#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include "stm32h7xx_hal.h"

#include "SEGGER_RTT.h"
#include "SEGGER_SYSVIEW.h"
#include "SEGGER_SYSVIEW_Conf.h"

#include "user_tasks.h"

#define SYSVIEW_TX_SIZE 1024

extern UART_HandleTypeDef huart1;

osThreadId_t g_user_sysview_task_handle;
osThreadAttr_t g_user_sysview_task_attributes = {
    .name = "SV_TASK",
    .stack_size = 256 * 4,
    .priority = (osPriority_t)osPriorityNormal,
};

osSemaphoreId_t g_user_sysview_uart_rx_semphr;
osSemaphoreId_t g_user_sysview_uart_tx_semphr;

uint8_t g_sysview_tx_buf[SYSVIEW_TX_SIZE] __attribute__((section(".dma_ram")));

static const U8 sysview_hello_message[] = {
    'S',
    'E',
    'G',
    'G',
    'E',
    'R',
    ' ',
    'S',
    'y',
    's',
    't',
    'e',
    'm',
    'V',
    'i',
    'e',
    'w',
    ' ',
    'V',
    '0' + SEGGER_SYSVIEW_MAJOR,
    '.',
    '0' + (SEGGER_SYSVIEW_MINOR / 10),
    '0' + (SEGGER_SYSVIEW_MINOR % 10),
    '.',
    '0' + (SEGGER_SYSVIEW_REV / 10),
    '0' + (SEGGER_SYSVIEW_REV % 10),
    '\0',
    0,
    0,
    0,
    0,
    0,
};

void _user_uart_recv_callback(UART_HandleTypeDef *huart) {
    osSemaphoreRelease(g_user_sysview_uart_rx_semphr);
}

void _user_uart_send_callback(UART_HandleTypeDef *huart) {
    osSemaphoreRelease(g_user_sysview_uart_tx_semphr);
}

void user_sysview_task(void *argument) {
    uint8_t rx_buf[1];

    int channel_id = SEGGER_SYSVIEW_GetChannelID();

    g_user_sysview_uart_rx_semphr = osSemaphoreNew(1U, 0U, NULL);
    if(g_user_sysview_uart_rx_semphr == NULL) osThreadExit();

    g_user_sysview_uart_tx_semphr = osSemaphoreNew(1U, 0U, NULL);
    if(g_user_sysview_uart_tx_semphr == NULL) osThreadExit();

    HAL_UART_RegisterCallback(&huart1, HAL_UART_RX_COMPLETE_CB_ID,
                              _user_uart_recv_callback);

    HAL_UART_RegisterCallback(&huart1, HAL_UART_TX_COMPLETE_CB_ID,
                              _user_uart_send_callback);

    HAL_UART_Transmit_DMA(&huart1, (uint8_t *)sysview_hello_message,
                      sizeof(sysview_hello_message));

    SEGGER_SYSVIEW_Start();

    HAL_UART_Receive_IT(&huart1, rx_buf, 1);

    for(;;) {
        if(osSemaphoreGetCount(g_user_sysview_uart_rx_semphr) > 0) {
            SEGGER_RTT_WriteDownBufferNoLock(channel_id, rx_buf, 1);
            osSemaphoreAcquire(g_user_sysview_uart_rx_semphr, osWaitForever);
            HAL_UART_Receive_IT(&huart1, rx_buf, 1);
        };
        if(osSemaphoreAcquire(g_user_sysview_uart_tx_semphr, 100) == osOK) {
            unsigned int tx_len = SEGGER_RTT_GetBytesInBuffer(channel_id);
            unsigned int real_len = SEGGER_RTT_ReadUpBufferNoLock(
                channel_id, g_sysview_tx_buf, ((tx_len > SYSVIEW_TX_SIZE) ? SYSVIEW_TX_SIZE : tx_len));
            if(real_len > 0) HAL_UART_Transmit_DMA(&huart1, g_sysview_tx_buf, real_len);
        }
        osDelay(50);
    }
}