/*
 * This ESP32 code is created by esp32io.com
 *
 * This ESP32 code is released in the public domain
 *
 * For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-keypad-lcd
 */

#include <Keypad.h>
#include <LiquidCrystal_I2C.h>

#define ROW_NUM     4 // four rows
#define COLUMN_NUM  4 // four columns

uint8_t valIndex;
uint8_t cursorPos;
char entered_value [6];
uint8_t state=0;;
int val1=0,val2=0;

char keys[ROW_NUM][COLUMN_NUM] = {
  {'1','2','3', 'A'},
  {'4','5','6', 'B'},
  {'7','8','9', 'C'},
  {'*','0','#', 'D'}
};

byte pin_rows[ROW_NUM]      = {12, 14, 27, 26}; // GPIO19, GPIO18, GPIO5, GPIO17 connect to the row pins
byte pin_column[COLUMN_NUM] = {25, 33, 32, 35};   // GPIO16, GPIO4, GPIO0, GPIO2 connect to the column pins

Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows

int cursorColumn = 0;


void enterTime()
{
  state = 1;
  memset(&entered_value[0], 0, sizeof(entered_value));
  cursorPos = 0;
  valIndex = 0;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Set clock then  ");
  lcd.setCursor(0, 1);
  lcd.print("press # to save.");
  delay(3000);
  lcd.clear();
}

void enterAlarm()
{
  state = 2;
  memset(&entered_value[0], 0, sizeof(entered_value));
  cursorPos = 0;
  valIndex = 0;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Enter alarm time");
  lcd.setCursor(0, 1);
  lcd.print("press # to save.");
  delay(3000);
  lcd.clear();
}

void nextChar(char key)
{
  if (valIndex < 6)
  {
    entered_value[valIndex] = key;
    lcd.setCursor(0, 0);
    lcd.print(entered_value);
    cursorPos++;
    valIndex++;
  }
}

void eraseChar()
{
  if (valIndex > 0 )
  {
    valIndex--;
    cursorPos--;
    entered_value[valIndex] = '\0';
    lcd.setCursor(cursorPos, 0);
    lcd.print(' ');
    lcd.setCursor(cursorPos, 0);
  }
}

void keyPadState0()
{
  char key = keypad.getKey();
  switch(key)
  {
    case '#':
      enterAlarm();
      break;
    case '*':
      enterTime();
      break;
    
  }
}

void keyPadState1()
{
  char key = keypad.getKey();
  switch(key)
  {
    case '#':
      val1=atoi(entered_value);
      state = 0;
      break;
    case '*':
      eraseChar();
      break;
    default:
      if (isDigit(key))
      {
        nextChar(key);
      }
      break;
  }
}

void keyPadState2()
{
  char key = keypad.getKey();
  switch(key)
  {
    case '#':
      val2=atoi(entered_value);
      state = 0;
      break;
    case '*':
      eraseChar();
      break;
    default:
      if (isDigit(key))
      {
        nextChar(key);
      }
      break;
  }
}

void getInput()
{
  switch (state)
  {
    case 0:
      keyPadState0();
      break;
    case 1:
      keyPadState1();
      break;
    case 2:
      keyPadState2();
      break;
  }
}

void setup(){
  lcd.init(); // initialize the lcd
  lcd.backlight();
}

void loop(){
  char key = keypad.getKey();

/*  if (key) {
    lcd.setCursor(cursorColumn, 0); // move cursor to   (cursorColumn, 0)
    lcd.print(key);                 // print key at (cursorColumn, 0)

    cursorColumn++;                 // move cursor to next position
    if(cursorColumn == 16) {        // if reaching limit, clear LCD
      lcd.clear();
      cursorColumn = 0;
    }
  }*/
 if (state == 0)
  {
    getInput(); }

}