#include "gameplay/ai.h"
#include "gameplay/gameactor.h"

#include "utility/raycaster.h"
#include "utility/script.h"

AI::AI(GameActor* actor, std::unique_ptr<Raycaster> raycaster)
	: state(AIState::Idle), raycaster(std::move(raycaster)), actor(actor), 
	  lastGCTime(std::chrono::high_resolution_clock::now()), GCTimeout(3)
{}

void AI::attachBehaviourScript(std::unique_ptr<AIScript> behaviour)
{
	// passing out instance of raycaster and this AI into our scripting api
	// pay special attention each ai script has control of only their own instance of ai!
	this->behaviour = std::move(behaviour);
	this->behaviour->lua["raycaster"] = sol::make_reference(this->behaviour->lua, raycaster.get());
	this->behaviour->lua["ai"] = sol::make_reference(this->behaviour->lua, this);

	idleFunc = this->behaviour->lua["idle"];
	patrolFunc = this->behaviour->lua["patrol"];
	alertFunc = this->behaviour->lua["alert"];
}

void AI::update()
{
	try {
		if (actor && target) {
			switch (state)
			{
			case AIState::Idle:
				if (idleFunc.valid())
				{
					auto result = idleFunc(actor, target);
					if (!result.valid())
					{
						sol::error err = result;
						std::cerr << "lua error: " << err.what() << std::endl;
					}
				}
				break;
			case AIState::Patrol:
				if (patrolFunc.valid())
				{
					auto result = patrolFunc(actor, target);
					if (!result.valid())
					{
						sol::error err = result;
						std::cerr << "lua error: " << err.what() << std::endl;
					}
				}
				break;
			case AIState::Alert:
				if (alertFunc.valid())
				{
					auto result = alertFunc(actor, target);
					if (!result.valid())
					{
						sol::error err = result;
						std::cerr << "lua error: " << err.what() << std::endl;
					}
				}
				break;
			}
		}
		std::chrono::high_resolution_clock::time_point curTime = std::chrono::high_resolution_clock::now();
		if (curTime - lastGCTime >= GCTimeout)
		{
			behaviour->lua.collect_gc();
			lastGCTime = curTime;
		}
	}
	catch (const std::exception& e) {
		std::cerr << "Error during AI update: " << e.what() << std::endl;
		state = AIState::Idle;
	}
}

AI::~AI()
{
	behaviour->lua["raycaster"] = sol::nil;
	behaviour->lua["ai"] = sol::nil;
	behaviour->lua["idle"] = sol::nil;
	behaviour->lua["patrol"] = sol::nil;
	behaviour->lua["alert"] = sol::nil;
	behaviour->lua.collect_gc();
}