#include <Keypad.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include "HX711.h"

// ---------------- LCD Setup ----------------
LiquidCrystal_I2C lcd(0x27, 16, 2);

// ---------------- Keypad Setup ----------------
const byte ROWS = 4;
const byte COLS = 4;

char keys[ROWS][COLS] = {
  {'1','2','3','+'},    // '+' used for Spoon Addition
  {'4','5','6','T'},    // 'T' = Tare Button
  {'7','8','9','U'},    // 'U' = Units Setting
  {'C','0','=','O'}     // 'O' = Tolerance On/Off
};

byte rowPins[ROWS] = {13, 12, 14, 27};
byte colPins[COLS] = {26, 25, 33, 32};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// ---------------- Load Cell Setup ----------------
HX711 scale;
#define DT  4   // HX711 DT pin
#define SCK 5   // HX711 SCK pin

float calibration_factor = -7050.0; // Adjust for your load cell
float targetWeight = 0;  
float tolerance = 0.5;  
bool toleranceOn = false;

// ---------------- Units ----------------
enum Unit {GRAM, KG, OUNCE, POUND, ML, FLOZ};
Unit currentUnit = GRAM;

const char* unitNames[] = {"g", "kg", "oz", "lb", "ml", "fl oz"};
float unitFactor[] = {1.0, 0.001, 0.035274, 0.00220462, 1.0, 0.033814}; 
// ml & fl oz require density assumption (for water-like liquids)

// ---------------- Variables ----------------
float cumulativeWeight = 0;
bool spoonAdditionMode = false;

// ---------------- Setup ----------------
void setup() {
  Serial.begin(115200);

  // LCD init
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Digital Spoon");
  delay(2000);
  lcd.clear();
  lcd.print("Initializing...");

  // HX711 init
  scale.begin(DT, SCK);
  scale.set_scale(calibration_factor);
  scale.tare();

  lcd.clear();
  lcd.print("Ready. Press key");
}

// ---------------- Main Loop ----------------
void loop() {
  char key = keypad.getKey();

  if (key) {
    handleKeypad(key);
  }

  // Display live reading
  float weight = getWeight();
  lcd.setCursor(0, 1);
  lcd.print(weight, 2);
  lcd.print(" ");
  lcd.print(unitNames[currentUnit]);
}

// ---------------- Functions ----------------
float getWeight() {
  float raw = scale.get_units();
  return raw * unitFactor[currentUnit];
}

void handleKeypad(char key) {
  switch (key) {
    case '+':  // Spoon addition
      spoonAdditionMode = true;
      cumulativeWeight += getWeight();
      lcd.clear();
      lcd.print("Added Spoon");
      delay(1000);
      showCumulative();
      break;

    case 'T':  // Tare
      scale.tare();
      lcd.clear();
      lcd.print("Tare Done");
      delay(1000);
      break;

    case 'U':  // Change Units
      currentUnit = (Unit)((currentUnit + 1) % 6);
      lcd.clear();
      lcd.print("Unit: ");
      lcd.print(unitNames[currentUnit]);
      delay(1000);
      break;

    case 'O':  // Toggle Tolerance
      toleranceOn = !toleranceOn;
      lcd.clear();
      if (toleranceOn) lcd.print("Tolerance ON");
      else lcd.print("Tolerance OFF");
      delay(1000);
      break;

    case '=':  // Finalize / Show result
      lcd.clear();
      if (spoonAdditionMode) {
        showCumulative();
      } else {
        lcd.print("Final: ");
        lcd.print(getWeight(), 2);
        lcd.print(" ");
        lcd.print(unitNames[currentUnit]);
      }
      delay(3000);
      lcd.clear();
      lcd.print("Ready. Press key");
      spoonAdditionMode = false;
      cumulativeWeight = 0;
      break;

    case 'C':  // Clear / Reset
      cumulativeWeight = 0;
      lcd.clear();
      lcd.print("Cleared");
      delay(1000);
      lcd.clear();
      lcd.print("Ready. Press key");
      break;
  }
}

void showCumulative() {
  lcd.clear();
  lcd.print("Total: ");
  lcd.print(cumulativeWeight, 2);
  lcd.print(" ");
  lcd.print(unitNames[currentUnit]);
}