// Weather station works.
#include <WiFi.h>
#include <DHT.h>
#include <PubSubClient.h>   // MQTT related
#include "ThingSpeak.h"

#define DHT_PIN 28          // the pin for DHT
#define DHT_TYPE DHT22      // DHT used

// wifi

const char* WIFI_NAME = "Wokwi-GUEST";     // wifi-ssid used? i dont know found it somewhere
const char* WIFI_PASS = "";                // define doesnt use = or ;

// thingspeak

const unsigned long CHANNEL_NUM = 3140359;        // const char apparently better for c++
const char* APIKEY = "K3OSK6OCVNHLZQ0H";          // unsigned allows bigger nums by disallowing negative nums
const char* SERVER = "api.thingspeak.com";

// mqtt

const char* mqtt_server = "broker.hivemq.com";    // public mqtt server (it's free)
const int mqtt_port = 1883;
const char* mqtt_topic = "veera_weatherstation";

// * tells the compiler "this variable holds the memory address where the string begins"
// Without the *, you're trying to fit an entire string into a single character var
// i could have just used string... wait which one is more space efficient?

DHT dht(DHT_PIN, DHT_TYPE);   // create sensor objectS
                              // DHT is class name
                              // dht is var name for instance
                              // pin and type are var para
WiFiClient CLIENT;            // create wifi client object
                              // class handles network stuff for wifi letting arduino speak with wifi
                              // lib doesnt have a handler to we have to make a thing that goes
                              // use THIS to transfer data
PubSubClient mqttClient(CLIENT);    // apparently you can also use client() here. aka same thing?

const char* clientId = "VeerasPicoWeatherStation";  // with this i can find my weather pico whenever with the given name

void SetUpMQTT(){       // start up
  mqttClient.setServer(mqtt_server, mqtt_port);
}

void setup() {
  // put your setup code here, to run once:
  Serial1.begin(115200);      // init. bits per second
  dht.begin();                // dht init
                              // when you init Serial1 you cant use Serial later

  SetUpMQTT();                // connect to MQTT and node.js
  Serial1.println("Connecting to WiFi...");
  WiFi.begin(WIFI_NAME, WIFI_PASS);     // wifi begin, using given wifi

while (WiFi.status() != WL_CONNECTED) {   // WL_CONNECTED is const from lib. says "connected to wifi"
    delay(1000);                          // WL_NO_SHIELD: No WiFi shield found. aka no wifi hardware
    Serial1.println("Connecting...");     // WL_IDLE_STATUS: Temporary status assigned when no changes
                                          // WL_CONNECT_FAILED: Connection failed
  }                                       // gives connection status as num
  // Wait for connection                  // compare the number to see if connected. if != 200 not connected
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial1.println("Connecting...");
  }

  Serial1.println("Connected to WiFi!");
  Serial1.print("IP Address: ");
  Serial1.println(WiFi.localIP());        // asks what is the device IP. used for debugging and advanced projects

  ThingSpeak.begin(CLIENT);  // INIT THINGSPEAK LIB

  //

  Serial1.println("Weather Station Initialized.");      // arduino simplified c++, print line
  Serial1.println("---");                               // empty line
  delay(20);                                            // delay for 20ms

  Serial1.println("Connected to WiFi!");
  Serial1.print("IP Address: ");
  Serial1.println(WiFi.localIP());

}

void reconnectMqtt(){   // reconnect if error
  if (mqttClient.connect(clientId)){
  Serial1.println("MQTT connected!");
  }
  else {
    // print error msg
    int errorCode = mqttClient.state();
    Serial1.print("MQTT failed, error: ");
    Serial1.println(errorCode);
  }
  delay(5000);  // 5 seconds
}

// pubilsh data
void publishData(float temp, float humid){
  char message[50];        // message while not str
  snprintf(message, sizeof(message),    // char limit set for str, rest as reads here // snprint() func: print the specified string till a specified length
      "{\"temp\":%.1f,\"humid\":%.1f}", temp, humid);  // message // THIS IS WHERE IT GOT THE THE t and h error from??? this is the JSON sent
      // here i would encrypt the JSON data that goes to broker
 
  // publish
  if (mqttClient.publish(mqtt_topic, message)){
    Serial1.print("Published: ");
    Serial1.println(message);
  } else {
    Serial1.println("Publish failed!");
  }
}

void loop() {
  
  // mqtt stuff
  if (!mqttClient.connected()){
    reconnectMqtt();
  }
  mqttClient.loop();

  float humid = dht.readHumidity();         // what it says, read humidity
  float temp = dht.readTemperature();       // ditto for temp

  if (isnan(humid) || isnan(temp)) {        // isnan aka not a number and || or operator
    Serial1.println("Failed to read from DHT sensor!");
    return;
  } else {
    Serial1.print("Humidity: ");
    Serial1.print(humid);
    Serial1.println("%");
    Serial1.print("Temperature: ");
    Serial1.print(temp);
    Serial1.println(" °C");
    Serial1.println();

    publishData(temp, humid);   // sent to MQTT
    sendToThingSpeak(temp, humid);

  }
  delay(20000); // this speeds up the simulation ms // thingspeak requires some 15-20s updates
}
// method
void sendToThingSpeak(float temp, float humid) {
  // Set the fields for ThingSpeak
  ThingSpeak.setField(1, temp);    // to thingspeak field 1 send temperature
  ThingSpeak.setField(2, humid);
  
  // Send data to ThingSpeak
  int responseCode = ThingSpeak.writeFields(CHANNEL_NUM, APIKEY);   // writes and sends back how everything is going
                                                                    // takes the fields, packages, sents to thingspeak, includes "address"
  // setField() is like contents of letter and writeFields is mailing it
  
  // Check the result
  if (responseCode == 200) {
    Serial1.println("Data sent to ThingSpeak!");
    Serial1.println("And sent to Server.js");
    Serial1.println("");
  } else {
    Serial1.print("Error sending to ThingSpeak. HTTP code: ");
    Serial1.println(responseCode);
    Serial1.println("Check your API key and channel number!");
    Serial1.println("---");
  }
}
// 10 mins is 600 000 ms