/**
 * @file bsp_usart.c
 * @author neozng
 * @brief  串口bsp层的实现
 * @version beta
 * @date 2022-11-01
 *
 * @copyright Copyright (c) 2022
 *
 */
#include "bsp_usart.h"
#include "stdlib.h"
#include "memory.h"

/* usart service instance, modules' info would be recoreded here using USARTRegister() */
/* usart服务实例,所有注册了usart的模块信息会被保存在这里 */
static uint8_t idx;
static USARTInstance *usart_instance[DEVICE_USART_CNT] = {NULL};

/**
 * @brief usart service will start automatically, after each module registered
 *        串口服务会在每个实例注册之后自动启用
 *
 * @param _instance instance owned by module,模块拥有的串口实例
 */
static void USARTServiceInit(USARTInstance *_instance)
{
    HAL_UARTEx_ReceiveToIdle_DMA(_instance->usart_handle, _instance->recv_buff, _instance->recv_buff_size);
    // 关闭dma half transfer中断防止两次进入HAL_UARTEx_RxEventCallback()
    // 这是HAL库的一个设计失误,发生DMA传输完成/半完成以及串口IDLE中断都会触发HAL_UARTEx_RxEventCallback()
    // 我们只希望处理第一种和第三种情况,因此直接关闭DMA半传输中断
    __HAL_DMA_DISABLE_IT(_instance->usart_handle->hdmarx, DMA_IT_HT);
}

USARTInstance *USARTRegister(USART_Init_Config_s *init_config)
{
    USARTInstance *instance = (USARTInstance *)malloc(sizeof(USARTInstance));
    memset(instance, 0, sizeof(USARTInstance));

    instance->usart_handle = init_config->usart_handle;
    instance->recv_buff_size = init_config->recv_buff_size;
    instance->module_callback = init_config->module_callback;

    usart_instance[idx++] = instance;
    return instance;
}

/* @todo 当前仅进行了形式上的封装,后续要进一步考虑是否将module的行为与bsp完全分离 */
void USARTSend(USARTInstance *_instance, uint8_t *send_buf, uint16_t send_size)
{
    HAL_UART_Transmit_DMA(_instance->usart_handle, send_buf, send_size);
}

/**
 * @brief 每次dma/idle中断发生时，都会调用此函数.对于每个uart实例会调用对应的回调进行进一步的处理
 *        例如:视觉协议解析/遥控器解析/裁判系统解析
 *
 * @todo  neozng给HAL库的github repo提了issue, ST在最新的一次更新中为此提供了一个HAL_UARTEx_GetRxEventType()函数
 *        这样就可以通过调用这个函数来确认是什么中断导致了回调函数的调用
 *
 * @note  because DMA half transfer iterrupt(DMA_IT_HT) would call this callback function too, so we just
 *        disable it when transfer complete using macro: __HAL_DMA_DISABLE_IT(huart->hdmarx,DMA_IT_HT)
 *        关闭dma half transfer中断防止两次进入HAL_UARTEx_RxEventCallback()
 *        这是HAL库的一个设计失误,发生DMA传输完成/半完成以及串口IDLE中断都会触发HAL_UARTEx_RxEventCallback()
 *        我们只希望处理，因此直接关闭DMA半传输中断第一种和第三种情况
 *
 * @param huart uart handle indicate which uart is being handled 发生中断的串口
 * @param Size not used temporarily,此次接收到的总数居量,暂时没用
 */
void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{
    for (uint8_t i = 0; i < idx; ++i)
    { // find the instance which is being handled
        if (huart == usart_instance[i]->usart_handle)
        { // call the callback function if it is not NULL
            if (usart_instance[i]->module_callback != NULL)
            {
                usart_instance[i]->module_callback();
                memset(usart_instance[i]->recv_buff, 0, Size); // 接收结束后清空buffer,对于变长数据是必要的
            }
            HAL_UARTEx_ReceiveToIdle_DMA(usart_instance[i]->usart_handle, usart_instance[i]->recv_buff, usart_instance[i]->recv_buff_size);
            __HAL_DMA_DISABLE_IT(usart_instance[i]->usart_handle->hdmarx, DMA_IT_HT);
            return; // break the loop
        }
    }
}

/**
 * @brief when error occurs in the process of send/receive,this function will be called
 *        then just simply restart send/receive.
 *
 * @note  most frequent error ex: parity/overrrun/frame error
 *
 * @param huart uart handle type, indicate where error comes from
 */
void HAL_UART_ErrorCallback(UART_HandleTypeDef *huart)
{
    for (uint8_t i = 0; i < idx; ++i)
    {
        if (huart == usart_instance[i]->usart_handle)
        {
            HAL_UARTEx_ReceiveToIdle_DMA(usart_instance[i]->usart_handle, usart_instance[i]->recv_buff, usart_instance[i]->recv_buff_size);
            __HAL_DMA_DISABLE_IT(usart_instance[i]->usart_handle->hdmarx, DMA_IT_HT);
            return;
        }
    }
}