/*
 * File:   main.c
 * Author: sfokin
 *
 * Created on March 17, 2024, 6:05 AM
 */
#pragma config FOSC = INTRCIO  // Oscillator Selection bits (INTOSC oscillator: CLKOUT function on GP4/OSC2/CLKOUT pin, I/O function on GP5/OSC1/CLKIN)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF      // Power-Up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = OFF      // GP3/MCLR pin function select (GP3/MCLR pin function is digital I/O, MCLR internally tied to VDD)
#pragma config BOREN = OFF      // Brown-out Detect Enable bit (BOD disabled)
#pragma config CP = OFF         // Code Protection bit (Program Memory code protection is disabled)
#pragma config CPD = OFF        // Data Code Protection bit (Data memory code protection is disabled)
#define _XTAL_FREQ 4000000
#define INPUT_PINS 0b00111011   // Pins: 0,1,3,4,5

#include <xc.h>
#include "common.h"
#include "main.h"
char STATE;
char btnState;

void __interrupt() handleInterrupt(void)
{
    clear_bit(INTCON, 7);
    
    if(test_bit(INTCON, 0))
    {
        handleIOC();
    }
    
    if(test_bit(PIR1, 0))
    {   
        handleTMR1(); 
    }
    
    set_bit(INTCON, 7);
    return;
}

void main(void)
{
    init();
    
    while(1)
    {
        sleep();
    }
    
    return;
}

static inline void init()
{
    //Configure GPIO
    GPIO = 0x0;                 //Clear GPIO port
    TRISIO = 0;                 //Clear TRISIO register
    ANSEL = 0;                  //Set all pins to digital IO
    TRISIO = INPUT_PINS;        //Set 0,1,3,4,5 pins as input
    INTCONbits.GIE = 1;         //Allow Global interrupts;
    INTCONbits.GPIE = 1;        //Allow interrupt on pin change
    clear_bit(OPTION_REG, 7);   //Global weak pull-up enable
    WPU = INPUT_PINS;           //Weak pull-up for 0,1,3,4,5 pins
    IOC = INPUT_PINS;           //IOC enable for 0,1,3,4,5 pins
    
    //Configure Timer 1
    TMR1 = 0;                   //Clear timer 1 value
    T1CONbits.TMR1ON = 0;       //Turn timer 1 Off
    T1CONbits.T1CKPS0 = 1;      //Set prescale 1:8
    T1CONbits.T1CKPS1 = 1;
    PIE1bits.TMR1IE = 1;        //Enable timer 1 overflow interrupt
    INTCONbits.PEIE = 1;        //Enable peripheral interrupt
       
    //Set default state
    STATE = 0;
}

static inline void handleTMR1()
{
    flip_bit(GPIO, 2);
    TMR1 = 0;
    clear_bit(PIR1, 0);
}

static inline void handleIOC()
{

    handleButtons(0);
    handleButtons(1);
    handleButtons(3);
    handleButtons(4);
    handleButtons(5);
    if(test_bit(btnState, 5))
    {
        STATE = STATE == 0 ? 1 : 0;
        TMR1 = 0;
        clear_bit(PIR1, 0);
    }

    clear_bit(INTCON, 0);
}

static inline void sleep()
{
    //prepare and go to sleep
    clear_bit(GPIO, 2); //Turn off led
    SLEEP();
}

static inline void handleButtons(char bit)
{
    clear_bit(btnState, bit);
    if(!test_bit(GPIO, bit))
    {
        __delay_ms(10);            
    }
    if(!test_bit(GPIO, bit))
    {
        set_bit(btnState, bit);
    }
}