class AnswerHow_IntentionAction extends IntentionAction {

	canHandle(intention:Term, ai:RuleBasedAI) : boolean
	{
		if (intention.functor.is_a(ai.o.getSort("action.answer.how"))) return true;
		return false;
	}


	execute(ir:IntentionRecord, ai:RuleBasedAI) : boolean
	{
		this.ir = ir;
		let intention:Term = ir.action;
		let requester:TermAttribute = ir.requester;

		if (intention.attributes.length == 2) {
			if (intention.attributes[1] instanceof ConstantTermAttribute) {
				let targetID:string = (<ConstantTermAttribute>intention.attributes[1]).value;
				console.log(ai.selfID + " answer followup how to " + targetID);
				// this is a follow up question! see if we can reconstruct the question...
				let context:NLContext = ai.contextForSpeakerWithoutCreatingANewOne(targetID);
				if (context != null) {
					// get the last sentence we said:
					let lastPerf:NLContextPerformative = context.lastPerformativeBy(ai.selfID);

					let newIntention:Term = null;
					if (lastPerf != null) newIntention = this.convertPerformativeToHowQuestionAnswerIntention(lastPerf, ai, context);
					if (newIntention != null) {
						intention = newIntention;
					} else {
						let term:Term = Term.fromString("action.talk('"+ai.selfID+"'[#id], perf.inform.answer("+requester+",'unknown'[symbol]))", ai.o);
						ai.intentions.push(new IntentionRecord(term, intention.attributes[1], null, null, ai.timeStamp));
						ir.succeeded = false;
						return true;
					}
				} else {
					// this should never happen
					let term:Term = Term.fromString("action.talk('"+ai.selfID+"'[#id], perf.inform.parseerror('"+context.speaker+"'[#id], #not(verb.understand('"+ai.selfID+"'[#id],#and(the(NOUN:'perf.question'[perf.question],S:[singular]),noun(NOUN,S))))))", ai.o);
					ai.intentions.push(new IntentionRecord(term, intention.attributes[1], null, null, ai.timeStamp));
					ir.succeeded = false;
					return true;
				}
			}
		}

		if (intention.attributes.length>=3 &&
			intention.attributes[2] instanceof TermTermAttribute) {
			let action:Term = (<TermTermAttribute>intention.attributes[2]).term;

			console.log(ai.selfID + " answer how: " + intention.attributes[2]);	
			// we add the sentence with negative sign, to see if it introduces a contradiction
			let target1:Sentence[] = [new Sentence([new Term(ai.o.getSort("relation.howto"),
															[new TermTermAttribute(action),
															 new VariableTermAttribute(ai.o.getSort("any"), "HOW")])],[false])];
			ai.queuedInferenceProcesses.push(new InferenceRecord(ai, [], [target1], 1, 0, false, null, new AnswerHow_InferenceEffect(intention)));
			// TODO: this should have some temporary value (in all actions that require inference or continuous execution)
			// that is then replaced with true/false after inference/continuous is done
			ir.succeeded = true;
			/*
			if (requester != null) {
				let term:Term = Term.fromString("action.talk('"+ai.selfID+"'[#id], perf.inform.answer("+requester+",'unknown'[symbol]))", ai.o);
				ai.intentions.push(new IntentionRecord(term, requester, null, null, ai.timeStamp));
			}
			*/
		}
		ir.succeeded = true;		
		return true;		
	}


	convertPerformativeToHowQuestionAnswerIntention(nlcp:NLContextPerformative, ai:RuleBasedAI, context:NLContext) : Term
	{
		if ((nlcp.performative.functor.is_a(ai.o.getSort("perf.request.action")) ||
		     nlcp.performative.functor.is_a(ai.o.getSort("perf.q.action"))) &&
			(nlcp.performative.attributes[1] instanceof TermTermAttribute)) {
			console.log("convertPerformativeToHowQuestionAnswerIntention: perf.request.action/perf.q.action");

			let predicate:Term = (<TermTermAttribute>nlcp.performative.attributes[1]).term;
			let newIntention:Term = new Term(ai.o.getSort("action.answer.how"),
									 		 [new ConstantTermAttribute(nlcp.speaker, ai.o.getSort("#id")),
											  nlcp.performative.attributes[0],
										 	  new TermTermAttribute(predicate)]);
			console.log("convertPerformativeToHowQuestionAnswerIntention, newIntention: " + newIntention);
			return newIntention;
		}

		return null;
	}


	saveToXML(ai:RuleBasedAI) : string
	{
		return "<IntentionAction type=\"AnswerHow_IntentionAction\"/>";
	}


	static loadFromXML(xml:Element, ai:RuleBasedAI) : IntentionAction
	{
		return new AnswerHow_IntentionAction();
	}
}