package pt.ist.renderers;

import java.util.Collection;

import pt.ist.renderers.components.HtmlComponent;
import pt.ist.renderers.components.HtmlText;
import pt.ist.renderers.layouts.Layout;
import pt.ist.renderers.schemas.Schema;
import pt.ist.renderers.utils.RenderKit;
import pt.ist.renderers.utils.RenderUtils;
import pt.ist.renderers.utils.RendererPropertyUtils;

/**
 * This renderer protects the presentation of the <code>null</code> value. If
 * you need to present the values of some slots but the holder object is null
 * you can use this renderer to present the value of another method instead.
 * 
 * @author rcro
 */
public class NullAsMethodRenderer extends FormatRenderer {

    private String subLayout;
    private String subSchema;

    private String alternativeMethod;

    private boolean moduleRelative;
    private boolean contextRelative;

    public String getSubLayout() {
	return this.subLayout;
    }

    public String getAlternativeMethod() {
	return alternativeMethod;
    }

    /**
     * The alternative method used to get the value if the original method
     * returns null.
     * 
     * @property
     */
    public void setAlternativeMethod(String alternativeMethod) {
	this.alternativeMethod = alternativeMethod;
    }

    /**
     * The layout used to represent the object.
     * 
     * @property
     */
    public void setSubLayout(String subLayout) {
	this.subLayout = subLayout;
    }

    public String getSubSchema() {
	return this.subSchema;
    }

    /**
     * The schema used when representing the object.
     * 
     * @property
     */
    public void setSubSchema(String subSchema) {
	this.subSchema = subSchema;
    }

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

	    @Override
	    public HtmlComponent createComponent(Object object, Class type) {
		Schema schema = RenderKit.getInstance().findSchema(getSubSchema());
		Object objectToRender = object;
		if (isEmpty(object) && getAlternativeMethod() != null) {
		    objectToRender = RendererPropertyUtils.getProperty(getTargetObject(object), getAlternativeMethod(), false);
		}
		if (getFormat() == null) {
		    return renderValue(objectToRender, type, schema, getSubLayout());
		} else {
		    String formatedObject = RenderUtils.getFormattedProperties(getFormat(), objectToRender);
		    return new HtmlText(formatedObject);
		}
	    }

	    private boolean isEmpty(Object object) {
		if (object == null || object.equals("")) {
		    return true;
		}

		if (object instanceof Collection) {
		    if (((Collection) object).isEmpty()) {
			return true;
		    }
		}

		return false;
	    }

	};
    }

    protected Object getTargetObject(Object object) {
	if (getContext().getParentContext() != null) {
	    return getContext().getParentContext().getMetaObject().getObject();
	} else {
	    return null;
	}
    }

    public boolean isContextRelative() {
	return contextRelative;
    }

    public void setContextRelative(boolean contextRelative) {
	this.contextRelative = contextRelative;
    }

    public boolean isModuleRelative() {
	return moduleRelative;
    }

    public void setModuleRelative(boolean moduleRelative) {
	this.moduleRelative = moduleRelative;
    }

}