#pragma once
#include <stdbool.h>
#include <stdint.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/crc.h>

/* ═══════════════════════════════════════════════════════════════════
 *  帧常量
 * ═══════════════════════════════════════════════════════════════════ */

/* 双帧头比单字节魔数更容易在连续字节流里完成包起始判定 */
#define PROTO_SYNC0           0xAAU
#define PROTO_SYNC1           0x55U
#define PROTO_TYPE_COP        0x01U /* 上行: 压力中心 (CoP) 帧        */
#define PROTO_TYPE_ENCODER    0x02U /* 上行: 电机编码器帧（预留）      */
#define PROTO_TYPE_RESISTANCE 0x10U /* 下行: 阻力参数 (K, B, Tau)     */
#define PROTO_TYPE_SPOTTER    0x11U /* 下行: Spotter Mode 保护阈值    */
#define PROTO_TYPE_HEARTBEAT  0x20U /* 下行: 心跳包                   */
#define PROTO_TYPE_CAL_CMD    0x30U /* 下行: 标定命令                  */
#define PROTO_TYPE_CAL_RESP   0x31U /* 上行: 标定响应                  */

/* CoP flags 位定义 */
#define COP_FLAG_FORCE_VALID 0x01U /* 总力 > 阈值，CoP 坐标有意义    */

/* ═══════════════════════════════════════════════════════════════════
 *  帧结构定义
 * ═══════════════════════════════════════════════════════════════════ */

/* ─── 上行: CoP 帧 (11 bytes, 50 Hz) ───
 *  [AA 55 01 flags cop_x(2) cop_y(2) force(2) crc]
 */
struct cop_frame_t {
    uint8_t sync0;
    uint8_t sync1;
    uint8_t type;
    uint8_t flags;
    int16_t cop_x;
    int16_t cop_y;
    int16_t force;
    uint8_t crc;
} __attribute__((packed));

union cop_pkt_t {
    struct cop_frame_t frame;
    uint8_t bytes[sizeof(struct cop_frame_t)];
};

/* ─── 上行: 电机编码器帧 (13 bytes, 预留) ───
 *  [AA 55 02 flags cable_length(4) velocity(4) crc]
 */
struct encoder_frame_t {
    uint8_t sync0;
    uint8_t sync1;
    uint8_t type;
    uint8_t flags;
    float cable_length;
    float velocity;
    uint8_t crc;
} __attribute__((packed));

union encoder_pkt_t {
    struct encoder_frame_t frame;
    uint8_t bytes[sizeof(struct encoder_frame_t)];
};

/* ─── 下行: 阻力参数帧 (16 bytes) ───
 *  [AA 55 10 K(4) B(4) Tau(4) crc]
 */
struct resistance_frame_t {
    uint8_t sync0;
    uint8_t sync1;
    uint8_t type;
    float K;
    float B;
    float Tau;
    uint8_t crc;
} __attribute__((packed));

union resistance_pkt_t {
    struct resistance_frame_t frame;
    uint8_t bytes[sizeof(struct resistance_frame_t)];
};

/* ─── 下行: Spotter Mode 帧 (9 bytes) ───
 *  [AA 55 11 threshold(4) enable crc]
 */
struct spotter_frame_t {
    uint8_t sync0;
    uint8_t sync1;
    uint8_t type;
    float threshold;
    uint8_t enable;
    uint8_t crc;
} __attribute__((packed));

union spotter_pkt_t {
    struct spotter_frame_t frame;
    uint8_t bytes[sizeof(struct spotter_frame_t)];
};

/* ─── 下行: 心跳帧 (5 bytes, ~1 Hz) ───
 *  [AA 55 20 counter crc]
 */
struct heartbeat_frame_t {
    uint8_t sync0;
    uint8_t sync1;
    uint8_t type;
    uint8_t counter;
    uint8_t crc;
} __attribute__((packed));

union heartbeat_pkt_t {
    struct heartbeat_frame_t frame;
    uint8_t bytes[sizeof(struct heartbeat_frame_t)];
};

/* ═══════════════════════════════════════════════════════════════════
 *  标定子命令码 & 状态码
 * ═══════════════════════════════════════════════════════════════════ */

#define CAL_SUBCMD_START_L1    0x01U
#define CAL_SUBCMD_TARE_CH     0x02U
#define CAL_SUBCMD_GAIN_CH     0x03U
#define CAL_SUBCMD_COMMIT_L1   0x04U
#define CAL_SUBCMD_ABORT       0x05U
#define CAL_SUBCMD_START_L2    0x10U
#define CAL_SUBCMD_RECORD_GRID 0x11U
#define CAL_SUBCMD_COMMIT_L2   0x12U
#define CAL_SUBCMD_ERASE       0x20U
#define CAL_SUBCMD_QUERY       0x21U

#define CAL_STATUS_OK        0x00U
#define CAL_STATUS_ERR_STATE 0x01U
#define CAL_STATUS_ERR_NVS   0x02U
#define CAL_STATUS_ERR_PARAM 0x03U

/* ─── 下行: 标定命令帧 (10 bytes) ───
 *  [AA 55 30 subcmd target param(4) crc]
 */
struct cal_cmd_frame_t {
    uint8_t sync0;
    uint8_t sync1;
    uint8_t type;
    uint8_t subcmd;
    uint8_t target;
    float param;
    uint8_t crc;
} __attribute__((packed));

union cal_cmd_pkt_t {
    struct cal_cmd_frame_t frame;
    uint8_t bytes[sizeof(struct cal_cmd_frame_t)];
};

/* ─── 上行: 标定响应帧 (14 bytes) ───
 *  [AA 55 31 status subcmd data(8) crc]
 */
struct cal_resp_frame_t {
    uint8_t sync0;
    uint8_t sync1;
    uint8_t type;
    uint8_t status;
    uint8_t subcmd;
    uint8_t data[8];
    uint8_t crc;
} __attribute__((packed));

union cal_resp_pkt_t {
    struct cal_resp_frame_t frame;
    uint8_t bytes[sizeof(struct cal_resp_frame_t)];
};

/* ═══════════════════════════════════════════════════════════════════
 *  下行消息队列 payload
 * ═══════════════════════════════════════════════════════════════════ */

struct comm_msg_resistance {
    float K, B, Tau;
};

struct comm_msg_spotter {
    float threshold;
    bool enable;
};

struct comm_msg_heartbeat {
    uint8_t counter;
};

enum comm_msg_type {
    COMM_MSG_RESISTANCE,
    COMM_MSG_SPOTTER,
    COMM_MSG_HEARTBEAT,
};

struct comm_msg {
    enum comm_msg_type type;
    union {
        struct comm_msg_resistance resistance;
        struct comm_msg_spotter spotter;
        struct comm_msg_heartbeat heartbeat;
    };
};

/* ═══════════════════════════════════════════════════════════════════
 *  协议层 API
 * ═══════════════════════════════════════════════════════════════════ */

/**
 * @brief 初始化协议层，注册 BLE 传输层收数据回调。
 *
 * 必须在 ble_transport_init() 之后调用。
 *
 * @retval 0 成功。
 */
int comm_protocol_init(void);

/**
 * @brief 组包并发送 CoP 上行帧。
 *
 * @param flags COP_FLAG_* 位组合。
 * @param cop_x 压力中心 X (cm)。
 * @param cop_y 压力中心 Y (cm)。
 * @param force 总力 (kg)。
 */
void comm_protocol_send_cop(uint8_t flags, int16_t cop_x, int16_t cop_y, int16_t force);

/**
 * @brief 组包并发送标定响应上行帧。
 *
 * @param status 结果状态码 (CAL_STATUS_*)。
 * @param subcmd 对应的子命令回显。
 * @param data 8 字节响应数据。
 */
void comm_protocol_send_cal_resp(uint8_t status, uint8_t subcmd, const uint8_t data[8]);

/**
 * @brief 获取下行消息队列指针，业务层通过 k_msgq_get() 消费。
 *
 * @return 指向内部 msgq 的指针。
 */
struct k_msgq *comm_protocol_get_msgq(void);