#include "player_input.hpp"
#include "godot_macros.h"
#include "godot_cpp/classes/input.hpp"
#include "godot_cpp/classes/input_event.hpp"
#include "godot_cpp/classes/input_event_mouse_motion.hpp"
#include "godot_cpp/variant/callable.hpp"
#include <algorithm>
#include <optional>

namespace godot {
void PlayerInput::_bind_methods() {}

Vector2 PlayerInput::lastMouseMotion{0.f, 0.f};
bool PlayerInput::primaryExists{false};

PlayerInput::Listener::Listener(String positive, String negative, Callable callable)
: actionNegative{negative}
, actionPositive{positive}
, callable{callable}
, isMouseEvent{positive.begins_with("_mouse_") || negative.begins_with("_mouse_")} {}

PlayerInput::Listener::Listener(String action, Callable callable)
: PlayerInput::Listener::Listener(action, String(), callable) {}

std::optional<float> PlayerInput::Listener::evaluate_action(String const &action) {
    Input *input = Input::get_singleton();
    if(action.begins_with("_mouse_")) {
        Vector2 vector = PlayerInput::get_last_mouse_motion();
        if(action.ends_with("_up"))
            return vector.y > 0.f ? vector.y : 0.f;
        else if(action.ends_with("_down"))
            return vector.y < 0.f ? -vector.y : 0.f;
        else if(action.ends_with("_right"))
            return vector.x > 0.f ? vector.x : 0.f;
        else if(action.ends_with("_left"))
            return vector.x < 0.f ? -vector.x : 0.f;
    }
    if(action.is_empty()) {
        return 0.f;
    } else {
        return float(input->is_action_pressed(action));
    }
}

bool PlayerInput::Listener::has_changed(Ref<InputEvent> const &event) {
    bool const mouse_changed{this->isMouseEvent && event->is_class("InputEventMouseMotion")};
    bool const negative_changed{!this->actionNegative.is_empty() && event->is_action(this->actionNegative)};
    bool const positive_changed{!this->actionPositive.is_empty() && event->is_action(this->actionPositive)};
    return mouse_changed || negative_changed || positive_changed;
}

float PlayerInput::Listener::evaluate(Ref<InputEvent> const &event) {
    std::optional<float> positive = PlayerInput::Listener::evaluate_action(this->actionPositive);
    std::optional<float> negative = PlayerInput::Listener::evaluate_action(this->actionNegative);
    if(!positive.has_value() || !negative.has_value())
        return 0.f;
    float newest = positive.value() - negative.value();
    if(this->lastCached != newest || this->isMouseEvent)
        this->callable.call(event, newest);
    return (this->lastCached = newest);
}

bool PlayerInput::Listener::operator==(godot::PlayerInput::Listener const& b) {
    return this->callable == b.callable
        && this->actionNegative == b.actionNegative
        && this->actionPositive == b.actionPositive;
}

Vector2 PlayerInput::get_last_mouse_motion() {
    return PlayerInput::lastMouseMotion;
}

void PlayerInput::_enter_tree() {
    GDGAMEONLY();
    if(!PlayerInput::primaryExists) {
        this->isPrimary = true;
        PlayerInput::primaryExists = true;
    }
}

void PlayerInput::_exit_tree() {
    GDGAMEONLY();
    if(this->isPrimary) {
        this->isPrimary = false;
        PlayerInput::primaryExists = false;
    }
}

void PlayerInput::_unhandled_input(Ref<InputEvent> const &event) {
    GDGAMEONLY();
    if(this->isPrimary && event->is_class("InputEventMouseMotion"))
        PlayerInput::lastMouseMotion = Object::cast_to<InputEventMouseMotion>(*event)->get_relative();
    for(Listener& listener: this->listeners) {
        if(listener.has_changed(event)) {
            listener.evaluate(event);
        }
    }
}

void PlayerInput::_process(double deltaTime) {
    if(this->isPrimary)
        PlayerInput::lastMouseMotion = {0.f, 0.f};
}

void PlayerInput::listen_to(Listener const& listener) {
    this->listeners.push_back(listener);
}

void PlayerInput::stop_listening(Node *node) {
    for(size_t i = 0; i < this->listeners.size(); ++i) {
        Listener& l = this->listeners.at(i);
        if(l.callable.get_object() == node) {
            this->listeners.erase(this->listeners.begin() + i);
            i--;
        }
    }
}

void PlayerInput::stop_listening(Listener const& listener) {
    std::vector<Listener>::iterator itr = std::find(this->listeners.begin(), this->listeners.end(), listener);
    if(itr != this->listeners.end())
        this->listeners.erase(itr);
}
}