/*******************************************************************************
 * Copyright (c) 2000, 2007 IBM Corporation and others.
 * Portion Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).
 * 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
 *     Nokia Corporation - Qt implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;

import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.internal.qt.OS;

/**
 * Instances of this class allow the user to navigate the file system and select
 * or enter a file name.
 * <dl>
 * <dt><b>Styles:</b></dt>
 * <dd>SAVE, OPEN, MULTI</dd>
 * <dt><b>Events:</b></dt>
 * <dd>(none)</dd>
 * </dl>
 * <p>
 * Note: Only one of the styles SAVE and OPEN may be specified.
 * </p>
 * <p>
 * IMPORTANT: This class is intended to be subclassed <em>only</em> within the
 * SWT implementation.
 * </p>
 */
public class FileDialog extends Dialog {
	String[] filterNames;
	String[] filterExtensions;
	String filterPath = "";
	String fileName;
	String[] fileNames = new String[] {};
	int filterIndex = -1;
	static final char SEPARATOR = '/'; // See QDir::fromNativeSeparators
	static final String EXTENSION_SEPARATOR = ";;";
	String dialogID;
	static int dialogCount;

	/**
	 * Constructs a new instance of this class given only its parent.
	 *
	 * @param parent
	 *            a shell which will be the parent of the new instance
	 *
	 * @exception IllegalArgumentException
	 *                <ul>
	 *                <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
	 *                </ul>
	 * @exception SWTException
	 *                <ul>
	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	 *                thread that created the parent</li>
	 *                <li>ERROR_INVALID_SUBCLASS - if this class is not an
	 *                allowed subclass</li>
	 *                </ul>
	 */
	public FileDialog(Shell parent) {
		this(parent, SWT.NULL);
	}

	/**
	 * Constructs a new instance of this class given its parent and a style
	 * value describing its behavior and appearance.
	 * <p>
	 * The style value is either one of the style constants defined in class
	 * <code>SWT</code> which is applicable to instances of this class, or must
	 * be built by <em>bitwise OR</em>'ing together (that is, using the
	 * <code>int</code> "|" operator) two or more of those <code>SWT</code>
	 * style constants. The class description lists the style constants that are
	 * applicable to the class. Style bits are also inherited from superclasses.
	 * </p>
	 *
	 * @param parent
	 *            a shell which will be the parent of the new instance
	 * @param style
	 *            the style of dialog to construct
	 *
	 * @exception IllegalArgumentException
	 *                <ul>
	 *                <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
	 *                </ul>
	 * @exception SWTException
	 *                <ul>
	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	 *                thread that created the parent</li>
	 *                <li>ERROR_INVALID_SUBCLASS - if this class is not an
	 *                allowed subclass</li>
	 *                </ul>
	 */
	public FileDialog(Shell parent, int style) {
		super(parent, checkStyle(parent, style));
		checkSubclass();
		dialogCount++;
		dialogID = toString() + String.valueOf(dialogCount);
	}

	static int checkStyle(Shell parent, int style) {
		style &= ~SWT.MIRRORED;
		if ((style & SWT.RIGHT_TO_LEFT) == 0) {
			if (parent != null) {
				if ((parent.style & SWT.RIGHT_TO_LEFT) != 0)
					style |= SWT.RIGHT_TO_LEFT;
			}
		}

		if ((style & SWT.OPEN) != 0 && (style & SWT.SAVE) != 0) {
			style &= ~SWT.OPEN;
		}

		if ((style & SWT.SAVE) != 0 && (style & SWT.MULTI) != 0) {
			style &= ~SWT.MULTI;
		}

		if ((style & SWT.LEFT_TO_RIGHT) != 0
				&& (style & SWT.RIGHT_TO_LEFT) != 0) {
			style &= ~SWT.LEFT_TO_RIGHT;
		}
		return style;
	}

	/**
	 * Returns the path of the first file that was selected in the dialog
	 * relative to the filter path, or an empty string if no such file has been
	 * selected.
	 *
	 * @return the relative path of the file
	 */
	public String getFileName() {
		return fileName;
	}

	/**
	 * Returns a (possibly empty) array with the paths of all files that were
	 * selected in the dialog relative to the filter path.
	 *
	 * @return the relative paths of the files
	 */
	public String[] getFileNames() {
		return fileNames;
	}

	/**
	 * Returns the file extensions which the dialog will use to filter the files
	 * it shows.
	 *
	 * @return the file extensions filter
	 */
	public String[] getFilterExtensions() {
		return filterExtensions;
	}

	/**
	 * Get the 0-based index of the file extension filter which was selected by
	 * the user, or -1 if no filter was selected.
	 * <p>
	 * This is an index into the FilterExtensions array and the FilterNames
	 * array.
	 * </p>
	 *
	 * @return index the file extension filter index
	 *
	 * @see #getFilterExtensions
	 * @see #getFilterNames
	 *
	 * @since 3.4
	 */
	public int getFilterIndex() {
		return filterIndex;
	}

	/**
	 * Returns the names that describe the filter extensions which the dialog
	 * will use to filter the files it shows.
	 *
	 * @return the list of filter names
	 */
	public String[] getFilterNames() {
		return filterNames;
	}

	/**
	 * Returns the directory path that the dialog will use, or an empty string
	 * if this is not set. File names in this path will appear in the dialog,
	 * filtered according to the filter extensions.
	 *
	 * @return the directory path string
	 *
	 * @see #setFilterExtensions
	 */
	public String getFilterPath() {
		return filterPath;
	}

	/**
	 * Makes the dialog visible and brings it to the front of the display.
	 *
	 * @return a string describing the absolute path of the first selected file,
	 *         or null if the dialog was cancelled or an error occurred
	 *
	 * @exception SWTException
	 *                <ul>
	 *                <li>ERROR_WIDGET_DISPOSED - if the dialog has been
	 *                disposed</li>
	 *                <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
	 *                thread that created the dialog</li>
	 *                </ul>
	 */
	public String open() {
		checkDialog();

		/*
		 * put filters and filter names into single string
		 */
		String filter = "";
		int filterCount = filterExtensions != null ? filterExtensions.length
				: -1;
		int filterNameCount = filterNames != null ? filterNames.length : -1;
		if (filterCount > 0) {
			filter += (filterNameCount > 0 ? filterNames[0] + " " : "") + "("
					+ filterExtensions[0] + ")";
			for (int i = 1; i < filterCount; i++) {
				filter += EXTENSION_SEPARATOR
						+ (i < filterNameCount ? filterNames[i] + " " : "")
						+ "(" + filterExtensions[i] + ")";
			}
		}

		/*
		 * get selected filter
		 */
		String selectedFilter = filterIndex > -1 && filterIndex < filterCount ? filterExtensions[filterIndex]
				: "";

		/*
		 * form full path
		 */
		int filterPathLength = filterPath != null ? filterPath.length() : 0;
		String fullPath = filterPathLength > 0 ? filterPath : "";
		int fileNameLength = fileName != null ? fileName.length() : 0;
		if (filterPathLength > 0 && fileNameLength > 0
				&& filterPath.charAt(filterPathLength - 1) != SEPARATOR) {
			/*
			 * adding a separator between filterPath and file name
			 */
			fullPath += SEPARATOR;
		}
		if (fileNameLength > 0) {
			fullPath += fileName;
		}

		DisposeListener listener = new DisposeListener() {
			public void widgetDisposed(DisposeEvent e) {
				if (e.widget == parent) {
					/*
					 * close dialogs which opened on top of parent
					 */
					OS.QDialog_swt_closeDialogs(parent.handle,
							dialogID);
				}

			}
		};

		/*
		 * listen to parent dispose event
		 */
		parent.addDisposeListener(listener);

		/*
		 * open dialog
		 */
		int qtLayoutDirection = (style & SWT.RIGHT_TO_LEFT) != 0 ? OS.QT_RIGHTTOLEFT
				: OS.QT_LEFTTORIGHT;
		String[] resultStrings;
		if ((style & SWT.SAVE) != 0) {
			resultStrings = OS.QFileDialog_swt_getSaveFileName(parent.handle,
					title, fullPath, filter, selectedFilter, dialogID,
					qtLayoutDirection);
		} else {
			if ((style & SWT.MULTI) != 0) {
				resultStrings = OS.QFileDialog_swt_getOpenFileNames(
						parent.handle, title, fullPath, filter, selectedFilter,
						dialogID, qtLayoutDirection);
			} else {
				resultStrings = OS.QFileDialog_swt_getOpenFileName(
						parent.handle, title, fullPath, filter, selectedFilter,
						dialogID, qtLayoutDirection);
			}
		}

		if (parent != null && !parent.isDisposed()) {
			parent.removeDisposeListener(listener);
		}

		parseResult(resultStrings);
		return resultStrings != null && resultStrings.length > 0 ? resultStrings[0]
				: null;
	}

	/*
	 * Array Parameter 'result' stores full paths of selected files with the
	 * last one in the array storing the selected filter
	 */
	private void parseResult(String[] result) {

		filterPath = null;
		fileNames = null;
		fileName = null;
		filterIndex = -1;

		if (result == null) {
			return;
		}
		int count = result.length;
		if (count < 1) {
			return;
		}

		/*
		 * get the first file name and filter path from dialog result
		 */
		fileNames = new String[count - 1];
		String fullPath = result[0];
		int separatorPos = -1;
		if (fullPath != null && fullPath.length() > 0) {
			separatorPos = fullPath.lastIndexOf(SEPARATOR);
			fileName = fullPath.substring(separatorPos + 1);
			fileNames[0] = fileName;
			filterPath = fullPath.substring(0, separatorPos);
		}

		/*
		 * get rest file names from dialog result
		 */
		for (int i = 1; i < count - 1; i++) {
			fullPath = result[i];
			if (fullPath != null && fullPath.length() > 0) {
				separatorPos = fullPath.lastIndexOf(SEPARATOR);
				fileNames[i] = fullPath.substring(separatorPos + 1);
			} else {
				fileNames[i] = null;
			}
		}

		/*
		 * get filter index
		 */
		int filterCount = filterExtensions==null ? 0 : filterExtensions.length;
		String selectedFilter = result[count - 1];
		filterIndex = -1;
		if (filterCount > 0 && selectedFilter != null) {
			selectedFilter = selectedFilter.substring(selectedFilter
					.indexOf('(') + 1);
			selectedFilter = selectedFilter.substring(0, selectedFilter
					.indexOf(')'));
			for (int i = 0; i < filterCount; i++) {
				if (filterExtensions[i].equals(selectedFilter)) {
					filterIndex = i;
					break;
				}
			}

		}

	}

	/**
	 * Set the initial filename which the dialog will select by default when
	 * opened to the argument, which may be null. The name will be prefixed with
	 * the filter path when one is supplied.
	 *
	 * @param string
	 *            the file name
	 */
	public void setFileName(String string) {
		fileName = string;
	}

	/**
	 * Set the file extensions which the dialog will use to filter the files it
	 * shows to the argument, which may be null.
	 * <p>
	 * The strings are platform specific. For example, on Windows, an extension
	 * filter string is typically of the form "*.extension", where "*.*" matches
	 * all files.
	 * </p>
	 *
	 * @param extensions
	 *            the file extension filter
	 *
	 * @see #setFilterNames to specify the user-friendly names corresponding to
	 *      the extensions
	 */
	public void setFilterExtensions(String[] extensions) {
		filterExtensions = extensions;
	}

	/**
	 * Set the 0-based index of the file extension filter which the dialog will
	 * use initially to filter the files it shows to the argument.
	 * <p>
	 * This is an index into the FilterExtensions array and the FilterNames
	 * array.
	 * </p>
	 *
	 * @param index
	 *            the file extension filter index
	 *
	 * @see #setFilterExtensions
	 * @see #setFilterNames
	 *
	 * @since 3.4
	 */
	public void setFilterIndex(int index) {
		filterIndex = index;
	}

	/**
	 * Sets the the names that describe the filter extensions which the dialog
	 * will use to filter the files it shows to the argument, which may be null.
	 * <p>
	 * Each name is a user-friendly short description shown for its
	 * corresponding filter. The <code>names</code> array must be the same
	 * length as the <code>extensions</code> array.
	 * </p>
	 *
	 * @param names
	 *            the list of filter names, or null for no filter names
	 *
	 * @see #setFilterExtensions
	 */
	public void setFilterNames(String[] names) {
		filterNames = names;
	}

	/**
	 * Sets the directory path that the dialog will use to the argument, which
	 * may be null. File names in this path will appear in the dialog, filtered
	 * according to the filter extensions. If the string is null, then the
	 * operating system's default filter path will be used.
	 * <p>
	 * Note that the path string is platform dependent. For convenience, either
	 * '/' or '\' can be used as a path separator.
	 * </p>
	 *
	 * @param string
	 *            the directory path
	 *
	 * @see #setFilterExtensions
	 */
	public void setFilterPath(String string) {
		filterPath = string;
	}

	void checkDialog() {
		if (parent == null)
			error(SWT.ERROR_WIDGET_DISPOSED);
		if (parent.isDisposed())
			error(SWT.ERROR_WIDGET_DISPOSED);
		Display display = parent.display;
		if (display == null)
			error(SWT.ERROR_WIDGET_DISPOSED);
		if (display.thread != Thread.currentThread())
			error(SWT.ERROR_THREAD_INVALID_ACCESS);
	}

}