#include "win32.h"

#include "args.h"
#include "core.h"
#include "main.h"
#include "window_manager.h"

#include <signal.h>

// 0x51E428
DirectDrawCreateProc* gDirectDrawCreateProc = NULL;

// 0x51E42C
DirectInputCreateAProc* gDirectInputCreateAProc = NULL;

// 0x51E430
DirectSoundCreateProc* gDirectSoundCreateProc = NULL;

// 0x51E434
HWND gProgramWindow = NULL;

// 0x51E438
HINSTANCE gInstance = NULL;

// 0x51E43C
LPSTR gCmdLine = NULL;

// 0x51E440
int gCmdShow = 0;

// 0x51E444
bool gProgramIsActive = false;

// GNW95MUTEX
HANDLE _GNW95_mutex = NULL;

// 0x51E44C
HMODULE gDDrawDLL = NULL;

// 0x51E450
HMODULE gDInputDLL = NULL;

// 0x51E454
HMODULE gDSoundDLL = NULL;

// 0x4DE700
int WINAPI WinMain(_In_ HINSTANCE hInst, _In_opt_ HINSTANCE hPrevInst, _In_ LPSTR lpCmdLine, _In_ int nCmdShow)
{
    CommandLineArguments args;

    _GNW95_mutex = CreateMutexA(0, TRUE, "GNW95MUTEX");
    if (GetLastError() == ERROR_SUCCESS) {
        ShowCursor(0);
        if (_InitClass(hInst)) {
            if (_InitInstance()) {
                if (_LoadDirectX()) {
                    gInstance = hInst;
                    gCmdLine = lpCmdLine;
                    gCmdShow = nCmdShow;
                    argsInit(&args);
                    if (argsParse(&args, lpCmdLine)) {
                        signal(1, _SignalHandler);
                        signal(3, _SignalHandler);
                        signal(5, _SignalHandler);
                        gProgramIsActive = true;
                        falloutMain(args.argc, args.argv);
                        argsFree(&args);
                        return 1;
                    }
                }
            }
        }
        CloseHandle(_GNW95_mutex);
    }
    return 0;
}

// 0x4DE7F4
ATOM _InitClass(HINSTANCE hInstance)
{
    WNDCLASSA wc;
    wc.style = 3;
    wc.lpfnWndProc = _WindowProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = NULL;
    wc.hCursor = NULL;
    wc.hbrBackground = NULL;
    wc.lpszMenuName = NULL;
    wc.lpszClassName = "GNW95 Class";

    return RegisterClassA(&wc);
}

// 0x4DE864
bool _InitInstance()
{
    OSVERSIONINFOA osvi;
    bool result;

    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOA);

#pragma warning(suppress : 4996 28159)
    if (!GetVersionExA(&osvi)) {
        return true;
    }

    result = true;

    if (osvi.dwPlatformId == 0 || osvi.dwPlatformId == 2 && osvi.dwMajorVersion < 4) {
        result = false;
    }

    if (!result) {
        MessageBoxA(NULL, "This program requires Windows 95 or Windows NT version 4.0 or greater.", "Wrong Windows Version", MB_ICONSTOP);
    }

    return result;
}

// 0x4DE8D0
bool _LoadDirectX()
{
    gDDrawDLL = LoadLibraryA("DDRAW.DLL");
    if (gDDrawDLL == NULL) {
        goto err;
    }

    gDirectDrawCreateProc = (DirectDrawCreateProc*)GetProcAddress(gDDrawDLL, "DirectDrawCreate");
    if (gDirectDrawCreateProc == NULL) {
        goto err;
    }

    gDInputDLL = LoadLibraryA("DINPUT.DLL");
    if (gDInputDLL == NULL) {
        goto err;
    }

    gDirectInputCreateAProc = (DirectInputCreateAProc*)GetProcAddress(gDInputDLL, "DirectInputCreateA");
    if (gDirectInputCreateAProc == NULL) {
        goto err;
    }

    gDSoundDLL = LoadLibraryA("DSOUND.DLL");
    if (gDSoundDLL == NULL) {
        goto err;
    }

    gDirectSoundCreateProc = (DirectSoundCreateProc*)GetProcAddress(gDSoundDLL, "DirectSoundCreate");
    if (gDirectSoundCreateProc == NULL) {
        goto err;
    }

    atexit(_UnloadDirectX);

    return true;

err:
    _UnloadDirectX();

    MessageBoxA(NULL, "This program requires Windows 95 with DirectX 3.0a or later or Windows NT version 4.0 with Service Pack 3 or greater.", "Could not load DirectX", MB_ICONSTOP);

    return false;
}

// 0x4DE988
void _UnloadDirectX(void)
{
    if (gDSoundDLL != NULL) {
        FreeLibrary(gDSoundDLL);
        gDSoundDLL = NULL;
        gDirectDrawCreateProc = NULL;
    }

    if (gDDrawDLL != NULL) {
        FreeLibrary(gDDrawDLL);
        gDDrawDLL = NULL;
        gDirectSoundCreateProc = NULL;
    }

    if (gDInputDLL != NULL) {
        FreeLibrary(gDInputDLL);
        gDInputDLL = NULL;
        gDirectInputCreateAProc = NULL;
    }
}

// 0x4DE9F4
void _SignalHandler(int sig)
{
    // TODO: Incomplete.
}

// 0x4DE9FC
LRESULT CALLBACK _WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg) {
    case WM_DESTROY:
        exit(EXIT_SUCCESS);
    case WM_PAINT:
        if (1) {
            RECT updateRect;
            if (GetUpdateRect(hWnd, &updateRect, FALSE)) {
                Rect rect;
                rect.left = updateRect.left;
                rect.top = updateRect.top;
                rect.right = updateRect.right - 1;
                rect.bottom = updateRect.bottom - 1;
                windowRefreshAll(&rect);
            }
        }
        break;
    case WM_ERASEBKGND:
        return 1;
    case WM_SETCURSOR:
        if ((HWND)wParam == gProgramWindow) {
            SetCursor(NULL);
            return 1;
        }
        break;
    case WM_SYSCOMMAND:
        switch (wParam & 0xFFF0) {
        case SC_SCREENSAVE:
        case SC_MONITORPOWER:
            return 0;
        }
        break;
    case WM_ACTIVATEAPP:
        gProgramIsActive = wParam;
        if (wParam) {
            _GNW95_hook_input(1);
            windowRefreshAll(&_scr_size);
        } else {
            _GNW95_hook_input(0);
        }

        return 0;
    }

    return DefWindowProc(hWnd, uMsg, wParam, lParam);
}