#include <WiFi.h>
#include "ThingSpeak.h"
#include <ESP32Servo.h>
#include <OneWire.h>
#include <DallasTemperature.h>

// --- WiFi & ThingSpeak Setup ---
const char* ssid = "Wokwi-GUEST";
const char* password = "";
unsigned long myChannelNumber = 3337884; 
const char* myWriteAPIKey = "FDANPCRQ6W7EWVOU"; 

WiFiClient client;

// --- Pin Definitions ---
#define TRIG_PIN 4      
#define ECHO_PIN 5      
#define SERVO_PIN 19    
#define PIR_PIN 2         
#define TEMP_PIN 21     
#define LDR_PIN 35      
#define GAS_PIN 34      
#define RED_LED 14
#define BLUE_LED 15
#define GREEN_LED 17
#define ORANGE_LED 18
#define YELLOW_LED 16

Servo myServo;
OneWire oneWire(TEMP_PIN);
DallasTemperature tempSensor(&oneWire);

unsigned long lastTime = 0;
const unsigned long postingInterval = 3000; // Sending to cloud every 3s

void setup() {
  Serial.begin(115200);
  
  // Initialize Sensor Pins
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(PIR_PIN, INPUT);
  
  // Initialize LED Pins
  pinMode(RED_LED, OUTPUT);
  pinMode(BLUE_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
  pinMode(ORANGE_LED, OUTPUT);
  pinMode(YELLOW_LED, OUTPUT);

  myServo.attach(SERVO_PIN);
  tempSensor.begin();

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi Connected!");
  
  ThingSpeak.begin(client); 
}

void loop() {
  // --- 1. SENSOR READINGS ---
  tempSensor.requestTemperatures();
  float temp = tempSensor.getTempCByIndex(0);

  digitalWrite(TRIG_PIN, LOW); delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH); delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int distance = pulseIn(ECHO_PIN, HIGH) * 0.034 / 2;

  int gas = analogRead(GAS_PIN);
  int ldr = analogRead(LDR_PIN);
  int motion = digitalRead(PIR_PIN);

  // --- 2. LOGIC CONDITIONS ---

  // Temperature Logic 
  if (temp < 50.0) {
    digitalWrite(BLUE_LED, HIGH); // Temp below 50
    digitalWrite(RED_LED, LOW);
  } else {
    digitalWrite(BLUE_LED, LOW);  // Above 50
    digitalWrite(RED_LED, HIGH);
  }

  // Gas Logic 
  if (gas > 2500) {
    digitalWrite(ORANGE_LED, HIGH);
  } else {
    digitalWrite(ORANGE_LED, LOW);
  }

  // Motion Logic 
  if (motion == HIGH) {
    digitalWrite(YELLOW_LED, HIGH);
  } else {
    digitalWrite(YELLOW_LED, LOW);
  }

  // Photoresistor Logic 
  // Brighter environment (Higher LDR value) = Dimmer LED (Lower PWM)
  int greenBrightness = map(ldr, 0, 4095, 255, 0);  // ESP32 analogRead is 0-4095. analogWrite is 0-255.
  analogWrite(GREEN_LED, greenBrightness);

  // Servo Logic (Proportional to distance)
  int servoAngle = map(distance, 0, 200, 0, 180); // Mapped 0-200cm to 0-180 degrees
  servoAngle = constrain(servoAngle, 0, 180); // Keep within bounds
  myServo.write(servoAngle);


  // --- 3. CLOUD UPDATES (ThingSpeak) ---
  if (millis() - lastTime > postingInterval) {
    ThingSpeak.setField(1, temp);
    ThingSpeak.setField(2, (float)distance);
    ThingSpeak.setField(3, (float)gas);
    ThingSpeak.setField(4, (float)ldr);
    ThingSpeak.setField(5, (float)motion);

    int status = ThingSpeak.writeFields(myChannelNumber, myWriteAPIKey);

    if (status == 200) {
      Serial.println("Cloud Update: Success");
    } else {
      Serial.println("Cloud Update: Failed (" + String(status) + ")");
    }
    lastTime = millis();
  }
}