#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_NeoPixel.h>

// Define OLED display dimensions
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

// Define OLED reset pin (or -1 if sharing Arduino reset pin)
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Define potentiometer pins
const int tempSetpointPotPin = A0;
const int hysteresisPotPin = A1;

// Define temperature sensor pin
const int tempSensorPin = A2;

// Define fan output pin
const int fanPin = 9;

// Define NeoPixel ring
#define LED_PIN 6
#define NUM_LEDS 16
Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

// Define temperature thresholds
const int temp20CResistance = 2000; // 2K ohm
const int temp4CResistance = 4000; // 4K ohm

// Define potentiometer resistance
const int potResistance = 1200; // 1.2K ohm

// Variables for temperature control
int setpointTemp = 25; // Initial setpoint temperature
int hysteresis = 2; // Initial hysteresis
int currentTemp = 0;

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

  // Initialize OLED display
  if (!display.begin(0x3c, OLED_RESET)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }
  display.display();
  delay(2000); // Pause for 2 seconds
  display.clearDisplay();

  // Set fan pin as output
  pinMode(fanPin, OUTPUT);

  // Initialize NeoPixel ring
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'
}

void loop() {
  // Read potentiometer values
  int tempSetpointReading = analogRead(tempSetpointPotPin);
  int hysteresisReading = analogRead(hysteresisPotPin);

  // Calculate setpoint temperature based on potentiometer reading
  setpointTemp = map(tempSetpointReading, 0, 1023, 4, 25);

  // Calculate hysteresis based on potentiometer reading
  hysteresis = map(hysteresisReading, 0, 1023, 1, 5);

  // Read temperature sensor
  int sensorValue = analogRead(tempSensorPin);

  // Convert sensor value to resistance
  int sensorResistance = map(sensorValue, 0, 1023, 0, 5000);

  // Convert resistance to temperature
  currentTemp = map(sensorResistance, temp20CResistance, temp4CResistance, 20, 4);

  // Display current temperature, setpoint temperature, hysteresis, and fan status on OLED
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);

  display.setCursor(0, 0);
  display.print("Temp: ");
  display.print(currentTemp);
  display.print("C");

  display.setCursor(0, 10);
  display.print("Setpoint: ");
  display.print(setpointTemp);
  display.print("C");

  display.setCursor(0, 20);
  display.print("Hysteresis: ");
  display.print(hysteresis);
  display.print("C");

  // Check if temperature is above setpoint + hysteresis
  if (currentTemp > setpointTemp + hysteresis) {
    digitalWrite(fanPin, HIGH); // Turn on fan
    display.setCursor(0, 30);
    display.print("Fan: ON ");
  } else if (currentTemp < setpointTemp) {
    digitalWrite(fanPin, LOW); // Turn off fan
    display.setCursor(0, 30);
    display.print("Fan: OFF");
  }

  // Update NeoPixel color based on temperature
  updateNeoPixelColor(currentTemp, setpointTemp);

  display.display();
  delay(1000); // Update every second
}

void updateNeoPixelColor(int currentTemp, int setpointTemp) {
  uint32_t color;

  if (currentTemp < setpointTemp) {
    // Blend from blue to green
    color = blendColor(strip.Color(0, 0, 255), strip.Color(0, 255, 0), map(currentTemp, setpointTemp - hysteresis, setpointTemp, 0, 255));
  } else {
    // Blend from green to red
    color = blendColor(strip.Color(0, 255, 0), strip.Color(255, 0, 0), map(currentTemp, setpointTemp, setpointTemp + hysteresis, 0, 255));
  }

  for (int i = 0; i < NUM_LEDS; i++) {
    strip.setPixelColor(i, color);
  }

  strip.show();
}

uint32_t blendColor(uint32_t color1, uint32_t color2, uint8_t blend) {
  uint8_t r1 = (color1 >> 16) & 0xFF;
  uint8_t g1 = (color1 >> 8) & 0xFF;
  uint8_t b1 = color1 & 0xFF;

  uint8_t r2 = (color2 >> 16) & 0xFF;
  uint8_t g2 = (color2 >> 8) & 0xFF;
  uint8_t b2 = color2 & 0xFF;

  uint8_t r = (r1 * (255 - blend) + r2 * blend) / 255;
  uint8_t g = (g1 * (255 - blend) + g2 * blend) / 255;
  uint8_t b = (b1 * (255 - blend) + b2 * blend) / 255;

  return strip.Color(r, g, b);
}