package pt.ist.renderers;

import org.apache.commons.collections.Predicate;

import pt.ist.renderers.components.HtmlComponent;
import pt.ist.renderers.components.HtmlHiddenField;
import pt.ist.renderers.components.HtmlInlineContainer;
import pt.ist.renderers.components.HtmlRadioButton;
import pt.ist.renderers.components.HtmlRadioButtonList;
import pt.ist.renderers.components.controllers.HtmlController;
import pt.ist.renderers.components.state.IViewState;
import pt.ist.renderers.components.state.ViewDestination;
import pt.ist.renderers.layouts.Layout;
import pt.ist.renderers.model.MetaSlot;

/**
 * This renderer can be used as the input for a list of objects. The list of
 * objects the user can choose will be presented as an html list were each list
 * item will contain the presentation of the object and a radio button that
 * allows to choose that particular object. When submiting, the selected object
 * will be the value passed to the slot.
 * 
 * <p>
 * Example: <form> <input type="radio" name="option"/>
 * <em>&lt;object A presentation&gt;</em><br/>
 * <input type="radio" name="option"/><em>&lt;object B presentation&gt;</em><br/>
 * <input type="radio" name="option"/><em>&lt;object C presentation&gt;</em>
 * </form>
 */
public class RadioButtonListRendererWithPostback extends RadioButtonListRenderer {

    private final String HIDDEN_NAME = "postback";

    private String destination;

    public String getDestination() {
	return destination;
    }

    public void setDestination(String destination) {
	this.destination = destination;
    }

    @Override
    protected Layout getLayout(Object object, Class type) {
	return new RadioButtonListLayoutWithPostback();
    }

    class RadioButtonListLayoutWithPostback extends RadioButtonListLayout {

	@Override
	public HtmlComponent createComponent(Object object, Class type) {
	    HtmlInlineContainer container = new HtmlInlineContainer();

	    String prefix = HtmlComponent.getValidIdOrName(((MetaSlot) getInputContext().getMetaObject()).getKey().toString()
		    .replaceAll("\\.", "_").replaceAll("\\:", "_"));

	    HtmlHiddenField hidden = new HtmlHiddenField(prefix + HIDDEN_NAME, "");

	    final HtmlRadioButtonList htmlComponent = (HtmlRadioButtonList) super.createComponent(object, type);
	    for (final HtmlRadioButton radioButton : htmlComponent.getRadioButtons()) {
		radioButton.setOnClick("this.form." + prefix + HIDDEN_NAME + ".value='true';this.form.submit();");
	    }
	    htmlComponent.setController(new PostBackController(hidden, destination));

	    container.addChild(hidden);
	    container.addChild(htmlComponent);

	    return container;
	}

	@Override
	public void applyStyle(HtmlComponent component) {
	    HtmlInlineContainer container = (HtmlInlineContainer) component;
	    HtmlComponent list = container.getChild(new Predicate() {

		@Override
		public boolean evaluate(Object arg0) {
		    return arg0 instanceof HtmlRadioButtonList;
		}

	    });
	    super.applyStyle(list);
	}
    }

    private static class PostBackController extends HtmlController {

	private final HtmlHiddenField hidden;

	private final String destination;

	public PostBackController(HtmlHiddenField hidden, String destination) {
	    this.hidden = hidden;
	    this.destination = destination;
	}

	@Override
	public void execute(IViewState viewState) {
	    if (hidden.getValue() != null && hidden.getValue().equalsIgnoreCase("true")) {
		String destinationName = this.destination == null ? "postback" : this.destination;
		ViewDestination destination = viewState.getDestination(destinationName);

		if (destination != null) {
		    viewState.setCurrentDestination(destination);
		} else {
		    viewState.setCurrentDestination("postBack");
		}

		hidden.setValue("false");
		viewState.setSkipValidation(true);
	    }

	}

    }

}