/**

 * 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.InputStream;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Collections;

import java.util.List;

import java.util.Map;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**

 *

 * @author Ing. František Kučera (frantovo.cz)

 */

public class Functions {

	private static final String NBSP = " ";

	private static final Pattern WHITESPACE_TO_REPLACE = Pattern.compile("\\n|\\r|\\t|" + NBSP);

	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);

	}

	private final static char[] HEX_ALPHABET = "0123456789abcdef".toCharArray();

	public static String toHex(byte[] bytes) {

		char[] hexChars = new char[bytes.length * 2];

		for (int j = 0; j < bytes.length; j++) {

			int v = bytes[j] & 0xFF;

			hexChars[j * 2] = HEX_ALPHABET[v >>> 4];

			hexChars[j * 2 + 1] = HEX_ALPHABET[v & 0x0F];

		}

		return new String(hexChars);

	}

	public static String readString(InputStream in) throws IOException {

		try (BufferedReader br = new BufferedReader(new InputStreamReader(in))) {

			StringBuilder result = new StringBuilder();

			for (String line = br.readLine(); line != null; line = br.readLine()) {

				result.append(line);

				result.append('\n');

			}

			return result.toString();

		}

	}

	/**

	 * @param <P> type of the last parent

	 * @param <T> type of the examined class

	 * @param type examined class

	 * @param lastParent the last parent type to stop at

	 * @return list of types starting with <code>type</code> and ending with <code>lastParent</code>

	 */

	public static <P, T extends P> List<Class<? extends P>> getClassHierarchy(Class<T> type, Class<P> lastParent) {

		List<Class<? extends P>> hierarchy = new ArrayList<>();

		for (Class current = type; current != null && lastParent.isAssignableFrom(current); current = current.getSuperclass()) {

			hierarchy.add(current);

		}

		return hierarchy;

	}

	/**

	 * TODO: support background or styles and move to ColorfulPrintWriter

	 *

	 * @param out

	 * @param valueString

	 * @param basicColor

	 * @param escapeColor

	 */

	public static void printValueWithWhitespaceReplaced(ColorfulPrintWriter out, String valueString, ColorfulPrintWriter.TerminalColor basicColor, ColorfulPrintWriter.TerminalColor escapeColor) {

		Matcher m = WHITESPACE_TO_REPLACE.matcher(valueString);

		int start = 0;

		while (m.find(start)) {

			printColorOrNot(out, basicColor, valueString.substring(start, m.start()));

			switch (m.group()) {

				case "\n":

					out.print(escapeColor, "↲");

					break;

				case "\r":

					out.print(escapeColor, "⏎");

					break;

				case "\t":

					out.print(escapeColor, "↹");

					break;

				case NBSP:

					out.print(escapeColor, "⎵");

					break;

				default:

					throw new IllegalStateException("Unexpected whitespace token: „" + m.group() + "“");

			}

			start = m.end();

		}

		printColorOrNot(out, basicColor, valueString.substring(start, valueString.length()));

	}

	private static void printColorOrNot(ColorfulPrintWriter out, ColorfulPrintWriter.TerminalColor color, String text) {

		if (color == null) {

			out.print(text);

		} else {

			out.print(color, text);

		}

	}

}