#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// WiFi credentials
char ssid[] = "";
char pass[] = "";

// MQTT broker details
const char* server = "";
const char* username = "notabot";
const char* password = "";

// Change as required
const char* topic = "Home/mailbox";
const char* msg = "You Got Mail!";
byte QoS = 2;
boolean retain = false;

WiFiClient espClient;
PubSubClient mqttClient(espClient);

void youGotMail() {
    Serial.println("You got mail!");
    while (!mqttClient.connected()) {
        Serial.print("Attempting MQTT connection...");
        // Attempt to connect
        if (mqttClient.connect("espbot", username, password, topic, QoS, retain, msg)) {
            Serial.println("connected");
            // Once connected, publish an announcement...
            if ( mqttClient.publish(topic, msg)) {
                Serial.println("Successfully published.");
            }
        } else {
            Serial.print("failed, rc=");
            Serial.print(mqttClient.state());
            Serial.println(" try again in 5 seconds");
            // Wait 5 seconds before retrying
            delay(5000);
        }
    }
}
void setup() {
    Serial.begin(115200);
    while (!Serial) {}
    Serial.print("Reading sensor: ");
    Serial.println(analogRead(A0));
    if (analogRead(A0) > 500) {
        // Connect to WiFi
        WiFi.begin(ssid, pass);
        while (WiFi.status() != WL_CONNECTED) {
            delay(500);
            Serial.print(".");
        }
        if (WL_CONNECTED) {
            Serial.println("Connected!");
        }

        pinMode(A0, INPUT);
        Serial.print("Reading sensor: ");
        Serial.println(analogRead(A0));
        mqttClient.setServer(server, 1883);
        // Run our notification logic
        youGotMail();
        mqttClient.disconnect();
        // I found that not disconnecting caused issues with my router...
        WiFi.disconnect(true);
    }
    // Sleep for 60 seconds
    ESP.deepSleep(60*1000000);
}

// The void loop is never reached when using deepSleep()
// All code must be executed in the setup() function.
void loop() {
}