// Learn about the ESP32 WiFi simulation in
// https://docs.wokwi.com/guides/esp32-wifi

#include <Wire.h>
#include <WiFi.h>
#include <Fsm.h>
#include <JC_Button.h>
#include <DS3232RTC.h>
#include <LiquidCrystal_I2C.h>

#define BUTTON_PIN_UP 18
#define BUTTON_PIN_DOWN 5
#define BUTTON_PIN_MENU_SELECT 19
#define BUTTON_PIN_BACK 4

#define SQW_PIN 23

#define DEBOUNCE_MS 20
#define PULLUP true
#define INVERT false

LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2);
DS3232RTC RTC;

/*
   Symbols
*/
byte bell_symbol[8] = {
  B00100,
  B01110,
  B01110,
  B01110,
  B01110,
  B11111,
  B00000,
  B00100
};

/*
   States of FSM
*/
enum STATES 
{
  MAIN,
  MENU_SET_ALARM,
  MENU_SET_TIME,
  MENU_SET_DATE,

  SET_HOUR,
  SET_MINUTE,

  SET_DAY,
  SET_MONTH,
  SET_YEAR,

  SET_ALARM_HOUR,
  SET_ALARM_MINUTE,
  SET_ALARM_ON_OFF,
  ALARM_TIME,
  // Otherwise, it times out after 5 seconds, discards the changes and returns to displaying the time
};

STATES state = MAIN;

enum BUTTONS
{
  BUTTON_LEFT,
  BUTTON_RIGHT,
  BUTTON_UP,
  BUTTON_DOWN,
  BUTTON_OK,
  BUTTON_BACK
};

int Hour;
int Minute;
int Second;

/*
   Transition callback functions
*/
void on_page_exit();
void on_main_page_enter();
void main_page_on_state();
void on_set_time_page_enter();
void set_time_page_on_state();

boolean is_button_prassed(Button button);
void check_button();
void get_time();
void display_time();
byte decToBcd(byte val);
byte bcdToDec(byte val);
void display_position(int digits);

/*
   Initialize push buttons
*/
Button buttonSelect(BUTTON_PIN_MENU_SELECT, DEBOUNCE_MS, PULLUP, INVERT);

/*
   Initialize states of fsm
*/
State state_main_page(&on_main_page_enter,
                      &main_page_on_state,
                      &on_page_exit);
State state_set_time_page(&on_set_time_page_enter,
                         &set_time_page_on_state,
                         &on_page_exit);

Fsm fsm(&state_main_page);

void spinner() {
  static int8_t counter = 0;
  const char* glyphs = "\xa1\xa5\xdb";
  LCD.setCursor(15, 1);
  LCD.print(glyphs[counter++]);
  if (counter == strlen(glyphs)) {
    counter = 0;
  }
}

void setup() {
  Serial.begin(115200);

  LCD.init();
  LCD.backlight();
  LCD.setCursor(0, 0);
  LCD.print("Connecting to ");
  LCD.setCursor(0, 1);
  LCD.print("WiFi ");

  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(250);
    spinner();
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  fsm.add_transition(&state_main_page, &state_set_time_page, BUTTON_OK, NULL);

  setSyncProvider(RTC.get);
  setSyncInterval(5);

  RTC.squareWave(DS3232RTC::SQWAVE_NONE);

  LCD.createChar(1, bell_symbol);
  LCD.clear();
}

void loop() {
  fsm.run_machine();
  delay(100);
}

void get_time() {
  Wire.beginTransmission(0x68);
  Wire.write(0); //set register to zero
  Wire.endTransmission();
  Wire.requestFrom(0x68, 3);// 3 bytes (sec, min, hour)
  Second = bcdToDec(Wire.read() & 0x7f);
  Minute = bcdToDec(Wire.read());
  Hour = bcdToDec(Wire.read() & 0x3f);
}

void display_time() {
  get_time();
  LCD.setCursor(0, 0);
  display_position(Hour);
  LCD.print(":");
  display_position(Minute);
  LCD.print(":");
  display_position(Second);
}

void on_page_exit() {
  LCD.clear();
}

void on_main_page_enter() {
  LCD.write(1);
  LCD.print("Welcome");
  delay(1000);
}

void main_page_on_state() {
  display_time();
  boolean isPressed = is_button_prassed(buttonSelect);
  
  if (isPressed) {
    fsm.trigger(BUTTON_OK);
  }
}

void on_set_time_page_enter() {
  LCD.setCursor(0, 0);
  LCD.print("setTime");
  delay(300);
}

void set_time_page_on_state() {
  boolean isPressed = is_button_prassed(buttonSelect);

  if (isPressed) {
    fsm.trigger(BUTTON_OK);
  }
}

boolean is_button_prassed(Button button) {
  button.read();
  return button.isPressed();
}

byte decToBcd(byte val) {
  return ( (val / 10 * 16) + (val % 10) );
}

byte bcdToDec(byte val) {
  return ( (val / 16 * 10) + (val % 16) );
}

void display_position(int digits) {
  if (digits < 10)
    LCD.print("0");
  LCD.print(digits);
}