#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stm32c0xx_hal.h>

// ST Nucleo Green user LED (PA5)
#define LED_PORT                GPIOA
#define LED_PIN                 GPIO_PIN_5

UART_HandleTypeDef huart2;

void SystemClock_Config(void);
static void MX_USART2_UART_Init(void);

void initGPIO()
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();  

    /*Configure GPIO pin : PA7 */
  GPIO_InitStruct.Pin = GPIO_PIN_7;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pin : PB14 */
  GPIO_InitStruct.Pin = GPIO_PIN_14;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  //__HAL_RCC_GPIOA_CLK_ENABLE();
}

void Left_LED_On(void) {
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_7, GPIO_PIN_SET);
}

void Left_LED_Off(void) {
    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_7, GPIO_PIN_RESET);
}

void Right_LED_On(void) {
    HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14, GPIO_PIN_SET);
}

void Right_LED_Off(void) {
  HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14, GPIO_PIN_RESET);
}

void Left_LED_Blink(void) {
	
  Left_LED_On();
  HAL_Delay(200);
  Left_LED_Off();
  HAL_Delay(200);
    
}

void Right_LED_Blink(void) {
   	
  Right_LED_On();
  HAL_Delay(200);
  Right_LED_Off();
  HAL_Delay(200);
    
}

int main(void)
{
  HAL_Init();
  SystemClock_Config();

  initGPIO();
  MX_USART2_UART_Init();

  printf("Input, %s!\n", "0 or 1");

uint8_t state = 0;
char received;

    while (1)
    {
       if (HAL_UART_Receive(&huart2, (uint8_t *)&received, 1, 150) == HAL_OK)
	    {
        if (received == '0') // Toggle LED on 't' received
        {
			    state = 0;
		    }
		    else if(received == '1')
		    {
			    state = 1;
		    }
	    }

      switch(state) { 
        case 0:
          Right_LED_Off();
          Left_LED_Blink();
          break;
        case 1: 
          Left_LED_Off();
          Right_LED_Blink();
          break;
      }
    }

  return 0;
}

/**
    @brief System Clock Configuration
    @retval None
*/
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the RCC Oscillators according to the specified parameters
    in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSIDiv = RCC_HSI_DIV1;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
                                | RCC_CLOCKTYPE_PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
    @brief USART2 Initialization Function
    @param None
    @retval None
*/
static void MX_USART2_UART_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  __HAL_RCC_GPIOA_CLK_ENABLE();
  // PA2     ------> USART2_TX
  // PA3     ------> USART2_RX
  GPIO_InitStruct.Pin = GPIO_PIN_2|GPIO_PIN_3;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.Alternate = GPIO_AF1_USART2;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
  
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart2.Init.ClockPrescaler = UART_PRESCALER_DIV1;
  huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
}


void Error_Handler(void)
{
  /* User can add his own implementation to report the HAL error return state */
}


// The following makes printf() write to USART2:

#define STDOUT_FILENO   1
#define STDERR_FILENO   2

int _write(int file, uint8_t *ptr, int len)
{
  switch (file)
  {
    case STDOUT_FILENO:
      HAL_UART_Transmit(&huart2, ptr, len, HAL_MAX_DELAY);
      break;

    case STDERR_FILENO:
      HAL_UART_Transmit(&huart2, ptr, len, HAL_MAX_DELAY);
      break;

    default:
      return -1;
  }

  return len;
}