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

// Define pin assignments
#define LED_RED_PIN       GPIO_PIN_4
#define LED_GREEN_PIN     GPIO_PIN_11
#define LED_TEAL_PIN      GPIO_PIN_9
#define LED_WHITE_PIN     GPIO_PIN_15

#define LED_PORT_CLK_ENABLE     __HAL_RCC_GPIOA_CLK_ENABLE

UART_HandleTypeDef huart2;

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

int main(void)
{
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    MX_USART2_UART_Init();

    char welcome_msg[] = "Input commands: RED_ON/GREEN_ON/TEAL_ON/WHITE_ON or RED_OFF/GREEN_OFF/TEAL_OFF/WHITE_OFF\n";
    HAL_UART_Transmit(&huart2, (uint8_t *)welcome_msg, strlen(welcome_msg), 100);

    char buffer[32]; 
    memset(buffer, 0, sizeof(buffer));

    while (1)
    {
        
        uint16_t i = 0;
        char c = 0;
        while (i < sizeof(buffer) - 1) {
            if (HAL_UART_Receive(&huart2, (uint8_t *)&c, 1, HAL_MAX_DELAY) == HAL_OK) {
                if (c == '\n') break; 
                buffer[i++] = c;
            }
        }
        buffer[i] = '\0'; 

        
        HAL_UART_Transmit(&huart2, (uint8_t *)buffer, strlen(buffer), 100);
        HAL_UART_Transmit(&huart2, (uint8_t *)"\n", 1, 100); 

        
        if (strstr(buffer, "RED_ON")) {
            HAL_GPIO_WritePin(GPIOA, LED_RED_PIN, GPIO_PIN_SET);
            HAL_UART_Transmit(&huart2, (uint8_t *)"RED_ON\n", strlen("RED_ON\n"), 100);
        }
        else if (strstr(buffer, "RED_OFF")) {
            HAL_GPIO_WritePin(GPIOA, LED_RED_PIN, GPIO_PIN_RESET);
            HAL_UART_Transmit(&huart2, (uint8_t *)"RED_OFF\n", strlen("RED_OFF\n"), 100);
        }
        else if (strstr(buffer, "GREEN_ON")) {
            HAL_GPIO_WritePin(GPIOA, LED_GREEN_PIN, GPIO_PIN_SET);
            HAL_UART_Transmit(&huart2, (uint8_t *)"GREEN_ON\n", strlen("GREEN_ON\n"), 100);
        }
        else if (strstr(buffer, "GREEN_OFF")) {
            HAL_GPIO_WritePin(GPIOA, LED_GREEN_PIN, GPIO_PIN_RESET);
            HAL_UART_Transmit(&huart2, (uint8_t *)"GREEN_OFF\n", strlen("GREEN_OFF\n"), 100);
        }
        else if (strstr(buffer, "TEAL_ON")) {
            HAL_GPIO_WritePin(GPIOA, LED_TEAL_PIN, GPIO_PIN_SET);
            HAL_UART_Transmit(&huart2, (uint8_t *)"TEAL_ON\n", strlen("TEAL_ON\n"), 100);
        }
        else if (strstr(buffer, "TEAL_OFF")) {
            HAL_GPIO_WritePin(GPIOA, LED_TEAL_PIN, GPIO_PIN_RESET);
            HAL_UART_Transmit(&huart2, (uint8_t *)"TEAL_OFF\n", strlen("TEAL_OFF\n"), 100);
        }
        else if (strstr(buffer, "WHITE_ON")) {
            HAL_GPIO_WritePin(GPIOA, LED_WHITE_PIN, GPIO_PIN_SET);
            HAL_UART_Transmit(&huart2, (uint8_t *)"WHITE_ON\n", strlen("WHITE_ON\n"), 100);
        }
        else if (strstr(buffer, "WHITE_OFF")) {
            HAL_GPIO_WritePin(GPIOA, LED_WHITE_PIN, GPIO_PIN_RESET);
            HAL_UART_Transmit(&huart2, (uint8_t *)"WHITE_OFF\n", strlen("WHITE_OFF\n"), 100);
        }

        memset(buffer, 0, sizeof(buffer)); 
    }

    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();
  }
}


static void MX_GPIO_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    __HAL_RCC_GPIOA_CLK_ENABLE();

    // Initialize LED GPIOs
    GPIO_InitStruct.Pin = LED_RED_PIN | LED_GREEN_PIN | LED_TEAL_PIN | LED_WHITE_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    // Set all LEDs off initially
    HAL_GPIO_WritePin(GPIOA, LED_RED_PIN | LED_GREEN_PIN | LED_TEAL_PIN | LED_WHITE_PIN, GPIO_PIN_RESET);
}

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;
}
*/