#include "Engine.h"

#include <chrono>
#include <thread>

Engine::ErrorCode Engine::run()
{
    ErrorCode errorCode =
            ErrorCode::success;

    auto lastUpdate =
            std::chrono::steady_clock::now();

    auto lag =
            std::chrono::milliseconds(0);

    const auto timeQuantum =
            std::chrono::milliseconds(15);

    while (!end())
    {
        // INPUT
        //=================================

        updateInput();

        //=================================

        // UPDATE
        //=================================

        auto now =
                std::chrono::steady_clock::now();

        lag +=
                std::chrono::duration_cast
                        <
                                std::chrono::milliseconds
                        >
                        (
                                now - lastUpdate
                        );

        lastUpdate = now;

        while (lag >= timeQuantum)
        {
            lag -= timeQuantum;

            update(
                    static_cast<int>(
                            timeQuantum.count()
                    )
            );
        }

        //=================================

        // RENDER
        //=================================

        if (!m_PaintDevice.ready())
        {
            errorCode =
                    ErrorCode::paint_device_not_ready;

            break;
        }

        m_PaintDevice.clear();

        render(m_PaintDevice);

        m_PaintDevice.render();

        //=================================

        std::this_thread::sleep_for(
                std::chrono::milliseconds(1)
        );
    }

    return errorCode;
}

void Engine::updateInput()
{
    int key = getch();

    while (key != ERR)
    {
        if (
                m_TrackedKeys.find(key)
                !=
                m_TrackedKeys.end()
                )
        {
            on_button_press(key);
        }

        key = getch();
    }
}

void Engine::track_key(int key)
{
    m_TrackedKeys.insert(key);
}

void Engine::untrack_key(int key)
{
    auto it =
            m_TrackedKeys.find(key);

    if (it != m_TrackedKeys.end())
    {
        m_TrackedKeys.erase(it);
    }
}