package foundation.data.rule;

import foundation.data.entity.Entity;
import foundation.data.object.IParamProvider;
import foundation.token.IUser;
import foundation.token.IUserManager;
import foundation.variant.expression.VariantExpression;
import foundation.variant.expression.VariantList;
import foundation.variant.expression.VariantSegment;
import foundation.variant.provider.DataEvent;
import foundation.variant.provider.VariantCenter;

public class VariantDefaultValueCreator extends FieldDefaultValueCreator {

	public VariantDefaultValueCreator() {
		type = FieldDefaultValueType.Variant;
	}
	
	@Override
	protected void setRule(String rule) {
		try {
			VariantExpression expression = new VariantExpression(rule);
			VariantList varinats = expression.getVariantList();
			
			if (varinats.isEmpty()) {
				return;
			}
			
			VariantSegment variant = varinats.get(0);
			String name = variant.getName();
			super.setRule(name);
		} 
		catch (Exception e) {
			e.printStackTrace();
		}
	}

	@Override
	public Object exec(DataEvent dataEvent, Entity entity, IParamProvider paramProvider) {
		IUser user = IUserManager.getCurrentUser();
		Object value = VariantCenter.getValue(dataEvent, rule, user);
		
		if (value != null) {
			entity.set(fieldName, value);
		}
		
		return value;
	}
	
}