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

/*
  Initialize stepper and set pins
*/

#define STEPS 800.0

Stepper stepper(STEPS, 11, 10);

/*
  Initialize LCD and set pins
*/

LiquidCrystal_I2C lcd(0x27, 16, 2);

/*
  Initialize keypad, set pins and keys
*/

const int ROW_NUM    = 4;
const int COLUMN_NUM = 4;

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] = {22, 24, 26, 28};
byte pin_column[COLUMN_NUM] = {36, 38, 40, 42};

Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );

/*
  Config relays
*/

#define RELAYS 4

struct Relay {
  int pin;
  bool status;
};

Relay relays[RELAYS] = {{44, false}, {44, false}, {44, false}, {44, false}}

void init_relays() {
  for (int i = 0; i < RELAYS; i++) {
    toggle_relay(i);
    pinMode(relays[i].pin, OUTPUT);
    digitalWrite(relays[i].pin, LOW);
  }
}

void toggle_relay(int relay_number) {
  int index = relay_number - 1 ;
  if (relays[index] != nullptr) {
    relays[index].status = !relays[index].status;
    digitalWrite(relays[index].pin, relays[index].status ? HIGH : LOW);
  }
}

void set_relay(int relay_number, bool status) {
  int index = relay_number - 1 ;
  if (relays[index] != nullptr) {
    relays[index].status = status;
  }
}

void toggle_relays() {
  for (int i = 0; i < RELAYS; i++) {
    toggle_relay(i);
  }
}

void set_relays(bool status) {
  for (int i = 0; i < RELAYS; i++) {
    set_relay(i, status);
  }
}

/*
  Functions prototype
*/

int int_prompt(String text, int default_value, char break_key);
int key_to_int(char key);
bool key_is_number(char key);

/*
  Initial program
*/

void setup() {
  lcd.init();
  lcd.backlight();
  Serial.begin(9600);
  Serial.println();
  init_relays();
}

/*
  Run program
*/

int speed = 0;
int degree = 0;
int dir = 0;

void loop() {
  if (speed && degree) {
    Serial.println("config stepper");

    stepper.setSpeed(speed);

    lcd.clear();

    char key;

    int step_count = STEPS * 1000 * degree / 360000;
    Serial.print("step count: ");
    Serial.println(step_count);

    Serial.println("start stepper");

    set_relays(true);

    while ((key = keypad.getKey()) != '*' && step_count > 0) {
      stepper.step(dir ? 1 : -1);
      step_count--;

      int int_key = key_to_int(key);
      if (key_is_number(key) && int_key >= 1 && int_key <= RELAYS) {
        toggle_relay(int_key);
      }
    }

    set_relays(false);
  }

  Serial.println("get inputs");

  speed = int_prompt("enter speed", speed, 'C');
  Serial.print("speed: ");
  Serial.println(speed);

  dir = int_prompt("enter direction", dir, 'C');
  Serial.print("direction: ");
  Serial.println(dir);

  degree = int_prompt("enter degree", degree, '#');
  Serial.print("degree: ");
  Serial.println(degree);
}


/*
  Print a question on LCD and get input from keypad
  and return result as number.
*/
int int_prompt(String text, int default_value, char break_key = 'c') {
  Serial.print("get input (");
  Serial.print(text);
  Serial.print("): ");

  text.concat(": ");

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(text.c_str());

  String input;

  //  if (default_value) {
  //   input.concat(default_value);
  //  }

  char key;
  while ((key = keypad.getKey()) != break_key) {
    if (key) {
      Serial.print(key);
    }

    if (key_is_number(key)) {
      input.concat(key);

      lcd.setCursor(0, 1);
      lcd.print(input.c_str());
    } else if (key == 'B') {
      input.remove(input.length() - 1);

      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print(text.c_str());
      lcd.setCursor(0, 1);
      lcd.print(input.c_str());
    }
  }

  Serial.println();

  return input.toInt();
}

int key_to_int(char key) {
  return key - 48;
}

/*
  Check pressed key of keypad is number or not.
*/
bool key_is_number(char key) {
  int number = key_to_int(key);
  bool is_number = number >= 0 && number <= 9;
  return is_number;
}