/*
 * This file is a part of EpnTAPClient.
 * This program aims to provide EPN-TAP support for software clients, like CASSIS spectrum analyzer.
 * See draft specifications: https://voparis-confluence.obspm.fr/pages/viewpage.action?pageId=559861
 * Copyright (C) 2016 Institut de Recherche en Astrophysique et Planétologie.
 * 
 * This program is free software: you can
 * redistribute it and/or modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or (at your option) any later
 * version. This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU General Public License for more details. You should have received a copy of
 * the GNU General Public License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 */

package eu.omp.irap.vespa.epntapclient.votable;

import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Logger;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import eu.omp.irap.vespa.epntapclient.utils.Const;

/**
 * @author N. Jourdane
 */
public class Utils {
	/** The logger for the class Utils. */
	private static final Logger logger = Logger.getLogger(Utils.class.getName());

	/** Private constructor to hide the implicit public one. */
	private Utils() {
	}

	/**
	 * StringJoiner has the same purpose of Java 8 StringJoiner, it has been rewritten for Java7
	 * compatibility.
	 * 
	 * @author N. Jourdane
	 */
	public static class StringJoiner {
		/** A list of words to join, ie. ["foo", "bar"]. */
		List<String> list;
		/** The string joiner separator to put between each word, ie. ';'. */
		String separator;
		/** The resulting string, ie. "foo;bar". */
		String string;

		/**
		 * Method constructor for the String joiner.
		 * 
		 * @param separator The string joiner separator to put between each word, ie. ';'.
		 */
		public StringJoiner(String separator) {
			this.separator = separator;
			this.list = new ArrayList<>();
			string = "";
		}

		/**
		 * add a new word to the joiner.
		 * 
		 * @param text The word to add.
		 */
		public void add(String text) {
			if ("".equals(string)) {
				string = text;
			} else {
				string += separator + text;
			}
		}

		@Override
		public String toString() {
			return string;
		}
	}

	/**
	 * Print the specified object in JSON format in a file on the temporary directory.
	 * 
	 * @param title The name of the file.
	 * @param obj the object to print in a file.
	 * @return The path of the file.
	 */
	public static String printObject(String title, Object obj) {
		Gson gson = new GsonBuilder().setPrettyPrinting().create();
		String json = gson.toJson(obj);
		String path = Const.TMP_DIR + "/" + title + ".json";
		try (FileWriter writer = new FileWriter(path)) {
			writer.write(json);

		} catch (IOException e) {
			logger.warning("Can not print in the file " + path + e);
		}
		logger.info("A json file representing " + title + " (" + obj.getClass().getName()
				+ ") has been created on " + path);

		return path;
	}
}