#include "behaviour_tree.h"
#include "behaviour_nodes/behaviour_composite.h"
#include "behaviour_nodes/behaviour_node.h"
#include "core/config/engine.h"
#include "core/object/class_db.h"
#include "core/object/object.h"
#include "core/variant/typed_array.h"

void BehaviourTree::_bind_methods() {
	ADD_SIGNAL(MethodInfo("current_behaviour_changed", PropertyInfo(Variant::OBJECT, "new_behaviour", PROPERTY_HINT_NODE_TYPE, "BehaviourNode")));
}

void BehaviourTree::process() {
	do {
		this->current->execute();
	} while (execute_next());
}

void BehaviourTree::_notification(int what) {
	if (Engine::get_singleton()->is_editor_hint()) {
		return;
	}
	switch (what) {
		default:
			return;
		case NOTIFICATION_READY:
			for (Variant var : get_children()) {
				if ((this->root = cast_to<BehaviourNode>(var))) {
					this->current = this->root;
					break;
				}
			}
			ERR_FAIL_COND_EDMSG(this->root == nullptr, "No valid BehaviourNode in BehaviourTree");
			set_process(true);
			return;
		case NOTIFICATION_PROCESS:
			process();
			return;
	}
}

bool BehaviourTree::execute_next() {
	BehaviourNode *next{ this->current->get_next() };
	if (next == this->current) {
		return false;
	} else {
		ERR_FAIL_COND_V_EDMSG(next == nullptr, false, vformat("%s::get_next returned a nullptr, repeating last node", this->current->get_class()));
		if (this->current != next->get_parent()) {
			this->current->exit();
		}
		if (this->current->get_parent() != next) {
			next->enter();
			emit_signal("current_behaviour_changed", next);
		}
		this->current = next;
		return this->current != this->root && (cast_to<BehaviourComposite>(this->current) || this->current->get_status() != BehaviourNode::Running);
	}
}