#include <stdint.h>
#include <stdbool.h>
#include "tm4c123gh6pm.h"

void GPIO_PORT_F_init(void)
{
    SYSCTL_RCGC2_R |= 0x00000020;             // ENABLE CLOCK TO GPIOF
    GPIO_PORTF_LOCK_R = 0x4C4F434B;           // UNLOCK COMMIT REGISTER
    GPIO_PORTF_CR_R   = 0x1F;                 // MAKE PORTF0 CONFIGURABLE
    GPIO_PORTF_DEN_R  = 0x1F;                 // SET PORTF DIGITAL ENABLE
    GPIO_PORTF_DIR_R  = 0x0E;                 // SET PF0, PF4 as input and PF1, PF2 and PF3 as output
    GPIO_PORTF_PUR_R  = 0x11;                 // PORTF PF0 and PF4 IS PULLED UP

    NVIC_EN0_R |= 1 << 30;
    GPIO_PORTF_IS_R  = 0x00;                 // Make it edge-sensitive
    GPIO_PORTF_IBE_R = 0x00;                 // Trigger on one edge
    GPIO_PORTF_IEV_R = 0x00;                  // Falling edge event
    GPIO_PORTF_IM_R  |= 0x11;                  // Unmask interrupts for PF0 and PF4
}

void GPIO_PORT_B_init(void)
{

        SYSCTL_RCGCGPIO_R |= 0x02;       // Enable clock to GPIOB
        SYSCTL_RCGCUART_R |= 0x02;       // Enable UART1 clock

        GPIO_PORTB_DEN_R |= 0x03;        // Enable PB0, PB1 as digital
        GPIO_PORTB_AFSEL_R |= 0x03;      // Enable alternate function on PB0, PB1

        GPIO_PORTB_PCTL_R = (GPIO_PORTB_PCTL_R & 0xFFFFFF00) | 0x00000011; // Set PB0, PB1 for UART

        UART1_CTL_R &= ~0x01;            // Disable UART1 during setup
        UART1_IBRD_R = 104;              // Set integer part of baud rate (for 9600 baud at 16 MHz clock)
        UART1_FBRD_R = 11;               // Set fractional part of baud rate
        UART1_LCRH_R = 0x62;             // 8-bit, odd parity, 1 stop bit
        UART1_CC_R = 0x00;               // Use system clock

        UART1_CTL_R |= 0x301;            // Enable UART1, RX, and TX

}

void UART1_WRITE(char data)
{
    while (UART1_FR_R & 0x20);       // Wait until TX FIFO is not full
    UART1_DR_R = data;               // Write data to UART data register
}

char UART1_READ(void)
{
    while (UART1_FR_R & 0x10);       // Wait until RX FIFO is not empty
    return (char)UART1_DR_R;         // Return received data
}

#define STCTRL *((volatile uint32_t *) 0xE000E010)          // control and status
#define STRELOAD *((volatile uint32_t *) 0xE000E014)        // reload value
#define STCURRENT *((volatile uint32_t *) 0xE000E018)       // current value

#define CLOCK_HZ 16000000       // CLOCK FREQUENCY OF EK-TM4C123GXL
#define SYSTICK_RELOAD_VALUE(us) ((CLOCK_HZ / 1000000) * (us) - 1)  // SYSTICK RELOAD VALUE

void systick_setting(void)                      // SYSTICK SETUP FUNCTION
{
    STRELOAD = SYSTICK_RELOAD_VALUE(1000);     // RELOAD VALUE FOR 1ms
    STCTRL |= (1 << 0) | (1 << 2);              // Enable SysTick with system clock
    STCURRENT = 0;                               // Clear current value
}


void delay(int us)                              //DEFINING DELAY FUNCTION
{
    STRELOAD = SYSTICK_RELOAD_VALUE(us);        // RELOAD VALUE FOR REQUIRED DELAY
    STCURRENT = 0;                               // Clear STCURRENT
    STCTRL |= (1 << 0) | (1 << 2);              // Enable SysTick
    while ((STCTRL & (1 << 16)) == 0);          // Wait until flag is set
    STCTRL &= 0x0;                               // Stop the timer
}

void STATUS_LED(char received_data)
{
    if (received_data == 0xAA)
    {
        GPIO_PORTF_DATA_R |= 0x08;   // Turn on Green LED (PF3)
        GPIO_PORTF_DATA_R &= ~0x04;  // Turn off Blue LED (PF2)

    }
    else if (received_data == 0xF0)
    {
        GPIO_PORTF_DATA_R |= 0x04;   // Turn on Blue LED (PF2)
        GPIO_PORTF_DATA_R &= ~0x08;  // Turn off Green LED (PF3)
    }
    else
    {
     GPIO_PORTF_DATA_R |= 0x02;
    }
    //delay(500000);
    //GPIO_PORTF_DATA_R &= 0x00;   // Turn on Green LED (PF3)

}


void GPIOF_interruptHandler(void)               // Interrupt handler for GPIO Port F
{
    //delay(200000); // Debounce delay
    // Check PF4 (Switch 2)
    if (GPIO_PORTF_RIS_R & 0x10)  // Check if PF4 caused the interrupt
    {
        //GPIO_PORTF_DATA_R |= 0x02;              // Toggle RED LED (PF1)
        //delay(500000);
        UART1_WRITE(0xF0);
        STATUS_LED(UART1_READ());
        //GPIO_PORTF_DATA_R = 0x00;              // Toggle RED LED (PF1)
        GPIO_PORTF_ICR_R = 0x10;                // Clear interrupt flag for PF4
    }

    // Check PF0 (Switch 1)
    if (GPIO_PORTF_RIS_R & 0x01)  // Check if PF0 caused the interrupt
    {
        //GPIO_PORTF_DATA_R |= 0x04;              // Toggle RED LED (PF1)
        //delay(500000);
        UART1_WRITE(0xAA);
        //GPIO_PORTF_DATA_R = 0x00;
        STATUS_LED(UART1_READ());
        GPIO_PORTF_ICR_R = 0x01;                // Clear interrupt flag for PF0
    }
}
int main(void)                                 // MAIN FUNCTION
{
    GPIO_PORT_F_init();                        // GPIO INITIALISATION FUNCTION
    GPIO_PORT_B_init();
    systick_setting();                         // SYSTICK SETUP
    while (1)
    {
        STATUS_LED(UART1_READ());
    }
}