/* MAG160C headless FFC cadence test - replicates the official demo FFC
 * timing from analysis/captures/libusb0_trace.txt:
 *   init: 66b 66c 66f -> FFC(0) -> START
 *   FFC(1) after ~10th complete frame  (switch stream to type=0)
 *   then every FFC_PERIOD frames: FFC(0), and FFC_GAP frames later FFC(1)
 * Target: type=0 stream keeps flowing for 1000+ frames without stalling.
 * Prints per-second progress; exits with 0 on success.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <windows.h>
#include <libusb.h>

#define FFC_PERIOD 400
#define FFC_GAP 9
#define WANT_FRAMES 1400

static libusb_context *g_ctx;
static libusb_device_handle *g_h;

static int sendcmd(unsigned magic, unsigned param, int len) {
    unsigned char cmd[8] = {0};
    cmd[0] = (unsigned char)(magic);
    cmd[1] = (unsigned char)(magic >> 8);
    cmd[2] = (unsigned char)(magic >> 16);
    cmd[3] = (unsigned char)(magic >> 24);
    if (len >= 8) {
        cmd[4] = (unsigned char)(param);
        cmd[5] = (unsigned char)(param >> 8);
        cmd[6] = (unsigned char)(param >> 16);
        cmd[7] = (unsigned char)(param >> 24);
    }
    int xfer = 0;
    if (libusb_bulk_transfer(g_h, 0x03, cmd, len, &xfer, 2000)) return -1;
    unsigned char resp[0x1000];
    if (libusb_bulk_transfer(g_h, 0x82, resp, sizeof(resp), &xfer, 2000)) return -1;
    return 0;
}

int main(void) {
    printf("MAG160C FFC cadence test (want %d frames)\n", WANT_FRAMES);
    if (libusb_init(&g_ctx)) { printf("libusb_init failed\n"); return 1; }
    libusb_device **list = NULL;
    ssize_t cnt = libusb_get_device_list(g_ctx, &list);
    for (ssize_t i = 0; i < cnt && !g_h; ++i) {
        struct libusb_device_descriptor d;
        libusb_get_device_descriptor(list[i], &d);
        if (d.idVendor == 0x833c) libusb_open(list[i], &g_h);
    }
    libusb_free_device_list(list, 1);
    if (!g_h) { printf("no device\n"); libusb_exit(g_ctx); return 1; }
    libusb_set_configuration(g_h, 2);
    libusb_set_configuration(g_h, 1);
    if (libusb_claim_interface(g_h, 0)) { printf("claim failed\n"); return 1; }

    if (sendcmd(0x6bb6b66b, 0, 4)) { printf("66b failed\n"); return 1; }
    if (sendcmd(0x6bb6b66c, 0, 4)) { printf("66c failed\n"); return 1; }
    if (sendcmd(0x6bb6b66f, 0, 4)) { printf("66f failed\n"); return 1; }
    if (sendcmd(0x6bb6b672, 0, 8)) { printf("FFC(0) pre failed\n"); return 1; }
    Sleep(100);
    if (sendcmd(0x6bb6b672, 0, 8)) { printf("FFC(0) pre2 failed\n"); return 1; }
    Sleep(300);
    if (sendcmd(0x6bb6b673, 0, 4)) { printf("START failed\n"); return 1; }
    Sleep(700);

    unsigned char frame[40000];
    unsigned prev = 0xffffffff;
    int nread = 0, n0 = 0, n1 = 0;
    int ffc_started = 0, ffc_cycle = 0, ffc_wait1 = 0;
    int stall_wakes = 0;
    DWORD t_start = GetTickCount();
    DWORD last_frame = t_start, last_wake = t_start;
    DWORD last_report = t_start;

    while (n0 < WANT_FRAMES) {
        unsigned char hdr[64];
        int xfer = 0;
        if (libusb_bulk_transfer(g_h, 0x81, hdr, sizeof(hdr), &xfer, 200) && xfer < 28) {
            DWORD now = GetTickCount();
            if (now - last_frame > 3000 && now - last_wake > 5000) {
                sendcmd(0x6bb6b672, 1, 8);
                last_wake = now;
                stall_wakes++;
                printf("  [stall watchdog] FFC(1) sent (%d)\n", stall_wakes);
            }
            continue;
        }
        if (xfer < 28) continue;
        unsigned m = (unsigned)hdr[0] | ((unsigned)hdr[1] << 8) |
                     ((unsigned)hdr[2] << 16) | ((unsigned)hdr[3] << 24);
        if (m != 0x1bb1b11b) continue;
        unsigned c = (unsigned)hdr[4] | ((unsigned)hdr[5] << 8) |
                     ((unsigned)hdr[6] << 16) | ((unsigned)hdr[7] << 24);
        if (c == prev) continue;
        prev = c;
        if (libusb_bulk_transfer(g_h, 0x81, frame, sizeof(frame), &xfer, 200) ||
            xfer < 38400) {
            continue;
        }
        unsigned type = (unsigned)hdr[12];
        nread++;
        last_frame = GetTickCount();
        if (type == 0) n0++; else n1++;

        if (!ffc_started && nread == 10) {
            sendcmd(0x6bb6b672, 1, 8);
            ffc_started = 1;
            ffc_cycle = 0;
            printf("  frame 10: FFC(1) sent -> type=0 mode\n");
            continue;
        }
        if (ffc_started) {
            ffc_cycle++;
            if (ffc_wait1 && ffc_cycle >= FFC_GAP) {
                sendcmd(0x6bb6b672, 1, 8);
                ffc_wait1 = 0;
                ffc_cycle = 0;
            } else if (!ffc_wait1 && ffc_cycle >= FFC_PERIOD) {
                sendcmd(0x6bb6b672, 0, 8);
                ffc_wait1 = 1;
                ffc_cycle = 0;
            }
        }
        DWORD now = GetTickCount();
        if (now - last_report >= 5000) {
            double secs = (now - t_start) / 1000.0;
            printf("  t=%6.1fs frames=%d (type0=%d type1=%d) fps=%.1f\n",
                   secs, nread, n0, n1, n0 / secs);
            last_report = now;
        }
    }
    DWORD t_end = GetTickCount();
    double secs = (t_end - t_start) / 1000.0;
    printf("\nDONE: %d frames in %.1fs (fps=%.1f) type0=%d type1=%d stall_wakes=%d\n",
           nread, secs, nread / secs, n0, n1, stall_wakes);
    int pass = (n0 >= 1000) ? 1 : 0;
    printf("%s\n", pass ? "PASS: type=0 stream >= 1000 frames" :
                        "FAIL: type=0 stream < 1000 frames");

    Sleep(300);
    libusb_clear_halt(g_h, 0x03);
    libusb_clear_halt(g_h, 0x82);
    sendcmd(0x6bb6b674, 0, 4);
    libusb_close(g_h);
    libusb_exit(g_ctx);
    return pass ? 0 : 2;
}