#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include "geometry.h"
#include "stream.h"        /* vgpu_publish_geometry */

/* GetDpiForMonitor lives in Shcore.dll (per-monitor DPI awareness API). Loaded dynamically so
 * the binary does not hard-depend on it; absence degrades dpi to "unknown" (0). */
typedef HRESULT (WINAPI *GetDpiForMonitor_t)(HMONITOR, int /*MDT_*/, UINT*, UINT*);
#define VGPU_MDT_EFFECTIVE_DPI 0

static UINT monitor_dpi(HMONITOR mon) {
    static GetDpiForMonitor_t fn = NULL;
    static int tried = 0;
    if (!tried) {
        HMODULE lib = LoadLibraryA("Shcore.dll");
        if (lib) fn = (GetDpiForMonitor_t)(void*)GetProcAddress(lib, "GetDpiForMonitor");
        tried = 1;
    }
    if (!fn || !mon) return 0u;
    UINT dx = 0, dy = 0;
    if (fn(mon, VGPU_MDT_EFFECTIVE_DPI, &dx, &dy) != S_OK || dx == 0u)
        return 0u;
    return dx;
}

static uint32_t monitor_refresh_mhz(HMONITOR mon) {
    MONITORINFOEXW mi; mi.cbSize = sizeof mi;
    if (!mon || !GetMonitorInfoW(mon, (MONITORINFO*)&mi))
        return 0u;
    DEVMODEW dm; ZeroMemory(&dm, sizeof dm); dm.dmSize = sizeof dm;
    if (!EnumDisplaySettingsW(mi.szDevice, ENUM_CURRENT_SETTINGS, &dm))
        return 0u;
    if (dm.dmDisplayFrequency <= 1u)   /* 0/1 = hardware default, not a real rate */
        return 0u;
    return (uint32_t)dm.dmDisplayFrequency * 1000u;   /* whole Hz -> milli-Hz */
}

void geometry_sample_and_publish(vgpu_ctx* ctx, int32_t cap_x, int32_t cap_y) {
    int32_t virt_x = (int32_t)GetSystemMetrics(SM_XVIRTUALSCREEN);
    int32_t virt_y = (int32_t)GetSystemMetrics(SM_YVIRTUALSCREEN);
    uint32_t virt_w = (uint32_t)GetSystemMetrics(SM_CXVIRTUALSCREEN);
    uint32_t virt_h = (uint32_t)GetSystemMetrics(SM_CYVIRTUALSCREEN);

    POINT origin = { cap_x, cap_y };
    HMONITOR mon = MonitorFromPoint(origin, MONITOR_DEFAULTTOPRIMARY);

    uint32_t dpi     = monitor_dpi(mon);
    uint32_t refresh = monitor_refresh_mhz(mon);

    vgpu_publish_geometry(&ctx->view, virt_x, virt_y, virt_w, virt_h,
                          cap_x, cap_y, dpi, refresh);
}