package be.nikiroo.jvcard.resources;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.Normalizer;
import java.text.Normalizer.Form;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.regex.Pattern;

import com.googlecode.lanterna.gui2.LinearLayout.Alignment;

public class StringUtils {
	static private Pattern marks = Pattern
			.compile("[\\p{InCombiningDiacriticalMarks}\\p{IsLm}\\p{IsSk}]+");

	/**
	 * Fix the size of the given {@link String} either with space-padding or by
	 * shortening it.
	 * 
	 * @param text
	 *            the {@link String} to fix
	 * @param width
	 *            the size of the resulting {@link String} if the text fits or
	 *            if cut is TRUE
	 * 
	 * @return the resulting {@link String} of size <i>size</i>
	 */
	static public String padString(String text, int width) {
		return padString(text, width, true, Alignment.Beginning);
	}

	/**
	 * Fix the size of the given {@link String} either with space-padding or by
	 * optionally shortening it.
	 * 
	 * @param text
	 *            the {@link String} to fix
	 * @param width
	 *            the size of the resulting {@link String} if the text fits or
	 *            if cut is TRUE
	 * @param cut
	 *            cut the {@link String} shorter if needed
	 * @param align
	 *            align the {@link String} in this position if we have enough
	 *            space
	 * 
	 * @return the resulting {@link String} of size <i>size</i> minimum
	 */
	static public String padString(String text, int width, boolean cut,
			Alignment align) {

		if (width >= 0) {
			if (text == null)
				text = "";

			int diff = width - text.length();

			if (diff < 0) {
				if (cut)
					text = text.substring(0, width);
			} else if (diff > 0) {
				if (diff < 2 && align != Alignment.End)
					align = Alignment.Beginning;

				switch (align) {
				case Beginning:
					text = text + new String(new char[diff]).replace('\0', ' ');
					break;
				case End:
					text = new String(new char[diff]).replace('\0', ' ') + text;
					break;
				case Center:
				case Fill:
				default:
					int pad1 = (diff) / 2;
					int pad2 = (diff + 1) / 2;
					text = new String(new char[pad1]).replace('\0', ' ') + text
							+ new String(new char[pad2]).replace('\0', ' ');
					break;
				}
			}
		}

		return text;
	}

	/**
	 * Sanitise the given input to make it more Terminal-friendly by removing
	 * combining characters.
	 * 
	 * @param input
	 *            the input to sanitise
	 * @param allowUnicode
	 *            allow Unicode or only allow ASCII Latin characters
	 * 
	 * @return the sanitised {@link String}
	 */
	static public String sanitize(String input, boolean allowUnicode) {
		return sanitize(input, allowUnicode, !allowUnicode);
	}

	/**
	 * Sanitise the given input to make it more Terminal-friendly by removing
	 * combining characters.
	 * 
	 * @param input
	 *            the input to sanitise
	 * @param allowUnicode
	 *            allow Unicode or only allow ASCII Latin characters
	 * @param removeAllAccents
	 *            TRUE to replace all accentuated characters by their non
	 *            accentuated counter-parts
	 * 
	 * @return the sanitised {@link String}
	 */
	static public String sanitize(String input, boolean allowUnicode,
			boolean removeAllAccents) {

		if (removeAllAccents) {
			input = Normalizer.normalize(input, Form.NFKD);
			input = marks.matcher(input).replaceAll("");
		}

		input = Normalizer.normalize(input, Form.NFKC);

		if (!allowUnicode) {
			StringBuilder builder = new StringBuilder();
			for (int index = 0; index < input.length(); index++) {
				char car = input.charAt(index);
				// displayable chars in ASCII are in the range 32<->255,
				// except DEL (127)
				if (car >= 32 && car <= 255 && car != 127) {
					builder.append(car);
				}
			}
			input = builder.toString();
		}

		return input;
	}

	/**
	 * Convert between time in milliseconds to {@link String} in a "static" way
	 * (to exchange data over the wire, for instance).
	 * 
	 * @param time
	 *            the time in milliseconds
	 * 
	 * @return the time as a {@link String}
	 */
	static public String fromTime(long time) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		return sdf.format(new Date(time));
	}

	/**
	 * Convert between time as a {@link String} to milliseconds in a "static"
	 * way (to exchange data over the wire, for instance).
	 * 
	 * @param time
	 *            the time as a {@link String}
	 * 
	 * @return the time in milliseconds
	 */
	static public long toTime(String display) {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		try {
			return sdf.parse(display).getTime();
		} catch (ParseException e) {
			return -1;
		}
	}

	/**
	 * Return a hash of the given {@link String}.
	 * 
	 * @param input
	 *            the input data
	 * 
	 * @return the hash
	 */
	static public String getHash(String input) {
		try {
			MessageDigest md = MessageDigest.getInstance("MD5");
			md.update(input.getBytes());
			byte byteData[] = md.digest();

			StringBuffer hexString = new StringBuffer();
			for (int i = 0; i < byteData.length; i++) {
				String hex = Integer.toHexString(0xff & byteData[i]);
				if (hex.length() == 1)
					hexString.append('0');
				hexString.append(hex);
			}

			return hexString.toString();
		} catch (NoSuchAlgorithmException e) {
			// all JVM most probably have an MD5 implementation, but even if
			// not, returning the input is "correct", if inefficient and
			// unsecure
			return input;
		}
	}
}