package org.gcube.portlets.widgets.ckandatapublisherwidget.client.ui;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.gcube.portlets.user.gcubewidgets.client.elements.Span;
import org.gcube.portlets.widgets.ckandatapublisherwidget.client.CKanPublisherService;
import org.gcube.portlets.widgets.ckandatapublisherwidget.client.CKanPublisherServiceAsync;
import org.gcube.portlets.widgets.ckandatapublisherwidget.client.events.DeleteCustomFieldEvent;
import org.gcube.portlets.widgets.ckandatapublisherwidget.client.events.DeleteCustomFieldEventHandler;
import org.gcube.portlets.widgets.ckandatapublisherwidget.shared.DatasetMetadataBean;
import org.gcube.portlets.widgets.ckandatapublisherwidget.shared.LicensesBean;

import com.github.gwtbootstrap.client.ui.AlertBlock;
import com.github.gwtbootstrap.client.ui.Button;
import com.github.gwtbootstrap.client.ui.CheckBox;
import com.github.gwtbootstrap.client.ui.ControlGroup;
import com.github.gwtbootstrap.client.ui.ListBox;
import com.github.gwtbootstrap.client.ui.Tab;
import com.github.gwtbootstrap.client.ui.TabPanel;
import com.github.gwtbootstrap.client.ui.TextArea;
import com.github.gwtbootstrap.client.ui.TextBox;
import com.github.gwtbootstrap.client.ui.base.ListItem;
import com.github.gwtbootstrap.client.ui.constants.AlertType;
import com.github.gwtbootstrap.client.ui.resources.Bootstrap.Tabs;
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.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.uibinder.client.UiBinder;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.uibinder.client.UiHandler;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * Edit metadata form for ckan dataset.
 * @author Costantino Perciante at ISTI-CNR (costantino.perciante@isti.cnr.it)
 */
public class EditMetadataForm extends Composite{

	/**
	 * Create a remote service proxy to talk to the server-side ckan service.
	 */
	private final CKanPublisherServiceAsync ckanServices = GWT.create(CKanPublisherService.class);

	private static EditMetadataFormUiBinder uiBinder = GWT
			.create(EditMetadataFormUiBinder.class);

	interface EditMetadataFormUiBinder extends
	UiBinder<Widget, EditMetadataForm> {
	}

	@UiField TextBox titleTextBox;
	@UiField TextArea descriptionTextarea;
	@UiField TextBox tagsEnterTextBox;
	@UiField FlowPanel tagsPanel;
	@UiField ListBox licenseListbox;
	@UiField ListBox visibilityListbox;
	@UiField ListBox organizationsListbox;
	@UiField TextBox versionTextbox;
	@UiField TextBox authorTextbox;
	@UiField TextBox authorEmailTextbox;
	@UiField TextBox maintainerTextbox;
	@UiField TextBox maintainerEmailTextbox;
	@UiField ControlGroup customFields;
	@UiField Button addCustomFieldButton;
	@UiField CheckBox addResourcesCheckBox;
	@UiField ControlGroup resourcesControlGroup;
	@UiField Button createButton;
	@UiField Button addResourcesButton;
	@UiField Button resetButton;
	@UiField AlertBlock infoBlock;
	@UiField AlertBlock onCreateAlertBlock;
	@UiField VerticalPanel resourcesPanel;

	// tab panel 
	private TabPanel tabPanel; 

	// add resource form
	AddResourceToDataset resourceForm;

	// tags list
	private List<String> tagsList = new ArrayList<String>();

	// the licenses
	private LicensesBean licenseBean;

	// event bus
	private final HandlerManager eventBus = new HandlerManager(null);

	// added custom field entries 
	List<CustomFieldEntry> customFieldEntriesList = new ArrayList<CustomFieldEntry>();

	// dataset metadata bean
	private DatasetMetadataBean receivedBean;

	// the owner
	private String owner;

	/**
	 * Invoked in the most general case
	 * @param owner
	 */
	public EditMetadataForm(String owner) {
		initWidget(uiBinder.createAndBindUi(this));

		this.owner = owner;

		// bind on events
		bind();

		// set info block
		setAlertBlock("Retrieving information, please wait...", AlertType.INFO, true);

		// disable create button
		createButton.setEnabled(false);
		resetButton.setEnabled(false);

		// get back the licenses and the metadata information 
		ckanServices.getDatasetBean(null, owner, new AsyncCallback<DatasetMetadataBean>() {

			@Override
			public void onSuccess(DatasetMetadataBean bean) {

				if(bean != null){

					// save it
					receivedBean = bean;

					// fill the form
					versionTextbox.setText(String.valueOf(bean.getVersion()));
					authorTextbox.setText(bean.getAuthor());
					authorEmailTextbox.setText(bean.getAuthorEmail());
					maintainerTextbox.setText(bean.getMaintainer());
					maintainerEmailTextbox.setText(bean.getMaintainerEmail());

					// set organizations
					List<String> organizations = bean.getOrganizationList();

					for (String organization : organizations) {
						organizationsListbox.addItem(organization);
					}

					// try to retrieve the licenses
					setAlertBlock("Retrieving licenses, please wait...", AlertType.INFO, true);
					ckanServices.getLicenses(new AsyncCallback<LicensesBean>() {

						@Override
						public void onSuccess(LicensesBean lBean) {

							if(lBean != null && !lBean.getLicenses().isEmpty()){

								licenseBean = lBean;

								// fill the listbox
								for(String license: licenseBean.getLicenses()){
									licenseListbox.addItem(license);
								}

								// everything went ok
								setAlertBlock("", AlertType.ERROR, false);
								createButton.setEnabled(true);
								resetButton.setEnabled(true);

							}else{
								setAlertBlock("Error while retrieving licenses, try to refresh the page", AlertType.ERROR, true);
							}
						}

						@Override
						public void onFailure(Throwable caught) {

							setAlertBlock("Error while retrieving licenses, try to refresh the page", AlertType.ERROR, true);

						}
					});

				}else{

					setAlertBlock("Error while retrieving information, try to refresh the page", AlertType.ERROR, true);
				}

			}

			@Override
			public void onFailure(Throwable caught) {

				setAlertBlock("Error while retrieving information, try to refresh the page", AlertType.ERROR, true);

			}
		});

		// hide the Add resources checkbox 
		resourcesControlGroup.setVisible(false);

	}

	/**
	 * Invoked when the workspace is used.
	 * @param idFolderWorkspace
	 * @param owner
	 */
	public EditMetadataForm(String idFolderWorkspace, String owner) {
		initWidget(uiBinder.createAndBindUi(this));

		this.owner = owner;

		// bind on events
		bind();

		// set info block
		setAlertBlock("Retrieving information, please wait...", AlertType.INFO, true);

		// disable create button
		createButton.setEnabled(false);
		resetButton.setEnabled(false);

		// get back the licenses and the metadata information from the workspace
		ckanServices.getDatasetBean(idFolderWorkspace, owner, new AsyncCallback<DatasetMetadataBean>() {

			@Override
			public void onSuccess(DatasetMetadataBean bean) {

				if(bean != null){

					// save it
					receivedBean = bean;

					// fill the form
					titleTextBox.setText(bean.getTitle());
					descriptionTextarea.setText(bean.getDescription());
					versionTextbox.setText(String.valueOf(bean.getVersion()));
					authorTextbox.setText(bean.getAuthor());
					authorEmailTextbox.setText(bean.getAuthorEmail());
					maintainerTextbox.setText(bean.getMaintainer());
					maintainerEmailTextbox.setText(bean.getMaintainerEmail());

					// set organizations
					List<String> organizations = bean.getOrganizationList();

					for (String organization : organizations) {

						organizationsListbox.addItem(organization);

					}

					// retrieve custom fields
					Map<String, String> customFieldsMap = bean.getCustomFields();	

					GWT.log("Custom fields is " + customFieldsMap);

					if(customFieldsMap != null){

						// get the keys and put them as tags
						Iterator<Entry<String, String>> iteratorOverCustomField = customFieldsMap.entrySet().iterator();

						while (iteratorOverCustomField.hasNext()) {
							Map.Entry<String, String> entry = (Map.Entry<String, String>) iteratorOverCustomField
									.next();

							// these are fixed key, variable value custom fields
							CustomFieldEntry toAdd = new CustomFieldEntry(eventBus, entry.getKey(), entry.getValue(), false);
							customFieldEntriesList.add(toAdd);
							customFields.add(toAdd);

							// add as tag
							addTagElement(entry.getKey());

						}
					}

					// try to retrieve the licenses
					setAlertBlock("Retrieving licenses, please wait...", AlertType.INFO, true);
					ckanServices.getLicenses(new AsyncCallback<LicensesBean>() {

						@Override
						public void onSuccess(LicensesBean lBean) {

							if(lBean != null && !lBean.getLicenses().isEmpty()){

								licenseBean = lBean;

								// fill the listbox
								for(String license: licenseBean.getLicenses()){

									licenseListbox.addItem(license);

								}

								// everything went ok
								setAlertBlock("", AlertType.ERROR, false);
								createButton.setEnabled(true);
								resetButton.setEnabled(true);

							}else{
								setAlertBlock("Error while retrieving licenses, try to refresh the page", AlertType.ERROR, true);
							}
						}

						@Override
						public void onFailure(Throwable caught) {

							setAlertBlock("Error while retrieving licenses, try to refresh the page", AlertType.ERROR, true);

						}
					});

				}else{

					setAlertBlock("Error while retrieving information, try to refresh the page", AlertType.ERROR, true);
				}

			}

			@Override
			public void onFailure(Throwable caught) {

				setAlertBlock("Error while retrieving information, try to refresh the page", AlertType.ERROR, true);

			}
		});

	}

	/**
	 * Bind on events
	 */
	private void bind() {

		// when a custom field is removed, remove it from the list
		eventBus.addHandler(DeleteCustomFieldEvent.TYPE, new DeleteCustomFieldEventHandler() {

			@Override
			public void onRemoveEntry(DeleteCustomFieldEvent event) {

				customFieldEntriesList.remove(event.getRemovedEntry());
				customFields.remove(event.getRemovedEntry());

			}
		});

	}

	@UiHandler("addCustomFieldButton")
	void addCustomFieldEvent(ClickEvent e){

		CustomFieldEntry toAdd = new CustomFieldEntry(eventBus, "", "", true);
		customFieldEntriesList.add(toAdd);
		customFields.add(toAdd);

	}

	@UiHandler("createButton")
	void createDatasetEvent(ClickEvent e){

		// validate data TODO
		boolean areDataValid = validateData();

		// Collect current data and send them to the server
		if(areDataValid){

			String title = titleTextBox.getValue();
			String description = descriptionTextarea.getText();
			String selectedLicense = licenseListbox.getSelectedItemText();
			String visibility = visibilityListbox.getSelectedItemText();
			long version = Long.valueOf(versionTextbox.getValue());
			String author = authorTextbox.getValue();
			String authorEmail = authorEmailTextbox.getValue();
			String maintainer = maintainerTextbox.getValue();
			String maintainerEmail = maintainerEmailTextbox.getValue();
			String chosenOrganization = organizationsListbox.getSelectedItemText();
			boolean addResources = addResourcesCheckBox.getValue();

			// fill the bean
			receivedBean.setAuthor(author);
			receivedBean.setAuthorEmail(authorEmail);
			receivedBean.setDescription(description);
			receivedBean.setLicense(selectedLicense);
			receivedBean.setMaintainer(maintainer);
			receivedBean.setMaintainerEmail(maintainerEmail);
			receivedBean.setVersion(version);
			receivedBean.setVisibility(visibility.equals("Public"));
			receivedBean.setTitle(title);
			receivedBean.setTags(tagsList);
			receivedBean.setSelectedOrganization(chosenOrganization);
			receivedBean.setAddResources(addResources);

			Map<String, String> customFieldsMap = new HashMap<String, String>();

			// prepare custom fields
			for(CustomFieldEntry customEntry : customFieldEntriesList){

				String key = customEntry.getKey();
				String value = customEntry.getValue();
				customFieldsMap.put(key, value);

			}

			receivedBean.setCustomFields(customFieldsMap);

			// invoke the create method
			createButton.setEnabled(false);
			resetButton.setEnabled(false);

			onCreateAlertBlock.setText("Trying to create dataset, please wait");
			onCreateAlertBlock.setVisible(true);

			ckanServices.createCKanDataset(receivedBean, new AsyncCallback<String>() {

				@Override
				public void onSuccess(final String datasetId) {

					if(datasetId != null){

						alertOnCreate("Dataset correctly created!", AlertType.SUCCESS);

						// disable dataset fields
						disableDatasetFields();

						// if we are in the "general case" we need to show a form for adding resources
						if(!resourcesControlGroup.isVisible()){

							createButton.setVisible(false);
							resetButton.setVisible(false);

							// show the add resources button
							addResourcesButton.setVisible(true);
							addResourcesButton.addClickHandler(new ClickHandler() {

								@Override
								public void onClick(ClickEvent event) {

									// hide the button
									addResourcesButton.setVisible(false);

									// TabPanel
									tabPanel = new TabPanel(Tabs.ABOVE);
									tabPanel.setWidth("100%");

									// add the form
									resourceForm = new AddResourceToDataset(eventBus, datasetId, owner);

									// tab for the form
									Tab formContainer = new Tab();
									formContainer.add(resourceForm);
									formContainer.setHeading("Add New Resource");
									tabPanel.add(formContainer);

									// tab for the added resources
									Tab addedResources = new Tab();
									addedResources.add(new AddedResourcesSummary(eventBus));
									addedResources.setHeading("Added Resource");
									tabPanel.add(addedResources);
									
									// add tabs to resources panel
									tabPanel.selectTab(0);
									resourcesPanel.add(tabPanel);
									resourcesPanel.setVisible(true);

								}
							});	
						}

					}else{

						alertOnCreate("Unable to create this dataset, please retry later", AlertType.ERROR);
					}

				}

				@Override
				public void onFailure(Throwable caught) {

					alertOnCreate("Unable to create this dataset, please retry later", AlertType.ERROR);

				}
			});
		}
	}

	/**
	 * On create show alert box and enable buttons
	 * @param text
	 * @param type
	 */
	private void alertOnCreate(String text, AlertType type){

		onCreateAlertBlock.setText(text);
		onCreateAlertBlock.setType(type);
		onCreateAlertBlock.setVisible(true);
		createButton.setEnabled(true);
		resetButton.setEnabled(true);

		// hide after some seconds
		Timer t = new Timer() {

			@Override
			public void run() {

				onCreateAlertBlock.setVisible(false);

			}
		};

		t.schedule(2000);
	}

	/**
	 * Validate data
	 * @return true on success
	 */
	private boolean validateData() {

		// TODO 
		return true;
	}

	@UiHandler("resetButton")
	void resetFormEvent(ClickEvent e){

		// reset main fields
		titleTextBox.setText("");
		descriptionTextarea.setText("");
		versionTextbox.setText("");
		authorTextbox.setText("");
		authorEmailTextbox.setText("");
		maintainerTextbox.setText("");
		maintainerEmailTextbox.setText("");
		removeTags();

		// delete custom fields
		for (CustomFieldEntry customField : customFieldEntriesList) {
			customField.removeFromParent();
		}
		customFieldEntriesList.clear();

	}

	/**
	 * Disable dataset editable fields
	 */
	protected void disableDatasetFields() {
		titleTextBox.setEnabled(false);
		descriptionTextarea.setEnabled(false);
		versionTextbox.setEnabled(false);
		authorTextbox.setEnabled(false);
		authorEmailTextbox.setEnabled(false);
		maintainerTextbox.setEnabled(false);
		maintainerEmailTextbox.setEnabled(false);
		visibilityListbox.setEnabled(false);
		tagsEnterTextBox.setEnabled(false);
		licenseListbox.setEnabled(false);
		organizationsListbox.setEnabled(false);
		addCustomFieldButton.setEnabled(false);
	}

	/**
	 * change alert block behavior.
	 * @param textToShow
	 * @param type
	 * @param visible
	 */
	private void setAlertBlock(String textToShow, AlertType type, boolean visible){

		infoBlock.setText(textToShow);
		infoBlock.setType(type);
		infoBlock.setVisible(visible);

	}

	@UiHandler("tagsEnterTextBox")
	void onAddTag(KeyDownEvent event){

		if (event.getNativeKeyCode() == KeyCodes.KEY_ENTER) {
			if (!"".equals(tagsEnterTextBox.getValue().trim())) {

				addTagElement(tagsEnterTextBox);

			}
		}
	}

	/**
	 * Add the tag as an element
	 */
	private void addTagElement(TextBox itemBox){

		if (itemBox.getValue() != null && !"".equals(itemBox.getValue().trim())) {

			if(tagsList.contains(itemBox.getValue()))
				return;

			final String value = itemBox.getValue();
			final ListItem displayItem = new ListItem();
			displayItem.setStyleName("tag-style");
			Span p = new Span(itemBox.getValue());

			Span span = new Span("x");
			span.setTitle("Remove this tag");
			span.addClickHandler(new ClickHandler() {
				public void onClick(ClickEvent clickEvent) {
					removeListItem(displayItem, value);
				}
			});

			span.setStyleName("tag-style-x");
			displayItem.add(p);
			displayItem.add(span);
			itemBox.setValue("");
			itemBox.setFocus(true);
			tagsPanel.add(displayItem);
			tagsList.add(value);
		}
	}

	/**
	 * Add the tag as an element
	 */
	private void addTagElement(final String tag){

		if(tagsList.contains(tag))
			return;

		final ListItem displayItem = new ListItem();
		displayItem.setStyleName("tag-style");
		Span p = new Span(tag);

		Span span = new Span("x");
		span.setTitle("Remove this tag");
		span.addClickHandler(new ClickHandler() {
			public void onClick(ClickEvent clickEvent) {
				removeListItem(displayItem, tag);
			}
		});

		span.setStyleName("tag-style-x");
		displayItem.add(p);
		displayItem.add(span);
		tagsPanel.add(displayItem);
		tagsList.add(tag);
	}

	/**
	 * Remove a tag from the list
	 * @param displayItem
	 */
	private void removeListItem(ListItem displayItem, String value) {
		GWT.log("Removing: " + displayItem.getWidget(0).getElement().getInnerHTML(), null);
		tagsList.remove(value);
		tagsPanel.remove(displayItem);
	}

	/**
	 * Remove all inserted tags
	 */
	private void removeTags(){

		tagsList.clear();
		tagsPanel.clear();

	}
}