/*
 * gd13_demo — 斑马线检测演示 (调用 zebra_detect.h)
 */
#include <opencv2/opencv.hpp>
#include <iostream>
#include <cstring>
#include <csignal>
#include <atomic>

#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <linux/fb.h>

#include "zebra_detect.h"

using namespace cv;
using namespace std;

static atomic<bool> g_running{true};
static void signal_handler(int) { g_running.store(false); }

static uint16_t rgb565(uint8_t r, uint8_t g, uint8_t b)
{
    return ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3);
}

static void display_on_fb(const Mat &bgr, uint16_t *fb_buf, int scr_w, int scr_h)
{
    Mat display;
    resize(bgr, display, Size(scr_w, scr_h));
    for (int y = 0; y < scr_h; ++y)
        for (int x = 0; x < scr_w; ++x)
        {
            Vec3b px = display.at<Vec3b>(y, x);
            fb_buf[y * scr_w + x] = rgb565(px[2], px[1], px[0]);
        }
}

int main(int argc, char *argv[])
{
    bool no_display = false;
    for (int i = 1; i < argc; ++i)
        if (strcmp(argv[i], "--no-display") == 0) no_display = true;

    signal(SIGINT,  signal_handler);
    signal(SIGTERM, signal_handler);

    VideoCapture cap(0);
    cap.open(0, CAP_V4L2);
    if (!cap.isOpened()) cap.open(0);
    if (!cap.isOpened()) { cerr << "摄像头打开失败" << endl; return 1; }
    printf("摄像头已打开\n");

    int fb_fd = -1;
    uint16_t *fb_buf = nullptr;
    int scr_w = 0, scr_h = 0;
    if (!no_display)
    {
        fb_fd = open("/dev/fb0", O_RDWR);
        if (fb_fd >= 0)
        {
            struct fb_var_screeninfo vinfo;
            ioctl(fb_fd, FBIOGET_VSCREENINFO, &vinfo);
            scr_w = vinfo.xres; scr_h = vinfo.yres;
            size_t fb_size = vinfo.yres_virtual * vinfo.xres_virtual * 2;
            fb_buf = (uint16_t *)mmap(nullptr, fb_size, PROT_READ|PROT_WRITE,
                                      MAP_SHARED, fb_fd, 0);
        }
    }

    Mat frame, result;
    printf("开始斑马线检测...\n");

    while (g_running)
    {
        if (!cap.read(frame) || frame.empty()) { usleep(5000); continue; }

        ZebraResult zr = detect_zebra_crossing(frame);

        result = frame.clone();
        if (zr.detected)
        {
            putText(result, "ZEBRA! dist=" + to_string(zr.distance_px) + "px",
                    Point(10, 30), FONT_HERSHEY_SIMPLEX, 0.8,
                    Scalar(0, 0, 255), 2);
            printf("ZEBRA detected | distance=%d px\n", zr.distance_px);
        }
        else
        {
            printf("not detected | distance=%d\n", zr.distance_px);
        }

        if (!no_display && fb_buf)
            display_on_fb(result, fb_buf, scr_w, scr_h);
    }

    cap.release();
    if (fb_buf) munmap(fb_buf, scr_w * scr_h * 2);
    if (fb_fd >= 0) close(fb_fd);
    return 0;
}