#include <stdint.h>

#define GPIO

#define RCC_BASE       0x40021000U
#define GPIOA_BASE     0x50000000U
#define LED_RED 5
#define LED_BLUE 4
#define Push_Button 3

#define RCC_IOPENR     (*(volatile uint32_t *)(RCC_BASE + 0x2C))
#define GPIOA_MODER    (*(volatile uint32_t *)(GPIOA_BASE + 0x00))
#define GPIOA_OTYPER    (*(volatile uint32_t *)(GPIOA_BASE + 0x04))
#define GPIOA_OSPEEDR    (*(volatile uint32_t *)(GPIOA_BASE + 0x08))
#define GPIOA_PUPDR    (*(volatile uint32_t *)(GPIOA_BASE + 0x0C))
#define GPIOA_IDR    (*(volatile uint32_t *)(GPIOA_BASE + 0x10))
#define GPIOA_ODR      (*(volatile uint32_t *)(GPIOA_BASE + 0x14))
#define GPIOA_BSRR      (*(volatile uint32_t *)(GPIOA_BASE + 0x18))

#define GPIO_PIN_0 0U
#define GPIO_PIN_1 1U
#define GPIO_PIN_2 2U
#define GPIO_PIN_3 3U
#define GPIO_PIN_4 4U
#define GPIO_PIN_5 5U
#define GPIO_PIN_6 6U
#define GPIO_PIN_7 7U
#define GPIO_PIN_8 8U
#define GPIO_PIN_9 9U
#define GPIO_PIN_10 10U
#define GPIO_PIN_11 11U
#define GPIO_PIN_12 12U
#define GPIO_PIN_13 13U
#define GPIO_PIN_14 14U
#define GPIO_PIN_15 15U

typedef enum {
    Input = 0U,
    Output,
    Analog,
    Alternative
} GPIO_MODE_t;

typedef enum {
    Push_Pull = 0U,
    Open_Drain

} GPIO_OTYPE_t;


typedef enum{
    Low_Speed = 0U,
    Medium_Speed,
    High_Speed,
    Very_High_Speed
}
GPIO_OSPEED_t;

typedef enum{
    No_Pull = 0U,
    Pull_Up,
    Pull_Down,
    Reserved
}
GPIO_PUPD_t;

typedef enum {
    GPIO_LOW = 0U,
    GPIO_HIGH
} GPIO_Value_t;


void delay(void){
  for (volatile uint32_t i = 0; i < 500000U; i++);
}

void GPIO_Init(uint8_t pin, GPIO_MODE_t mode, GPIO_OTYPE_t outputType, GPIO_OSPEED_t outputSpeed, GPIO_PUPD_t pullUpDown)
{
    GPIOA_MODER &= ~(3UL << (pin * 2));
    GPIOA_MODER |= ((uint32_t)(mode << (pin*2))); // Setiing Mode(Output,Input,Alternate,Analog) 

    GPIOA_OTYPER &= ~(1UL << pin);
    GPIOA_OTYPER |= (uint32_t)(outputType << pin); // Setting PullUpDown or Open drain

    GPIOA_OSPEEDR &= ~(3UL << (pin * 2));
    GPIOA_OSPEEDR |= ((uint32_t)(outputSpeed << (pin*2))); // Setting Speed of GPIO pin

    GPIOA_PUPDR  &= ~(3UL << (pin * 2));
    GPIOA_PUPDR  |= ((uint32_t)(pullUpDown << (pin*2))); //Setting GPIO as Pull Up or Down

}


void GPIO_Write(uint8_t pin, GPIO_Value_t value){
  if(value){

        GPIOA_BSRR = (1UL << pin); //Set the pin or On the LED
        // port->BSRR |= (1UL << pin);
    }
  else{

        GPIOA_BSRR = (1UL << (pin + 16U)); // Reset the pin or Off the LED
        // port->BSRR |= (1UL << (pin + 16));
      }  
}

GPIO_Value_t GPIO_Read(uint8_t pin)
{
    if (GPIOA->IDR & (1U << pin))
    {
        return GPIO_HIGH;
    }
    else
    {
        return GPIO_LOW;
    }
}

int main(void)
{
  GPIO_Init(LED_RED,Output,Push_Pull,Low_Speed,No_Pull);
  GPIO_Init(LED_BLUE,Output,Push_Pull,Low_Speed,No_Pull);
  GPIO_Init(Push_Button,Output,Push_Pull,Low_Speed,Pull_Down);

    while (1)
    {
      GPIO_Value_t readbutton = GPIO_Read(Push_Button);
      if(readbutton == 1){
        GPIO_Write(LED_RED,GPIO_HIGH);
        GPIO_Write(LED_BLUE,GPIO_LOW);
      }
      else{
        GPIO_Write(LED_RED,GPIO_LOW);
        GPIO_Write(LED_BLUE,GPIO_HIGH);
      }
    }
}