#include "main.h"

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

int main(void)
{
    HAL_Init();

    SystemClock_Config();

    MX_GPIO_Init();

    GPIO_PinState last_button_state = GPIO_PIN_RESET;
    GPIO_PinState current_button_state;

    while (1)
    {
        current_button_state =
            HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_9);

        /* Detect button press */
        if ((current_button_state == GPIO_PIN_SET) &&
            (last_button_state == GPIO_PIN_RESET))
        {
            HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_11);

            /* Debounce */
            HAL_Delay(200);
        }

        last_button_state = current_button_state;
    }
}


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

    RCC_OscInitStruct.OscillatorType =
        RCC_OSCILLATORTYPE_HSE;

    RCC_OscInitStruct.HSEState =
        RCC_HSE_ON;

    RCC_OscInitStruct.HSEPredivValue =
        RCC_HSE_PREDIV_DIV1;

    RCC_OscInitStruct.HSIState =
        RCC_HSI_ON;

    RCC_OscInitStruct.PLL.PLLState =
        RCC_PLL_ON;

    RCC_OscInitStruct.PLL.PLLSource =
        RCC_PLLSOURCE_HSE;

    RCC_OscInitStruct.PLL.PLLMUL =
        RCC_PLL_MUL9;

    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    {
        Error_Handler();
    }

    RCC_ClkInitStruct.ClockType =
        RCC_CLOCKTYPE_HCLK |
        RCC_CLOCKTYPE_SYSCLK |
        RCC_CLOCKTYPE_PCLK1 |
        RCC_CLOCKTYPE_PCLK2;

    RCC_ClkInitStruct.SYSCLKSource =
        RCC_SYSCLKSOURCE_PLLCLK;

    RCC_ClkInitStruct.AHBCLKDivider =
        RCC_SYSCLK_DIV1;

    RCC_ClkInitStruct.APB1CLKDivider =
        RCC_HCLK_DIV2;

    RCC_ClkInitStruct.APB2CLKDivider =
        RCC_HCLK_DIV1;

    if (HAL_RCC_ClockConfig(
            &RCC_ClkInitStruct,
            FLASH_LATENCY_2) != HAL_OK)
    {
        Error_Handler();
    }
}


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

    __HAL_RCC_GPIOA_CLK_ENABLE();

    /* =====================================================
       PA11 = LED
       ===================================================== */

    HAL_GPIO_WritePin(
        GPIOA,
        GPIO_PIN_11,
        GPIO_PIN_RESET
    );

    GPIO_InitStruct.Pin =
        GPIO_PIN_11;

    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
    );


    /* =====================================================
       PA9 = BUTTON
       ===================================================== */

    GPIO_InitStruct.Pin =
        GPIO_PIN_9;

    GPIO_InitStruct.Mode =
        GPIO_MODE_INPUT;

    GPIO_InitStruct.Pull =
        GPIO_PULLDOWN;

    GPIO_InitStruct.Speed =
        GPIO_SPEED_FREQ_LOW;

    HAL_GPIO_Init(
        GPIOA,
        &GPIO_InitStruct
    );
}


void Error_Handler(void)
{
    __disable_irq();

    while (1)
    {
    }
}