#include "state_machine.hpp"
#include "state.hpp"
#include "utils/godot_macros.h"
#include <godot_cpp/classes/scene_tree.hpp>
#include <godot_cpp/variant/string_name.hpp>
#include <godot_cpp/variant/utility_functions.hpp>

namespace godot {
void StateMachine::_bind_methods() {
#define CLASSNAME StateMachine
    GDPROPERTY(initial_state, Variant::STRING_NAME);
}

void StateMachine::_enter_tree() { GDGAMEONLY();
    this->override_state(this->initial_state);
}

void StateMachine::_exit_tree() { GDGAMEONLY();
    for(KeyValue<StringName, IState*> kvp : available)
        if(!kvp.value->as_node()->is_inside_tree())
            kvp.value->as_node()->queue_free();
}

void StateMachine::_process(double delta_time) { GDGAMEONLY();
    if(this->state)
        this->override_state(this->state->get_next());
}

void StateMachine::override_state(StringName next) {
    // don't change state if target is current
    if(this->state != nullptr && next == this->state->as_node()->get_class())
        return;
    if(this->state)
        this->remove_child(this->state->as_node());
    if(next.is_empty()) {
        this->state = nullptr;
        return;
    }
    // instantiate new state if this type is not yet available
    if(!this->available.has(next)) {
        IState *instance = dynamic_cast<IState*>(Object::cast_to<Node>(ClassDB::instantiate(next)));
        if(instance == nullptr) {
            UtilityFunctions::push_error("Failure to instantiate state with class '", next, "'");
            return;
        }
        this->available.insert(next, instance);
        instance->init(this->get_parent(), this);
        instance->as_node()->set_process_mode(ProcessMode::PROCESS_MODE_INHERIT);
    }
    // set the new state and add it to the tree
    this->state = this->available.get(next);
    this->add_child(this->state->as_node());
}

void StateMachine::set_initial_state(StringName name) {
    this->initial_state = name;
}

StringName StateMachine::get_initial_state() const {
    return this->initial_state;
}
}