#include <FastLED.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Pin Definitions
#define LED_PIN 11
#define BUTTON_1_PIN 10
#define BUTTON_2_PIN 9
#define BUTTON_3_PIN 8
#define BUTTON_4_PIN 7
#define NUM_LEDS 4

// Initialize LED strip
CRGB leds[NUM_LEDS];

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

// Resistor bands and RGB values
struct ResistorBand {
  String colorName;
  String digit;    // For first and second band
  String multiplier; // For third band
  String tolerance;  // For fourth band
  CRGB colorRGB;
};

// Define resistor bands
ResistorBand bands[] = {
  {"Black", "0", "1", "", CRGB::Black},   // Black
  {"Brown", "1", "10", "±1%", CRGB(150, 75, 0)}, // Brown
  {"Red", "2", "100", "±2%", CRGB::Red},  // Red
  {"Orange", "3", "1k", "", CRGB::Orange},   // Orange
  {"Yellow", "4", "10k", "", CRGB::Yellow},  // Yellow
  {"Green", "5", "100k", "±0.5%", CRGB::Green},  // Green
  {"Blue", "6", "1M", "±0.25%", CRGB::Blue},  // Blue
  {"Violet", "7", "10M", "±0.1%", CRGB(138, 43, 226)}, // Violet
  {"Gray", "8", "100M", "±0.05%", CRGB::Gray}, // Gray
  {"White", "9", "", "", CRGB::White},   // White
  {"Gold", "", "0.1", "±5%", CRGB(255, 215, 0)},   // Gold
  {"Silver", "", "0.01", "±10%", CRGB(192, 192, 192)}  // Silver
};

// Variables to store the current state of the resistor bands
int bandIndices[4] = {0, 0, 0, 0}; // Stores the indices of the current selected color for each band

void setup() {
  // Setup buttons
  pinMode(BUTTON_1_PIN, INPUT_PULLUP);
  pinMode(BUTTON_2_PIN, INPUT_PULLUP);
  pinMode(BUTTON_3_PIN, INPUT_PULLUP);
  pinMode(BUTTON_4_PIN, INPUT_PULLUP);

  // Initialize LED
  FastLED.addLeds<NEOPIXEL, LED_PIN>(leds, NUM_LEDS);

  // Initialize LCD
  lcd.init();
  lcd.backlight();

  // Display initial resistor value
  displayResistorInfo();
}

void loop() {
  if (digitalRead(BUTTON_1_PIN) == LOW) {
    changeBandColor(0);
    displayResistorInfo();
    delay(500);  // Debounce delay
  }
  if (digitalRead(BUTTON_2_PIN) == LOW) {
    changeBandColor(1);
    displayResistorInfo();
    delay(500);  // Debounce delay
  }
  if (digitalRead(BUTTON_3_PIN) == LOW) {
    changeBandColor(2);
    displayResistorInfo();
    delay(500);  // Debounce delay
  }
  if (digitalRead(BUTTON_4_PIN) == LOW) {
    changeBandColor(3);
    displayResistorInfo();
    delay(500);  // Debounce delay
  }
}

// Function to change the color of the specified band
void changeBandColor(int band) {
  bandIndices[band]++;
  if (band < 2) { // For first two digits
    bandIndices[band] %= 10; // Cycle through 0-9
  } else if (band == 2) { // Multiplier
    bandIndices[band] %= 12; // Cycle through 12 colors including Gold and Silver
  } else if (band == 3) { // Tolerance
    bandIndices[band] %= 5; // Cycle through 5 tolerance values
  }
  
  // Update the color of the LED corresponding to the band
  leds[band] = bands[bandIndices[band]].colorRGB;
  FastLED.show();
}

// Function to display the current resistor info on the LCD
void displayResistorInfo() {
  lcd.clear();
  lcd.setCursor(0, 0);
  
  String resistanceValue = bands[bandIndices[0]].digit + bands[bandIndices[1]].digit;
  resistanceValue += " x " + bands[bandIndices[2]].multiplier;
  
  lcd.print("Res: " + resistanceValue + "ohms");
  
  lcd.setCursor(0, 1);
  lcd.print("Tol: " + bands[bandIndices[3]].tolerance);
}