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

// Stepper motor configuration
const int stepsPerRevolution = 200; // Change this to match your motor's specifications
Stepper myStepper(stepsPerRevolution, 10, 11, 12, 13); // Pins for the stepper motor

const uint8_t ROWS = 4; // Four rows
const uint8_t COLS = 4; // Four columns

// Define the keymap
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '.', '0', '#', 'D' } // Change '*' to '.'
};

// Define the column and row pins
uint8_t colPins[COLS] = { 5, 4, 3, 2 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 9, 8, 7, 6 }; // Pins connected to R1, R2, R3, R4

// Create an instance of the Keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// Create an instance of the LCD display (I2C address 0x27, 16x2)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Use the built-in LED
const int ledPin = 13; // Pin for the built-in LED

// Push button pins
const int BUTTON_RESET = A0; // Pin for reset button
const int BUTTON_REPEAT = A1; // Pin for repeat button

// Variables to store angle input
char angleInput[6]; // To hold 3 digits, 1 '.', and 1 digit + null terminator
int index = 0;      // Current index in the angleInput array
int currentSteps = 0; // Track the current position in steps
float totalRotation = 0; // Track the total angle rotation
float userRotation = 0; // Track user-initiated rotations

void setup() {
  Serial.begin(9600);
  lcd.begin(16, 2);
  lcd.backlight();
  lcd.clear();

  showIntro(1, " Rotary Indexer", "   by David");
  displayIntroScreen(2, "Use the # key", "for next page");
  displayIntroScreen(3, "A Rotate 90 Deg", "B Index to 0 Deg");
  displayIntroScreen(4, "C to Clear Input", "D to Input Angle");
  displayIntroScreen(5, "Ex.Angle  180.0", "or 72.55");
  displayIntroScreen(6, "Then press D key", " to index motor");

  pinMode(ledPin, OUTPUT);
  pinMode(BUTTON_RESET, INPUT_PULLUP); // Use internal pull-up for reset button
  pinMode(BUTTON_REPEAT, INPUT_PULLUP); // Use internal pull-up for repeat button

  myStepper.setSpeed(30);
}

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

  // Check for button presses
  if (digitalRead(BUTTON_RESET) == LOW) {
    returnToZeroPosition(); // Reset the display and return to zero
    resetDisplay(); // Clear the input
    return; // Skip the rest of the loop
  }
  
  if (key != NO_KEY) {
    Serial.println(key);

    switch (key) {
      case '#':
        displayNextScreen(); // Only works for intro screens
        break;
      case 'C':
        // Only clear the input if still typing
        if (index < 5) {
          clearTopRow();
          index = 0; // Reset index
          angleInput[0] = '\0'; // Clear angle input
        }
        break;
      case 'D':
        if (index == 5) {
          moveStepperMotor();
          userRotation += atof(angleInput); // Update user rotation
          displayUserRotation(); // Show user rotation after moving
          clearTopRow(); // Clear the top row for the next input
          index = 0; 
          angleInput[0] = '\0'; 
        }
        break;
      case 'A':
        rotateStepperBy90Degrees(); // Rotate motor by 90 degrees
        break;
      case 'B':
        returnToZeroPosition(); // Return to zero position
        userRotation = 0; // Reset user rotation count
        clearTopRow(); // Clear the top row
        lcd.setCursor(0, 1);
        lcd.print("User: 0 Deg    "); // Display 0 Deg on the bottom row
        break;
      default:
        if (index < 5) {
          angleInput[index] = key; 
          angleInput[index + 1] = '\0';
          displayCurrentInput();
          index++;

          if (index == 5) {
            displayAngle(); // Optionally show the input angle before pressing D
          }
        }
        break;
    }
  }

  // Check the repeat button
  if (digitalRead(BUTTON_REPEAT) == LOW) {
    delay(200); // Debounce delay
  }
}

void showIntro(int screenNumber, const char* line1, const char* line2) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(line1);
  lcd.setCursor(0, 1);
  lcd.print(line2);
  delay(3000);
  lcd.clear();
}

void displayIntroScreen(int screenNumber, const char* line1, const char* line2) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(line1);
  lcd.setCursor(0, 1);
  lcd.print(line2);
  
  while (true) {
    char key = keypad.getKey();
    if (key == '#') {
      lcd.clear();
      return;
    }
  }
}

void displayNextScreen() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Next Screen");
  lcd.setCursor(0, 1);
  lcd.print("Ready to Input");
  delay(3000);
  lcd.clear();
}

void displayCurrentInput() {
  lcd.setCursor(0, 0);
  lcd.print(angleInput);
}

void displayAngle() {
  lcd.setCursor(0, 0);
  lcd.print(angleInput);
  lcd.print(" Deg");
}

void clearTopRow() {
  lcd.setCursor(0, 0);
  lcd.print("                "); 
}

void resetDisplay() {
  lcd.clear();
  index = 0;
  angleInput[0] = '\0';
  digitalWrite(ledPin, LOW);
}

void moveStepperMotor() {
  float angle = atof(angleInput);
  int steps = (angle / 360.0) * stepsPerRevolution;
  myStepper.step(steps);
  currentSteps += steps; // Update current steps
}

void returnToZeroPosition() {
  clearTopRow();
  lcd.setCursor(0, 0);
  lcd.print("Returning to 0");

  myStepper.step(-currentSteps);
  // totalRotation remains unchanged
  currentSteps = 0; // Reset current steps for the position
  delay(1000);
  clearTopRow();
  lcd.setCursor(0, 1);
  lcd.print("User: 0 Deg    "); // Display 0 Deg on the bottom row
}

void displayUserRotation() {
  lcd.setCursor(0, 1);
  lcd.print("User: ");
  lcd.print(userRotation);
  lcd.print(" Deg    "); // Display user rotation
}

// Function to rotate stepper motor by 90 degrees
void rotateStepperBy90Degrees() {
  lcd.setCursor(0, 0);
  lcd.print("Rotating 90 Deg");
  myStepper.step(stepsPerRevolution / 4); // Move 90 degrees (1/4 of a revolution)
  currentSteps += stepsPerRevolution / 4; // Update current steps
  userRotation += 90.0; // Update user rotation as well
  displayUserRotation(); // Show updated user rotation
}