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

// ST Nucleo Green user LED (PA3)
#define LED_PORT                GPIOA
#define LED_PIN                 GPIO_PIN_3
#define LED_PORT_CLK_ENABLE     __HAL_RCC_GPIOA_CLK_ENABLE

UART_HandleTypeDef huart2;

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

void osSystickHandler(void)
{
  // 1 Hz blinking:
  if ((HAL_GetTick() % 500) == 0)
  {
    HAL_GPIO_TogglePin(LED_PORT, LED_PIN);
  }
}

void initGPIO()
{
  GPIO_InitTypeDef GPIO_Config;

  GPIO_Config.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_Config.Pull = GPIO_NOPULL;
  GPIO_Config.Speed = GPIO_SPEED_FREQ_HIGH;

  GPIO_Config.Pin = LED_PIN;

  LED_PORT_CLK_ENABLE();
  HAL_GPIO_Init(LED_PORT, &GPIO_Config);

  __HAL_RCC_GPIOA_CLK_ENABLE();
}

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

  initGPIO();
  MX_USART2_UART_Init();

  printf("Hello, %s!\n", "Wokwi");

  HAL_GPIO_TogglePin(LED_PORT, LED_PIN);

  while (1);

  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;
}


// ==============================================================
// ==============================================================
// ==============================================================


#if 0
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stm32c0xx_hal.h>

//#include "stm32c031xx.h"
//#include "debug.h"


const int PINledAlive =  						LED_BUILTIN;
#define LEDBLINK_PERIOD             2000UL                                // 2000 ms
#define LEDFLICK_ON                 50UL                                  // 50 ms
#define LEDON_DIVIDER               10UL                                  // divisor of period
#define LEDBLINK_TIMEOUT            LEDBLINK_PERIOD/LEDON_DIVIDER         //  x-x-.....x-x-.....
#define LED_OFFSTATE 								LOW


// ST Nucleo Green user LED (PA3)
#define LED1_PORT                GPIOA
#define LED1_PIN                 GPIO_PIN_3
#define LED1_PORT_CLK_ENABLE     __HAL_RCC_GPIOA_CLK_ENABLE

UART_HandleTypeDef huart2;

// -------------------------------------------
void SystemClock_Config(void);
static void MX_USART2_UART_Init(void);


// -------------------------------------------
void osSystickHandler(void)
{
  // 1 Hz blinking:
  if ((HAL_GetTick() % 500) == 0)
  {
    HAL_GPIO_TogglePin(LED1_PORT, LED1_PIN);
  }
}

// -------------------------------------------
void initGPIO()
{
  GPIO_InitTypeDef GPIO_Config;

  GPIO_Config.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_Config.Pull = GPIO_NOPULL;
  GPIO_Config.Speed = GPIO_SPEED_FREQ_HIGH;

  GPIO_Config.Pin = LED1_PIN;

  LED1_PORT_CLK_ENABLE();
  HAL_GPIO_Init(LED1_PORT, &GPIO_Config);

  __HAL_RCC_GPIOA_CLK_ENABLE();
}

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

  initGPIO();
  MX_USART2_UART_Init();

	//LedAlive_Init();

  printf("Hello, %s!\n", "Wokwi");

  HAL_GPIO_TogglePin(LED1_PORT, LED1_PIN);

  while (1) {
    	//LedAlive_Blink(PINledAlive, LEDBLINK_TIMEOUT);
  };

  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;
}

/* ================================================================
   =                                                              =
	 ================================================================ */
void LedAlive_Init(void) 
{
	pinMode(PINledAlive, OUTPUT);   // Onboard LED;
  digitalWrite(PINledAlive, LED_OFFSTATE);           // led off
}

/* ================================================================
   =                                                              =
	 ================================================================ */
void LedAlive_Blink(int ledport, uint32_t ledtimeout)
{
  if (ledtimeout == 0) return;
  
  static uint32_t ledPeriodTimeout = millis();
  static uint32_t ledOnTimeout = millis();
  static uint32_t ledCount = 0;
  
  if ((millis()-ledPeriodTimeout) > ledtimeout) {
    ledPeriodTimeout += ledtimeout;                           // reset Period counter  
    if( ++ledCount > LEDON_DIVIDER-1) {
      ledCount = 0;               // reset ON counter
      digitalWrite(ledport, LED_OFFSTATE);                             // led Off
    }
  }
  if (ledCount > LEDON_DIVIDER-2){
    if ((millis() - ledOnTimeout) > LEDFLICK_ON) {
      digitalWrite(ledport, !digitalRead(ledport));           // led toggle
      ledOnTimeout += LEDFLICK_ON;                            // reset ON counter      
    }
  }
}
#endif

// -------------------------------------------
#if 0
/*
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  SerialPrintf("%s\n\r", "Hello, STM32!");

  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, HIGH);

}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}
*/
#endif