package org.litesoft.sandbox.csapp.client.widgets;

import com.google.gwt.user.client.*;
import com.google.gwt.user.client.ui.*;

public class UploadWidget extends Composite implements IsWidget
{
    private static int instance = 1;

    private FileUpload upload = new FileUpload();
    private String servletPath;
    private Timer timer;

    public UploadWidget()
    {
        initWidget( new FormPanel() );
        FormPanel form = getFormPanel();
        form.setWidget( upload );
        upload.setName( "UploadWidget" + instance++ );

        // Because we're going to add a FileUpload widget, we'll need to set the
        // form to use the POST method, and multipart MIME encoding.
        form.setEncoding( FormPanel.ENCODING_MULTIPART );
        form.setMethod( FormPanel.METHOD_POST );
        form.addSubmitCompleteHandler( new FormPanel.SubmitCompleteHandler()
        {
            @Override
            public void onSubmitComplete( FormPanel.SubmitCompleteEvent event )
            {
                submitResponse( event.getResults() );
            }
        } );
    }

    protected FormPanel getFormPanel()
    {
        return (FormPanel) getWidget();
    }

    public void setServletPath( String url )
    {
        servletPath = noEmpty( url );
    }

    public void setSize( String width )
    {
        if ( null != (width = noEmpty( width )) )
        {
            upload.getElement().setAttribute( "size", width );
        }
    }

    @Override
    protected void onAttach()
    {
        super.onAttach();
        startTimer();
    }

    @Override
    protected void onDetach()
    {
        stopTimer();
        super.onDetach();
    }

    private void stopTimer()
    {
        if ( timer != null )
        {
            timer.cancel();
            timer = null;
        }
    }

    private void startTimer()
    {
        stopTimer();
        (timer = new Timer()
        {
            @Override
            public void run()
            {
                String filename = noEmpty( upload.getFilename() );
                if ( filename != null )
                {
                    upload.setEnabled( false );
                    stopTimer();
                    submitForm( filename );
                }
            }
        }).scheduleRepeating( 250 );
    }

    private void resetUploadWidget()
    {
        upload.setEnabled( true );
        getFormPanel().reset();
        startTimer();
    }

    private String noEmpty( String string )
    {
        if ( string != null )
        {
            if ( (string = string.trim()).length() != 0 )
            {
                return string;
            }
        }
        return null;
    }

    private void submitForm( String filename )
    {
        System.out.println( "UploadWidget.submitForm: " + filename + " to " + servletPath);
        if ( servletPath == null )
        {
            Window.alert( "No Servlet Path Set" );
            return;
        }
        FormPanel form = getFormPanel();
        form.setAction( servletPath );
        form.submit();
    }

    private void submitResponse( String pHtmlResponse )
    {
        // Truly Bad Url:
        // null

        // No Servlet:
        // <h2>HTTP ERROR: 404</h2><pre>NOT_FOUND</pre>
        // <p>RequestURI=/v2/TestSubmit</p><p><i><small><a href="http://jetty.mortbay.org/">Powered by Jetty://</a></small></i></p><br>
        // <br>
        // <br>
        // <br>
        // ...


        System.out.println( "UploadWidget.onSubmitComplete:\n" + pHtmlResponse );
        resetUploadWidget();
    }
}