// user32.c - Win32 user interface stubs (no window manager yet)
#include <stdint.h>
#include <stddef.h>

// ---------------------------------------------------------------------------
// Syscall stubs (from syscall.dll)
// ---------------------------------------------------------------------------
extern void SysScreenBlit(int x, int y, int w, int h, const uint32_t* pixels);
extern void SysYield(void);
extern void SysDebugPrint(const char* str);
extern uint32_t SysKbPoll(void);

// ---------------------------------------------------------------------------
// Types
// ---------------------------------------------------------------------------
typedef void* HWND;

#define IDOK     1
#define IDCANCEL 2

// ---------------------------------------------------------------------------
// Keyboard
// ---------------------------------------------------------------------------

// GetAsyncKeyState: returns non-zero if a key is available in the input
// buffer.  We have no per-key state, so the vKey argument is ignored and
// the high bit (key-down) is set whenever SysKbPoll reports data waiting.
__declspec(dllexport) short GetAsyncKeyState(int vKey) {
    (void)vKey;
    // High bit (0x8000 / INT16_MIN) = key is down.
    // Low bit = key pressed since last call; we have no per-key history to
    // track, so it is left clear.
    return SysKbPoll() ? (short)(-32768) : 0;
}

// ---------------------------------------------------------------------------
// Screen output
// ---------------------------------------------------------------------------

// BitBlt is the only graphical primitive available at this stage.
__declspec(dllexport) void BitBlt(int x, int y, int w, int h, const uint32_t* pixels) {
    SysScreenBlit(x, y, w, h, pixels);
}

// ---------------------------------------------------------------------------
// Message loop (stubs - always return 0 / no messages)
// ---------------------------------------------------------------------------
__declspec(dllexport) int GetMessage(void* msg, HWND hwnd,
                                      unsigned int min, unsigned int max) {
    (void)msg; (void)hwnd; (void)min; (void)max;
    SysYield();
    return 0;
}

__declspec(dllexport) int DispatchMessage(const void* msg) { (void)msg; return 0; }

// ---------------------------------------------------------------------------
// Window queries (stubs - no WM exists yet, all return NULL / 0)
// ---------------------------------------------------------------------------
__declspec(dllexport) HWND GetDesktopWindow(void) { return (HWND)0; }
__declspec(dllexport) HWND GetActiveWindow(void)  { return (HWND)0; }
__declspec(dllexport) HWND GetTopWindow(HWND hwnd){ (void)hwnd; return (HWND)0; }

__declspec(dllexport) HWND GetWindow(HWND hwnd, unsigned int cmd) {
    (void)hwnd; (void)cmd; return (HWND)0;
}

__declspec(dllexport) long GetWindowLongA(HWND hwnd, int index) {
    (void)hwnd; (void)index; return 0;
}

__declspec(dllexport) intptr_t GetWindowLongPtrA(HWND hwnd, int index) {
    (void)hwnd; (void)index; return 0;
}

__declspec(dllexport) unsigned long GetWindowThreadProcessId(HWND hwnd, unsigned long* pid) {
    (void)hwnd;
    if (pid) *pid = 1;
    return 1; // Thread ID
}

// ---------------------------------------------------------------------------
// Dialogs
// ---------------------------------------------------------------------------
__declspec(dllexport) int MessageBoxA(HWND hwnd, const char* text,
                                       const char* caption, unsigned int type) {
    (void)hwnd; (void)text; (void)caption; (void)type;
    // No UI available, console
    SysDebugPrint(text);
    return IDOK;
}