package gueei.binding.converters;

import gueei.binding.AttributeInjector;
import gueei.binding.AttributeInjector.InjectParams;
import gueei.binding.Binder.InflateResult;
import gueei.binding.Converter;
import gueei.binding.DynamicObject;
import gueei.binding.IObservable;
import gueei.binding.viewAttributes.templates.Layout;

import java.util.ArrayList;

/**
 * INJECT binding statements into layout templates. <br/>
 * Most probably those templates came from external libraries (e.g. android) that you cannot change <br/>
 * This is much more convenient than everytime you need to copy those standard templates. <br/>
 * <br/>
 * 
 * The most common usage is on those templates for spinners, listviews (e.g. @android:layout/simple_list_item1). <br/>
 * Suppose We need to inject the statement to the textview (@android:id/textview1), then: <br/>
 * binding:itemTemplate="INJECT(@android:layout/simple_list_item1, { id=@android:id/textview1, attr='text', statement='Name' })" <br/>
 * Note it is possible to inject more than one attribute, for example you can change the color of the above mentioned text view too: <br/>
 * binding:itemTemplate="INJECT(@android:layout/simple_list_item1, { id=@android:id/textview1, attr='text', statement='Name' }, { id=@android:id/textview1, attr='backgroundColor', statement='ARGB(255,0,0)' })" <br/>
 * @usage layout params ...
 * 
 * @arg layout gueei.binding.viewAttributes.templates.Layout Layout of the template-to-inject
 * @arg params DynamicObject
 * 
 * @item id integer Android Id value of the widget 
 * @item attr Attribute name of that widget
 * @item statement Binding Statement to be injected
 *
 * @return gueei.binding.viewAttributes.templates.Layout
 */
public class INJECT extends Converter<Layout> {
	public INJECT(IObservable<?>[] dependents) {
		super(Layout.class, dependents);
	}

	@Override
	public Layout calculateValue(Object... args) throws Exception {
		if (args.length<1 || !(args[0] instanceof Layout)) return null;
		if (args.length<2) return (Layout)args[0];
		return new InjectLayout((Layout)args[0], process(args));
	}
	
	
	private static InjectParams[] process(Object[] args){
		ArrayList<InjectParams> injectParams = new ArrayList<InjectParams>();
		int len = args.length;
		if (args.length<2) return new InjectParams[0];
		for(int i=1; i<len; i++){
			if (!(args[i] instanceof DynamicObject)) continue;
			try{
				DynamicObject p = (DynamicObject)args[i];
				InjectParams param = new InjectParams();
				param.Id = (Integer)p.getObservableByName("id").get();
				param.AttrName = p.getObservableByName("attr").get().toString();
				param.Statement = p.getObservableByName("statement").get().toString();
				injectParams.add(param);
			}catch(Exception e){ continue; }
		}
		return injectParams.toArray(new InjectParams[0]);
	}
	
	public static class InjectLayout extends Layout{
		private final Layout mLayout;
		private final InjectParams[] mParams;
		
		@Override
		public void onAfterInflate(InflateResult result, int position) {
			super.onAfterInflate(result, position);
			AttributeInjector.inject(mParams, result);
		}

		public InjectLayout(Layout layout, InjectParams[] params) {
			super(layout.getDefaultLayoutId());
			mLayout = layout;
			mParams = params;
		}

		@Override
		public int getLayoutTypeId(int pos) {
			return mLayout.getLayoutTypeId(pos);
		}

		@Override
		public int getLayoutId(int pos) {
			return mLayout.getLayoutId(pos);
		}

		@Override
		public int getTemplateCount() {
			return mLayout.getTemplateCount();
		}
		
	}
}