#include "app.h"
#include "aio.h"
#include "buffer_manager.h"
#include "config.h"
#include "gfx.h"
#include "renderer_api.h"

extern void __RegisterRuntimeCVars(void);

VY_CVAR_I(rt_Fullscreen, "Show window in fullscreen mode. [0/1] Default: 0", 0);
VY_CVAR_I(rt_WindowWidth, "Window width. Default: 1024", 1024);
VY_CVAR_I(rt_WindowHeight, "Window height. Default: 768", 768);

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>

static LRESULT CALLBACK win32WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
    switch (uMsg) {
    case WM_CLOSE:
        PostQuitMessage(0);
        return 0;
    default:
        return DefWindowProcW(hWnd, uMsg, wParam, lParam);
    }
}

VY_DLLEXPORT int
vyWin32Entry(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int nCmdShow) {

    __RegisterRuntimeCVars();
    vyRegisterRendererCVars();

    /* TODO: Parse the cvar config file */

    if (vyInitBufferManager() != VY_SUCCESS) {
        vyReportError("BUFFERMGR", "Init failed.");
        return 1;
    }

    if (vyInitFileTab(1024) != VY_SUCCESS) {
        vyReportError("FTAB", "Init failed.");
        return 1;
    }

    if (vyInitAIO(0) != VY_SUCCESS) {
        vyReportError("AIO", "Init failed.");
        return 1;
    }

    WNDCLASSEXW wndclass = {
        .cbSize        = sizeof(wndclass),
        .hInstance     = hInstance,
        .lpszClassName = L"vyWndClass",
        .style         = CS_OWNDC,
        .lpfnWndProc   = win32WndProc,
    };
    if (!RegisterClassExW(&wndclass)) {
        vyReportError("CORE", "RegisterClassEx failed: %u", GetLastError());
        return 1;
    }

    HWND wnd = NULL;
    if (rt_Fullscreen.i) {
        /* Fullscreen window */
        int w = GetSystemMetrics(SM_CXSCREEN);
        int h = GetSystemMetrics(SM_CYSCREEN);
        wnd   = CreateWindowExW(WS_EX_APPWINDOW,
                              L"vyWndClass",
                              L"Voyage",
                              WS_POPUP,
                              0,
                              0,
                              w,
                              h,
                              NULL,
                              NULL,
                              hInstance,
                              NULL);
        ShowWindow(wnd, SW_SHOW);
    } else {
        /* Windowed mode */
        int w = rt_WindowWidth.i;
        int h = rt_WindowHeight.i;
        wnd   = CreateWindowExW(WS_EX_APPWINDOW,
                              L"vyWndClass",
                              L"Voyage",
                              WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU,
                              CW_USEDEFAULT,
                              CW_USEDEFAULT,
                              w,
                              h,
                              NULL,
                              NULL,
                              hInstance,
                              NULL);
        ShowWindow(wnd, SW_SHOW);
    }

    if (!wnd) {
        vyReportError("CORE", "Failed to create the game window: %u", GetLastError());
        return 1;
    }

    vy_renderer_init_info renderer_info = {.hWnd = wnd, .hInstance = hInstance};
    if (!vyInitGFX(&renderer_info)) {
        vyReportError("GFX", "Init failed.");
        return 1;
    }

    /* Main Loop */
    bool keep_running = true;
    while (keep_running) {
        MSG msg;
        while (PeekMessageW(&msg, NULL, 0, 0, PM_REMOVE)) {
            if (msg.message == WM_QUIT) {
                keep_running = false;
            } else {
                TranslateMessage(&msg);
                DispatchMessageW(&msg);
            }
        }
    }

    vyShutdownGFX();

    DestroyWindow(wnd);
    UnregisterClassW(L"vyWndClass", hInstance);

    vyShutdownAIO();
    vyShutdownAIO();
    vyShutdownFileTab();
    vyShutdownBufferManager();

    return 0;
}

#elif defined(VY_USE_XLIB)

#include <X11/Xlib.h>
#include <assert.h>

static void xlibSetFullscreen(Display *dpy, int screen, Window window, bool enable) {
    Atom wm_state      = XInternAtom(dpy, "_NET_W_STATE", False);
    Atom wm_fullscreen = XInternAtom(dpy, "_NET_WM_STATE_FULLSCREEN", False);
    if (wm_state == None || wm_fullscreen == None) {
        vyLog("CORE", "Window manager does not support fullscreen mode.");
        return;
    }

#define _NET_WM_STATE_REMOVE     0
#define _NET_WM_STATE_ADD        1
#define EVENT_SOURCE_APPLICATION 1
    XEvent ev;
    ev.type                 = ClientMessage;
    ev.xclient.display      = dpy;
    ev.xclient.window       = window;
    ev.xclient.message_type = wm_state;
    ev.xclient.format       = 32;
    ev.xclient.data.l[0]    = (enable) ? _NET_WM_STATE_ADD : _NET_WM_STATE_REMOVE;
    ev.xclient.data.l[1]    = wm_fullscreen;
    ev.xclient.data.l[2]    = 0;
    ev.xclient.data.l[3]    = EVENT_SOURCE_APPLICATION;
    ev.xclient.data.l[4]    = 0;

    Window root_window = XRootWindow(dpy, screen);
    long ev_mask       = SubstructureRedirectMask;

    if (!XSendEvent(dpy, root_window, False, ev_mask, &ev)) {
        vyReportError("CORE", "Failed to send x11 fullscreen event.");
    }

#undef _NET_WM_STATE_ADD
#undef _NET_WM_STATE_REMOVE
#undef EVENT_SOURCE_APPLICATION
}

VY_DLLEXPORT int vyXlibEntry(int argc, char **argv) {
    __RegisterRuntimeCVars();
    vyRegisterRendererCVars();

    if (vyInitBufferManager() != VY_SUCCESS) {
        vyReportError("BUFFERMGR", "Init failed.");
        return 1;
    }

    if (vyInitFileTab(1024) != VY_SUCCESS) {
        vyReportError("FTAB", "Init failed.");
        return 1;
    }

    if (vyInitAIO(0) != VY_SUCCESS) {
        vyReportError("AIO", "Init failed.");
        return 1;
    }

    Display *dpy = XOpenDisplay(NULL);
    if (!dpy) {
        vyReportError("CORE", "Failed to open default display");
        return 1;
    }
    int screen = DefaultScreen(dpy);
    Window window;
    int w  = rt_WindowWidth.i;
    int h  = rt_WindowHeight.i;
    window = XCreateSimpleWindow(dpy,
                                 RootWindow(dpy, screen),
                                 10,
                                 10,
                                 w,
                                 h,
                                 1,
                                 BlackPixel(dpy, screen),
                                 WhitePixel(dpy, screen));
    XSelectInput(dpy, window, KeyPressMask);
    XMapWindow(dpy, window);
    XStoreName(dpy, window, "Voyage");

    Atom wm_close = XInternAtom(dpy, "WM_DELETE_WINDOW", False);
    if (!wm_close) {
        vyReportError("CORE", "Failed to find WM_DELETE_WINDOW atom.");
        XDestroyWindow(dpy, window);
        XCloseDisplay(dpy);
        return 1;
    }
    XSetWMProtocols(dpy, window, &wm_close, 1);

    if (rt_Fullscreen.i)
        xlibSetFullscreen(dpy, screen, window, true);

    vy_renderer_init_info renderer_info = {.display = dpy, .window = window};
    if (!vyInitGFX(&renderer_info)) {
        vyReportError("GFX", "Init failed.");
        return 1;
    }

    /* Main Loop */
    bool keep_running = true;
    while (keep_running) {
        while (XEventsQueued(dpy, QueuedAlready) > 0) {
            XEvent event;
            XNextEvent(dpy, &event);
            switch (event.type) {
            case KeyPress:
                break;
            case ButtonPressMask:
                /* Mouse down */
                break;
            case PointerMotionMask:
                /* Mouse movement */
                break;
            case ClientMessage:
                if (event.xclient.data.l[0] == (long)wm_close) {
                    vyLog("CORE", "Received WM_DELETE_WINDOW");
                    keep_running = false;
                }
                break;
            }
        }
    }

    vyShutdownGFX();
    XDestroyWindow(dpy, window);
    XCloseDisplay(dpy);
    vyShutdownAIO();
    vyShutdownFileTab();
    vyShutdownBufferManager();

    return 0;
}

#endif