#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
//#include <Adafruit_Si5351.h>
#include "si5351.h"
#include "stdlib.h"
#include "hardware/adc.h"
#include "hardware/gpio.h"
//#include "pgmspace.h"

// User Preferences
#define IF         455
#define BAND_INIT  2
#define XT_CAL_F   33000
#define S_GAIN     303
#define tunestep   1
#define band       2
#define rx_tx      0  
#define adc        26 

// Encoder Pins
#define ENCODER_PIN_A 7   // GPIO2
#define ENCODER_PIN_B 8   // GPIO3
#define ENCODER_BUTTON 9   // GPIO3

Adafruit_SSD1306 display = Adafruit_SSD1306(128, 64, &Wire);
//Adafruit_Si5351 si5351 = Adafruit_Si5351(0x60);
Si5351  si5351(0x60);

unsigned long freq, freqold, fstep;
long  interfreq = IF, interfreqold = 0;
long cal = XT_CAL_F;
unsigned int smval;
long encoder = 0;
byte stp, n = 1;
byte count, x, xo;
bool sts = 0;
unsigned int period = 100;
unsigned long time_now = 0;

void setup() {
    // Initialize Pico ADC
    adc_init();
    adc_gpio_init(adc);

    // Initialize I2C
    Wire.begin();
    display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
    display.clearDisplay();
    display.setTextColor(WHITE);
    display.display();

    // Set up GPIO Pins
    gpio_init(tunestep);
    gpio_set_dir(tunestep, GPIO_IN);
    gpio_pull_up(tunestep);

    gpio_init(band);
    gpio_set_dir(band, GPIO_IN);
    gpio_pull_up(band);

    gpio_init(rx_tx);
    gpio_set_dir(rx_tx, GPIO_IN);
    gpio_pull_up(rx_tx);

    si5351.init(SI5351_CRYSTAL_LOAD_8PF, 0, 0);
    si5351.set_correction(cal, SI5351_PLL_INPUT_XO);
    si5351.drive_strength(SI5351_CLK0, SI5351_DRIVE_8MA);
    si5351.output_enable(SI5351_CLK0, 1);
    si5351.output_enable(SI5351_CLK1, 0);
    si5351.output_enable(SI5351_CLK2, 0);

    count = BAND_INIT;
    bandpresets();
    stp = 4;
    setstep();
}

void loop() {
    long newPosition = encoderRead();  // Custom function for encoder read on Pico
    if (newPosition != encoder) {
        if (newPosition > encoder) {
            set_frequency(1);  // Clockwise
        } else {
            set_frequency(-1); // Counter-clockwise
        }
        encoder = newPosition;
    }

    if (freqold != freq) {
        time_now = to_ms_since_boot(get_absolute_time());
        tunegen();
        freqold = freq;
    }

    if (interfreqold != interfreq) {
        time_now = to_ms_since_boot(get_absolute_time());
        tunegen();
        interfreqold = interfreq;
    }

    if (xo != x) {
        time_now = to_ms_since_boot(get_absolute_time());
        xo = x;
    }

    if (gpio_get(tunestep) == 0) {
        time_now = to_ms_since_boot(get_absolute_time()) + 300;
        setstep();
        sleep_ms(300);
    }

    if (gpio_get(band) == 0) {
        time_now = to_ms_since_boot(get_absolute_time()) + 300;
        inc_preset();
        sleep_ms(300);
    }

    if (gpio_get(rx_tx) == 0) {
        time_now = to_ms_since_boot(get_absolute_time()) + 300;
        sts = 1;  // TX mode
    } else {
        sts = 0;  // RX mode
    }

    if ((time_now + period) > to_ms_since_boot(get_absolute_time())) {
        displayfreq();
        layout();
    }
    sgnalread();
}

// Other functions remain unchanged with slight modifications to read GPIOs, use Pico's `sleep_ms` instead of `delay`, and handle ADC differently.

void encoderRead() {
    // Implement the encoder reading logic using GPIO on Pico
}

// Other functions remain unchanged, adapted for Pico-specific GPIO and ADC calls.