/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.metrics.graphite;

import org.apache.flink.annotation.PublicEvolving;
import org.apache.flink.dropwizard.ScheduledDropwizardReporter;
import org.apache.flink.metrics.MetricConfig;
import org.apache.flink.metrics.reporter.InstantiateViaFactory;

import com.codahale.metrics.ScheduledReporter;
import com.codahale.metrics.graphite.Graphite;
import com.codahale.metrics.graphite.GraphiteUDP;

import java.util.concurrent.TimeUnit;

/**
 * This class acts as a factory for the {@link com.codahale.metrics.graphite.GraphiteReporter} and allows using it as a
 * Flink reporter.
 */
@PublicEvolving
@InstantiateViaFactory(factoryClassName = "org.apache.flink.metrics.graphite.GraphiteReporterFactory")
public class GraphiteReporter extends ScheduledDropwizardReporter {

	public static final String ARG_PROTOCOL = "protocol";

	private enum Protocol {
		TCP,
		UDP
	}

	@Override
	public ScheduledReporter getReporter(MetricConfig config) {
		String host = config.getString(ARG_HOST, null);
		int port = config.getInteger(ARG_PORT, -1);

		if (host == null || host.length() == 0 || port < 1) {
			throw new IllegalArgumentException("Invalid host/port configuration. Host: " + host + " Port: " + port);
		}

		String prefix = config.getString(ARG_PREFIX, null);
		String conversionRate = config.getString(ARG_CONVERSION_RATE, null);
		String conversionDuration = config.getString(ARG_CONVERSION_DURATION, null);
		String protocol = config.getString(ARG_PROTOCOL, "TCP");

		com.codahale.metrics.graphite.GraphiteReporter.Builder builder =
			com.codahale.metrics.graphite.GraphiteReporter.forRegistry(registry);

		if (prefix != null) {
			builder.prefixedWith(prefix);
		}

		if (conversionRate != null) {
			builder.convertRatesTo(TimeUnit.valueOf(conversionRate));
		}

		if (conversionDuration != null) {
			builder.convertDurationsTo(TimeUnit.valueOf(conversionDuration));
		}

		Protocol prot;
		try {
			prot = Protocol.valueOf(protocol);
		} catch (IllegalArgumentException iae) {
			log.warn("Invalid protocol configuration: " + protocol + " Expected: TCP or UDP, defaulting to TCP.");
			prot = Protocol.TCP;
		}

		log.info("Configured GraphiteReporter with {host:{}, port:{}, protocol:{}}", host, port, prot);
		switch(prot) {
			case UDP:
				return builder.build(new GraphiteUDP(host, port));
			case TCP:
			default:
				return builder.build(new Graphite(host, port));
		}
	}
}
