#include <Arduino.h>
#include <WiFi.h>
#include <ESP_Mail_Client.h>
#include <ThingSpeak.h>

#define WIFI_SSID "102"
#define WIFI_PASSWORD "12345678"
#define SMTP_HOST "smtp.gmail.com"
#define SMTP_PORT 465
#define AUTHOR_EMAIL "[email protected]"
#define AUTHOR_PASSWORD "tderjwiigdfiwevc"
#define RECIPIENT_EMAIL "[email protected]"
// ThingSpeak credentials
const int myChannelNumber = 2838297;
const char* myApiKey = "WEQW3NBH8LOHW2PB";
unsigned long sendDataPrevMillis = 0;
SMTPSession smtp;
WiFiClient client;
void smtpCallback(SMTP_Status status) {
    Serial.println(status.info());
    if (status.success()) {
        Serial.println("Email sent successfully!");
    } else {
       // Serial.printf("Error: %s\n", status.info().c_str());
    }
}

void setup() {
    Serial.begin(115200);
    Serial.println("Connecting to WiFi...");
    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("\nWiFi connected.");

    ThingSpeak.begin(client);
}

void sendEmailAlert(float temperature) {
  smtp.debug(1);
  smtp.callback(smtpCallback);

  Session_Config config;
  config.server.host_name = SMTP_HOST;
  config.server.port = SMTP_PORT;
  config.login.email = AUTHOR_EMAIL;
  config.login.password = AUTHOR_PASSWORD;
  config.login.user_domain = "";
  
  SMTP_Message message;
  message.sender.name = "ESP32 Alert";
  message.sender.email = AUTHOR_EMAIL;
  message.subject = "Temperature Alert!";
  message.addRecipient("Receiver", RECIPIENT_EMAIL);
  
  String msg = "Warning! High Temperature Detected: " + String(temperature) + "°C";
  message.text.content = msg;
  
  if (!smtp.connect(&config)) { 
    Serial.println("Failed to connect to SMTP server");
     return;
  }
  if (!MailClient.sendMail(&smtp, &message)) Serial.println("Failed to send email.");
}

void loop() {
    // No need for continuous execution
    if ((millis() - sendDataPrevMillis > 5000 || sendDataPrevMillis == 0)) {
        sendDataPrevMillis = millis();

        if (WiFi.status() != WL_CONNECTED) {
            Serial.println("WiFi not connected! Reconnecting...");
            WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
            return;
        }

        int temperature = random(20, 50);  // Simulated temperature data
        float humidity = random(30, 90);  // Simulated humidity data

        Serial.println("Temperature: " + String(temperature) + "°C, Humidity: " + String(humidity) + "%");

        // Send data to ThingSpeak
        ThingSpeak.setField(1, temperature);
        ThingSpeak.setField(2, humidity);

        int x = ThingSpeak.writeFields(myChannelNumber, myApiKey);
        if (x == 200) {
            Serial.println("ThingSpeak update successful.");
        } else {
            Serial.println("ThingSpeak update failed. HTTP error: " + String(x));
        }

        // Send email alert if temperature exceeds threshold
        if (temperature > 40) {
            Serial.println("High temperature detected! Sending email...");
            sendEmailAlert(temperature);
            delay(100000);   // its for debugging for giving time to see mail sending or not
        }
        
    }
}