#include <WiFi.h>
#include <HTTPClient.h>
#include <PubSubClient.h>

// Wi-Fi Credentials
const char* ssid = "Wokwi-GUEST";   // Use your real WiFi if not using Wokwi sim
const char* password = "";

// MQTT Settings
const char* mqtt_server = "mqtt.eclipseprojects.io"; // <-- Your Node-RED/MQTT broker IP
const char* mqtt_topic = "ESP32"; // <-- Must match topic in Node-RED

// OpenWeatherMap API
const char* weather_url = "http://api.openweathermap.org/data/2.5/weather?q=Cape%20Town&appid=36e6822e65b17aac7b918af60ee321db&units=metric";

WiFiClient espClient;
PubSubClient client(espClient);

void connectWiFi() {
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
}

void connectMQTT() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    String clientId = "ESP32Client-" + String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" trying again in 5 seconds");
      delay(5000);
    }
  }
}

void fetchWeatherAndPublish() {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin(weather_url);
    http.setTimeout(10000);  // 10s timeout
    int httpCode = http.GET();

    if (httpCode == HTTP_CODE_OK) {
      String payload = http.getString();
      Serial.println("Weather data received:");
      Serial.println(payload);

      if (client.connected()) {
        // Safely copy string to C-style buffer
        size_t len = payload.length() + 1;
        char mqttPayload[len];
        payload.toCharArray(mqttPayload, len);

        client.publish(mqtt_topic, mqttPayload);
        Serial.println("Published to Node-RED via MQTT");
      } else {
        Serial.println("MQTT not connected");
      }
    } else {
      Serial.print("HTTP Error: ");
      Serial.println(httpCode);
    }

    http.end();
  } else {
    Serial.println("WiFi not connected");
  }
}

void setup() {
  Serial.begin(115200);
  connectWiFi();

  client.setServer(mqtt_server, 1883);
  client.setBufferSize(2048); // To fit full JSON response

  connectMQTT();
}

void loop() {
  if (!client.connected()) {
    connectMQTT();
  }
  client.loop();

  fetchWeatherAndPublish();

  delay(60000); // every 60 seconds
}