/*
 * 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 com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.json.client.JSONObject;
import com.google.gwt.json.client.JSONParser;
import com.google.gwt.json.client.JSONValue;
import com.google.gwt.user.client.ui.FormPanel;
import com.google.gwt.user.client.ui.SimplePanel;
import com.google.gwt.user.client.ui.FormPanel.SubmitCompleteEvent;
import com.google.gwt.user.client.ui.FormPanel.SubmitCompleteHandler;

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 EditFilePanel extends SimplePanel implements FileEventListener, HasFileEventHandlers {
	final FormPanel form = new FormPanel();

	private FilePanel image = null;

	private FileHolderHandler handler = null;

	private FileHolder fileHolder = null;

	public EditFilePanel(FileHolderHandler newHandler) {
		super();
		handler = newHandler;
		image = new FilePanel(newHandler);
		form.setAction(handler.getPostUrl());
		form.setEncoding(FormPanel.ENCODING_MULTIPART);
		form.setMethod(FormPanel.METHOD_POST);
		form.setWidget(image);

		image.setFieldName("image");
		image.addFileEventHandler(this);

		form.addSubmitCompleteHandler(new SubmitCompleteHandler() {

			public void onSubmitComplete(SubmitCompleteEvent event) {
				// When the form submission is successfully completed, this event is
				// fired. Assuming the service returned a response of type text/html,
				// we can get the result text here (see the FormPanel documentation for
				// further explanation).
				JSONValue jsonValue = JSONParser.parseLenient(event.getResults());
				JSONObject real = jsonValue.isObject();
				String stat = getValueFor("result", real);

				if ("succes".equals(stat)) {
					String fileName = getValueFor("fileName", real);
					String fileType = getValueFor("fileType", real);
					String fileSize = getValueFor("fileSize", real);
					if (fileHolder == null) {
						fileHolder = new FileHolder();
					}
					fileHolder.setName(fileName);
					fileHolder.setUploaded(true);
					fileHolder.setSave(image.shouldSave());
					fileHolder.setSize(fileSize);
					fileHolder.setType(fileType);
					reportUploadComplete();
				} else {
					image.resetPanel();
					// info.setUploaded(false);
				}
			}
		});

		super.setWidget(form);

	}

	private boolean edeting = true;

	public void setEdeting(boolean newState) {
		if (edeting != newState) {
			edeting = newState;
			setUrlStates();
		}
	}

	private static String getValueFor(String name, JSONObject real) {
		JSONValue data = real.get(name);
		String stat = null;
		if (data != null) {
			if (data.isString() == null) {
				stat = data.isArray().get(0).isString().stringValue();
			} else {
				stat = data.isString().stringValue();
			}
		}
		return stat;
	}

	private void reportUploadComplete() {
		image.setInfo(fileHolder.getName(), createViewUrl(fileHolder));
		setUrlStates();
		image.setSelectedForSave(true);
		FileEvent.fire(this, FileUploadAction.UPLOAD_DONE);

	}

	public FileHolder getFileInfo() {
		return fileHolder;
	}

	public void setFile(FileHolder newInfo) {
		fileHolder = newInfo;
		image.setUploadState(!edeting);
		if (fileHolder != null) {
			image.setInfo(fileHolder.getName(), createViewUrl(newInfo));
		} else {
			image.resetPanel();
		}
		setUrlStates();
	}

	private void setUrlStates() {
		if(edeting){
			image.setUploadState(fileHolder != null);
			image.setAddActionVisible(fileHolder == null && !image.isFileFieldVisible());
			image.setSaveVisible(fileHolder != null);
			image.setRemoveVisible(fileHolder != null && (fileHolder.isStored() || fileHolder.isUploaded()));
		} else {
			image.setUploadState(true);
			image.setAddActionVisible(false);
			image.setSaveVisible(false);
			image.setRemoveVisible(false);
		}
	}

	public boolean isSave() {
		return fileHolder != null && fileHolder.isSave() && image.shouldSave();
	}

	private String createViewUrl(FileHolder holder) {
		final StringBuffer result = new StringBuffer();
		result.append(handler.getPostUrl());
		result.append("?name=" + holder.getName());
		if (holder.isStored()) {
			result.append("&stored=true");
		}
		result.append(handler.getDownloadParameters(holder));
		return result.toString();
	}

	public void setShowAddImage(boolean newState) {
		image.setAddActionVisible(newState);
	}

	public void handleFileEvent(FileEvent newEvent) {
		switch (newEvent.getCommand()) {
		case FILE_SELECTED: {
			form.submit();
			break;
		}
		case UPLOAD_DONE: {
			image.setSelectedForSave(true);
			break;
		}
		case FILE_REMOVED: {
			// Cancel the upload
			fileHolder = null;
			image.setSelectedForSave(false);
			image.resetPanel();
			
			break;
		}
		case FILE_SELECTION_CHANGE: {
			fileHolder.setSave(image.shouldSave());
			break;
		}
		}
		setUrlStates();
		FileEvent.fire(this, newEvent.getCommand());
	}

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

}