//Dstl (c) Crown Copyright 2017
package uk.gov.dstl.baleen.core.metrics;

import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import org.elasticsearch.metrics.ElasticsearchReporter;
import org.slf4j.LoggerFactory;

import uk.gov.dstl.baleen.exceptions.BaleenException;

import com.codahale.metrics.ConsoleReporter;
import com.codahale.metrics.CsvReporter;
import com.codahale.metrics.MetricRegistry;
import com.codahale.metrics.ScheduledReporter;
import com.codahale.metrics.Slf4jReporter;

/**
 * Helper utility class to capture the creation of the different reporter types.
 * See each {@link MetricsFactory} for configuration details and examples.
 *
 * 
 *
 */
public class ReporterUtils {

	private ReporterUtils() {

	}

	/**
	 * Create a new console reporter.
	 *
	 * @param metricRegistry
	 *            the registry to report on
	 * @param config
	 *            the configuration map (see {@link MetricsFactory})
	 * @return the reporter instance
	 */
	public static ScheduledReporter createConsoleReporter(MetricRegistry metricRegistry, Map<String, Object> config) {

		return ConsoleReporter.forRegistry(metricRegistry).convertRatesTo(getRatesUnit(config))
				.convertDurationsTo(getDurationUnit(config)).build();
	}

	/**
	 * Create a new CSV reporter.
	 *
	 * @param metricRegistry
	 *            the registry to report on
	 * @param config
	 *            the configuration map (see {@link MetricsFactory})
	 * @return the reporter instance
	 */
	public static ScheduledReporter createCsvReporter(MetricRegistry metricRegistry, Map<String, Object> config)
		throws BaleenException{
		String directoryPath = (String) config.getOrDefault("directory", "metrics");
		File directory = new File(directoryPath);

		if (!directory.exists() && !directory.mkdirs()){
			throw new BaleenException("Unable to create directories for CSV Reporter");
		}

		return CsvReporter.forRegistry(metricRegistry).convertRatesTo(getRatesUnit(config))
				.convertDurationsTo(getDurationUnit(config)).build(directory);
	}

	/**
	 * Create a new CSV reporter.
	 *
	 * @param metricRegistry
	 *            the registry to report on
	 * @param config
	 *            the configuration map (see {@link MetricsFactory})
	 * @return the reporter instance
	 */
	public static ScheduledReporter createSlf4jReporter(MetricRegistry metricRegistry, Map<String, Object> config) {
		String loggerName = (String) config.getOrDefault("logger", "metrics:reporter");

		return Slf4jReporter.forRegistry(metricRegistry).convertRatesTo(getRatesUnit(config))
				.convertDurationsTo(getDurationUnit(config)).outputTo(LoggerFactory.getLogger(loggerName)).build();
	}

	/**
	 * Create a new ElasticSearch reporter.
	 *
	 * @param metricRegistry
	 *            the registry to report on
	 * @param config
	 *            the configuration map (see {@link MetricsFactory})
	 * @return the reporter instance
	 */
	public static ScheduledReporter createElasticSearchReporter(MetricRegistry metricRegistry,
			Map<String, Object> config) throws BaleenException {
		try {
			String server = (String) config.getOrDefault("server", "localhost:9200");
			String index = (String) config.getOrDefault("index", "metrics");
			int timeout = (int) config.getOrDefault("timeout", 1000);
			int bulkSize = (int) config.getOrDefault("bulkSize", 2500);

			return ElasticsearchReporter.forRegistry(metricRegistry).convertRatesTo(getRatesUnit(config))
					.convertDurationsTo(getDurationUnit(config)).bulkSize(bulkSize).hosts(server).index(index)
					.timeout(timeout).build();
		} catch (IOException e) {
			throw new BaleenException("Unable to create ElasticSearch reporter", e);
		}
	}

	private static TimeUnit getDurationUnit(Map<String, Object> config) {
		String durationUnit = (String) config.getOrDefault("durationUnit", TimeUnit.SECONDS.name());
		return TimeUnit.valueOf(durationUnit.toUpperCase());
	}

	private static TimeUnit getRatesUnit(Map<String, Object> config) {
		String rateUnit = (String) config.getOrDefault("rateUnit", TimeUnit.SECONDS.name());
		return TimeUnit.valueOf(rateUnit.toUpperCase());
	}

}