package com.firefly.codec.http2.model;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;

/**
 * ThreadLocal data parsers for HTTP style dates
 *
 */
public class DateParser {
	private static final TimeZone __GMT = TimeZone.getTimeZone("GMT");

	static {
		__GMT.setID("GMT");
	}

	final static String __dateReceiveFmt[] = { "EEE, dd MMM yyyy HH:mm:ss zzz", "EEE, dd-MMM-yy HH:mm:ss",
			"EEE MMM dd HH:mm:ss yyyy",

			"EEE, dd MMM yyyy HH:mm:ss", "EEE dd MMM yyyy HH:mm:ss zzz", "EEE dd MMM yyyy HH:mm:ss",
			"EEE MMM dd yyyy HH:mm:ss zzz", "EEE MMM dd yyyy HH:mm:ss", "EEE MMM-dd-yyyy HH:mm:ss zzz",
			"EEE MMM-dd-yyyy HH:mm:ss", "dd MMM yyyy HH:mm:ss zzz", "dd MMM yyyy HH:mm:ss", "dd-MMM-yy HH:mm:ss zzz",
			"dd-MMM-yy HH:mm:ss", "MMM dd HH:mm:ss yyyy zzz", "MMM dd HH:mm:ss yyyy", "EEE MMM dd HH:mm:ss yyyy zzz",
			"EEE, MMM dd HH:mm:ss yyyy zzz", "EEE, MMM dd HH:mm:ss yyyy", "EEE, dd-MMM-yy HH:mm:ss zzz",
			"EEE dd-MMM-yy HH:mm:ss zzz", "EEE dd-MMM-yy HH:mm:ss", };

	public static long parseDate(String date) {
		return __dateParser.get().parse(date);
	}

	private static final ThreadLocal<DateParser> __dateParser = new ThreadLocal<DateParser>() {
		@Override
		protected DateParser initialValue() {
			return new DateParser();
		}
	};

	final SimpleDateFormat _dateReceive[] = new SimpleDateFormat[__dateReceiveFmt.length];

	private long parse(final String dateVal) {
		for (int i = 0; i < _dateReceive.length; i++) {
			if (_dateReceive[i] == null) {
				_dateReceive[i] = new SimpleDateFormat(__dateReceiveFmt[i], Locale.US);
				_dateReceive[i].setTimeZone(__GMT);
			}

			try {
				Date date = (Date) _dateReceive[i].parseObject(dateVal);
				return date.getTime();
			} catch (java.lang.Exception e) {
				// log.ignore(e);
			}
		}

		if (dateVal.endsWith(" GMT")) {
			final String val = dateVal.substring(0, dateVal.length() - 4);

			for (SimpleDateFormat element : _dateReceive) {
				try {
					Date date = (Date) element.parseObject(val);
					return date.getTime();
				} catch (java.lang.Exception e) {
					// log.ignore(e);
				}
			}
		}
		return -1;
	}
}