/*
 * Copyright 2007 Future Earth, info@future-earth.eu
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package eu.future.earth.gwt.client.file;

import org.cobogw.gwt.user.client.CSS;

import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.ui.Anchor;
import com.google.gwt.user.client.ui.CheckBox;
import com.google.gwt.user.client.ui.FileUpload;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.SimplePanel;

import eu.future.earth.gwt.client.events.FileEvent;
import eu.future.earth.gwt.client.events.FileEventListener;
import eu.future.earth.gwt.client.events.FileUploadAction;
import eu.future.earth.gwt.client.events.HasFileEventHandlers;

public class FilePanel extends HorizontalPanel implements ClickHandler, HasFileEventHandlers {

	private FileText texts = (FileText) GWT.create(FileText.class);

	private SimplePanel holder = new SimplePanel();

	private FileUpload fileField = new FileUpload();

	private int maxDetectionDelay = 3000;

	private Anchor addAction = new Anchor(texts.add());

	private Anchor remove = new Anchor(texts.remove());

	private CheckBox checkBoxForSave = new CheckBox();

	private HTML info = new HTML();

	private FileHolderHandler handler = null;

	private HandlerRegistration addListener = null;

	public FilePanel(FileHolderHandler newhandler) {
		super();
		handler = newhandler;
		super.setSpacing(0);

		super.add(checkBoxForSave);
		super.add(holder);
		holder.add(fileField);
		super.add(info);
		super.add(addAction);
		super.add(remove);

		addListener = addAction.addClickHandler(this);
		remove.addClickHandler(this);
		checkBoxForSave.addClickHandler(this);

		checkBoxForSave.setVisible(false);
		remove.setVisible(false);
		info.setVisible(false);
		fileField.setVisible(false);
		checkBoxForSave.setValue(true);
		CSS.setProperty(checkBoxForSave, CSS.A.MARGIN_RIGHT, "3px");
		CSS.setProperty(holder, CSS.A.MARGIN_RIGHT, "3px");
		CSS.setProperty(info, CSS.A.MARGIN_RIGHT, "3px");
		CSS.setProperty(info, CSS.A.MARGIN_RIGHT, "3px");
	}

	private String fieldname = null;

	public void setFieldName(String newName) {
		fieldname = newName;
		fileField.setName(fieldname);
	}

	private String url = null;

	private String fileName = null;

	public void setInfo(String newName, String newUrl) {
		fileName = newName;
		url = newUrl;
		setUploadState(uploadState);
	}

	private boolean uploadState = false;

	public boolean hasImageSelected() {
		return fileField.getFilename() != null && fileField.getFilename().length() > 0;
	}

	public String getFileName() {
		if (fileName == null) {
			return fileField.getFilename();
		} else {
			return fileName;
		}
	}

	public void resetPanel() {
		if (hasImageSelected()) {
			holder.remove(fileField);
			fileField = new FileUpload();
			fileField.setName(fieldname);
			holder.setWidget(fileField);
			fileField.setVisible(false);
		}
	}

	public void setAddActionVisible(boolean newState) {
		addAction.setVisible(newState);
	}

	public void setSaveVisible(boolean newState) {
		if (handler.showViewLink()) {
			checkBoxForSave.setVisible(newState);
		} else {
			checkBoxForSave.setVisible(false);
		}
	}

	public void setRemoveVisible(boolean newState) {
		remove.setVisible(newState);
	}

	public void setUploadState(boolean newState) {
		uploadState = newState;
		remove.setVisible(!newState);
		if (handler.showViewLink()) {
			checkBoxForSave.setVisible(newState);
		} else {
			checkBoxForSave.setVisible(false);
		}
		if (newState) {
			info.setHTML("<a href='" + url + " '  >" + getFileName() + "</a>");
		} else {
			info.setText(getFileName());
		}
		if (handler.showViewLink()) {
			if (uploadState) {
				info.setVisible(true);
			} else {
				info.setVisible(false);
			}
		} else {
			info.setVisible(false);
		}
	}

	public void setSelectedForSave(boolean newState) {
		checkBoxForSave.setValue(newState);
	}

	public boolean isFileFieldVisible() {
		// Window.alert("Visible " + fileField.isVisible());
		return fileField.isVisible();
	}

	/**
	 * Timer for that start after the click on determining if a file is present.
	 */
	private Timer filePresentTimer = null;

	private void selectFileAction() {
		// image.se
		if (getBrowserType().indexOf("ie") > -1) {
			jsClickUpload(fileField.getElement());
		} else {
			addAction.setVisible(false);
			fileField.setVisible(true);
		}

		filePresentTimer = new Timer() {
			public void run() {
				if (hasImageSelected()) {
					fireFileSelectedEvent();
				}
			}
		};
		filePresentTimer.scheduleRepeating(maxDetectionDelay);
	}

	private void fireFileSelectedEvent() {
		fileField.setVisible(false);
		addAction.setVisible(false);
		// addListener.removeHandler();
		remove.setVisible(true);
		info.setText(getFileName());
		if (handler.showViewLink()) {
			info.setVisible(true);
		}
		filePresentTimer.cancel();
		FileEvent.fire(this, FileUploadAction.FILE_SELECTED);
	}

	public void onClick(ClickEvent widget) {
		if (widget.getSource() == addAction) {
			selectFileAction();
		}
		if (widget.getSource() == remove) {
			FileEvent.fire(this, FileUploadAction.FILE_REMOVED);
		}
		if (widget.getSource() == checkBoxForSave) {
			FileEvent.fire(this, FileUploadAction.FILE_SELECTION_CHANGE);
		}
	}

	public boolean shouldSave() {
		return checkBoxForSave.getValue();
	}

	private native String getBrowserType() /*-{ 
											var ua = navigator.userAgent.toLowerCase(); 
											if (ua.indexOf("opera") != -1) { 
											return "opera"; 
											} 
											else if (ua.indexOf("webkit") != -1) { 
											return "safari"; 
											} 
											else if ((ua.indexOf("msie 6.0") != -1) || 
											(ua.indexOf("msie 7.0") != -1)) { 
											return "ie6"; 
											} 
											else if (ua.indexOf("gecko") != -1) { 
											var result = /rv:([0-9]+)\.([0-9]+)/.exec(ua); 
											if (result && result.length == 3) { 
											var version = (parseInt(result[1]) * 10) + 
											parseInt(result[2]); 
											if (version >= 18) 
											return "gecko1_8"; 
											} 
											return "gecko"; 
											} 
											return "unknown"; 
											}-*/;

	native void jsClickUpload(Element pElement) /*-{ 
												pElement.click(); 
												}-*/;

	@Override
	public HandlerRegistration addFileEventHandler(FileEventListener handler) {
		return addHandler(handler, FileEvent.getType());
	}

}