/**
 * SQL-DK
 * Copyright © 2013 František Kučera (frantovo.cz)
 *
 * 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 info.globalcode.sql.dk;

import info.globalcode.sql.dk.configuration.NameIdentified;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;

/**
 *
 * @author Ing. František Kučera (frantovo.cz)
 */
public class Functions {

	private Functions() {
	}

	public static boolean equalz(Object a, Object b) {
		return a == null ? b == null : a.equals(b);
	}

	/**
	 *
	 * @param text String to be examinated
	 * @param trim whether text should be trimmed before examination
	 * @return whether text is not empty and one or more characters long (after prospective trim)
	 */
	public static boolean isEmpty(String text, boolean trim) {
		if (text == null) {
			return true;
		} else {
			if (trim) {
				text = text.trim();
			}
			return text.isEmpty();
		}
	}

	/**
	 * @see #isEmpty(java.lang.String, boolean)
	 */
	public static boolean isNotEmpty(String text, boolean trim) {
		return !isEmpty(text, trim);
	}

	public boolean isEmpty(Collection c) {
		return c == null || c.isEmpty();
	}

	public boolean isNotEmpty(Collection c) {
		return !isEmpty(c);
	}

	public boolean isEmpty(Map m) {
		return m == null || m.isEmpty();
	}

	public boolean isNotEmpty(Map m) {
		return !isEmpty(m);
	}

	/**
	 * @return empty collection if given one is null | or the original one
	 */
	public static <T> Collection<T> notNull(Collection<T> c) {
		if (c == null) {
			return Collections.emptyList();
		} else {
			return c;
		}
	}

	public static <T extends NameIdentified> T findByName(Collection<T> collection, String name) {
		for (T element : notNull(collection)) {
			if (element != null && equalz(element.getName(), name)) {
				return element;
			}
		}

		return null;
	}

	/**
	 * Copy file from Java resources to file system.
	 */
	public static void installResource(String resourceName, File target) throws IOException {
		try (BufferedReader reader = new BufferedReader(new InputStreamReader(Functions.class.getClassLoader().getResourceAsStream(resourceName)))) {
			try (PrintWriter writer = new PrintWriter(target)) {
				while (true) {
					String line = reader.readLine();
					if (line == null) {
						break;
					} else {
						writer.println(line);
					}
				}
			}
		}
	}

	public static String rpad(String s, int n) {
		if (n > 0) {
			return String.format("%1$-" + n + "s", s);
		} else {
			return s;
		}
	}

	public static String lpad(String s, int n) {
		if (n > 0) {
			return String.format("%1$" + n + "s", s);
		} else {
			return s;
		}
	}

	public static String repeat(char ch, int count) {
		char[] array = new char[count];
		Arrays.fill(array, ch);
		return new String(array);
	}
}