#include "input.h"

#include <SDL3/SDL.h>   

#include <algorithm>      // Para find
#include <iostream>       // Para basic_ostream, operator<<, cout, endl
#include <iterator>       // Para distance
#include <unordered_map>  // Para unordered_map, operator==, _Node_cons...
#include <utility>        // Para pair

// [SINGLETON]
Input* Input::input_ = nullptr;

// [SINGLETON] Crearemos el objeto con esta función estática
void Input::init(const std::string& game_controller_db_path) {
    Input::input_ = new Input(game_controller_db_path);
}

// [SINGLETON] Destruiremos el objeto con esta función estática
void Input::destroy() {
    delete Input::input_;
}

// [SINGLETON] Con este método obtenemos el objeto y podemos trabajar con él
Input* Input::get() {
    return Input::input_;
}

// Constructor
Input::Input(const std::string& game_controller_db_path)
    : game_controller_db_path_(game_controller_db_path) {
    // Busca si hay mandos conectados
    discoverGameControllers();

    // Inicializa los vectores
    key_bindings_.resize(static_cast<int>(InputAction::SIZE), KeyBindings());
    controller_bindings_.resize(num_gamepads_, std::vector<ControllerBindings>(static_cast<int>(InputAction::SIZE), ControllerBindings()));

    // Listado de los inputs para jugar que utilizan botones, ni palancas ni crucetas
    button_inputs_ = {InputAction::JUMP};
}

// Asigna inputs a teclas
void Input::bindKey(InputAction input, SDL_Scancode code) {
    key_bindings_.at(static_cast<int>(input)).scancode = code;
}

// Asigna inputs a botones del mando
void Input::bindGameControllerButton(int controller_index, InputAction input, SDL_GameControllerButton button) {
    if (controller_index < num_gamepads_) {
        controller_bindings_.at(controller_index).at(static_cast<int>(input)).button = button;
    }
}

// Asigna inputs a botones del mando
void Input::bindGameControllerButton(int controller_index, InputAction input_target, InputAction input_source) {
    if (controller_index < num_gamepads_) {
        controller_bindings_.at(controller_index).at(static_cast<int>(input_target)).button = controller_bindings_.at(controller_index).at(static_cast<int>(input_source)).button;
    }
}

// Comprueba si un input esta activo
bool Input::checkInput(InputAction input, bool repeat, InputDeviceToUse device, int controller_index) {
    bool success_keyboard = false;
    bool success_controller = false;
    const int input_index = static_cast<int>(input);

    if (device == InputDeviceToUse::KEYBOARD || device == InputDeviceToUse::ANY) {
        const Uint8* keyStates = SDL_GetKeyboardState(nullptr);

        if (repeat) {
            success_keyboard = keyStates[key_bindings_[input_index].scancode] != 0;
        } else {
            if (!key_bindings_[input_index].active) {
                if (keyStates[key_bindings_[input_index].scancode] != 0) {
                    key_bindings_[input_index].active = true;
                    success_keyboard = true;
                } else {
                    success_keyboard = false;
                }
            } else {
                if (keyStates[key_bindings_[input_index].scancode] == 0) {
                    key_bindings_[input_index].active = false;
                }
                success_keyboard = false;
            }
        }
    }

    if (gameControllerFound() && controller_index >= 0 && controller_index < num_gamepads_) {
        if ((device == InputDeviceToUse::CONTROLLER) || (device == InputDeviceToUse::ANY)) {
            success_controller = checkAxisInput(input, controller_index, repeat);

            if (!success_controller) {
                if (repeat) {
                    success_controller = SDL_GameControllerGetButton(connected_controllers_.at(controller_index), controller_bindings_.at(controller_index).at(input_index).button) != 0;
                } else {
                    if (!controller_bindings_.at(controller_index).at(input_index).active) {
                        if (SDL_GameControllerGetButton(connected_controllers_.at(controller_index), controller_bindings_.at(controller_index).at(input_index).button) != 0) {
                            controller_bindings_.at(controller_index).at(input_index).active = true;
                            success_controller = true;
                        } else {
                            success_controller = false;
                        }
                    } else {
                        if (SDL_GameControllerGetButton(connected_controllers_.at(controller_index), controller_bindings_.at(controller_index).at(input_index).button) == 0) {
                            controller_bindings_.at(controller_index).at(input_index).active = false;
                        }
                        success_controller = false;
                    }
                }
            }
        }
    }

    return (success_keyboard || success_controller);
}

// Comprueba si hay almenos un input activo
bool Input::checkAnyInput(InputDeviceToUse device, int controller_index) {
    if (device == InputDeviceToUse::KEYBOARD || device == InputDeviceToUse::ANY) {
        const Uint8* mKeystates = SDL_GetKeyboardState(nullptr);

        for (int i = 0; i < (int)key_bindings_.size(); ++i) {
            if (mKeystates[key_bindings_[i].scancode] != 0 && !key_bindings_[i].active) {
                key_bindings_[i].active = true;
                return true;
            }
        }
    }

    if (gameControllerFound()) {
        if (device == InputDeviceToUse::CONTROLLER || device == InputDeviceToUse::ANY) {
            for (int i = 0; i < (int)controller_bindings_.size(); ++i) {
                if (SDL_GameControllerGetButton(connected_controllers_[controller_index], controller_bindings_[controller_index][i].button) != 0 && !controller_bindings_[controller_index][i].active) {
                    controller_bindings_[controller_index][i].active = true;
                    return true;
                }
            }
        }
    }

    return false;
}

// Busca si hay mandos conectados
bool Input::discoverGameControllers() {
    bool found = false;

    if (SDL_WasInit(SDL_INIT_GAMECONTROLLER) != 1) {
        SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER);
    }

    if (SDL_GameControllerAddMappingsFromFile(game_controller_db_path_.c_str()) < 0) {
        std::cout << "Error, could not load " << game_controller_db_path_.c_str() << " file: " << SDL_GetError() << std::endl;
    }

    num_joysticks_ = SDL_NumJoysticks();
    num_gamepads_ = 0;

    // Cuenta el número de mandos
    joysticks_.clear();
    for (int i = 0; i < num_joysticks_; ++i) {
        auto joy = SDL_JoystickOpen(i);
        joysticks_.push_back(joy);
        if (SDL_IsGameController(i)) {
            num_gamepads_++;
        }
    }

    std::cout << "\n** LOOKING FOR GAME CONTROLLERS" << std::endl;
    if (num_joysticks_ != num_gamepads_) {
        std::cout << "Joysticks found: " << num_joysticks_ << std::endl;
        std::cout << "Gamepads found : " << num_gamepads_ << std::endl;
    } else {
        std::cout << "Gamepads found: " << num_gamepads_ << std::endl;
    }

    if (num_gamepads_ > 0) {
        found = true;

        for (int i = 0; i < num_gamepads_; i++) {
            // Abre el mando y lo añade a la lista
            auto pad = SDL_GameControllerOpen(i);
            if (SDL_GameControllerGetAttached(pad) == 1) {
                connected_controllers_.push_back(pad);
                const std::string name = SDL_GameControllerNameForIndex(i);
                std::cout << "#" << i << ": " << name << std::endl;
                controller_names_.push_back(name);
            } else {
                std::cout << "SDL_GetError() = " << SDL_GetError() << std::endl;
            }
        }

        SDL_GameControllerEventState(SDL_ENABLE);
    }

    std::cout << "\n** FINISHED LOOKING FOR GAME CONTROLLERS" << std::endl;
    return found;
}

// Comprueba si hay algun mando conectado
bool Input::gameControllerFound() { return num_gamepads_ > 0 ? true : false; }

// Obten el nombre de un mando de juego
std::string Input::getControllerName(int controller_index) const { return num_gamepads_ > 0 ? controller_names_.at(controller_index) : std::string(); }

// Obten el número de mandos conectados
int Input::getNumControllers() const { return num_gamepads_; }

// Obtiene el indice del controlador a partir de un event.id
int Input::getJoyIndex(int id) const {
    for (int i = 0; i < num_joysticks_; ++i) {
        if (SDL_JoystickInstanceID(joysticks_[i]) == id) {
            return i;
        }
    }
    return -1;
}

// Obtiene el SDL_GameControllerButton asignado a un input
SDL_GameControllerButton Input::getControllerBinding(int controller_index, InputAction input) const {
    return controller_bindings_[controller_index][static_cast<int>(input)].button;
}

// Obtiene el indice a partir del nombre del mando
int Input::getIndexByName(const std::string& name) const {
    auto it = std::find(controller_names_.begin(), controller_names_.end(), name);
    return it != controller_names_.end() ? std::distance(controller_names_.begin(), it) : -1;
}

// Comprueba el eje del mando
bool Input::checkAxisInput(InputAction input, int controller_index, bool repeat) {
    // Umbral para considerar el eje como activo
    const Sint16 threshold = 30000;
    bool axis_active_now = false;

    switch (input) {
        case InputAction::LEFT:
            axis_active_now = SDL_GameControllerGetAxis(connected_controllers_[controller_index], SDL_CONTROLLER_AXIS_LEFTX) < -threshold;
            break;
        case InputAction::RIGHT:
            axis_active_now = SDL_GameControllerGetAxis(connected_controllers_[controller_index], SDL_CONTROLLER_AXIS_LEFTX) > threshold;
            break;
        case InputAction::UP:
            axis_active_now = SDL_GameControllerGetAxis(connected_controllers_[controller_index], SDL_CONTROLLER_AXIS_LEFTY) < -threshold;
            break;
        case InputAction::DOWN:
            axis_active_now = SDL_GameControllerGetAxis(connected_controllers_[controller_index], SDL_CONTROLLER_AXIS_LEFTY) > threshold;
            break;
        default:
            return false;
    }

    // Referencia al binding correspondiente
    auto& binding = controller_bindings_.at(controller_index).at(static_cast<int>(input));

    if (repeat) {
        // Si se permite repetir, simplemente devolvemos el estado actual
        return axis_active_now;
    } else {
        // Si no se permite repetir, aplicamos la lógica de transición
        if (axis_active_now && !binding.axis_active) {
            // Transición de inactivo a activo
            binding.axis_active = true;
            return true;
        } else if (!axis_active_now && binding.axis_active) {
            // Transición de activo a inactivo
            binding.axis_active = false;
        }
        // Mantener el estado actual
        return false;
    }
}