/*-
 * ============LICENSE_START=======================================================
 * PROJECT
 * ================================================================================
 * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Licensed 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.
 * ============LICENSE_END=========================================================
 */

package org.onap.dcae.controller;

import org.json.JSONArray;
import org.json.JSONObject;
import org.json.JSONTokener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Map;

public class FetchDynamicConfig {

	private static final Logger log = LoggerFactory.getLogger(FetchDynamicConfig.class);

	static String configFile = "/opt/app/KV-Configuration.json";
	static String url;
	static String retString;

	public FetchDynamicConfig() {
	}

	public static void main(String[] args) {
		Map<String, String> env = System.getenv();
		for (Map.Entry<String, String> entry : env.entrySet()) {
			log.info("%s=%s%n", entry.getKey(), entry.getValue());
		}

		if (env.containsKey("CONSUL_HOST") && env.containsKey("CONFIG_BINDING_SERVICE")
				&& env.containsKey("HOSTNAME")) {
			log.info(">>>Dynamic configuration to be fetched from ConfigBindingService");
			url = env.get("CONSUL_HOST") + ":8500/v1/catalog/service/" + env.get("CONFIG_BINDING_SERVICE");

			retString = executecurl(url);
			// consul return as array
			JSONTokener temp = new JSONTokener(retString);
			JSONObject cbsjobj = (JSONObject) new JSONArray(temp).get(0);

			String urlPart1 = null;
			if (cbsjobj.has("ServiceAddress") && cbsjobj.has("ServicePort")) {
				urlPart1 = cbsjobj.getString("ServiceAddress") + ":" + cbsjobj.getInt("ServicePort");
			}

			log.info("CONFIG_BINDING_SERVICE DNS RESOLVED:" + urlPart1);
			url = urlPart1 + "/service_component/" + env.get("HOSTNAME");
			retString = executecurl(url);

			JSONObject jsonObject = new JSONObject(new JSONTokener(retString));
			try (FileWriter file = new FileWriter(configFile)) {
				file.write(jsonObject.toString());

				log.info("Successfully Copied JSON Object to file /opt/app/KV-Configuration.json");
			} catch (IOException e) {
				log.error("Error in writing configuration into file /opt/app/KV-Configuration.json " + jsonObject, e);
				e.printStackTrace();
			}
		} else {
			log.info(">>>Static configuration to be used");
		}

	}

	public static String executecurl(String url) {

		String[] command = { "curl", "-v", url };
		ProcessBuilder process = new ProcessBuilder(command);
		Process p;
		String result = null;
		try {
			p = process.start();
			InputStreamReader ipr = new InputStreamReader(p.getInputStream());
			BufferedReader reader = new BufferedReader(ipr);
			StringBuilder builder = new StringBuilder();
			String line;

			while ((line = reader.readLine()) != null) {
				builder.append(line);
			}
			result = builder.toString();
			log.info(result);

			reader.close();
			ipr.close();
		} catch (IOException e) {
			log.error("error", e);
			e.printStackTrace();
		}
		return result;

	}

}