/**
 * @file motor_state.cpp
 * @brief 多电机状态表实现 — CAN STATUS 帧识别、内存缓存、SPI 推送序列化。
 *
 * 所有函数仅在主循环上下文调用（taskCanRxParse / taskHeartbeat / pushStep），
 * 无 ISR 竞态，不需要临界区保护。
 */

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

/* ── 全局状态表实例 ── */
static MotorStateTable s_motorTable = {};

namespace MotorState {

MotorStateTable &table()
{
    return s_motorTable;
}

void onCanFrame(uint8_t channel, uint32_t id, const uint8_t *data, uint8_t len)
{
    /* BOOT 心跳 0x103（固定 ID，不带节点号）：电机在 Bootloader IDLE 每 ~10ms 发一次。
     * 记录最近收到时刻与通道，供网页显示独立 BOOT 状态（不归属任何 Nx）。
     * 注意：必须在 STATUS 掩码过滤之前拦截，否则 0x103 会被下面的掩码判断丢弃。 */
    if (id == kOtaBootHeartbeatId) {
        s_motorTable.boot_hb_sec  = g_app_uptime_sec;
        s_motorTable.boot_channel = channel;
        s_motorTable.boot_active  = 1U;
        /* 0x103 仅更新 boot_active 状态，不再串口打印（高频心跳会刷屏）。 */
        return;
    }

    /* 掩码匹配 STATUS ID: 0x000N0100 */
    if ((id & kMotorStatusIdMask) != kMotorStatusIdMatch) {
        return;
    }

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

    MotorSlot &slot = s_motorTable.slots[node - 1U];

    slot.node_id      = node;
    slot.channel      = channel;
    slot.online       = 1U;
    slot.dlc          = (len <= kMotorStatusDlc) ? len : kMotorStatusDlc;
    slot.rx_count++;
    slot.last_rx_sec  = g_app_uptime_sec;
    slot.seq          = ++s_motorTable.global_seq;

    /* 拷贝原始 payload */
    std::memcpy(slot.data, data, slot.dlc);
    if (slot.dlc < kMotorStatusDlc) {
        std::memset(&slot.data[slot.dlc], 0, kMotorStatusDlc - slot.dlc);
    }
}

void checkOffline()
{
    const uint32_t now = g_app_uptime_sec;
    uint8_t active = 0U;

    for (uint8_t i = 0U; i < kMotorMaxNodes; ++i) {
        MotorSlot &slot = s_motorTable.slots[i];
        if (slot.node_id == 0U) {
            continue; /* 空槽 */
        }
        if ((now - slot.last_rx_sec) >= kMotorOfflineSec) {
            slot.online = 0U;
        }
        if (slot.online != 0U) {
            active++;
        }
    }
    s_motorTable.active_count = active;

    /* BOOT 心跳超时：>kBootHeartbeatTimeoutSec 无 0x103 → 电机已退出 BOOT。 */
    if (s_motorTable.boot_active != 0U &&
        (now - s_motorTable.boot_hb_sec) >= kBootHeartbeatTimeoutSec) {
        s_motorTable.boot_active = 0U;
    }
}

uint16_t buildPayload(uint8_t page, uint8_t *buf, uint16_t maxLen)
{
    if (page >= kMotorTotalPages || buf == nullptr) {
        return 0U;
    }

    /* 需要的最小空间: header + 至少 1 entry */
    const uint16_t needed = kMotorPageHeaderLen + kMotorEntrySize;
    if (maxLen < needed) {
        return 0U;
    }

    const uint8_t startIdx = static_cast<uint8_t>(page * kMotorEntriesPerPage);
    uint8_t count = 0U;

    /* Header (4B) */
    buf[0] = page;
    buf[1] = kMotorTotalPages;
    buf[2] = 0U; /* entry_count, 稍后回填 */
    /* bit[6:0]=在线电机数，bit7=BOOT 心跳(0x103)活跃标志（供网页显示独立 BOOT 状态）。
     * active_count 上限 9，bit7 空闲可复用，旧解析方读到会多算 128，故 ESP32 侧需掩 0x7F。 */
    buf[3] = static_cast<uint8_t>((s_motorTable.active_count & 0x7FU)
                                  | (s_motorTable.boot_active ? kMotorActiveBootBit : 0U));

    uint16_t offset = kMotorPageHeaderLen;

    for (uint8_t i = 0U; i < kMotorEntriesPerPage; ++i) {
        const uint8_t slotIdx = static_cast<uint8_t>(startIdx + i);
        if (slotIdx >= kMotorMaxNodes) {
            break;
        }

        const MotorSlot &slot = s_motorTable.slots[slotIdx];
        if (slot.node_id == 0U) {
            continue; /* 跳过空槽 */
        }

        /* 检查剩余空间 */
        if (offset + kMotorEntrySize > maxLen) {
            break;
        }

        buf[offset + 0U] = slot.node_id;
        buf[offset + 1U] = slot.channel;
        buf[offset + 2U] = slot.online;
        buf[offset + 3U] = slot.dlc;
        writeU32Le(&buf[offset + 4U], slot.rx_count);
        writeU32Le(&buf[offset + 8U], slot.seq);
        std::memcpy(&buf[offset + 12U], slot.data, kMotorStatusDlc);

        offset += kMotorEntrySize;
        count++;
    }

    buf[2] = count;
    return offset;
}

} // namespace MotorState