/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;

import java.text.DateFormatSymbols;
import java.util.Calendar;

import org.eclipse.swt.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.carbon.LongDateRec;
import org.eclipse.swt.internal.carbon.OS;

public class DateTime extends Composite {
	LongDateRec dateRec;

	static final int MIN_YEAR = 1752; // Gregorian switchover in North America: September 19, 1752
	static final int MAX_YEAR = 9999;
	
	/* Emulated Calendar variables */
	Color foreground, background;
	Calendar calendar;
	DateFormatSymbols formatSymbols;
	Button monthDown, monthUp, yearDown, yearUp;
	static final int MARGIN_WIDTH = 2;
	static final int MARGIN_HEIGHT = 1;

public DateTime (Composite parent, int style) {
	super (parent, checkStyle (style) | ((style & SWT.CALENDAR) != 0 ? SWT.NO_REDRAW_RESIZE : 0));
	if ((this.style & SWT.CALENDAR) != 0) {
		calendar = Calendar.getInstance();
		formatSymbols = new DateFormatSymbols();

		Listener listener = new Listener() {
			public void handleEvent(Event event) {
				switch(event.type) {
					case SWT.Paint:		handlePaint(event); break;
					case SWT.Resize:	handleResize(event); break;
					case SWT.MouseDown:	handleMouseDown(event); break;
					case SWT.KeyDown:	handleKeyDown(event); break;
					case SWT.Traverse:	handleTraverse(event); break;
				}
			}
		};
		addListener(SWT.Paint, listener);
		addListener(SWT.Resize, listener);
		addListener(SWT.MouseDown, listener);
		addListener(SWT.KeyDown, listener);
		addListener(SWT.Traverse, listener);
		yearDown = new Button(this, SWT.ARROW | SWT.LEFT);
		//yearDown.setToolTipText(SWT.getMessage ("SWT_Last_Year")); //$NON-NLS-1$
		monthDown = new Button(this, SWT.ARROW | SWT.LEFT);
		//monthDown.setToolTipText(SWT.getMessage ("SWT_Last_Month")); //$NON-NLS-1$
		monthUp = new Button(this, SWT.ARROW | SWT.RIGHT);
		//monthUp.setToolTipText(SWT.getMessage ("SWT_Next_Month")); //$NON-NLS-1$
		yearUp = new Button(this, SWT.ARROW | SWT.RIGHT);
		//yearUp.setToolTipText(SWT.getMessage ("SWT_Next_Year")); //$NON-NLS-1$
		listener = new Listener() {
			public void handleEvent(Event event) {
				handleSelection(event);
			}
		};
		yearDown.addListener(SWT.Selection, listener);
		monthDown.addListener(SWT.Selection, listener);
		monthUp.addListener(SWT.Selection, listener);
		yearUp.addListener(SWT.Selection, listener);
	
	}
}

static int checkStyle (int style) {
	/*
	* Even though it is legal to create this widget
	* with scroll bars, they serve no useful purpose
	* because they do not automatically scroll the
	* widget's client area.  The fix is to clear
	* the SWT style.
	*/
	style &= ~(SWT.H_SCROLL | SWT.V_SCROLL);
	return checkBits (style, SWT.DATE, SWT.TIME, SWT.CALENDAR, 0, 0, 0);
}

protected void checkSubclass () {
	if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}

public void addSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	TypedListener typedListener = new TypedListener (listener);
	addListener (SWT.Selection, typedListener);
	addListener (SWT.DefaultSelection, typedListener);
}

public Point computeSize (int wHint, int hHint, boolean changed) {
	checkWidget ();
	int width = 0, height = 0;
	if (wHint == SWT.DEFAULT || hHint == SWT.DEFAULT) {
		if ((style & SWT.CALENDAR) != 0) {
			Point cellSize = getCellSize(null);
			Point buttonSize = monthDown.computeSize(SWT.DEFAULT, SWT.DEFAULT, changed);
			width = cellSize.x * 7;
			height = cellSize.y * 7 + Math.max(cellSize.y, buttonSize.y);
		} else {
			// TODO: get the height of the current font
			height = 20;
			// TODO: max with the height of the up/down buttons
			int upDownHeight = 24;
			height = Math.max (height, upDownHeight);
			
			// TODO: determine the stringWidth of date or time string in current font (take code from GC)
			String string = "00/00/0000"; // TODO: these strings should be locale-specific
			if ((style & SWT.TIME) != 0) string = "00:00:00 AM";
			GC gc = new GC(this);
			width = gc.stringExtent(string).x;
			gc.dispose();
			// TODO: max with the height of the up/down buttons (maybe plus some margin?)
			int upDownWidth = 20;
			width += upDownWidth + 5; // MARGIN
		}
	}
	if (width == 0) width = DEFAULT_WIDTH;
	if (height == 0) height = DEFAULT_HEIGHT;
	if (wHint != SWT.DEFAULT) width = wHint;
	if (hHint != SWT.DEFAULT) height = hHint;
	int border = getBorderWidth ();
	width += border * 2; height += border * 2;
	return new Point (width, height);
}

void createHandle () {
	int clockType = 0;
	if ((style & SWT.TIME) != 0) clockType = OS.kControlClockTypeHourMinuteSecond;
	if ((style & SWT.DATE) != 0) clockType = OS.kControlClockTypeMonthDayYear;
	if (clockType != 0) { /* SWT.DATE and SWT.TIME */
		int clockFlags = OS.kControlClockFlagStandard;
		int [] outControl = new int [1];
		int window = OS.GetControlOwner (parent.handle);
		OS.CreateClockControl(window, null, clockType, clockFlags, outControl);
		if (outControl [0] == 0) error (SWT.ERROR_NO_HANDLES);
		handle = outControl [0];
	} else { /* SWT.CALENDAR */
		// TODO: on Cocoa, can use NSDatePicker - otherwise, use emulated:
		super.createHandle();
	}
}

void createWidget() {
	super.createWidget ();
	getDate();
}

void drawDay(GC gc, Point cellSize, int day) {
	int cell = getCell(day);
	Point location = getCellLocation(cell, cellSize);
	String str = String.valueOf(day);
	Point extent = gc.stringExtent(str);
	int date = calendar.get(Calendar.DAY_OF_MONTH);
	if (day == date) {
		Display display = getDisplay();
		gc.setBackground(display.getSystemColor(SWT.COLOR_LIST_SELECTION));
		gc.setForeground(display.getSystemColor(SWT.COLOR_LIST_SELECTION_TEXT));
		gc.fillRectangle(location.x, location.y, cellSize.x, cellSize.y);
	}
	gc.drawString(str, location.x + (cellSize.x - extent.x) / 2, location.y + (cellSize.y - extent.y) / 2, true);
	if (day == date) {
		gc.setBackground(getBackground());
		gc.setForeground(getForeground());
	}
}

void drawDays(GC gc, Point cellSize, Rectangle client) {
	gc.setBackground(getBackground());
	gc.setForeground(getForeground());
	gc.fillRectangle(0, cellSize.y, client.width, cellSize.y * 7);
	int firstDay = calendar.getActualMinimum(Calendar.DAY_OF_MONTH);
	int lastDay = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
	for (int day = firstDay; day <= lastDay; day++) {
		drawDay(gc, cellSize, day);
	}
}

void drawDaysOfWeek(GC gc, Point cellSize, Rectangle client) {
	Display display = getDisplay();
	gc.setBackground(display.getSystemColor(SWT.COLOR_WIDGET_BACKGROUND));
	gc.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_FOREGROUND));
	gc.fillRectangle(0, 0, client.width, cellSize.y);
	String[] days = formatSymbols.getShortWeekdays();
	int x = 0, y = 0; 
	for (int i = 1; i < days.length; i++) {
		String day = days[i];
		Point extent = gc.stringExtent(day);
		gc.drawString(day, x + (cellSize.x - extent.x) / 2, y + (cellSize.y - extent.y) / 2, true);
		x += cellSize.x;
	}
	gc.drawLine(0, cellSize.y - 1, client.width, cellSize.y - 1);
}

void drawMonth(GC gc, Point cellSize, Rectangle client) {
	Display display = getDisplay();
	gc.setBackground(display.getSystemColor(SWT.COLOR_WIDGET_BACKGROUND));
	gc.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_FOREGROUND));
	int y = cellSize.y * 7;
	gc.fillRectangle(0, y, client.width, cellSize.y);
	gc.drawLine(0, y - 1, client.width, y - 1);
	String str = formatSymbols.getShortMonths()[calendar.get(Calendar.MONTH)] + ", " + calendar.get(Calendar.YEAR);
	Point extent = gc.stringExtent(str);
	gc.drawString(str, (cellSize.x * 7 - extent.x) / 2, y + (cellSize.y - extent.y) / 2, true);
}

void handleKeyDown(Event event) {
	int newDay = calendar.get(Calendar.DAY_OF_MONTH);
	switch (event.keyCode) {
		case SWT.ARROW_DOWN: newDay += 7; break;
		case SWT.ARROW_UP: newDay -= 7; break;
		case SWT.ARROW_RIGHT: newDay += 1; break;
		case SWT.ARROW_LEFT: newDay -= 1; break;
	}
	setDay(newDay, true);
}

void handleMouseDown(Event event) {
	setFocus();
	Point cellSize = getCellSize(null);
	int column = event.x / cellSize.x;
	int row = event.y / cellSize.y;	
	int cell = row * 7 + column;
	int newDay = getDate(cell);
	setDay(newDay, true);
}

void handlePaint(Event event) {
	GC gc = event.gc;
	Rectangle client = getClientArea();
	Point cellSize = getCellSize(gc);
	drawDaysOfWeek(gc, cellSize, client);
	drawDays(gc, cellSize, client);
	drawMonth(gc, cellSize, client);
}

void handleResize(Event event) {
	yearDown.pack();
	monthDown.pack();
	monthUp.pack();
	yearUp.pack();
	Point cellSize = getCellSize(null);
	Point size = monthDown.getSize();
	int height = Math.max(cellSize.y, size.y);
	int y = cellSize.y * 7 + (height - size.y) / 2;
	yearDown.setLocation(0, y);
	monthDown.setLocation(size.x, y);
	int x = cellSize.x * 7 - size.x;
	monthUp.setLocation(x - size.x, y);
	yearUp.setLocation(x, y);
}

void handleSelection(Event event) {
	if (event.widget == monthDown) {
		calendar.add(Calendar.MONTH, -1);
	} else if (event.widget == monthUp) {
		calendar.add(Calendar.MONTH, 1);
	} else if (event.widget == yearDown) {
		calendar.add(Calendar.YEAR, -1);
	} else if (event.widget == yearUp) {				
		calendar.add(Calendar.YEAR, 1);
	} else {
		return;
	}
	redraw();
	notifyListeners(SWT.Selection, new Event());
}

void handleTraverse(Event event) {
	switch (event.detail) {
		case SWT.TRAVERSE_ESCAPE:
		case SWT.TRAVERSE_PAGE_NEXT:
		case SWT.TRAVERSE_PAGE_PREVIOUS:
		case SWT.TRAVERSE_RETURN:
		case SWT.TRAVERSE_TAB_NEXT:
		case SWT.TRAVERSE_TAB_PREVIOUS:
			event.doit = true;
			break;
	}	
}

Point getCellSize(GC gc) {
	boolean dispose = gc == null; 
	if (gc == null) gc = new GC(this);
	int width = 0, height = 0;
	String[] days = formatSymbols.getShortWeekdays();
	for (int i = 0; i < days.length; i++) {
		Point extent = gc.stringExtent(days[i]);
		width = Math.max(width, extent.x);
		height = Math.max(height, extent.y);
	}
	int firstDay = calendar.getMinimum(Calendar.DAY_OF_MONTH);
	int lastDay = calendar.getMaximum(Calendar.DAY_OF_MONTH);
	for (int day = firstDay; day <= lastDay; day++) {
		Point extent = gc.stringExtent(String.valueOf(day));
		width = Math.max(width, extent.x);
		height = Math.max(height, extent.y);	
	}
	if (dispose) gc.dispose();
	return new Point(width + MARGIN_WIDTH * 2, height + MARGIN_HEIGHT * 2);
}

Point getCellLocation(int cell, Point cellSize) {
	return new Point(cell % 7 * cellSize.x, cell / 7 * cellSize.y);
}

int getCell(int date) {
	int day = calendar.get(Calendar.DAY_OF_MONTH);
	calendar.set(Calendar.DAY_OF_MONTH, 1);
	int result = date + calendar.get(Calendar.DAY_OF_WEEK) + 5;
	calendar.set(Calendar.DAY_OF_MONTH, day);
	return result;
}

void getDate() {
	dateRec = new LongDateRec ();
	OS.GetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec, null);
}

int getDate(int cell) {
	int day = calendar.get(Calendar.DAY_OF_MONTH);
	calendar.set(Calendar.DAY_OF_MONTH, 1);
	int result = cell - calendar.get(Calendar.DAY_OF_WEEK) - 5;
	calendar.set(Calendar.DAY_OF_MONTH, day);
	return result;
}

public Color getBackground() {
	checkWidget();
	if (background == null) {
		return getDisplay().getSystemColor(SWT.COLOR_LIST_BACKGROUND);
	}
	return background;
}

public Color getForeground() {
	checkWidget();
	if (foreground == null) {
		return getDisplay().getSystemColor(SWT.COLOR_LIST_FOREGROUND);
	}
	return foreground;
}

public int getDay () {
	checkWidget ();
	if ((style & SWT.CALENDAR) != 0) {
		return calendar.get(Calendar.DAY_OF_MONTH);
	}
	getDate();
	return dateRec.day;
}

public int getHour () {
	checkWidget ();
	if ((style & SWT.CALENDAR) != 0) {
		return calendar.get(Calendar.HOUR_OF_DAY);
	}
	getDate();
	return dateRec.hour;
}

public int getMinute () {
	checkWidget ();
	if ((style & SWT.CALENDAR) != 0) {
		return calendar.get(Calendar.MINUTE);
	}
	getDate();
	return dateRec.minute;
}

public int getMonth () {
	checkWidget ();
	if ((style & SWT.CALENDAR) != 0) {
		return calendar.get(Calendar.MONTH) + 1;
	}
	getDate();
	return dateRec.month;
}

public int getSecond () {
	checkWidget ();
	if ((style & SWT.CALENDAR) != 0) {
		return calendar.get(Calendar.SECOND);
	}
	getDate();
	return dateRec.second;
}

public int getYear () {
	checkWidget ();
	if ((style & SWT.CALENDAR) != 0) {
		return calendar.get(Calendar.YEAR);
	}
	getDate();
	return dateRec.year;
}

void hookEvents () {
	super.hookEvents ();
	if (OS.VERSION >= 0x1040) {
		int clockProc = display.clockProc;
		int [] mask = new int [] {
				OS.kEventClassClockView, OS.kEventClockDateOrTimeChanged,
		};
		int controlTarget = OS.GetControlEventTarget (handle);
		OS.InstallEventHandler (controlTarget, clockProc, mask.length / 2, mask, handle, null);
	}
}

boolean isValid(int fieldName, int value) {
	Calendar calendar = Calendar.getInstance();
	calendar.set(Calendar.YEAR, dateRec.year);
	calendar.set(Calendar.MONTH, dateRec.month - 1);
	int min = calendar.getActualMinimum(fieldName);
	int max = calendar.getActualMaximum(fieldName);
	return value >= min && value <= max;
}

int kEventClockDateOrTimeChanged (int nextHandler, int theEvent, int userData) {
	sendSelectionEvent ();
	return OS.noErr;
}

int kEventControlHit (int nextHandler, int theEvent, int userData) {
	int result = super.kEventControlHit (nextHandler, theEvent, userData);
	if (result == OS.noErr) return result;
	if (OS.VERSION < 0x1040) sendSelectionEvent ();
	return result;
}

int kEventTextInputUnicodeForKeyEvent (int nextHandler, int theEvent, int userData) {
	int result = super.kEventTextInputUnicodeForKeyEvent (nextHandler, theEvent, userData);
	if (result == OS.noErr) return result;
	if (OS.VERSION < 0x1040) sendSelectionEvent ();
	return result;
}

void redraw(int cell, Point cellSize) {
	Point location = getCellLocation(cell, cellSize);
	redraw(location.x, location.y, cellSize.x, cellSize.y, false);	
}

void releaseWidget () {
	super.releaseWidget();
	dateRec = null;
}

public void removeSelectionListener (SelectionListener listener) {
	checkWidget ();
	if (listener == null) error (SWT.ERROR_NULL_ARGUMENT);
	if (eventTable == null) return;
	eventTable.unhook (SWT.Selection, listener);
	eventTable.unhook (SWT.DefaultSelection, listener);	
}

void sendSelectionEvent () {
	LongDateRec rec = new LongDateRec ();
	OS.GetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, rec, null);
	if (rec.second != dateRec.second ||
		rec.minute != dateRec.minute ||
		rec.hour != dateRec.hour ||
		rec.day != dateRec.day ||
		rec.month != dateRec.month ||
		rec.year != dateRec.year) {
		dateRec = rec;
		postEvent (SWT.Selection);
	}
}

public void setBackground(Color color) {
	checkWidget();
	super.setBackground(color);
	background = color;
}

public void setForeground(Color color) {
	checkWidget();
	super.setForeground(color);
	foreground = color;
}

void setDay(int newDay, boolean notify) {
	int firstDay = calendar.getActualMinimum(Calendar.DAY_OF_MONTH);
	int lastDay = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
	if (!(firstDay <= newDay && newDay <= lastDay)) return;
	Point cellSize = getCellSize(null);
	redraw(getCell(calendar.get(Calendar.DAY_OF_MONTH)), cellSize);
	calendar.set(Calendar.DAY_OF_MONTH, newDay);
	redraw(getCell(calendar.get(Calendar.DAY_OF_MONTH)), cellSize);
	if (notify) notifyListeners(SWT.Selection, new Event());
}

public void setDay (int day) {
	checkWidget ();
	if (!isValid(Calendar.DAY_OF_MONTH, day)) return;
	if ((style & SWT.CALENDAR) != 0) {
		setDay(day, false);
	} else {
		dateRec.day = (short)day;
		OS.SetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec);
		OS.GetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec, null);
		redraw();
	}
}

public void setHour (int hour) {
	checkWidget ();
	if (!isValid(Calendar.HOUR_OF_DAY, hour)) return;
	if ((style & SWT.CALENDAR) != 0) {
		calendar.set(Calendar.HOUR_OF_DAY, hour);
	} else {
		dateRec.hour = (short)hour;
		OS.SetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec);
		OS.GetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec, null);
	}
	redraw();
}

public void setMinute (int minute) {
	checkWidget ();
	if (!isValid(Calendar.MINUTE, minute)) return;
	if ((style & SWT.CALENDAR) != 0) {
		calendar.set(Calendar.MINUTE, minute);
	} else {
		dateRec.minute = (short)minute;
		OS.SetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec);
		OS.GetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec, null);
	}
	redraw();
}

public void setMonth (int month) {
	checkWidget ();
	if (!isValid(Calendar.MONTH, month - 1)) return;
	if ((style & SWT.CALENDAR) != 0) {
		calendar.set(Calendar.MONTH, month - 1);
	} else {
		dateRec.month = (short)month;
		OS.SetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec);
		OS.GetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec, null);
	}
	redraw();
}

public void setSecond (int second) {
	checkWidget ();
	if (!isValid(Calendar.SECOND, second)) return;
	if ((style & SWT.CALENDAR) != 0) {
		calendar.set(Calendar.SECOND, second);
	} else {
		dateRec.second = (short)second;
		OS.SetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec);
		OS.GetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec, null);
	}
	redraw();
}

public void setYear (int year) {
	checkWidget ();
	//if (!isValid(Calendar.YEAR, year)) return;
	if (year < MIN_YEAR || year > MAX_YEAR) return;
	if ((style & SWT.CALENDAR) != 0) {
		calendar.set(Calendar.YEAR, year);
	} else {
		dateRec.year = (short)year;
		OS.SetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec);
		OS.GetControlData (handle, (short)OS.kControlEntireControl, OS.kControlClockLongDateTag, LongDateRec.sizeof, dateRec, null);
	}
	redraw();
}
}