#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stm32l0xx_hal.h>

#define ADC_CHANNEL ADC_CHANNEL_6  // ADC channel corresponding to PA7 (A6)

// Define PWM period value
uint32_t period = 1000; // 1 kHz PWM frequency

// Timer handle and channel
TIM_HandleTypeDef htim2;
uint32_t channel = TIM_CHANNEL_1;

// LED pin configuration
GPIO_InitTypeDef led_pin;

// ADC handle
ADC_HandleTypeDef hadc;

// Function prototypes
void SystemClock_Config(void);
void Error_Handler(void);

int main(void)
{
  // Initialize HAL
  HAL_Init();

  // Configure system clock
  SystemClock_Config();

  // Configure LED pin for A6 (PA7)
  led_pin.Pin = GPIO_PIN_7;
  led_pin.Mode = GPIO_MODE_AF_PP;
  led_pin.Pull = GPIO_NOPULL;
  led_pin.Speed = GPIO_SPEED_FREQ_HIGH;
  HAL_GPIO_Init(GPIOA, &led_pin);

  // Configure TIM2 for PWM
  htim2.Instance = TIM2;
  htim2.Init.Prescaler = 4; // Set prescaler for desired PWM frequency
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = period;
  htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
  HAL_TIM_PWM_Init(&htim2);

  // Start PWM on channel 1
  HAL_TIM_PWM_Start(&htim2, channel);

  // Configure ADC
  __HAL_RCC_ADC1_CLK_ENABLE();
  hadc.Instance = ADC1;
  hadc.Init.ClockPrescaler = ADC_CLOCKPRESCALER_PCLK_DIV4;
  hadc.Init.Resolution = ADC_RESOLUTION12b;
  hadc.Init.ScanConvMode = DISABLE;
  hadc.Init.ContinuousConvMode = DISABLE;
  hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
  HAL_ADC_Init(&hadc);

  // Configure PA7 (A6) as analog input
  ADC_ChannelConfTypeDef sConfig;
  sConfig.Channel = ADC_CHANNEL_6;
  sConfig.Rank = 1;
  hadc.Init.SamplingTime = ADC_SAMPLETIME_19CYCLES_5;
  HAL_ADC_ConfigChannel(&hadc, &sConfig);

  while (1)
  {
    uint16_t adc_value;

    HAL_ADC_Start(&hadc);
    HAL_ADC_PollForConversion(&hadc, HAL_MAX_DELAY);
    adc_value = HAL_ADC_GetValue(&hadc);

    // Map ADC value to duty cycle range (0 to period)
    uint32_t duty_cycle = (adc_value * period) / 4095;

    // Update PWM duty cycle
    __HAL_TIM_SET_COMPARE(&htim2, channel, duty_cycle);

    // Print ADC value for debugging
    printf("ADC Value: %d\n", adc_value);

    HAL_Delay(100);
  }

  return 0;
}

// System Clock Configuration
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  // Configure the main internal regulator output voltage
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  // Initializes the CPU, AHB, and APB busses clocks
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  // Initializes the CPU, AHB, and APB busses clocks
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}

// Error Handler
void Error_Handler(void)
{
  while (1)
  {
    // Error occurred, stay in an infinite loop
  }
}

#ifdef USE_FULL_ASSERT
void assert_failed(uint8_t *file, uint32_t line)
{
  // User can add their own implementation to report the file name and line number,
  // ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line)
  while (1)
  {
  }
}
#endif