// Native surface multithreaded present test.
// Multiple user threads present one process-private surface to catch mapping and scratch-buffer races.

#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include <ntlite/syscall.h>

#define SURFACE_W 96u
#define SURFACE_H 64u
#define THREAD_COUNT 4u
#define ITERATIONS 32u

typedef struct WORKER_STATE {
    uint32_t Index;
    uint32_t Surface;
    uint8_t* Base;
    uint32_t Pitch;
    uint32_t Status;
    uint32_t IterationsDone;
} WORKER_STATE;

static WORKER_STATE gWorkers[THREAD_COUNT];

static void print(const char* s) {
    SYS_WRITE_CONSOLE_REQUEST req = { SysSvFromCstr(s) };
    SysWriteConsole(&req);
}

static void print_u64(uint64_t v) {
    char buf[32];
    int i = 0;
    if (v == 0) { print("0"); return; }
    while (v && i < (int)sizeof(buf)) {
        buf[i++] = (char)('0' + (v % 10));
        v /= 10;
    }
    while (i--) {
        char c = buf[i];
        SYS_WRITE_CONSOLE_REQUEST req = { SysSvFromParts(&c, 1) };
        SysWriteConsole(&req);
    }
}

static void exit_now(int code) {
    while (true) SysExitProcess(code);
}

static void fail(const char* msg) {
    print("surface_multithread_present: ");
    print(msg);
    print("\n");
    exit_now(1);
}

static void fail_status(const char* what, uint32_t status) {
    print("surface_multithread_present: ");
    print(what);
    print(" failed status=");
    print_u64(status);
    print("\n");
    exit_now(1);
}

static void worker_main(uintptr_t arg) {
    WORKER_STATE* st = (WORKER_STATE*)arg;
    if (!st) SysExitThread(1);
    uint32_t bandHeight = SURFACE_H / THREAD_COUNT;
    uint32_t y0 = st->Index * bandHeight;
    uint32_t h = bandHeight;
    if (st->Index == THREAD_COUNT - 1)
        h = SURFACE_H - y0;

    for (uint32_t iter = 0; iter < ITERATIONS; ++iter) {
        for (uint32_t y = 0; y < h; ++y) {
            uint32_t* row = (uint32_t*)(st->Base + (size_t)(y0 + y) * st->Pitch);
            for (uint32_t x = 0; x < SURFACE_W; ++x)
                row[x] = 0x00010101u * ((st->Index + 1u) * 32u + (iter & 31u));
        }

        DISPLAY_RECT rect = { 0, (int32_t)y0, (int32_t)SURFACE_W, (int32_t)h };
        uint32_t s = SysPresentSurface(st->Surface, &rect, 1);
        if (s != NTLSTATUS_SUCCESS) {
            st->Status = s;
            SysExitThread(1);
        }
        st->IterationsDone++;
        SysYield();
    }

    st->Status = NTLSTATUS_SUCCESS;
    SysExitThread(0);
}

int main(void) {
    print("surface_multithread_present: start\n");

    uint32_t surface = 0;
    SYS_CREATE_SURFACE_REQUEST req;
    memset(&req, 0, sizeof(req));
    req.Size = sizeof(req);
    req.Width = SURFACE_W;
    req.Height = SURFACE_H;
    req.Format = SYS_SURFACE_FORMAT_XRGB8888;
    req.Flags = SYS_SURFACE_FLAG_NONE;
    req.HandleOut = &surface;
    uint32_t s = SysCreateSurface(&req);
    if (s != NTLSTATUS_SUCCESS) fail_status("create surface", s);

    void* base = 0;
    uint32_t pitch = 0;
    s = SysMapSurface(surface, &base, &pitch);
    if (s != NTLSTATUS_SUCCESS) fail_status("map surface", s);
    if (!base || pitch < SURFACE_W * sizeof(uint32_t)) fail("invalid mapping");

    uint32_t handles[THREAD_COUNT];
    uint32_t tids[THREAD_COUNT];
    memset(handles, 0, sizeof(handles));
    memset(tids, 0, sizeof(tids));
    memset(gWorkers, 0, sizeof(gWorkers));

    for (uint32_t i = 0; i < THREAD_COUNT; ++i) {
        gWorkers[i].Index = i;
        gWorkers[i].Surface = surface;
        gWorkers[i].Base = (uint8_t*)base;
        gWorkers[i].Pitch = pitch;
        gWorkers[i].Status = NTLSTATUS_PENDING;
        SYS_CREATE_THREAD_REQUEST req = {
            (uintptr_t)worker_main,
            (uintptr_t)&gWorkers[i],
            1,
            0,
            &handles[i],
            &tids[i]
        };
        s = SysCreateThread(&req);
        if (s != NTLSTATUS_SUCCESS) fail_status("create thread", s);
    }

    for (uint32_t i = 0; i < THREAD_COUNT; ++i) {
        s = SysWait(handles[i], SYS_WAIT_FLAG_NONE);
        if (s != NTLSTATUS_SUCCESS) fail_status("wait thread", s);
        SysCloseHandle(handles[i]);
    }

    for (uint32_t i = 0; i < THREAD_COUNT; ++i) {
        if (gWorkers[i].Status != NTLSTATUS_SUCCESS) {
            print("surface_multithread_present: worker ");
            print_u64(i);
            print(" status=");
            print_u64(gWorkers[i].Status);
            print(" iterations=");
            print_u64(gWorkers[i].IterationsDone);
            print("\n");
            exit_now(1);
        }
        if (gWorkers[i].IterationsDone != ITERATIONS) fail("worker iteration count mismatch");
    }

    SysCloseHandle(surface);
    print("surface_multithread_present: PASS\n");
    exit_now(0);
    return 0;
}