/**
 * @file motor_version.cpp
 * @brief 多电机版本缓存实现 — CAN 版本应答帧(0x00FF)识别、缓存、0xC6 序列化。
 *
 * 所有函数仅在主循环上下文调用（taskCanRxParse / pushStep），无 ISR 竞态。
 * 与 motor_state.cpp 不同：版本是事件驱动（收到应答才缓存+推送），无周期任务、
 * 无离线判定；pushStep 在 app_spi_cmd_motor_version.cpp（含 SPI 依赖）。
 */

#include "device/motor_version.h"
#include "device/spi/app_spi_command_defs.h"
#include <cstring>

/* ── 全局版本表实例 ── */
static MotorVersionTable s_verTable = {};

namespace MotorVersion {

MotorVersionTable &table()
{
    return s_verTable;
}

void onCanFrame(uint8_t channel, uint32_t id, const uint8_t *data, uint8_t len)
{
    (void)channel;

    /* 掩码匹配版本应答 ID: 0x000N00FF */
    if ((id & kMotorVersionIdMask) != kMotorVersionIdMatch) {
        return;
    }

    const uint8_t node = static_cast<uint8_t>((id >> 16) & 0x0FU);
    if (node < 1U || node > kMotorVersionMaxNodes) {
        return;
    }
    if (data == nullptr || len < 1U) {
        return;
    }

    MotorVersionSlot &slot = s_verTable.slots[node - 1U];

    slot.node_id = node;
    slot.seq     = ++s_verTable.global_seq;

    /* 拷贝原始 payload（不足补 0，超长截断） */
    const uint8_t n = (len <= kMotorVersionDlc) ? len : kMotorVersionDlc;
    std::memcpy(slot.version, data, n);
    if (n < kMotorVersionDlc) {
        std::memset(&slot.version[n], 0, kMotorVersionDlc - n);
    }

    slot.dirty = 1U; /* 标记待推送 */
}

bool hasPending()
{
    for (uint8_t i = 0U; i < kMotorVersionMaxNodes; ++i) {
        if (s_verTable.slots[i].dirty != 0U) {
            return true;
        }
    }
    return false;
}

uint16_t buildPayload(uint8_t *buf, uint16_t maxLen)
{
    if (buf == nullptr || maxLen < kMotorVersionHeaderLen) {
        return 0U;
    }

    /* Header (2B): count 稍后回填, rsvd=0 */
    buf[0] = 0U;
    buf[1] = 0U;

    uint16_t offset = kMotorVersionHeaderLen;
    uint8_t  count  = 0U;

    for (uint8_t i = 0U; i < kMotorVersionMaxNodes; ++i) {
        MotorVersionSlot &slot = s_verTable.slots[i];
        if (slot.dirty == 0U) {
            continue;
        }
        /* 检查剩余空间；装不下则保留 dirty 待下轮（不丢） */
        if (offset + kMotorVersionEntrySize > maxLen) {
            break;
        }

        buf[offset + 0U] = slot.node_id;
        writeU32Le(&buf[offset + 1U], slot.seq);
        std::memcpy(&buf[offset + 5U], slot.version, kMotorVersionDlc);

        offset += kMotorVersionEntrySize;
        count++;
        slot.dirty = 0U; /* 已打包进本次推送 */
    }

    if (count == 0U) {
        return 0U;
    }
    buf[0] = count;
    return offset;
}

} // namespace MotorVersion