package org.simantics.xml.sax.base.datatypes.literal;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

import org.simantics.databoard.Bindings;
import org.simantics.databoard.binding.Binding;
import org.simantics.databoard.util.Bean;

public class DateTime extends Bean implements org.simantics.xml.sax.base.datatypes.adt.DateTime {

	public static final Binding BINDING = Bindings.getBindingUnchecked(DateTime.class);

	public int year;
	public byte month;
	public byte day;
	public byte hours;
	public byte minutes;
	public byte seconds;
	public int offset;
	
	public DateTime(){
		super(BINDING);
	}

	public DateTime(int year, int month, int day, int hours, int minutes, int seconds) {
		this(year, month, day, hours, minutes, seconds, java.lang.Integer.MIN_VALUE);
	}
	
	public DateTime(int year, int month, int day, int hours, int minutes, int seconds, int offset) {
		super(BINDING);
		if (month <= 0 || month > 12) throw new IllegalArgumentException("Month must be between 1 - 12, got " + month);
		if (day <= 0 || day > 31) throw new IllegalArgumentException("Day must be between 1 - 31, got " + day);
		if (hours < 0 || hours > 23) throw new IllegalArgumentException("Hours must be between 0 - 23, got " + hours);
		if (minutes < 0 || minutes > 59) throw new IllegalArgumentException("Minutes must be between 0 - 59, got " + minutes);
		if (seconds < 0 || seconds > 59) throw new IllegalArgumentException("Seconds must be between 0 - 59, got " + seconds);
		this.year = year;
		this.month = (byte)month;
		this.day = (byte)day;
		this.hours = (byte)hours;
		this.minutes = (byte)minutes;
		this.seconds = (byte)seconds;
		this.offset = offset;
	}

	@Override
	public int getYear() {
		return year;
	}

	@Override
	public int getMonth() {
		return month;
	}

	@Override
	public int getDate() {
		return day;
	}

	@Override
	public int getHours() {
		return hours;
	}

	@Override
	public int getMinutes() {
		return minutes;
	}

	@Override
	public int getSeconds() {
		return seconds;
	}

	@Override
	public int getTimezoneOffset() {
		return offset;
	}

	@Override
	public Date getJavaDate() {
		Calendar c = Calendar.getInstance();
		c.set(year, month, day, hours, minutes, seconds);
		if (offset != Integer.MIN_VALUE) {
			c.setTimeZone(TimeZone.getTimeZone(TimeZone.getAvailableIDs(offset*60*1000)[0]));
		}
		return c.getTime();
	}
	
	@Override
	public int compare(org.simantics.xml.sax.base.datatypes.adt.DateTime o) {
		// FIXME: take account time offset 
		if (getYear() != o.getYear())
			return getYear() - o.getYear();
		if (getMonth() != o.getMonth())
			return getMonth() - o.getMonth();
		if (getDate() != o.getDate())
			return getDate() - o.getDate();
		if (getHours() != o.getHours())
			return getHours() - o.getHours();
		if (getMinutes() != o.getMinutes())
			return getMinutes() - o.getMinutes();
		if (getSeconds() != o.getSeconds())
			return getSeconds() - o.getSeconds();
		return 0;
	}
	
	public static DateTime parseDateTime(String dateString) {
		// FIXME: XML specification allows any number of second decimals!
		// FIXME: endOfDayFrag handling is missing.
		String[] formats = new String[]{"yyyy-MM-dd'T'HH:mm:ssXXX", "yyyy-MM-dd'T'HH:mm:ssSSSSSSSXXX","yyyy-MM-dd'T'HH:mm:ss", "yyyy-MM-dd'T'HH:mm:ssSSSSSSS"};
		boolean[] timezone = new boolean[]{true, true,false,false};
		for (int i = 0; i< formats.length; i++) {
			String format = formats[i];
			try {
				SimpleDateFormat dateFormat = new SimpleDateFormat(format);
				java.util.Date n = dateFormat.parse(dateString);
				if (timezone[i]) {
					return new DateTime(n.getYear()+1900, n.getMonth()+1, n.getDate(), n.getHours(),n.getMinutes(), n.getSeconds(), n.getTimezoneOffset());
				}
				return new DateTime(n.getYear()+1900, n.getMonth()+1, n.getDate(), n.getHours(),n.getMinutes(), n.getSeconds());
			}  catch (ParseException e) {
				
			}
		}

		throw new IllegalArgumentException("Time is not in proper format " + dateString);
	}
	
	@Override
	public String toString() {
		return year + "-" + month + "-"+day + "T"+hours+ ":" + minutes + ":"+seconds;
	}

}