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

#define DEBUG 1

uint8_t ident_code = 0;

void prompt_message();
void parse_message();
void normalize_pot_readings(int adc_raw, bool percentage);
int get_pot_readings();
void send_ident_controller(uint8_t code);
void send_message(char *message); 
void get_identification_code();
void sample_register();
void pulse_clock();

const uint32_t clockPin = 3;
const uint32_t dataPin = 2;
const uint32_t latchPin = 4;
const uint32_t analogPotPin = 26;
const uint adc_max = (1 << 12) - 1;

int main() {
  stdio_init_all();

  gpio_init(clockPin);
  gpio_set_dir(clockPin, GPIO_OUT);

  gpio_init(latchPin);
  gpio_set_dir(latchPin, GPIO_OUT);

  gpio_init(dataPin);
  gpio_set_dir(dataPin, GPIO_IN);

  adc_init();
  adc_gpio_init(analogPotPin);

  prompt_message();
  while (1) {
    /*
    get_identification_code();
    sleep_ms(500);

    send_ident_controller(ident_code);
    
    get_pot_readings();
    normalize_pot_readings(get_pot_readings(),false);

    */
    parse_message();
    //sleep_ms(500);


  }

}

void prompt_message() {
  printf("Write a message please \n");
}
void parse_message() {
  char c = getchar();
  printf("%c", c);
}

void normalize_pot_readings(int adc_raw, bool percentage) {
  float value;
  if (percentage) {
    value = (adc_raw / (float)adc_max);
  } else {
    value = (adc_raw / (float)adc_max) - .5f;
  }

    if (DEBUG) {
    printf("raw values : %d \t normalized values %.2f \n",
                         adc_raw,
                         value); 
    }
}

int get_pot_readings() {
  adc_select_input(0);
  int adc = adc_read();
  return adc;
}

void send_ident_controller(uint8_t code) {
  switch(code) {
    case 0xff:
    send_message("Potentiometer identified");
    break;

    default:
    send_message("Keyboard identified");
  }

}
void send_message(char *message) {
  printf(message);
  printf("\n");
}
void get_identification_code() {
  sample_register();
    for (int i = 0; i <= 7; i++) {
      uint8_t buf;
      buf = gpio_get(dataPin);
      ident_code = (ident_code << 1) + buf;
      pulse_clock();
    }
}

void sample_register() {
  gpio_put(latchPin, 0);
  gpio_put(latchPin, 1);
}

void pulse_clock() {
  gpio_put(clockPin, 1); // Shift out the next bit
  gpio_put(clockPin, 0);
}