#include <windows.h>
#include <gl/GL.h>
#include <stdio.h>

#include "game.hpp"

struct wincontext_t {
    HWND window;
    HDC device_context;
    i32 width;
    i32 height;
};

static wincontext_t wincontext;
static input_t input;

LRESULT WndProc(HWND window, UINT message, WPARAM wparam, LPARAM lparam)
{
    LRESULT result = 0;
    switch (message) {
    case WM_DESTROY:
    case WM_QUIT:
        wincontext.running = 0;
        break;
    case WM_KEYDOWN:
        switch (wparam) {
        case VK_ESCAPE:
            input.escape.current = 1;
            break;
        default:
            break;
        }
        break;
    case WM_KEYUP:
        switch (wparam) {
        case VK_ESCAPE:
            input.escape.current = 0;
            break;
        default:
            break;
        }
        break;
    case WM_SIZE:
        wincontext.width = LOWORD(lparam);
        wincontext.height = HIWORD(lparam);
        glViewport(wincontext.width, wincontext.height);
        break;
    default:
        result = DefWindowProc(window, message, wparam, lparam);
    }
    return result;
}

void update_input(input_t *input)
{
    input->escape.last = input->escape.current;
}

i32 init_win(HINSTANCE instance, i32 show_cmd, i32 width, i32 height)
{
    WNDCLASSA window_class = {};
    window_class.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
    window_class.lpfnWndProc = (WNDPROC)WndProc;
    window_class.hInstance = instance;
    window_class.hCursor = LoadCursor(0, IDC_ARROW);
    window_class.lpszClassName = "window class";
    if (!RegisterClass(&window_class)) {
        printf("error: failed to register window class\n");
        return 0;
    }

    wincontext.width = width;
    wincontext.height = height;
    wincontext.window = CreateWindow(window_class.lpszClassName, "game", WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT, CW_USEDEFAULT, wincontext.width, wincontext.height, 0, 0, instance, 0);
    if (!wincontext.window) {
        printf("error: failed to create a window\n");
        return 0;
    }

    wincontext.running = 1;

    wincontext.device_context = GetDC(wincontext.window);
    if (!wincontext.device_context) {
        printf("error: failed to get device context\n");
        return 0;
    }

    PIXELFORMATDESCRIPTOR pixel_format_desc = {};
    pixel_format_desc.nSize = sizeof(PIXELFORMATDESCRIPTOR);
    pixel_format_desc.nVersion = 1;
    pixel_format_desc.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
    pixel_format_desc.cColorBits = 32;
    pixel_format_desc.cAlphaBits = 8;
    pixel_format_desc.cDepthBits = 24;

    i32 pixel_format = ChoosePixelFormat(wincontext.device_context, &pixel_format_desc);
    if (!pixel_format) {
        printf("error: failed to choose pixel format\n");
        return 0;
    }
    if (!SetPixelFormat(wincontext.device_context, pixel_format, &pixel_format_desc)) {
        printf("error: failed to set pixel format\n");
        return 0;
    }

    HGLRC gl_context = wglCreateContext(wincontext.device_context);
    if (!gl_context) {
        printf("error: failed to create gl context\n");
        return 0;
    }
    if (!wglMakeCurrent(wincontext.device_context, gl_context)) {
        printf("error: failed to make gl context current\n");
        return 0;
    }

    ShowWindow(wincontext.window, show_cmd);
    UpdateWindow(wincontext.window);

    return 1;
}

void handle_win_events()
{
    MSG messages;
    while (PeekMessage(&messages, 0, 0, 0, PM_REMOVE)) {
        TranslateMessage(&messages);
        DispatchMessage(&messages);
    }
}

int WinMain(HINSTANCE instance, HINSTANCE prev_instance, LPSTR cmdline, int show_cmd)
{
    if (!init_win(instance, show_cmd, 1600, 900))
        return 1;

    if (!init_game()) {
    }

    while (wincontext.running) {
        handle_win_events();
        game_update_and_render(input);
        update_input(&input);
        SwapBuffers(wincontext.device_context);
    }

    return 0;
}