#include "stm32c0xx_hal.h"

#define RELAY_Pin GPIO_PIN_9
#define RELAY_GPIO_Port GPIOA
#define LDR_Pin   GPIO_PIN_0
#define LDR_GPIO_Port GPIOA

ADC_HandleTypeDef hadc1;

enum State { OFF=0, ON };

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_ADC1_Init(void);

void Set_Relay(uint8_t val)
{
    HAL_GPIO_WritePin(RELAY_GPIO_Port, RELAY_Pin, val ? GPIO_PIN_SET : GPIO_PIN_RESET);
}

uint16_t Read_LDR(void)
{
    HAL_ADC_Start(&hadc1);
    HAL_ADC_PollForConversion(&hadc1, HAL_MAX_DELAY);
    uint16_t val = HAL_ADC_GetValue(&hadc1);
    HAL_ADC_Stop(&hadc1);
    return val;
}

int main(void)
{
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    MX_ADC1_Init();

    enum State current_state = OFF;
    const uint16_t threshold = 2000;

    while(1)
    {
        uint16_t ldr_val = Read_LDR();

        switch(current_state)
        {
            case OFF:
                Set_Relay(0);
                if(ldr_val < threshold) current_state = ON;
                break;

            case ON:
                Set_Relay(1);
                if(ldr_val >= threshold) current_state = OFF;
                break;
        }

        HAL_Delay(100);
    }
}

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

    // Реле
    HAL_GPIO_WritePin(RELAY_GPIO_Port, RELAY_Pin, GPIO_PIN_RESET);
    GPIO_InitStruct.Pin = RELAY_Pin;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    HAL_GPIO_Init(RELAY_GPIO_Port, &GPIO_InitStruct);

    // LDR
    GPIO_InitStruct.Pin = LDR_Pin;
    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(LDR_GPIO_Port, &GPIO_InitStruct);
}

static void MX_ADC1_Init(void)
{
    ADC_ChannelConfTypeDef sConfig = {0};

    hadc1.Instance = ADC1;
    hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
    hadc1.Init.Resolution = ADC_RESOLUTION_12B;
    hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
    hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;
    hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
    hadc1.Init.LowPowerAutoWait = DISABLE;
    hadc1.Init.LowPowerAutoPowerOff = DISABLE;
    hadc1.Init.ContinuousConvMode = DISABLE;
    hadc1.Init.NbrOfConversion = 1;
    hadc1.Init.DiscontinuousConvMode = DISABLE;
    hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
    hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
    hadc1.Init.DMAContinuousRequests = DISABLE;
    hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;
    hadc1.Init.SamplingTimeCommon1 = ADC_SAMPLETIME_1CYCLE_5;
    hadc1.Init.OversamplingMode = DISABLE;
    if(HAL_ADC_Init(&hadc1) != HAL_OK) while(1);

    sConfig.Channel = ADC_CHANNEL_0;
    sConfig.Rank = ADC_REGULAR_RANK_1;
    sConfig.SamplingTime = ADC_SAMPLINGTIME_COMMON_1;
    if(HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK) while(1);
}

void SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

    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) while(1);

    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV1;
    if(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) while(1);
}

void Error_Handler(void) { __disable_irq(); while(1) {} }