/**
 * @file shell_port.c
 */

#include "shell.h"
#include "stm32f4xx_hal.h"
#include "usart.h"
#include "shell_port.h"

Shell shell;
char shellBuffer[512];

// DMA接收缓冲区和shell环形缓冲区
#define SHELL_UART_DMA_BUF_SIZE 256
#define SHELL_UART_RX_BUF_SIZE 128
static uint8_t shell_uart_dma_buf[SHELL_UART_DMA_BUF_SIZE];
static uint8_t shell_uart_rx_buf[SHELL_UART_RX_BUF_SIZE];
static volatile uint16_t shell_uart_rx_head = 0;
static volatile uint16_t shell_uart_rx_tail = 0;
static volatile uint16_t shell_uart_dma_last_pos = 0;

/**
 * @brief 用户shell写
 *
 * @param data 数据
 * @param len 数据长度
 *
 * @return short 实际写入的数据长度
 */
short userShellWrite(char *data, unsigned short len)
{
    HAL_UART_Transmit(&huart1, (uint8_t *)data, len, 0x1FF);
    return len;
}

/**
 * @brief 用户shell读
 *
 * @param data 数据
 * @param len 数据长度
 *
 * @return short 实际读取到
 */

// 从环形缓冲区读取数据
short userShellRead(char *data, unsigned short len)
{
    unsigned short count = 0;
    while (count < len)
    {
        if (shell_uart_rx_head == shell_uart_rx_tail)
        {
            // 缓冲区无数据
            break;
        }
        data[count++] = shell_uart_rx_buf[shell_uart_rx_tail];
        shell_uart_rx_tail = (shell_uart_rx_tail + 1) % SHELL_UART_RX_BUF_SIZE;
    }
    return count;
}

/**
 * @brief 用户shell初始化
 *
 */
void userShellInit(void)
{
    shell.write = userShellWrite;
    shell.read = userShellRead;
    shell.lock = NULL;
    shell.unlock = NULL;
    shellInit(&shell, shellBuffer, 512);

    // 启动DMA接收
    HAL_UART_Receive_DMA(&huart1, shell_uart_dma_buf, SHELL_UART_DMA_BUF_SIZE);
    // 使能空闲中断
    __HAL_UART_ENABLE_IT(&huart1, UART_IT_IDLE);
}

// USART1 空闲中断处理（DMA新数据转入shell缓冲区）
void shell_uart_rx_idle_callback(void)
{
    uint16_t dma_pos = SHELL_UART_DMA_BUF_SIZE - __HAL_DMA_GET_COUNTER(huart1.hdmarx);
    uint16_t data_len = (dma_pos >= shell_uart_dma_last_pos) ? (dma_pos - shell_uart_dma_last_pos) : (SHELL_UART_DMA_BUF_SIZE - shell_uart_dma_last_pos + dma_pos);
    for (uint16_t i = 0; i < data_len; i++)
    {
        uint8_t ch = shell_uart_dma_buf[(shell_uart_dma_last_pos + i) % SHELL_UART_DMA_BUF_SIZE];
        uint16_t next = (shell_uart_rx_head + 1) % SHELL_UART_RX_BUF_SIZE;
        if (next != shell_uart_rx_tail)
        {
            shell_uart_rx_buf[shell_uart_rx_head] = ch;
            shell_uart_rx_head = next;
        }
    }
    shell_uart_dma_last_pos = dma_pos;
}
// CEVENT_EXPORT(EVENT_INIT_STAGE2, userShellInit);