#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Encoder.h>
#include <Adafruit_NeoPixel.h>
#include <SD.h>
#include <SPI.h>

#define CLK_PIN 2
#define DT_PIN 3
#define SW_PIN 4
#define VOLTAGE_PIN 9  // PWM pin for analog output
#define LED_PIN 6      // Pin for WS2812 data signal
#define NUM_LEDS 16    // Number of LEDs in the ring
#define SD_CS_PIN 10   // Chip select pin for the SD card

Encoder myEnc(CLK_PIN, DT_PIN);
LiquidCrystal_I2C lcd(0x27, 16, 2);
Adafruit_NeoPixel strip(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

volatile bool buttonPressed = false;
int voltageValue = 0;
File dataFile;

void handleButtonPress() {
    buttonPressed = true;
}

void setup() {
    // Initialize Serial for debugging
    Serial.begin(9600);

    // Initialize LCD
    lcd.begin(16, 2);
    lcd.backlight();
    lcd.setCursor(0, 0);
    lcd.print("Voltage Control");

    // Initialize encoder
    pinMode(SW_PIN, INPUT_PULLUP);
    attachInterrupt(digitalPinToInterrupt(SW_PIN), handleButtonPress, FALLING);

    // Initialize PWM pin
    pinMode(VOLTAGE_PIN, OUTPUT);

    // Initialize WS2812 LED ring
    strip.begin();
    strip.show();  // Initialize all pixels to 'off'

    // Initialize SD card
    if (!SD.begin(SD_CS_PIN)) {
        lcd.setCursor(0, 1);
        lcd.print("SD Init Failed!");
        Serial.println("SD card initialization failed!");
        while (1);
    }
    lcd.setCursor(0, 1);
    lcd.print("SD Init Success");
    Serial.println("SD card initialized successfully.");
}

void loop() {
    // Read encoder value
    long newValue = myEnc.read() / 1;  // Adjust scaling if needed
    if (newValue != voltageValue) {
        voltageValue = newValue;
        if (voltageValue < 0) voltageValue = 0;
        if (voltageValue > 255) voltageValue = 255;

        // Update PWM output
        analogWrite(VOLTAGE_PIN, voltageValue);

        // Update LCD display
        lcd.setCursor(0, 1);
        lcd.print("Voltage: ");
        lcd.print(voltageValue * (5.0 / 255.0), 2);
        lcd.print(" V  ");

        // Update WS2812 LED ring brightness
        uint8_t brightness = map(voltageValue, 0, 255, 0, 255);
        for (int i = 0; i < NUM_LEDS; i++) {
            strip.setPixelColor(i, strip.Color(brightness, 0, 0));  // Red color with variable brightness
        }
        strip.show();

        // Save voltage and time to SD card
        dataFile = SD.open("datalog.txt", FILE_WRITE);
        if (dataFile) {
            dataFile.print("Time: ");
            dataFile.print(millis() / 1000);
            dataFile.print("s, Voltage: ");
            dataFile.print(voltageValue * (5.0 / 255.0), 2);
            dataFile.println(" V");
            dataFile.close();
            Serial.println("Data written to SD card.");
        } else {
            lcd.setCursor(0, 1);
            lcd.print("SD Write Failed");
            Serial.println("Failed to write to SD card.");
        }
    }

    // Handle button press
    if (buttonPressed) {
        buttonPressed = false;
        myEnc.write(0);
        voltageValue = 0;
        analogWrite(VOLTAGE_PIN, voltageValue);
        lcd.setCursor(0, 1);
        lcd.print("Voltage: 0.00 V  ");

        // Turn off WS2812 LED ring
        for (int i = 0; i < NUM_LEDS; i++) {
            strip.setPixelColor(i, strip.Color(0, 0, 0));  // Turn off all LEDs
        }
        strip.show();
    }
}