#include <stdio.h>
#include "pico/stdlib.h"
#include "hardware/pio.h"
#include "hardware/gpio.h"
#include "stdlib.h"
#include "unistd.h"

// Define pins
const unsigned uint8_t pins[] = {
	// Rotary encoder
	{ "EN_PhaseA", 10, GPIO_OUT},
	{ "EN_PhaseB", 11, GPIO_OUT},
	{ "EN_switch", 12, GPIO_OUT}, // SW
	// Switch register
	{ "SR_data", 13, GPIO_OUT}, // data pin
	{ "SR_latch", 14, GPIO_OUT}, // latch pin
	{ "SR_clock", 15, GPIO_OUT}, // clock pin
	// Test pin
	{ "T_LED", 20, GPIO_OUT},
};
const uint8_t pinCount = 24;
// Define bit strings
const char* bitString = "101010101010101010101010";
const char* prvString = "";
// Initialise pins
void init_pins() {

	// Initialize GPIO pin
	gpio_init(pins[3]);
	// Set GPIO pin directions
	gpio_set_dir(pins[3], GPIO_OUT);
}
// returns the output from the encoder
void encoder_callback(uint gpio, uint32_t events) {
	uint32_t gpio_state = 0;

	gpio_state = (gpio_get_all() >> 10) & 0b0111;  	// get all GPIO them mask out all but bits 10, 11, 12
													// This will need to change to match which GPIO pins are being used.
	
	static bool ccw_fall = 0;  //bool used when falling edge is triggered
	static bool cw_fall = 0;
	uint8_t enc_value = 0;

	enc_value = (gpio_state & 0x03);
	if (gpio == pins[0]) {
		if ((!cw_fall) && (enc_value == 0b10)) // cw_fall is set to TRUE when phase A interrupt is triggered
			cw_fall = 1; 
		if ((ccw_fall) && (enc_value == 0b00)) {  // if ccw_fall is already set to true from a previous B phase trigger, the ccw event will be triggered  
			cw_fall = 0;
			ccw_fall = 0;
			//do something here,  for now it is just printing out CW or CCW
			printf("CCW \r\n");
		}
	}
	if (gpio == pins[1]) {
		if ((!ccw_fall) && (enc_value == 0b01)) //ccw leading edge is true
			ccw_fall = 1;

		if ((cw_fall) && (enc_value == 0b00)) { //cw trigger
			cw_fall = 0;
			ccw_fall = 0;
			//do something here,  for now it is just printing out CW or CCW
			printf("CW \r\n");
		}
	}	
}
// Function to shift data into the 74HC595 register
void shift(const char* data) {
	// Start data sending
	gpio_put(pins[4], 0);
	gpio_put(pins[5], 0);
	gpio_put(pins[4], 1);

	// Load data in reverse order
	for (int i = 0; i < pinCount; i++) {
		gpio_put(pins[5], 0);
		gpio_put(pins[3], (data[i] == '1') ? 1 : 0);
		gpio_put(pins[5], 1);
	}

	// Store data on register
	gpio_put(pins[4], 0);
	gpio_put(pins[4], 1);
}

int main() {
	stdio_init_all();

	// Initialize GPIO pins
	init_pins();

	gpio_put(pins[6], 1);

	while (1) {
		if(prvString != bitString) {
		// Call the shift function
		shift(bitString);
		prvString = bitString;
		sleep_ms(500);
		}
	}
}