/*
 * 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 com.epam.dlab;

import com.epam.dlab.configuration.BillingToolConfiguration;
import com.epam.dlab.configuration.BillingToolConfigurationFactory;
import com.epam.dlab.core.parser.ParserBase;
import com.epam.dlab.dto.billing.BillingData;
import com.epam.dlab.exceptions.DlabException;
import com.epam.dlab.exceptions.InitializationException;
import com.epam.dlab.util.ServiceUtils;
import org.bson.Document;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;

import java.time.LocalDate;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;

import static com.epam.dlab.model.aws.ReportLine.FIELD_COST;
import static com.epam.dlab.model.aws.ReportLine.FIELD_CURRENCY_CODE;
import static com.epam.dlab.model.aws.ReportLine.FIELD_DLAB_ID;
import static com.epam.dlab.model.aws.ReportLine.FIELD_PRODUCT;
import static com.epam.dlab.model.aws.ReportLine.FIELD_RESOURCE_TYPE;
import static com.epam.dlab.model.aws.ReportLine.FIELD_USAGE_DATE;

@Service
public class BillingServiceImpl implements BillingService {
	private static final Logger LOGGER = LoggerFactory.getLogger(BillingServiceImpl.class);
	private static BillingToolConfiguration configuration;

	public List<BillingData> getBillingData() {
		try {
			ParserBase parser = configuration.build();

			LOGGER.info("Try to load billing report for configuration: {}", configuration);
			List<BillingData> billingData = parser.parse()
					.stream()
					.map(this::toBillingData)
					.collect(Collectors.toList());

			if (!parser.getStatistics().isEmpty()) {
				LOGGER.info("Billing report parser statistics:");
				for (int i = 0; i < parser.getStatistics().size(); i++) {
					LOGGER.info("  {}", parser.getStatistics().get(i).toString());
				}
			}

			return billingData;
		} catch (Exception e) {
			LOGGER.error("Something went wrong ", e);
			return Collections.emptyList();
		}
	}

	private BillingData toBillingData(Document billingData) {
		return BillingData.builder()
				.tag(billingData.getString(FIELD_DLAB_ID).toLowerCase())
				.usageDateFrom(Optional.ofNullable(billingData.getString(FIELD_USAGE_DATE)).map(LocalDate::parse).orElse(null))
				.usageDateTo(Optional.ofNullable(billingData.getString(FIELD_USAGE_DATE)).map(LocalDate::parse).orElse(null))
				.usageDate(billingData.getString(FIELD_USAGE_DATE))
				.product(billingData.getString(FIELD_PRODUCT))
				.usageType(billingData.getString(FIELD_RESOURCE_TYPE))
				.cost(billingData.getDouble(FIELD_COST))
				.currency(billingData.getString(FIELD_CURRENCY_CODE))
				.build();
	}

	public static void initialize(String filename) throws InitializationException {
		LOGGER.debug("Billing report configuration file: {}", filename);
		configuration = BillingToolConfigurationFactory.build(filename, BillingToolConfiguration.class);
	}

	public static void startApplication(String[] args) throws InitializationException {
		if (ServiceUtils.printAppVersion(BillingTool.class, args)) {
			return;
		}

		String confName = null;
		for (int i = 0; i < args.length; i++) {
			if (BillingTool.isKey("help", args[i])) {
				i++;
				Help.usage(i < args.length ? Arrays.copyOfRange(args, i, args.length) : null);
				return;
			} else if (BillingTool.isKey("conf", args[i])) {
				i++;
				if (i < args.length) {
					confName = args[i];
				} else {
					throw new InitializationException("Missing the name of configuration file");
				}
			}
		}

		if (confName == null) {
			Help.usage();
			throw new InitializationException("Missing arguments");
		}

		BillingTool.setLoggerLevel();
		try {
			initialize(confName);
		} catch (Exception e) {
			throw new DlabException("Billing scheduler failed", e);
		}
	}
}