#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <stm32f1xx_hal.h>

// LED is connected to PB0
#define LED_PORT                GPIOB
#define LED_PIN                 GPIO_PIN_0
#define LED_PORT_CLK_ENABLE     __HAL_RCC_GPIOB_CLK_ENABLE

// Button is connected to PA11 with pull-up (active low)
#define BUTTON_PORT             GPIOA
#define BUTTON_PIN              GPIO_PIN_1
#define BUTTON_PORT_CLK_ENABLE  __HAL_RCC_GPIOA_CLK_ENABLE



/* Private function prototypes */
void SystemClock_Config(void);
void RCC_SystemClock_Config(void);
void GPIO_Init(void);
void GPIO_Output_Config(void);
void Button_Init(void);

void Error_Handler(const char *error);

void SysTick_Handler(void)
{
    HAL_IncTick();

    // Check button state and control LED
    if (HAL_GPIO_ReadPin(BUTTON_PORT, BUTTON_PIN) == GPIO_PIN_RESET)
    {
        // Button is pressed (pulled to GND) - turn LED ON
        HAL_GPIO_WritePin(LED_PORT, LED_PIN, GPIO_PIN_SET);
    }
    else
    {
        // Button is released (pull-up) - turn LED OFF
        HAL_GPIO_WritePin(LED_PORT, LED_PIN, GPIO_PIN_RESET);
    }
}

int main(void)
{
   
    /* HAL initialization */
    HAL_Init();

    /* Set the SYSCLK at maximum frequency (72 MHz) */
    RCC_SystemClock_Config();

    GPIO_Init();
    GPIO_Output_Config();
    Button_Init();  // Initialize button
}

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.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;

    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
        Error_Handler("SystemClock config error");
    }

    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("SystemClock config error");
    }
}

void RCC_SystemClock_Config(void)
{
    RCC_ClkInitTypeDef rccClkInit;
    RCC_OscInitTypeDef rccOscInit;

    rccOscInit.OscillatorType = RCC_OSCILLATORTYPE_HSE;
    rccOscInit.HSEState       = RCC_HSE_ON;
    rccOscInit.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
    rccOscInit.PLL.PLLState   = RCC_PLL_ON;
    rccOscInit.PLL.PLLSource  = RCC_PLLSOURCE_HSE;
    rccOscInit.PLL.PLLMUL     = RCC_PLL_MUL9;

    if (HAL_RCC_OscConfig(&rccOscInit) != HAL_OK)
    {
        Error_Handler("RCC config error");
    }

    rccClkInit.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK |
                                 RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    rccClkInit.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK;
    rccClkInit.AHBCLKDivider  = RCC_SYSCLK_DIV1;
    rccClkInit.APB2CLKDivider = RCC_HCLK_DIV1;
    rccClkInit.APB1CLKDivider = RCC_HCLK_DIV2;

    if (HAL_RCC_ClockConfig(&rccClkInit, FLASH_LATENCY_2) != HAL_OK)
    {
        Error_Handler("RCC config error");
    }
}

void GPIO_Init(void)
{
    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);

    // Initially turn off the LED
    HAL_GPIO_WritePin(LED_PORT, LED_PIN, GPIO_PIN_RESET);

    __HAL_RCC_GPIOC_CLK_ENABLE();
    __HAL_RCC_GPIOA_CLK_ENABLE();
}

void Button_Init(void)
{
    GPIO_InitTypeDef GPIO_Config;

    BUTTON_PORT_CLK_ENABLE();

    GPIO_Config.Pin = BUTTON_PIN;
    GPIO_Config.Mode = GPIO_MODE_INPUT;
    GPIO_Config.Pull = GPIO_PULLUP;  // Internal pull-up resistor
    GPIO_Config.Speed = GPIO_SPEED_FREQ_HIGH;
    
    HAL_GPIO_Init(BUTTON_PORT, &GPIO_Config);
}

void GPIO_Output_Config(void)
{
    GPIO_InitTypeDef gpioInit;

    __HAL_RCC_GPIOB_CLK_ENABLE();

    gpioInit.Pin   = GPIO_PIN_7 | GPIO_PIN_8;
    gpioInit.Mode  = GPIO_MODE_OUTPUT_PP;
    gpioInit.Speed = GPIO_SPEED_FREQ_LOW;
    HAL_GPIO_Init(GPIOB, &gpioInit);
}

void Error_Handler(const char *error)
{
}