#!/bin/sh

MYSQL="mysql --defaults-file=/etc/zabbix/my.cnf"
MYSQLADMIN="mysqladmin --defaults-file=/etc/zabbix/my.cnf"
MODE="$1"

case "$MODE" in
	version)
		$MYSQL -V
		;;
	ping)
		$MYSQLADMIN ping |\
			fgrep -c alive
		;;
	global_status)
		$MYSQL -BNe "SHOW GLOBAL STATUS WHERE variable_name='"$2"'" |\
			awk '
				{
					gsub("ON", "1", $2);
					gsub("OFF", "0", $2);

					gsub("Non-Primary", "2", $2);
					gsub("Primary", "1", $2);
					gsub("Disconnected", "0", $2);

					print $2;
				}'
		;;
	global_variables)
		$MYSQL -BNe "SHOW GLOBAL VARIABLES WHERE variable_name='"$2"'" |\
			awk '
				{ 
					gsub("one-thread-per-connection", "0", $2);
					gsub("pool-of-threads", "1", $2);
					gsub("no-threads", "2", $2);

					print $2;
				}'
		;;
	extended_status)
		$MYSQLADMIN extended-status |\
			awk -F"|" -v NAME=$2 '
				{
					gsub(" ", "", $2);
					if ($2 == NAME) {
						gsub(" ", "", $3);
						print $3;
					}
				}'
		;;
	innodb_metrics)
		$MYSQL -BNe "SELECT $3 FROM information_schema.innodb_metrics WHERE name = '"$2"'"
		;;
	trx_rseg_history_len)
		$MYSQL -BNe 'SHOW ENGINE INNODB STATUS\G' |\
			awk '/^History list length/ { print $4; }'
		;;
	trx_duration_max)
		$MYSQL -BNe '
				SELECT IFNULL(MAX(UNIX_TIMESTAMP(NOW()) - UNIX_TIMESTAMP(trx_started)), 0)
				FROM information_schema.innodb_trx;'
		;;
	used_log_lsn)
		$MYSQL -BNe 'SHOW ENGINE INNODB STATUS\G' |\
			awk '
				/^Log sequence number/ { log_lsn_current = $4; }
				/^Last checkpoint at/ { log_lsn_last_checkpoint = $4; }
				END { print log_lsn_current - log_lsn_last_checkpoint; }'
		;;
        max_checkpoint_age)
                $MYSQL -BNe 'SHOW ENGINE INNODB STATUS\G' |\
                        awk '/^Max checkpoint age/ { print $4; }'
                ;;
	slave_workers_idle)
		$MYSQL -BNe "
				SELECT COUNT(*)
				FROM information_schema.processlist
				WHERE user = 'system user'
				  AND state = 'Waiting for an event from Coordinator'"
		;;
	channels_discover)
		$MYSQL -e "SHOW SLAVE STATUS\G" |\
		       awk '
			BEGIN {
				printf "{\"data\":[";
				n = 0;
			}
			
			/Channel_Name:/ {
				if (n == 1) {
					printf ",";
				}
				gsub("Channel_Name:", "", $0);
				gsub(/^ *| *$/, "", $0);
				printf "{\"{#REPLICATION_CHANNEL}\":\"%s\"}", $0;
				n = 1;
			}
			END {
				printf "]}";
			}'
		;;
	channel_status)
		$MYSQL -e "SHOW SLAVE STATUS\G" |\
			awk -F":" -v CHANNEL="$2" -v NAME="$3" '
				BEGIN {
					v = "";
					n = "";
				}

				/Channel_Name:/ {
					gsub("Channel_Name:", "", $0);
					gsub(/^ *| *$/, "", $0);
					n = $0;
				}

				{
					if (index($0, " " NAME ":")) {
						gsub(NAME ":", "", $0);
						gsub(/^ *| *$/, "", $0);
						gsub("Connecting", "2", $0);
						gsub("Yes", "1", $0);
						gsub("No", "0", $0);
						v = $0;
					}
				}
				
				/^\*+ [^1]/ {
					if (n == CHANNEL) {
						print v;
					}
				}

				END {
					if (n == CHANNEL) {
						print v;
					}
				}'
		;;
	wsrep_hang_count)
		$MYSQL -BNe "SELECT COUNT(*) FROM information_schema.processlist WHERE time > 10 AND state LIKE 'wsrep: initiating replication for write set (-1)'"
		;;
        health)
		for i in 1 2 3 ; do
			timeout 9 $MYSQL -BNe "SELECT 1 LIMIT 0"
			if [ "$?" -eq "0" ]; then
				echo "0"
				exit
			fi
		done
		echo "1"
		;;
esac