#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP085_U.h>
#include <DHT.h>
#include <WiFi.h>
#include <HTTPClient.h>
#include <ThingSpeak.h>

#define DHT_PIN 23
#define LDR_PIN 13 // Change this to your LDR pin

const char *ssid = "And"; // Replace with your WiFi SSID
const char *password = "0987654321"; // Replace with your WiFi password
const char *thingSpeakApiKey = "Z83OBBORHGEXUOG2"; // Replace with your ThingSpeak API key
const long channelId = 2332728;

WiFiClient client;

const int mq7Pin = 34;
const int mq135Pin = 35;
const int rainSensorPin = 33;

const int COThreshold = 25;
const int CO2Threshold = 5000;

float V_RL_MQ7 = 0.4;
float R_L_MQ7 = 10;
float S_MQ7 = 60;

float A_MQ135_CO2 = 400;
float B_MQ135_CO2 = 0.35;
float C_MQ135_CO2 = -0.48;

DHT dht(DHT_PIN, DHT22);
Adafruit_BMP085_Unified bmp;

void setup() {
  Serial.begin(9600);
  Serial.println("Gas Sensor Testing:");

  pinMode(rainSensorPin, INPUT);

  connectToWiFi();

  ThingSpeak.begin(client);
  dht.begin();

  // Set custom SDA and SCL pins for ESP32
  Wire.begin(21, 22); // SDA is GPIO21, and SCL is GPIO22 for ESP32

  if (!bmp.begin()) {
    Serial.println("Could not find a valid BMP085 sensor, check wiring!");
    while (1) {}
  }
}

void loop() {
  float temperature, humidity;

  int mq7RawValue = analogRead(mq7Pin);
  int mq135RawValue = analogRead(mq135Pin);

  float mq7Voltage = mq7RawValue * (3.3 / 4095.0);
  float mq135Voltage = mq135RawValue * (3.3 / 4095.0);

  float mq7PPM = (mq7Voltage - V_RL_MQ7) * (R_L_MQ7 / S_MQ7);
  float mq135PPM_CO2 = A_MQ135_CO2 * pow((mq135Voltage / B_MQ135_CO2), C_MQ135_CO2);

  Serial.print("MQ7 PPM (CO): ");
  Serial.print(mq7PPM);
  Serial.print("\t MQ135 PPM (CO2): ");
  Serial.println(mq135PPM_CO2);

  checkAndSendToThingSpeak(mq7PPM, mq135PPM_CO2);

  int rainValue = analogRead(rainSensorPin);
  Serial.print("Rain sensor value: ");
  Serial.println(rainValue);

  sensors_event_t event;
  bmp.getEvent(&event);
  if (event.pressure) {
    float pressure = event.pressure;
    Serial.print("Pressure: ");
    Serial.print(pressure);
    Serial.println(" hPa");
  } else {
    Serial.println("BMP180 Sensor Error");
  }

  temperature = dht.readTemperature();
  humidity = dht.readHumidity();

  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print(" °C\tHumidity: ");
  Serial.print(humidity);
  Serial.println(" %");

  int ldrValue = analogRead(LDR_PIN);
  Serial.print("LDR Sensor Value: ");
  Serial.println(ldrValue);

  if (mq7PPM > COThreshold || mq135PPM_CO2 > CO2Threshold) {
    Serial.println("Gas Alert!");

    if (mq7PPM > COThreshold) {
      Serial.println("CO in excess");
    } else if (mq135PPM_CO2 > CO2Threshold) {
      Serial.println("CO2 in excess");
    } else if (rainValue > 3000) {
      Serial.println("Rain detected");
    }
  } else {
    Serial.println("...");
  }

  delay(1000);
}

void connectToWiFi() {
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }
  Serial.println("Connected to WiFi");
}

void checkAndSendToThingSpeak(float mq7, float mq135_CO2) {
  float temperature, humidity;

  if (mq7 > COThreshold) {
    Serial.println("Beware, polluted air! High CO concentration detected!");
    triggerIFTTTEvent("Alert1");
    triggerIFTTTEvent("Alert2");
  }

  if (mq135_CO2 > CO2Threshold) {
    Serial.println("Beware, polluted air! High CO2 concentration detected!");
    triggerIFTTTEvent("Alert1");
    triggerIFTTTEvent("Alert2");
  }

  temperature = dht.readTemperature();
  humidity = dht.readHumidity();

  if (WiFi.status() == WL_CONNECTED) {
    ThingSpeak.setField(1, mq7);
    ThingSpeak.setField(2, mq135_CO2);
    ThingSpeak.setField(3, temperature);
    ThingSpeak.setField(4, humidity);

    int response = ThingSpeak.writeFields(channelId, thingSpeakApiKey);
    if (response == 200) {
      Serial.println("Data sent to ThingSpeak successfully!");
    } else {
      Serial.println("Error sending data to ThingSpeak. HTTP error code " + String(response));
    }
  } else {
    Serial.println("WiFi is not connected. Data not sent to ThingSpeak.");
  }
}

void triggerIFTTTEvent(String eventName) {
  String url = "https://maker.ifttt.com/trigger/" + eventName + "/json/with/key/cTPpOQswoK28BaLYucoHpQ";
  HTTPClient http;
  http.begin(url);
  int httpResponseCode = http.GET();
  http.end();

  Serial.println("IFTTT event triggered: " + eventName);
}