package pt.ist.renderers;

import pt.ist.renderers.components.HtmlComponent;
import pt.ist.renderers.components.HtmlText;
import pt.ist.renderers.layouts.Layout;
import pt.ist.renderers.utils.RenderUtils;

/**
 * This renderer allows you to produce a short textual description of 
 * an object by using a simple format string.
 * 
 * @author cfgi
 */
public class FormatRenderer extends OutputRenderer {

    private boolean useParent;

    private String format;
    
    private Boolean escaped;

    public String getFormat() {
        return this.format;
    }

    /**
     * The format is simple string with a few rules to indicate where slot values
     * will be placed. An example string is
     * <pre>
     *  "${name} is ${age} years old"
     * </pre>
     * Assuming that we are taking about an object that represents a person and
     * has a <code>getName()</code> and <code>getAge()</code> methods this format
     * would produce something like: <code>"Jane Doe is 20 years old"</code>
     * <p>
     * Any literal text will be present in the output. Slot values can be including
     * by surrounding the slot name in <code>${&lt;slot.name&gt;}</code>. Additionally
     * you can indicate how to format each value. This is specially usefull if you 
     * want to present dates.
     * <pre>
     * "${name} was born in a ${birthdate,%ta}
     * </pre>
     * Could present something like <code>"Jane Doe was born in a Sunday"</code>. 
     * You can use use the same syntax that is accepted by 
     * #{@link String#format(java.lang.String, java.lang.Object[])}. 
     * 
     * @property
     */
    public void setFormat(String format) {
        this.format = format;
    }

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

    public Boolean getEscaped() {
	return escaped;
    }

    public void setEscaped(Boolean escaped) {
	this.escaped = escaped;
    }

    public boolean isUseParent() {
	return this.useParent;
    }

    /**
     * This property can be used when presenting an object's slot. If this
     * property is true the object that will be considered when replacing the
     * properties in the link will be the parent object, that is, the object
     * that contains the slot being presented.
     * 
     * <p>
     * Off course, if this property is false (the default) the object that will
     * be considered is the object initialy being presented.
     * 
     * @property
     */
    public void setUseParent(boolean useParent) {
	this.useParent = useParent;
    }

    private class FormatLayout extends Layout {

        @Override
        public HtmlComponent createComponent(Object object, Class type) {
	    Object usedObject = getTargetObject(object);
	    if (usedObject == null) {
                return new HtmlText();
            }
            
	    String formatedObject = RenderUtils.getFormattedProperties(getFormat(), usedObject);
	    return getEscaped() != null ? new HtmlText(formatedObject, getEscaped()) : new HtmlText(formatedObject);
        }

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