#!/bin/bash
set -e

logFile="/var/log/mysql/error.log"
dateFile="/tmp/mysql_scheduler_log-lastdate"
logSchema="util"
logTable="eventLog"
pattern='^\d{4}-\d{2}-\d{2}\s+\d{1,2}:\d{2}:\d{2}\s+\d+\s+\[ERROR\] Event Scheduler:'
purgeDays=30

quote() {
	local str=${1//\'/\'\'/}
	local str=${str//\\/\\\\}
	echo "'$str'"
}

mysql -e "SELECT TRUE" > /dev/null 2>&1
if [ "$?" -ne "0" ]; then
	exit
fi

tableExists=$(mysql -Ns -e "SHOW TABLES FROM $logSchema LIKE '$logTable'")

if [ -z "$tableExists" ]; then
	mysql <<-EOF
		CREATE SCHEMA IF NOT EXISTS $logSchema;
		CREATE TABLE $logSchema.$logTable (
			id int(11) NOT NULL AUTO_INCREMENT,
			date datetime NOT NULL,
			event varchar(512) NOT NULL,
			error varchar(1024) NOT NULL,
			PRIMARY KEY (id),
			KEY date (date)
		) ENGINE=InnoDB COMMENT='Event scheduler error log';
	EOF
fi

if [ -f "$dateFile" ]; then
	read -r fromDate < "$dateFile"
else
	fromDate=$(date -d "-$purgeDays days" +%s)
fi

toDate=$(date +%s)

grep -P "$pattern" "$logFile" | awk -v fromDate="$fromDate" -v toDate="$toDate" '{
	split($1, date, "-");
	split($2, time, ":");
	timestamp = mktime(date[1]" "date[2]" "date[3]" "time[1]" "time[2]" "time[3])
	if (timestamp >= fromDate && timestamp < toDate) {
		printf $1" "$2" "$7;
		for (i=8; i<=NF; i++) printf FS $i ;
		print "";
	}
}' | \
while read line; do
	date="$(echo "$line" | cut -d' ' -f1,2)"
	event="$(echo "$line" | cut -d' ' -f3)"
	error="$(echo "$line" | cut -d' ' -f4-)"

	mysql <<-EOF
		INSERT INTO $logSchema.$logTable SET
			date = $(quote "$date"),
			event = $(quote "$event"),
			error = $(quote "$error")
	EOF
done

echo "$toDate" > "$dateFile"
mysql <<-EOF
	DELETE FROM $logSchema.$logTable
		WHERE date < TIMESTAMPADD(DAY, -$purgeDays, NOW())
EOF