/* Capture type=0 frames and dump spatial/temporal statistics to reveal
 * fixed-pattern noise (mura), bad pixels, and startup-vs-settled behavior.
 * Writes per-pixel mean over N frames + frame-level row/col profiles.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <windows.h>
#include <libusb.h>

#define W 160
#define H 120
#define NPIX (W * H)

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;
}

/* return 1 on a valid type=0 frame */
static int read_frame(unsigned char *frame, unsigned *type) {
    unsigned char hdr[64];
    static unsigned prev = 0xffffffff;
    int xfer = 0;
    if (libusb_bulk_transfer(g_h, 0x81, hdr, sizeof(hdr), &xfer, 200) && xfer < 28) return 0;
    if (xfer < 28) return 0;
    unsigned m = (unsigned)hdr[0] | ((unsigned)hdr[1] << 8) |
                 ((unsigned)hdr[2] << 16) | ((unsigned)hdr[3] << 24);
    if (m != 0x1bb1b11b) return 0;
    unsigned c = (unsigned)hdr[4] | ((unsigned)hdr[5] << 8) |
                 ((unsigned)hdr[6] << 16) | ((unsigned)hdr[7] << 24);
    if (c == prev) return 0;
    prev = c;
    if (libusb_bulk_transfer(g_h, 0x81, frame, 40000, &xfer, 200) || xfer < 38400) return 0;
    *type = (unsigned)hdr[12];
    return 1;
}

int main(int argc, char **argv) {
    int nframes = argc > 1 ? atoi(argv[1]) : 200;
    const char *out = argc > 2 ? argv[2] : "frame_stats.txt";
    if (libusb_init(&g_ctx)) 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"); return 1; }
    libusb_set_configuration(g_h, 2);
    libusb_set_configuration(g_h, 1);
    if (libusb_claim_interface(g_h, 0)) return 1;
    sendcmd(0x6bb6b66b, 0, 4);
    sendcmd(0x6bb6b66c, 0, 4);
    sendcmd(0x6bb6b66f, 0, 4);
    sendcmd(0x6bb6b672, 0, 8);
    Sleep(100);
    sendcmd(0x6bb6b672, 0, 8);
    Sleep(300);
    sendcmd(0x6bb6b673, 0, 4);
    Sleep(700);

    unsigned char frame[40000];
    unsigned type = 1;
    /* drain + FFC(1) after ~10 complete frames switches the stream to
     * type=0 (verified cadence) */
    int drained = 0;
    for (int i = 0; i < 120; ++i) {
        if (!read_frame(frame, &type)) { Sleep(10); continue; }
        drained++;
        if (drained == 10) {
            sendcmd(0x6bb6b672, 1, 8);
            Sleep(200);
        }
        if (type == 0) break;
    }
    if (type != 0) {
        printf("failed to reach type=0 stream\n");
        return 3;
    }

    double mean[NPIX];
    memset(mean, 0, sizeof(mean));
    double row[H], col[W];
    memset(row, 0, sizeof(row));
    memset(col, 0, sizeof(col));
    unsigned short last[NPIX];
    double delta_sum = 0;
    int delta_n = 0;
    int got = 0, type0 = 0, type1 = 0;

    FILE *f = fopen(out, "w");
    if (!f) return 2;

    for (int n = 0; n < nframes; ++n) {
        if (!read_frame(frame, &type)) { Sleep(10); n--; continue; }
        got++;
        if (type) { type1++; continue; }
        type0++;
        /* frame stats */
        long fr_sum = 0;
        unsigned fr_min = 65535, fr_max = 0;
        for (int i = 0; i < NPIX; ++i) {
            unsigned v = (unsigned)frame[i * 2 + 28] | ((unsigned)frame[i * 2 + 29] << 8);
            mean[i] += v;
            fr_sum += v;
            if (v < fr_min) fr_min = v;
            if (v > fr_max) fr_max = v;
            if (got > 1) {
                int d = (int)v - (int)last[i];
                if (d < 0) d = -d;
                delta_sum += d;
                delta_n++;
            }
            last[i] = (unsigned short)v;
        }
        fprintf(f, "FRAME %d type0 mean=%.0f min=%u max=%u meandelta=%.1f\n",
                n, (double)fr_sum / NPIX, fr_min, fr_max,
                delta_n ? delta_sum / delta_n : 0);
        delta_sum = 0;
        delta_n = 0;
    }
    for (int i = 0; i < NPIX; ++i) mean[i] /= type0 ? type0 : 1;
    for (int y = 0; y < H; ++y) {
        double s = 0;
        for (int x = 0; x < W; ++x) s += mean[y * W + x];
        row[y] = s / W;
    }
    for (int x = 0; x < W; ++x) {
        double s = 0;
        for (int y = 0; y < H; ++y) s += mean[y * W + x];
        col[x] = s / H;
    }
    /* per-pixel deviation from row+col model (mura detection) */
    fprintf(f, "\nROW_PROFILE:\n");
    for (int y = 0; y < H; ++y) fprintf(f, "%d %.1f\n", y, row[y]);
    fprintf(f, "\nCOL_PROFILE:\n");
    for (int x = 0; x < W; ++x) fprintf(f, "%d %.1f\n", x, col[x]);
    fprintf(f, "\nPIXEL_DEVIATION (mean - row - col + global):\n");
    double gm = 0;
    for (int i = 0; i < NPIX; ++i) gm += mean[i];
    gm /= NPIX;
    for (int y = 0; y < H; ++y) {
        for (int x = 0; x < W; ++x) {
            double dev = mean[y * W + x] - row[y] - col[x] + gm;
            fprintf(f, "%d %d %.1f\n", x, y, dev);
        }
    }
    fclose(f);
    printf("captured %d frames (type0=%d type1=%d) -> %s\n", got, type0, type1, out);

    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 0;
}