/*
 * rs485_700bs.c
 * DLD154Pro RS485 700BS 从机协议实现
 *
 * 物理层: RS485 半双工, 9600 8N1, PA14=TX PA15=RX PA13=RE
 * 帧格式: 主机 3 字节 (STX ADDR XOR), 从机可变长
 * 心跳:  空闲 5s / 故障 1s / 事件立即
 *
 * 2026-07-23 初始实现
 */
#include "CONFIG.h"
#include "CH59x_common.h"
#include "cmcng.h"
#include "rs485_700bs.h"
#include "storage.h"
#include <string.h>

/*===========================================================================
 * UART0 中断接收缓冲
 *===========================================================================*/
#define RS485_RX_BUF_SIZE   16
static uint8_t  _rx_buf[RS485_RX_BUF_SIZE];
static uint8_t  _rx_len = 0;
static uint32_t _rx_last_tick = 0;   // 帧间隔计时 (3.5 字符 ≈ 4ms @9600)

/*===========================================================================
 * 心跳 & 状态追踪
 *===========================================================================*/
static uint32_t _hb_last_ms = 0;      // 上次心跳时刻
static uint8_t  _hb_need_init = 1;    // 需要发 0xA1 首次心跳
static uint8_t  _last_car_state = 0;  // car_state 快照 (翻转沿检测)
static uint8_t  _last_loop_state = 0; // loop_state 快照

/*===========================================================================
 * RS485 方向控制 (PA13)
 *===========================================================================*/
#define RS485_RE_TX()    GPIOA_SetBits(GPIO_Pin_13)
#define RS485_RE_RX()    GPIOA_ResetBits(GPIO_Pin_13)

/*===========================================================================
 * UART0 初始化 — 9600 8N1, 中断接收
 *===========================================================================*/
void rs485_init(void)
{
    /* PA14=TX(推挽), PA15=RX(上拉输入), PA13=RE(推挽, 默认接收) */
    GPIOA_SetBits(GPIO_Pin_13);           // RE 先拉高, GPIO 模式
    GPIOA_ModeCfg(GPIO_Pin_14, GPIO_ModeOut_PP_5mA);
    GPIOA_ModeCfg(GPIO_Pin_15, GPIO_ModeIN_PU);
    GPIOA_ModeCfg(GPIO_Pin_13, GPIO_ModeOut_PP_5mA);

    /* UART0 外设: 9600 8N1 */
    UART0_BaudRateCfg(RS485_BAUD);
    R8_UART0_LCR = 0x03;     // 8 数据位, 1 停止位, 无校验
    R8_UART0_MCR = 0x04;     // RE=0 进入接收模式

    /* 中断: 接收可用 */
    UART0_CLR_RXFIFO();
    UART0_ByteTrigCfg(UART_1BYTE_TRIG);   // 每收到 1 字节触发中断
    UART0_INTCfg(ENABLE, RB_IER_RECV_RDY | RB_IER_LINE_STAT);
    PFIC_EnableIRQ(UART0_IRQn);

    RS485_RE_RX();  // 默认接收模式
    PRINT("RS485: init ok, addr=%d, baud=%d\n", g_rs485_id, RS485_BAUD);
}

/*===========================================================================
 * 发送一帧 — 切 RE=TX, 发完等 1ms, 切回 RE=RX
 *===========================================================================*/
static void rs485_send(const uint8_t *data, uint8_t len)
{
    RS485_RE_TX();
    mDelayuS(100);  // 总线稳定

    for (uint8_t i = 0; i < len; i++) {
        while (R8_UART0_TFC == 0);   // 等 TX FIFO 空
        R8_UART0_THR = data[i];
    }
    while (R8_UART0_TFC == 0);       // 等最后一字节发完
    mDelayuS(500);                    // 等待停止位 + 总线释放
    UART0_CLR_TXFIFO();
    RS485_RE_RX();
}

/*===========================================================================
 * 命令处理
 *===========================================================================*/

/* 0xFA — 查询有车状态 + 线圈好坏 */
static void handle_query_status(uint8_t addr)
{
    extern uint8_t loop1_LOOP_OK;
    uint8_t data = addr & 0x1F;       // bit4-0 = 地址
    if (g_loop_acs_info.car_state)    data |= 0x80;  // bit7 = 有车
    if (!loop1_LOOP_OK)               data |= 0x20;  // bit5 = 线圈断开 (LOOP_OK=0)
    uint8_t buf[3] = { RSP_STATUS, data, (uint8_t)(RSP_STATUS ^ data) };
    rs485_send(buf, 3);
}

/* 0x1B — 查询线圈频率 */
static void handle_query_freq(uint8_t addr)
{
    uint32_t freq = g_loop_acs_info.frequent;  // Hz
    uint8_t buf[6];
    buf[0] = RSP_FREQ;
    buf[1] = (uint8_t)((freq >> 16) & 0xFF);  // Fre_1 (MSB)
    buf[2] = (uint8_t)((freq >> 8) & 0xFF);   // Fre_2
    buf[3] = (uint8_t)(freq & 0xFF);           // Fre_3 (LSB)
    buf[4] = addr & 0x1F;
    buf[5] = buf[0] ^ buf[1] ^ buf[2] ^ buf[3] ^ buf[4];
    rs485_send(buf, 6);
}

/* 0x2C — 复位初始化线圈 */
static void handle_reset_init(uint8_t addr)
{
    (void)addr;
    extern uint8_t  g_loop_stable;
    extern uint8_t  loop1_LOOP_OK0;
    extern uint8_t  loop1_LC_Reset;
    extern uint8_t  loop1_INI_LOOP;
    extern uint16_t loop1_stable_cnt;
    extern uint16_t LC_Hold_CNT;
    extern uint32_t loop1_ORG_CNT, loop1_ORG_SUM;

    loop1_LC_Reset   = 1;
    loop1_INI_LOOP   = 1;
    loop1_LOOP_OK0   = 0;
    g_loop_stable    = 0;
    loop1_stable_cnt = 0;
    LC_Hold_CNT      = 0;
    loop1_ORG_CNT    = 0;
    loop1_ORG_SUM    = 0;
    _hb_need_init    = 1;
    _last_car_state  = (_last_car_state ^ 1);
    PRINT("RS485: coil reset init\n");
}

/* 0x3D — 查询拨码 DIP1-5 (DLD154Pro 无物理拨码, 从 BLE 配置映射) */
static void handle_query_dip(uint8_t addr)
{
    uint8_t data = 0;
    uint8_t sens = g_loop_cng_unit.sensitvity & 0x0F;        // 灵敏度 0-3
    data |= (sens & 0x01);                                    // DIP1 = bit0
    data |= ((sens >> 1) & 0x01) << 1;                        // DIP2 = bit1
    if (g_loop_cng_unit.output_mode & 0x01)  data |= 0x04;    // DIP3 = bit2 (1=脉冲)
    if (g_loop_cng_unit.exist_mode == 0)     data |= 0x08;    // DIP4 = bit3 (0=永久→ON=1)
    if (g_loop_cng_unit.delay_time > 0)      data |= 0x10;    // DIP5 = bit4 (>0=启用延时)
    uint8_t buf[4] = { RSP_DIP, data, (uint8_t)(addr & 0x1F),
                       (uint8_t)(RSP_DIP ^ data ^ (addr & 0x1F)) };
    rs485_send(buf, 4);
}

/*===========================================================================
 * 心跳上报 (0xAA) — 空闲 5s / 故障 1s / 事件立即
 *===========================================================================*/

/* Fre_Err 计算: bit0=下限异常, bit4=上限异常 */
static uint8_t calc_freq_err(uint32_t freq)
{
    (void)freq;
    /* DLD154Pro 未实现频率越限检测, 始终返回 0 */
    return 0x00;
}

static void rs485_send_heartbeat(void)
{
    extern uint8_t loop1_LOOP_OK;
    uint32_t freq = g_loop_acs_info.frequent;
    uint8_t  st   = g_rs485_id & 0x1F;

    if (g_loop_acs_info.car_state)  st |= 0x80;  // bit7=有车
    if (!loop1_LOOP_OK)             st |= 0x20;  // bit5=线圈断开

    uint8_t buf[9];
    buf[0] = HB_PREAMBLE;                        // 0xAA
    buf[1] = _hb_need_init ? HB_INIT_FIRST : HB_INIT_NORMAL;
    _hb_need_init = 0;
    buf[2] = st;                                 // State
    buf[3] = calc_freq_err(freq);                // Fre_Err
    buf[4] = (uint8_t)((freq >> 16) & 0xFF);     // Fre_1
    buf[5] = (uint8_t)((freq >> 8) & 0xFF);      // Fre_2
    buf[6] = (uint8_t)(freq & 0xFF);             // Fre_3
    buf[7] = g_rs485_id & 0x1F;                  // ADDR
    buf[8] = buf[0];
    for (uint8_t i = 1; i < 8; i++) buf[8] ^= buf[i];

    rs485_send(buf, 9);
}

/*===========================================================================
 * 帧解析 & 主循环
 *===========================================================================*/

/* UART0 接收中断 (每字节触发) */
__attribute__((interrupt("WCH-Interrupt-fast")))
void UART0_IRQHandler(void)
{
    switch (UART0_GetITFlag()) {
        case UART_II_RECV_RDY:                     // 接收数据就绪
            if (_rx_len < RS485_RX_BUF_SIZE) {
                _rx_buf[_rx_len++] = UART0_RecvByte();
            } else {
                _rx_len = 0;  // 溢出, 丢弃
            }
            _rx_last_tick = mstick();
            break;

        case UART_II_LINE_STAT:                    // 线路状态 (帧错误/溢出等)
            UART0_GetLinSTA();                     // 读 LSR 清状态
            break;

        default:
            break;
    }
}

/* 处理收到的完整帧 */
static void rs485_process_frame(void)
{
    if (_rx_len < 3) return;  // 最少 3 字节

    /* XOR 校验: STX ^ ADDR/CMD */
    uint8_t stx  = _rx_buf[0];
    uint8_t addr = _rx_buf[1];
    uint8_t xorr = _rx_buf[2];

    if ((stx ^ addr) != xorr) {
        PRINT("RS485: XOR fail %02X %02X %02X\n", stx, addr, xorr);
        _rx_len = 0;
        return;
    }

    /* 地址匹配检查 (0x2C 复位命令全地址响应) */
    if (stx != CMD_RESET_INIT && (addr & 0x1F) != (g_rs485_id & 0x1F)) {
        _rx_len = 0;
        return;  // 不是给我的
    }

    switch (stx) {
        case CMD_QUERY_STATUS:  handle_query_status(addr);  break;
        case CMD_QUERY_FREQ:    handle_query_freq(addr);    break;
        case CMD_RESET_INIT:    handle_reset_init(addr);    break;
        case CMD_QUERY_DIP:     handle_query_dip(addr);     break;
        default:
            PRINT("RS485: unknown cmd 0x%02X\n", stx);
            break;
    }

    _rx_len = 0;
}

/* 主循环调用 — 帧超时检测 + 周期心跳 */
void rs485_poll(void)
{
    /* 帧超时: 3.5 字符 ≈ 4ms @9600, 10ms 足够 */
    if (_rx_len > 0 && mstick() - _rx_last_tick > 10) {
        rs485_process_frame();
    }

    /* 心跳上报 */
    extern uint8_t loop1_LOOP_OK;
    uint32_t now = mstick();
    uint8_t  car_state  = g_loop_acs_info.car_state;
    uint8_t  loop_state = loop1_LOOP_OK;  // 1=正常, 0=断开
    uint32_t interval;

    /* 事件触发: car_state 翻转沿 → 立即上报 */
    if (car_state != _last_car_state) {
        _last_car_state = car_state;
        rs485_send_heartbeat();
        _hb_last_ms = now;
        return;
    }
    /* 线圈状态变化 → 立即上报 */
    if (loop_state != _last_loop_state) {
        _last_loop_state = loop_state;
        rs485_send_heartbeat();
        _hb_last_ms = now;
        return;
    }

    /* 周期心跳 */
    interval = (!loop_state) ? RS485_FAULT_MS : RS485_HEARTBEAT_MS;
    if (now - _hb_last_ms >= interval) {
        rs485_send_heartbeat();
        _hb_last_ms = now;
    }
}

/* 强制立即上报 (由外部事件触发) */
void rs485_event_notify(void)
{
    _last_car_state = (_last_car_state ^ 1);  // 强制触发
}

void rs485_loop_notify(void)
{
    _last_loop_state = (_last_loop_state ^ 1);  // 强制触发
}

void rs485_reset_heartbeat(void)
{
    _hb_need_init = 1;
    _hb_last_ms = 0;  // 立即触发首次心跳
}