out: "$timeout	
				fi	
			done
			if [ $debug -eq 1 ] ; then
				echo "arrancado"
			fi
		;;
		"stop")
			if [ $debug -eq 1 ] ; then
				echo "parando"
			fi
			if on_systemd; then
			    systemctl $1 mysql >/dev/null 2>/dev/null || true
			else
			    service mysql $1 >/dev/null 2>/dev/null || true
			fi

			killall -TERM mysqld_safe mysqld >/dev/null 2>/dev/null || true
			sleep 1
			killall -KILL mysqld_safe mysqld >/dev/null 2>/dev/null || true
			timeout=0
			while  true  ; do
				is_mysql_alive || true 
				if [ $alive -eq 1 ] ; then break ; fi
				if [ $timeout -eq $limit ] ; then
					echo "Error al parar"
					exit 1
				fi
				timeout=$(($timeout+1))
				sleep 1
				if [ $debug -eq 1 ] ; then
					echo "time out: "$timeout	
				fi
			done
			if [ $debug -eq 1 ] ; then
				echo "parado"
			fi
			;;
		*)	echo "Error en param"
			;;
	esac
	return 0
}

mysql_safe_process(){
	local timeout

	if [ $debug -eq 1 ] ; then
		echo "+++++++++++++++++++++++entering mysql safe mode "$1
	fi 	

	case "$1" in
		"start")
			if [ $debug -eq 1 ] ; then
				echo "arrancando"
			fi
			#Check if paths are OK
			[ -d /var/run/mysqld ] || mkdir /var/run/mysqld && chmod 700 /var/run/mysqld && chown mysql:mysql /var/run/mysqld
			/usr/bin/mysqld_safe --skip-grant-tables >/dev/null 2>/dev/null &
			timeout=0
			while  true  ; do
				is_mysql_alive || true 
				if [ $alive -eq 0 ] ; then break ; fi
				if [ $timeout -eq $limit ] ; then
					echo "Error al arrancar safe"
					exit 1
				fi
				timeout=$(($timeout+1))
				sleep 1
				if [ $debug -eq 1 ] ; then
					echo "time out: "$timeout
				fi
					
			done
			if [ $debug -eq 1 ] ; then
				echo "arrancado"
			fi
		;;
		"stop")
			if [ $debug -eq 1 ] ; then
				echo "parando"
			fi
			killall -TERM  mysqld_safe mysqld >/dev/null 2>/dev/null >/dev/null || true
			sleep 1
			killall -KILL  mysqld_safe mysqld >/dev/null 2>/dev/null >/dev/null || true
			timeout=0
			while  true  ; do
				is_mysql_alive || true 
				if [ $alive -eq 1 ] ; then break ; fi
				if [ $timeout -eq $limit ] ; then
					echo "Error al parar safe"
					exit 1
				fi
				if [ $timeout -gt 1 ] ; then
				    if on_systemd; then
					systemctl start mysql >/dev/null 2>/dev/null ||true
					systemctl stop mysql >/dev/null 2>/dev/null ||true
				    else
					service mysql start >/dev/null 2>/dev/null || true
					service mysql stop >/dev/null 2>/dev/null || true
				    fi
				fi
				timeout=$(($timeout+1))
				killall -TERM  mysqld_safe mysqld >/dev/null 2>/dev/null >/dev/null || true
				sleep 1
				killall -KILL  mysqld_safe mysqld >/dev/null 2>/dev/null >/dev/null || true
				if [ $debug -eq 1 ] ; then
					echo "time out: "$timeout
				fi
			done
			if [ $debug -eq 1 ] ; then
				echo "parado"
			fi
			;;
		*)	echo "Error en param"
			;;
	esac
	return 0
}

test_password(){
	#with sudo always test passwd is ok, must use other user than root
	if sudo --user nobody mysql -u $user -p$passwd < $sqltest 2>/dev/null; then
		if [ $debug -eq 1 ] ; then
			echo "test passwd ok"
		fi 
		#rm -f $sqltest
		return 0
	fi
	return 1
}

configure (){

	need_restart=0

	if ! is_utf8_present; then
		do_create_utf8_cnf
		need_restart=1
		
	fi
		

	if is_mycnf_present && is_mysql_alive ; then
		do_get_passwd
		if test_password ; then
			if [ $debug -eq 1 ] ; then
				echo "initial test passed. exit"
			fi
			
			if [ $need_restart -eq 1 ]; then
			    if on_systemd; then
				systemctl restart mysql
			    else
				service mysql restart
			    fi
			fi
			
			exit 0
		fi	
	fi

	mysql_safe_process stop 2>/dev/null
	mysql_process start 2>/dev/null

	if is_mycnf_present ; then
		# If my.cnf file exists then sync in mysql
		do_get_passwd
		if [ $debug -eq 1 ] ; then
			echo "mycnf_present"
		fi 
	else
		# If not present my.cnf then we create a passwd
		# and a my.cnf file
		do_create_passwd
		if [ $debug -eq 1 ] ; then
			echo "mycnf_not_present"
		fi 
	fi

	# Test mysql password
	if is_mysql_alive ; then
		if [ $debug -eq 1 ] ; then
			echo "mysql alive"
		fi 
		if test_password ; then
			exit 0
		fi
		if [ $debug -eq 1 ] ; then
			echo "Mysql password not synced with mycnf file"
		fi 
	else
		echo " * Mysql database server is not running"
		exit 0
	fi

	echo " * Mysql database server running, setting Safe Mode"

	mysql_process stop 2>/dev/null

	if [ $debug -eq 1 ] ; then	
		if is_mysql_alive ; then
			echo "mysqld not killed"
		fi
	fi
	# Mysql is started in safe mode

	mysql_safe_process start 2>/dev/null

	if [ $debug -eq 1 ] ; then
		echo "mysql_safe mode"
	fi

	if is_mysql_alive ; then
		# Sql statement to set password created
		do_write_passSql
		sqlTemp=$SQLQUERY_UPDATE
		# Password is assigned in mysql 
		if [ $debug -eq 1 ] ; then
			echo $sqlTemp
		fi
		echo "$sqlTemp" | mysql 		
		echo " * Mysql root password assigned"
	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

	mysql_safe_process stop 2>/dev/null
	
	mysql_process start

	return 0
}

# main
if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root" 1>&2
   exit 1
fi

if [ $# -eq 2 ] ; then
	if [ $2 == "-d" ] ; then
 		debug=1
 	fi
fi


case "$1" in
	"-a"|"--alive_mysql")
		if is_mysql_alive ; then
			echo "YES"
		else
			echo "NO"
		fi
		;;
	"-i"|"--initialize")
		configure
		;;
	"-g"|"--get_password")
		do_get_passwd
		echo $passwd
		;;
	"-p"|"--present_mycnf")
		if is_mycnf_present ; then
			echo "YES"
		else
			echo "NO"
		fi
		;;
	*)	echo "usage:  mysql_root_passwd -a (--alive_mysql) | -i (--initialize) | -g (--get_password) | -p (--present_mycnf)"
		;;
esac

exit 0