#include "window.h"
#include <cstdint>
#include <iostream>

namespace Donut
{
    static bool s_glfw_initialized = false;
    static uint32_t s_glfw_window_count = 0;

    Window::Window(const std::string& title, int width, int height)
        : m_title(title), m_width(width), 
          m_height(height), m_is_closed(false)
    {
        init();
    }

    Window::~Window()
    {
        shutdown();
    }

    void Window::init()
    {
        if (!s_glfw_initialized)
        {
            int success = glfwInit();
            if (!success)
            {
                std::cout << "Could not initialize GLFW!" << std::endl;
                return;
            }

            s_glfw_initialized = true;
        }

        m_window = glfwCreateWindow(m_width, m_height, m_title.c_str(), nullptr, nullptr);
        if (!m_window)
        {
            std::cout << "Could not create GLFW window!" << std::endl;
            glfwTerminate();
            return;
        }

        glfwMakeContextCurrent(m_window);
        glfwSetWindowUserPointer(m_window, this);

        glfwSetErrorCallback(glfw_error_callback);
        glfwSetWindowCloseCallback(m_window, glfw_window_close_callback);
        glfwSetWindowSizeCallback(m_window, glfw_window_size_callback);
        glfwSetWindowFocusCallback(m_window, glfw_window_focus_callback);
        glfwSetWindowPosCallback(m_window, glfw_window_pos_callback);
        glfwSetKeyCallback(m_window, glfw_key_callback);
        glfwSetCharCallback(m_window, glfw_char_callback);
        glfwSetMouseButtonCallback(m_window, glfw_mouse_button_callback);
        glfwSetScrollCallback(m_window, glfw_mouse_scroll_callback);
        glfwSetCursorPosCallback(m_window, glfw_cursor_pos_callback);

        s_glfw_window_count++;
    }

    void Window::shutdown()
    {
        glfwDestroyWindow(m_window);
        s_glfw_window_count--;

        if (s_glfw_window_count == 0)
        {
            glfwTerminate();
            s_glfw_initialized = false;
        }
    }

    void Window::on_update() const
    {
        glfwPollEvents();
        glfwSwapBuffers(m_window);
    }

    bool Window::should_close() const
    {
        return glfwWindowShouldClose(m_window) || m_is_closed;
    }

    void Window::glfw_error_callback(int error, const char* description)
    {
        std::cout << "GLFW Error (" << error << "): " << description << std::endl;
    }

    void Window::glfw_window_close_callback(GLFWwindow* window)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        WindowCloseEvent event;
        win->m_event_handler.on_event(event);
    }

    void Window::glfw_window_size_callback(GLFWwindow* window, int width, int height)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        win->m_width = width;
        win->m_height = height;
        
        WindowResizeEvent event(width, height);
        win->m_event_handler.on_event(event);
    }

    void Window::glfw_window_focus_callback(GLFWwindow* window, int focused)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        
        if (focused)
        {
            WindowFocusEvent event;
            win->m_event_handler.on_event(event);
        }
        else
        {
            WindowLostFocusEvent event;
            win->m_event_handler.on_event(event);
        }
    }

    void Window::glfw_window_pos_callback(GLFWwindow* window, int xpos, int ypos)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        WindowMovedEvent event(xpos, ypos);
        win->m_event_handler.on_event(event);
    }

    void Window::glfw_key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        
        switch (action)
        {
            case GLFW_PRESS:
            {
                KeyPressedEvent event(key, false);
                win->m_event_handler.on_event(event);
            } break;
            case GLFW_RELEASE:
            {
                KeyReleasedEvent event(key);
                win->m_event_handler.on_event(event);
            } break;
            case GLFW_REPEAT:
            {
                KeyPressedEvent event(key, true);
                win->m_event_handler.on_event(event);
            } break;
        }
    }

    void Window::glfw_char_callback(GLFWwindow* window, unsigned int keycode)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        KeyTypedEvent event(keycode);
        win->m_event_handler.on_event(event);
    }

    void Window::glfw_mouse_button_callback(GLFWwindow* window, int button, int action, int mods)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        
        switch (action)
        {
            case GLFW_PRESS:
            {
                MouseButtonPressedEvent event(button);
                win->m_event_handler.on_event(event);
            } break;
            case GLFW_RELEASE:
            {
                MouseButtonReleasedEvent event(button);
                win->m_event_handler.on_event(event);
                break;
            }
        }
    }

    void Window::glfw_mouse_scroll_callback(GLFWwindow* window, double x_offset, double y_offset)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        MouseScrolledEvent event((float)x_offset, (float)y_offset);
        win->m_event_handler.on_event(event);
    }

    void Window::glfw_cursor_pos_callback(GLFWwindow* window, double x_pos, double y_pos)
    {
        Window* win = static_cast<Window*>(glfwGetWindowUserPointer(window));
        MouseMovedEvent event((float)x_pos, (float)y_pos);
        win->m_event_handler.on_event(event);
    }
}