#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 <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_base_speed   = 20.0f;
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::mutex        g_vision_mutex;
static int               g_tick       = 0;
static int               g_frame_cnt  = 0;
static int               g_bad_frame  = 0;
static int               g_empty_cnt  = 0;
static FrameBuffer*      g_fb_ptr     = nullptr;

// =========================================================
// 5ms 回调
// =========================================================

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;
}

static void sched_10ms(float dt)
{
    // 1. 视觉处理
    cv::Mat bgr = camera_capture();
    if (!bgr.empty())
    {
        std::lock_guard<std::mutex> lock(g_vision_mutex);
        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;

        // 十字路口锁定直行
        if (element_is_cross())
            info.deviation = 0.0f;

        g_vision_yaw = info.deviation;
        g_base_speed = info.base_speed;
        info.line_valid = (sr.lines.left_valid + sr.lines.right_valid) >= 1;

        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 — 验证屏幕在刷新
            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);

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

        // 截帧到文件
        if (read_config_flag(CFG_SAVE_IMG, false))
        {
            static int save_cnt = 0;
            char fname[64];
            snprintf(fname, sizeof(fname), "./capture_%04d.jpg", save_cnt++);
            cv::imwrite(fname, bgr);
            printf("[SAVE] %s (%dx%d)\n", fname, bgr.cols, bgr.rows);
        }

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

    // 2. 舵机转向
    servo_set_angle(g_vision_yaw);

    // 3. 差速辅助
    float steer = g_vision_yaw;
    float curve_factor = (std::abs(g_vision_yaw) < 0.1f) ? 1.0f : 0.8f;
    float base_spd = g_user_speed * curve_factor;
    float diff = steer * 0.15f * g_user_speed;
    float pwm_l = base_spd + diff;
    float pwm_r = base_spd - diff;

    motor_set_pwm(MOTOR_LEFT,  pwm_l);
    motor_set_pwm(MOTOR_RIGHT, pwm_r);
}

static void sched_1s()
{
    g_print_flag.store(1);
    printf("[FPS] 视觉: %d  丢线: %d  空帧: %d\n",
           g_frame_cnt, g_bad_frame, g_empty_cnt);
    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);
    }
}

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);

            if (g_tick % 2 == 0) sched_10ms(dt);

            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();

    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;  // 5ms
    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);
    printf("[SCHED] 调度器启动\n");
}

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

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