#!/bin/sh

CACHE_NODES=auto
SCRIPT_DIR=`dirname $0`

disable_gcache_purging() {
	echo "$CACHE_NODES" \
		| while read CACHE_NODE ; do
			echo -n "`date +%Y%m%d-%H%M%S` Disabling purging galera cache... "
			mysql -h$CACHE_NODE "$DB" -e "SET GLOBAL wsrep_provider_options='gcache.freeze_purge_at_seqno = now'"
			if [ "$?" -eq "0" ] ; then
				echo "done"
			else
				echo "failed"
				exit 1
			fi
		done
}

enable_cluster_purging() {
	echo "$CACHE_NODES" \
		| while read CACHE_NODE ; do
			echo -n "`date +%Y%m%d-%H%M%S` Enabling purging galera cache... "
			mysql -h$CACHE_NODE mysql -e "SET GLOBAL wsrep_provider_options='gcache.freeze_purge_at_seqno = -1'"
			if [ "$?" -eq "0" ] ; then
				echo "done"
			else
				echo "failed"
				exit 1
			fi
		done
}

wait_node_synced() {
	echo -n "`date +%Y%m%d-%H%M%S` Checking cluster state..."
	while true ; do
		state=`mysql mysql -ABNe "SHOW GLOBAL STATUS WHERE Variable_name = 'wsrep_local_state_comment'"`
		if [ "$?" -ne "0" ] ; then
			echo " failed"
			sleep 1
			continue
		fi

		state=`echo -n "$state" | cut -f2`
		if [ "$state" != "Synced" ] ; then
			echo -n "."
			sleep 1
			continue
		fi

		break
	done
	echo " synced"
}

quit() {
	mysql "$DB" -ABNe "
		SET sql_log_bin = 1;
		SET wsrep_on = 1;
		SET GLOBAL wsrep_desync = 0;" >/dev/null 2>&1

	wait_node_synced

	enable_cluster_purging

	exit
}

wait_cluster_ready() {
	echo "$CACHE_NODES" \
		| while read CACHE_NODE ; do
			echo -n "`date +%Y%m%d-%H%M%S` Checking node $CACHE_NODE... "
			WSREP_STATE=`mysql -h $CACHE_NODE -Ne 'SELECT variable_value FROM performance_schema.global_status WHERE variable_name = "wsrep_ready";'`
			if [ "$?" -ne "0" ] ; then
				echo "failed"
				exit 1
			fi
			if [ "$WSREP_STATE" != "ON" ] ; then
				echo "not synced"
				exit 1
			fi
			echo "synced"
		done
}

wait_cluster_queue() {
	echo "$CACHE_NODES" \
		| while read CACHE_NODE ; do
			echo -n "`date +%Y%m%d-%H%M%S` Waiting node $CACHE_NODE queue..."
			while true ; do
				CURRENT_QUEUE=`mysql -h $CACHE_NODE -Ne 'SELECT variable_value FROM performance_schema.global_status WHERE variable_name = "wsrep_local_recv_queue";'`
				if [ "$?" -ne "0" ] ; then
					echo " failed"
					exit 1
				fi
				if [ "$CURRENT_QUEUE" -eq "0" ] ; then
					break
				fi
				echo -n "."
				sleep 30
			done
			echo " done"
		done
}

analyze_tables() {
	mysql information_schema -ABNe "SELECT table_schema, table_name FROM tables WHERE table_type = 'BASE TABLE' AND engine = 'InnoDB';" \
		| while read DB TABLE ; do
			echo -n "`date +%Y%m%d-%H%M%S` Analyzing table $DB.$TABLE... "
			grep -sq "^$DB.$TABLE$" "$SCRIPT_DIR/tables_analyzed.txt"
			if [ "$?" -eq "0" ] ; then
				echo "already done"
				continue
			fi
			mysql "$DB" -ABNe "
				SET GLOBAL wsrep_desync = 1;
				SET wsrep_on = 0;
				SET sql_log_bin = 0;
				ANALYZE TABLE \`$TABLE\`;
				SET sql_log_bin = 1;
				SET wsrep_on = 1;
				SET GLOBAL wsrep_desync = 0;" >/dev/null 2>&1
			if [ "$?" -eq "0" ] ; then
				echo "done"
				echo "$DB.$TABLE" >> "$SCRIPT_DIR/tables_analyzed.txt"
			else
				echo "failed"
				exit 1
			fi

			wait_node_synced
		done
}

alter_tables() {
	mysql information_schema -ABNe "SELECT table_schema, table_name FROM tables WHERE table_type = 'BASE TABLE' AND engine = 'InnoDB' AND data_free > 0 ORDER BY data_free / (data_length + index_length) DESC;" \
		| while read DB TABLE ; do
			echo -n "`date +%Y%m%d-%H%M%S` Altering table $DB.$TABLE... "
			grep -sq "^$DB.$TABLE$" "$SCRIPT_DIR/tables_altered.txt"
			if [ "$?" -eq "0" ] ; then
				echo "already done"
				continue
			fi

			mysql "$DB" -ABNe "
				SET GLOBAL wsrep_desync = 1;
				SET wsrep_on = 0;
				SET sql_log_bin = 0;
				ALTER TABLE \`$TABLE\` ENGINE=InnoDB;
				SET sql_log_bin = 1;
				SET wsrep_on = 1;
				SET GLOBAL wsrep_desync = 0;" >/dev/null 2>&1
			if [ "$?" -eq "0" ] ; then
				echo "done"
				echo "$DB.$TABLE" >> "$SCRIPT_DIR/tables_altered.txt"
			else
				echo "failed"
				mysql "$DB" -ABNe "
					SET wsrep_on = 1;
					SET GLOBAL wsrep_desync = 0;
					SET sql_log_bin = 1;" >/dev/null 2>&1
				#exit 1
			fi

			wait_node_synced
		done
}

if [ "$CACHE_NODES" = "auto" ] ; then
	CURRENT_NODE=`mysql mysql -BNe "SHOW GLOBAL VARIABLES WHERE Variable_name = 'wsrep_node_address'" | sed -e 's/^wsrep_node_address[ \t]*//g'`
	ALL_NODES=`mysql mysql -BNe "SHOW GLOBAL VARIABLES WHERE Variable_name = 'wsrep_cluster_address'" | sed -e 's;^wsrep_cluster_address.*gcomm://;;g; s/,/\n/g'`
	CACHE_NODES=`echo "$ALL_NODES" | grep -v "^$CURRENT_NODE$"`
fi

trap quit INT QUIT

wait_cluster_ready
wait_cluster_queue

disable_gcache_purging

analyze_tables
alter_tables

enable_cluster_purging