#include "hw_can.h"
#include "main.h"
#include "FreeRTOS.h"
#include "task.h"

void hwCanInit(void)
{
    CAN_FilterTypeDef   filter;

    /* 16-bit ID List 滤波: 每个 filter bank 容纳 4 个标准帧 ID
     * 标准帧 ID 必须左移 5 位 (STID 在寄存器位[15:5])
     *
     * 本设备需接收 0x180-0x18A 全部 ID (多设备升级寻址范围)
     *   0x180-0x18A = 11 个 ID, 需 3 个 bank (12 槽位)
     *   Bank0: 0x180-0x183   Bank1: 0x184-0x187   Bank2: 0x188-0x18B
     * 具体哪个ID是本设备的, 由软件层 IAP_CAN_RX_ID 精确过滤 */

    /* Bank 0: 0x180-0x183 → FIFO0 */
    filter.FilterIdHigh      = 0x180U << 5;    /* ID0 = 0x180 */
    filter.FilterIdLow       = 0x181U << 5;    /* ID1 = 0x181 */
    filter.FilterMaskIdHigh  = 0x182U << 5;    /* ID2 = 0x182 */
    filter.FilterMaskIdLow   = 0x183U << 5;    /* ID3 = 0x183 */
    filter.FilterFIFOAssignment = CAN_FILTER_FIFO0;
    filter.FilterBank        = 0;
    filter.FilterMode        = CAN_FILTERMODE_IDLIST;  /* ID List 方式 */
    filter.FilterScale       = CAN_FILTERSCALE_16BIT;  /* 16位 */
    filter.FilterActivation  = CAN_FILTER_ENABLE;      /* 使能 */
    filter.SlaveStartFilterBank = 14;                  /* 全部分配给CAN1 */
    if (HAL_CAN_ConfigFilter(&hcan, &filter) != HAL_OK)
    {
    }

    /* Bank 1: 0x184-0x187 → FIFO0 */
    filter.FilterIdHigh      = 0x184U << 5;    /* ID0 = 0x184 */
    filter.FilterIdLow       = 0x185U << 5;    /* ID1 = 0x185 */
    filter.FilterMaskIdHigh  = 0x186U << 5;    /* ID2 = 0x186 */
    filter.FilterMaskIdLow   = 0x187U << 5;    /* ID3 = 0x187 */
    filter.FilterFIFOAssignment = CAN_FILTER_FIFO0;
    filter.FilterBank        = 1;
    HAL_CAN_ConfigFilter(&hcan, &filter);

    /* Bank 2: 0x188-0x18B → FIFO1 (0x18A 为寻址上限, 0x18B 预留) */
    filter.FilterIdHigh      = 0x188U << 5;    /* ID0 = 0x188 */
    filter.FilterIdLow       = 0x189U << 5;    /* ID1 = 0x189 */
    filter.FilterMaskIdHigh  = 0x18AU << 5;    /* ID2 = 0x18A */
    filter.FilterMaskIdLow   = 0x18BU << 5;    /* ID3 = 0x18B (预留) */
    filter.FilterFIFOAssignment = CAN_FILTER_FIFO1;
    filter.FilterBank        = 2;
    HAL_CAN_ConfigFilter(&hcan, &filter);

    HAL_CAN_Start(&hcan);

    /* 使能接收 FIFO 中断 + 发送完成中断 */
    HAL_CAN_ActivateNotification(&hcan, CAN_IT_RX_FIFO0_MSG_PENDING
                                     | CAN_IT_RX_FIFO1_MSG_PENDING
                                     | CAN_IT_TX_MAILBOX_EMPTY);
}

uint8_t hwCanSend(uint32_t id, uint8_t *data, uint8_t dlc)
{
#if 1
    CAN_TxHeaderTypeDef  tx_header;
    uint32_t             tx_mailbox;
    uint32_t             wait = 20000;

    /* 无空闲发送邮箱时短超时忙等（不osDelay，避免任务挂起导致积压） */
    /* 500kbps下一帧约130µs，3个邮箱最慢约400µs释放 */
    while (HAL_CAN_GetTxMailboxesFreeLevel(&hcan) == 0)
    {
        if (--wait == 0)
        {
            return 0;   /* 超时放弃（总线异常） */
        }
    }

    /* 组织发送帧头 */
    tx_header.StdId = id;          /* 标准帧ID */
    tx_header.ExtId = 0;           /* 扩展帧ID未用 */
    tx_header.IDE   = CAN_ID_STD;  /* 标准帧 */
    tx_header.RTR   = CAN_RTR_DATA;/* 数据帧 */
    tx_header.DLC   = dlc;         /* 数据长度 0~8 */

    /* 临界区保护HAL_CAN_AddTxMessage，防止RX中断中HAL_CAN_GetRxMessage
       的HAL_LOCK冲突（仅几μs，不影响实时性） */
    taskENTER_CRITICAL();
    HAL_StatusTypeDef status = HAL_CAN_AddTxMessage(&hcan, &tx_header, data, &tx_mailbox);
    taskEXIT_CRITICAL();

    if (status != HAL_OK)
    {
        return 0;
    }

    return 1;
#else
uint32_t mailbox;

    /* 选择空闲邮箱(直接读TSR寄存器) */
    if (hcan.Instance->TSR & CAN_TSR_TME0) mailbox = 0;
    else if (hcan.Instance->TSR & CAN_TSR_TME1) mailbox = 1;
    else if (hcan.Instance->TSR & CAN_TSR_TME2) mailbox = 2;
    else return 0;  /* 无空闲邮箱 */

    /* 设置ID(标准帧,ID左移21位) */
    hcan.Instance->sTxMailBox[mailbox].TIR = (id << 21) | CAN_RTR_DATA | CAN_ID_STD;

    /* 设置DLC */
    hcan.Instance->sTxMailBox[mailbox].TDTR = dlc;

    /* 设置数据(直接写TDLR/TDHR寄存器,立即拷贝) */
    hcan.Instance->sTxMailBox[mailbox].TDLR = ((uint32_t)data[3]<<24)|((uint32_t)data[2]<<16)|((uint32_t)data[1]<<8)|data[0];
    hcan.Instance->sTxMailBox[mailbox].TDHR = ((uint32_t)data[7]<<24)|((uint32_t)data[6]<<16)|((uint32_t)data[5]<<8)|data[4];

    /* 请求发送 */
    hcan.Instance->sTxMailBox[mailbox].TIR |= CAN_TI0R_TXRQ;

    return 1;
#endif
}