/***
 * 
 * Copyright (C) 2008 Alessandro La Rosa
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Contact: alessandro.larosa@gmail.com
 *
 * Author: Alessandro La Rosa
 */

import java.util.Calendar;
import java.util.Date;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Font;
import javax.microedition.lcdui.Graphics;

public class CalendarWidget
{
	static final String[] MONTH_LABELS = new String[]{
		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
	};
	static final String[] WEEKDAY_LABELS = new String[]{
		"M", "T", "W", "T", "F", "S", "S"
	};
	/* starting week day: 0 for monday, 6 for sunday */
	public int startWeekday = 0;
	
	/* elements padding */
	public int padding = 1;
	
	/* cells border properties */
	public int borderWidth = 4;
	public int borderColor = 0x0000ff;
	
	/* weekday labels properties */
	public Font weekdayFont = Font.getDefaultFont();
	public int weekdayBgColor = 0x0000ff;
	public int weekdayColor = 0xffffff;
	
	/* header (month-year label) properties */
	public Font headerFont = Font.getDefaultFont();
	public int headerBgColor = 0x0000ff;
	public int headerColor = 0xffffff;
	
	/* cells properties */
	public Font font = Font.getDefaultFont();
	public int foreColor = 0x000000;
	public int bgColor = 0x9999ff;
	public int selectedBgColor = 0xffff00;
	public int selectedForeColor = 0xff0000;
	
	/* internal properties */
	int width = 0;
	int height = 0;
	int headerHeight = 0;
	int weekHeight = 0;
	int cellWidth = 0;
	int cellHeight = 0;
	
	/* internal time properties */
	long currentTimestamp = 0;
	Calendar calendar = null;
	int weeks = 0;
	
public CalendarWidget(Date date)
{
	calendar = Calendar.getInstance();
	
	//we'll see these 2 methods later
	setDate(date);
	
	initialize();
}
public Date getSelectedDate()
{
	return calendar.getTime();
}
public void setDate(Date d)
{
	currentTimestamp = d.getTime();
	
	calendar.setTime(d);
	
	//weeks number can change, depending on week starting day and month total days
	this.weeks = (int)Math.ceil(((double)getStartWeekday() + getMonthDays()) / 7);
}
public void setDate(long timestamp)
{
	setDate(new Date(timestamp));
}
void initialize()
{
	//let's initialize calendar size
	this.cellWidth = font.stringWidth("MM") + 2 * padding;
	this.cellHeight = font.getHeight() + 2 * padding;
	
	this.headerHeight = headerFont.getHeight() + 2 * padding;
	this.weekHeight = weekdayFont.getHeight() + 2 * padding;
	
	this.width = 7 * (cellWidth + borderWidth) + borderWidth;
	initHeight();
}
void initHeight()
{
	this.height = 
		headerHeight + weekHeight + 
		this.weeks * (cellHeight + borderWidth) + borderWidth;
}
int getMonthDays()
{
	int month = calendar.get(Calendar.MONTH);
	
	switch(month)
	{
	case 3:
	case 5:
	case 8:
	case 10:
		return 30;
	case 1:
		return calendar.get(Calendar.YEAR) % 4 == 0 && calendar.get(Calendar.YEAR) % 100 != 0 ? 29 : 28;
	default:
		return 31;
	}
}
int getStartWeekday()
{
	//let's create a new calendar with same month and year, but with day 1
	Calendar c = Calendar.getInstance();
	
	c.set(Calendar.MONTH, calendar.get(Calendar.MONTH));
	c.set(Calendar.YEAR, calendar.get(Calendar.YEAR));
	c.set(Calendar.DAY_OF_MONTH, 1);
	
	//we must normalize DAY_OF_WEEK returned value
	return (c.get(Calendar.DAY_OF_WEEK) + 5) % 7;
}
public void keyPressed(int key)
{
	switch(key)
	{
	case Canvas.UP:
		go(-7);
		break;
	case Canvas.DOWN:
		go(7);
		break;
	case Canvas.RIGHT:
		go(1);
		break;
	case Canvas.LEFT:
		go(-1);
		break;
	}
}
void go(int delta)
{
	int prevMonth = calendar.get(Calendar.MONTH);
	
	setDate(currentTimestamp + 86400000 * delta);

	//we have to check if month has changed
	//if yes, we have to recalculate month height
	//since weeks number could be changed
	if(calendar.get(Calendar.MONTH) != prevMonth)
	{
		initHeight();
	}
}
public void paint(Graphics g)
{
	//painting background
	g.setColor(bgColor);
	g.fillRect(0, 0, width, height);
	
	//painting header (month-year label)
	g.setFont(headerFont);
	g.setColor(headerColor);
	g.drawString(MONTH_LABELS[calendar.get(Calendar.MONTH)] + " " + calendar.get(Calendar.YEAR), width / 2, padding, Graphics.TOP | Graphics.HCENTER);
	
	//painting week days labels
	g.translate(0, headerHeight);
	
	g.setColor(weekdayBgColor);
	g.fillRect(0, 0, width, weekHeight);
	
	g.setColor(weekdayColor);
	g.setFont(weekdayFont);
	
	for(int i = 0; i < 7; i++)
	{
		g.drawString(WEEKDAY_LABELS[(i + startWeekday) % 7],
			borderWidth + i * (cellWidth + borderWidth) + cellWidth / 2,
			padding,
			Graphics.TOP | Graphics.HCENTER
		);
	}
	
	//painting cells borders
	g.translate(0, weekHeight);
	
	g.setColor(borderColor);
	
	for(int i = 0; i <= weeks; i++)
	{
		g.fillRect(0, i * (cellHeight + borderWidth), width, borderWidth);
	}
	for(int i = 0; i <= 7; i++)
	{
		g.fillRect(i * (cellWidth + borderWidth), 0, borderWidth, height - headerHeight - weekHeight);
	}
	
	//painting days
	int days = getMonthDays();
	int dayIndex = (getStartWeekday() - this.startWeekday + 7) % 7;
	
	g.setColor(foreColor);
	
	int currentDay = calendar.get(Calendar.DAY_OF_MONTH);
	
	for(int i = 0; i < days; i++)
	{
		int weekday = (dayIndex + i) % 7;
		int row = (dayIndex + i) / 7;
		
		int x = borderWidth + weekday * (cellWidth + borderWidth) + cellWidth / 2;
		int y = borderWidth + row * (cellHeight + borderWidth) + padding;
	
		//if this is the current day, we'll use selected bg and fore colors
		if(i + 1 == currentDay)
		{
			g.setColor(selectedBgColor);
			g.fillRect(
				borderWidth + weekday * (cellWidth + borderWidth), 
				borderWidth + row * (cellHeight + borderWidth), 
				cellWidth, cellHeight);
			g.setColor(selectedForeColor);
		}
		
		g.drawString("" + (i + 1), x, y, Graphics.TOP | Graphics.HCENTER);
		
		//if this is the current day, we must restore standard fore color 
		if(i + 1 == currentDay)
		{
			g.setColor(foreColor);
		}
	}
	//let's traslate back!
	g.translate(0, - headerHeight - weekHeight);
}
}