#include "scheduler.hpp"
#include "types.hpp"
#include "hal/gpio.hpp"
#include "hal/framebuffer.hpp"
#include "hal/encoder.hpp"
#include "control/pid.hpp"
#include "control/imu.hpp"
#include "control/motor.hpp"
#include "control/servo.hpp"
#include "vision/camera.hpp"
#include "vision/preprocess.hpp"
#include "vision/search.hpp"
#include "vision/element.hpp"
#include "strategy/deviation.hpp"
#include "strategy/speed.hpp"
#include "debug/draw.hpp"
#include "debug/config.hpp"
#include "model/model.hpp"

#include <atomic>
#include <chrono>
#include <thread>
#include <mutex>
#include <cstdio>
#include <sys/timerfd.h>
#include <sys/epoll.h>
#include <unistd.h>

// =========================================================
// 全局控制对象
// =========================================================
static YawTracker   g_imu;
static Encoder*     g_enc_l   = nullptr;
static Encoder*     g_enc_r   = nullptr;
static PID          g_pid_speed_l(0.6f, 0.2f, 0.0f, 0.0f, PID_INCREMENTAL, 100.0f, 50.0f);
static PID          g_pid_speed_r(0.6f, 0.2f, 0.0f, 0.0f, PID_INCREMENTAL, 100.0f, 50.0f);

static float        g_vision_yaw   = 0.0f;
static float        g_speed_l      = 0.0f;
static float        g_speed_r      = 0.0f;
static float        g_user_speed   = 11.0f;

static std::atomic<bool> g_sched_running{false};
std::atomic<int>         g_print_flag{0};
static int               g_timer_fd   = -1;
static int               g_epoll_fd   = -1;
static std::thread       g_sched_thread;
static std::thread       g_model_thread;
static FrameBuffer*      g_fb_ptr     = nullptr;

static int               g_tick       = 0;
static int               g_frame_cnt  = 0;
static int               g_bad_frame  = 0;
static int               g_empty_cnt  = 0;

// =========================================================
// 帧率控制
// =========================================================
static int      g_vision_fps  = 60;
static int      g_model_fps   = 20;
static float    g_vision_acc  = 0;     // 累计 ms

// =========================================================
// 模型异步 — 双缓冲检测结果
// =========================================================
static constexpr int MAX_DET = 16;
struct DetResult {
    int   count = 0;
    DetectBox boxes[MAX_DET];
    int   frame_id = 0;
};
static DetResult  g_det[2];
static std::atomic<int> g_det_idx{0};    // 当前写入索引
static std::atomic<bool> g_det_new{false};
static std::atomic<int> g_model_frame{0};

static int model_interval_ms() { return g_model_fps > 0 ? 1000 / g_model_fps : 50; }
static int vision_interval_ms() { return g_vision_fps > 0 ? 1000 / g_vision_fps : 17; }

// =========================================================
// 5ms 回调 — 传感器
// =========================================================
static void sched_5ms(float dt)
{
    if (g_enc_l) g_enc_l->update();
    if (g_enc_r) g_enc_r->update();
    g_imu.update(dt);
    g_speed_l = g_enc_l ? g_enc_l->getRPS() : 0;
    g_speed_r = g_enc_r ? g_enc_r->getRPS() : 0;
}

// =========================================================
// 视觉回调 — 按 vision_fps 节流
// =========================================================
static void sched_vision()
{
    cv::Mat bgr = camera_capture();
    if (!bgr.empty())
    {
        preprocess_run(bgr);

        SearchResult sr;
        search_run(sr);

        TrackInfo info;
        element_recognize(sr, info);

        fit_midline(sr.lines);
        info.deviation = calc_deviation(sr.lines);
        info.base_speed = calc_base_speed(info);
        info.curvature  = info.deviation;

        if (element_is_cross())
            info.deviation = 0.0f;

        g_vision_yaw = info.deviation;
        bool line_ok = (sr.lines.left_valid || sr.lines.right_valid);
        if (!line_ok) ++g_bad_frame;

        // LCD 预览 — 原始摄像头画面 + 车道线
        if (read_config_flag(CFG_SHOW_IMG, false) && g_fb_ptr)
        {
            cv::Mat rgb;
            cv::cvtColor(bgr, rgb, cv::COLOR_BGR2RGB);
            cv::Mat disp;
            cv::resize(rgb, disp, cv::Size(g_fb_ptr->width(), g_fb_ptr->height()));

            int fw = g_fb_ptr->width();
            int fh = g_fb_ptr->height();
            float sx = (float)fw / IMAGE_WIDTH;
            float sy = (float)fh / IMAGE_HEIGHT;

            for (int y = 0; y < IPM_ROW_COUNT; ++y)
            {
                int dy = (int)(y * sy);
                if (sr.lines.left[y] > 0)
                    cv::line(disp, cv::Point((int)(sr.lines.left[y] * sx), dy),
                             cv::Point((int)(sr.lines.left[y] * sx), dy), cv::Scalar(255,0,0), 5);
                if (sr.lines.right[y] > 0)
                    cv::line(disp, cv::Point((int)(sr.lines.right[y] * sx), dy),
                             cv::Point((int)(sr.lines.right[y] * sx), dy), cv::Scalar(0,255,0), 5);
                if (sr.lines.mid[y] > 0)
                    cv::line(disp, cv::Point((int)(sr.lines.mid[y] * sx), dy),
                             cv::Point((int)(sr.lines.mid[y] * sx), dy), cv::Scalar(255,255,0), 5);
            }

            // 帧计数闪烁点
            static int blink = 0;
            blink = (blink + 1) % 20;
            cv::circle(disp, cv::Point(10, fh - 10), 5,
                       blink < 10 ? cv::Scalar(255,255,255) : cv::Scalar(0,0,0), -1);

            // 绘制模型检测框
            int di = g_det_idx.load();
            const DetResult& dr = g_det[di];
            for (int i = 0; i < dr.count; ++i)
            {
                int x1 = (int)((dr.boxes[i].cx - dr.boxes[i].w/2) * sx);
                int y1 = (int)((dr.boxes[i].cy - dr.boxes[i].h/2) * sy);
                int x2 = (int)((dr.boxes[i].cx + dr.boxes[i].w/2) * sx);
                int y2 = (int)((dr.boxes[i].cy + dr.boxes[i].h/2) * sy);
                cv::Scalar color = (dr.boxes[i].cls == 0) ? cv::Scalar(0,0,255) :
                                   (dr.boxes[i].cls == 1) ? cv::Scalar(0,255,255) :
                                                             cv::Scalar(255,0,255);
                cv::rectangle(disp, cv::Point(x1,y1), cv::Point(x2,y2), color, 2);
            }

            g_fb_ptr->write(disp.data, g_fb_ptr->width(), g_fb_ptr->height());
        }

        // 截帧
        if (read_config_flag(CFG_SAVE_IMG, false))
        {
            static int save_cnt = 0;
            char fn[64];
            snprintf(fn, sizeof(fn), "./capture_%04d.jpg", save_cnt++);
            cv::imwrite(fn, bgr);
        }

        ++g_frame_cnt;
    }
    else
    {
        ++g_empty_cnt;
    }
}

// =========================================================
// 持续控制 — 每 tick 都跑 (舵机 + 差速)
// =========================================================
static void sched_control()
{
    servo_set_angle(g_vision_yaw);

    float steer = g_vision_yaw;
    float curve_factor = (std::abs(steer) < 0.1f) ? 1.0f : 0.8f;
    float base_spd = g_user_speed * curve_factor;
    float diff = steer * 0.15f * g_user_speed;
    motor_set_pwm(MOTOR_LEFT,  base_spd + diff);
    motor_set_pwm(MOTOR_RIGHT, base_spd - diff);
}

// =========================================================
// 1 秒回调 — 热读参数 + 统计
// =========================================================
static void sched_1s()
{
    g_print_flag.store(1);

    // 帧率配置
    double vfps = read_config_double(CFG_VISION_FPS, 60.0);
    double mfps = read_config_double(CFG_MODEL_FPS,  20.0);
    g_vision_fps = std::max(1, std::min(100, (int)vfps));
    g_model_fps  = std::max(1, std::min(50,  (int)mfps));

    printf("[FPS] vision:%d model:%d  vision_frames:%d  bad_line:%d  empty:%d  det:%d\n",
           g_vision_fps, g_model_fps, g_frame_cnt, g_bad_frame, g_empty_cnt, g_model_frame.exchange(0));
    g_frame_cnt = 0; g_bad_frame = 0; g_empty_cnt = 0;

    double speed_val = read_config_double(CFG_SPEED, 11.0);
    g_user_speed = static_cast<float>(speed_val);

    if (read_config_flag(CFG_START, false))
    {
        double kp = read_config_double(CFG_SERVO_KP, 3.5);
        double ki = read_config_double(CFG_SERVO_KI, 0.3);
        double kd = read_config_double(CFG_SERVO_KD, 0.2);
        servo_set_pid(kp, ki, kd);

        double deadband = read_config_double(CFG_DEADBAND, 0.03);
        double gain     = read_config_double(CFG_STEER_GAIN, 1.5);
        servo_set_deadband(static_cast<float>(deadband));
        servo_set_steer_gain(static_cast<float>(gain));

        double mkp = read_config_double(CFG_MOTOR_KP, 0.6);
        double mki = read_config_double(CFG_MOTOR_KI, 0.2);
        double mkd = read_config_double(CFG_MOTOR_KD, 0.0);
        g_pid_speed_l.setPID(mkp, mki, mkd);
        g_pid_speed_r.setPID(mkp, mki, mkd);
    }
}

// =========================================================
// 模型异步线程
// =========================================================
static void model_thread_loop()
{
    printf("[MODEL] 线程启动, 目标 %d FPS\n", g_model_fps);

    while (g_sched_running.load())
    {
        int interval = model_interval_ms();
        std::this_thread::sleep_for(std::chrono::milliseconds(interval));

        if (!model_ready()) continue;

        cv::Mat bgr = camera_capture();
        if (bgr.empty()) continue;

        int wi = 1 - g_det_idx.load();  // 写到对侧缓冲区
        DetResult& dr = g_det[wi];

        dr.count = model_detect(bgr.data, bgr.cols, bgr.rows,
                                dr.boxes, MAX_DET, 0.7f);
        dr.frame_id++;
        g_det_idx.store(wi);
        g_det_new.store(true);
        g_model_frame.fetch_add(1);
    }
    printf("[MODEL] 线程退出\n");
}

// =========================================================
// 主调度循环
// =========================================================
static void scheduler_loop()
{
    epoll_event ev;
    while (g_sched_running.load())
    {
        int n = epoll_wait(g_epoll_fd, &ev, 1, 10);
        if (n <= 0) continue;

        uint64 expirations;
        read(g_timer_fd, &expirations, sizeof(expirations));

        for (uint64 i = 0; i < expirations; ++i)
        {
            float dt = 0.005f;

            sched_5ms(dt);

            // 视觉按 FPS 节流
            g_vision_acc += 5.0f;
            float vis_interval = (float)vision_interval_ms();
            if (g_vision_acc >= vis_interval)
            {
                sched_vision();
                g_vision_acc -= vis_interval;
            }

            // 持续控制 (每 tick)
            sched_control();

            if (g_tick % 200 == 0) sched_1s();

            ++g_tick;
        }
    }
}

// =========================================================
// 初始化
// =========================================================
bool scheduler_init(FrameBuffer* fb)
{
    g_fb_ptr = fb;

    motor_init();
    servo_init();
    servo_center();
    motor_enable(true);

    g_enc_l = new Encoder(ENCODER_LEFT_CHANNEL,  ENCODER_LEFT_DIR_GPIO,  1);
    g_enc_r = new Encoder(ENCODER_RIGHT_CHANNEL, ENCODER_RIGHT_DIR_GPIO, -1);

    g_imu.begin(IMU_DEVICE, IMU_BAUDRATE);

    preprocess_init();
    element_init();
    speed_strategy_reset();

    // 模型初始化
    if (model_init("./model/nanodet.bin"))
        printf("[SCHED] 模型已加载\n");
    else
        printf("[SCHED] 模型加载失败, 继续无模型运行\n");

    // timerfd 5ms
    g_timer_fd = timerfd_create(CLOCK_MONOTONIC, 0);
    if (g_timer_fd < 0) { printf("[SCHED] timerfd create failed\n"); return false; }

    itimerspec its;
    its.it_interval.tv_sec  = 0;
    its.it_interval.tv_nsec = 5 * 1000 * 1000;
    its.it_value = its.it_interval;
    timerfd_settime(g_timer_fd, 0, &its, nullptr);

    g_epoll_fd = epoll_create1(0);
    epoll_event ev;
    ev.events = EPOLLIN;
    ev.data.fd = g_timer_fd;
    epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, g_timer_fd, &ev);

    printf("[SCHED] 调度器初始化完成 (5ms)\n");
    return true;
}

void scheduler_start()
{
    g_sched_running.store(true);
    g_sched_thread = std::thread(scheduler_loop);
    g_model_thread = std::thread(model_thread_loop);
    printf("[SCHED] 调度器启动 (vision=%dFPS model=%dFPS)\n", g_vision_fps, g_model_fps);
}

void scheduler_stop()
{
    g_sched_running.store(false);

    if (g_model_thread.joinable())
        g_model_thread.join();
    if (g_sched_thread.joinable())
        g_sched_thread.join();

    motor_stop_all();
    servo_center();

    if (g_enc_l) { delete g_enc_l; g_enc_l = nullptr; }
    if (g_enc_r) { delete g_enc_r; g_enc_r = nullptr; }

    model_deinit();
    close(g_timer_fd);
    close(g_epoll_fd);
    printf("[SCHED] 调度器停止\n");
}