#include <WiFi.h>
#include <PubSubClient.h>
#include <string>
#include <iostream>

#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"

/*  für PS-RAM-Einstellungen
platformio.ini:      // ? muss hinzugefügt werden in Platformio.ini
build_flags = -DBOARD_HAS_PSRAM
              -DCONFIG_SPIRAM_USE_MALLOC
              -mfix-esp32-psram-cache-issue      */

#define TFT_DC 2
#define TFT_CS 15
#define rand 7
Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);

// #define width 240
// #define hight 320



const char *ssid = "Wokwi-GUEST";        // Enter your Wi-Fi name
const char *password = "";               // Enter Wi-Fi password


// ---------------------   function  definitions  -----------------------------
void callback(char *topic, byte *payload, unsigned int length);
void reconnect();

void maske (void);
void temperature (int);
void humidity (int);
void diverses ();
void farbpixel ();




// MQTT Broker: https://docs.emqx.com/en/cloud/latest/connect_to_deployments/esp32.html
const char *mqtt_broker = "broker.emqx.io";
const char *topic = "emqx/topic/esp32/";      // = SENDING / transmitting data-topic
const char *mqtt_username = "emqx";           // "emqx"
const char *mqtt_password = "public";         // "public"
const int mqtt_port = 1883;
const int mqtt_pause = 500;                   // give time to communicate (client - broker)
String client_id = "";                        // Identifikation des esp32 am mqtt-broker
char *topic_message = "bli-bla-blu";
String mqttMessageReceived = "";


WiFiClient wifiClient;                         // WiFi-Client definition -> is handed over
PubSubClient mqttclient(wifiClient);               // to MQTT=PubSubClient "mqttclient"
// AsyncMqttClient mqttclient;



// ---------------------------   setup  ---------------------------
void setup() {
    Serial.begin(115200);                           // Set software serial baud to 115200;
    
    WiFi.begin(ssid, password);                     // Connecting to a WiFi network
    Serial.print("Connecting to WiFi...");

    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println(""); Serial.println("Connected to the Wi-Fi network");
    Serial.print("IP address: ");  Serial.println(WiFi.localIP());
    

    mqttclient.setServer(mqtt_broker, mqtt_port);       //connecting to a mqtt broker
    mqttclient.setCallback(callback);                   // "callback" = function for message output

    while (!mqttclient.connected()) {
        client_id = mqtt_username;
        // String client_id = "esp32-mqttclient-";    // now global defined
        client_id += String(WiFi.macAddress());
        Serial.printf("The mqttclient %s connects to the public MQTT broker\n", client_id.c_str());
        if (mqttclient.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
            Serial.printf("Public EMQX MQTT broker connected\n\n");
            Serial.printf("client_id %s\n", client_id.c_str());
            Serial.printf("WiFi MAC : %s\n", WiFi.macAddress().c_str());      // ---- c_str()
            Serial.printf("mqttclient.state() %d\n\n", mqttclient.state());
            Serial.printf("WiFi.status() %d\n\n", WiFi.status());
        } else {
            Serial.print("failed with state ");
            Serial.print(mqttclient.state());
            delay(2000);
        }
      mqttclient.subscribe(topic);      // 1. subscription to topic, REsubscription in reconnect()
    }
    //  ili9341 setup
    tft.begin();
}



// ------------------------  global  variables  --------------------
const long timetowait = 5000;
long lastMsg = 0;





// ---------------------   main / loop()  function ----------------
void loop() {

  long now = millis();
  if (now - lastMsg > timetowait) {
    lastMsg = now;
    //  code to handle within the mqtt-loop

    if (!mqttclient.connected()) { reconnect();  }

    // loop() checks input & output buffer and triggers action
    // loop() sends data received in buffer -> mqttclient.publish, 
    // triggers actions=callback depending on the received data -> mqttclient.subscibe
    mqttclient.loop();                 


    // value convertion:
    // dtostrf(float_value, min_width, num_digits_after_decimal, where_to_store_string);
    // dtostrf(value_float, 6,2, value_char);

    // integer to string:
    // itoa(-31596,char_array,10); //(integer, char_array, base)#
    // itoa: int = 2 Byte == nur für 4 Stellen geeignet
    // ltoa (value_int, value_char, 4);
    

    // --------------   Publish and subscribe  --------------
    mqttclient.publish(topic, topic_message);    // publishing data
    mqttclient.subscribe(topic);                 // receiving data

    Serial.print("Message arrived in topic: ");
    Serial.print(topic);
    Serial.print(". Message: "); Serial.println (mqttMessageReceived);

    delay(mqtt_pause);                       // give time to communicate (mqttclient - broker)
  }

  
  delay(4000); 
}
//  --------------------   end  main  / loop() -------------------------



//  --------------------   callback  function   ------------------------
void callback(char* topic, byte* payload, unsigned int length) {
    String messageTemp;
    for (int i = 0; i < length; i++) {
        messageTemp += (char)payload[i];
    }
    mqttMessageReceived = messageTemp;
}


/*
Message consists of: topic, payload.
  topic: separated with "/", home/office/lamp (home = top-level, ...)
  payload: value, can be everything, "text", true, json { temp: 33, pressure: 400 }

    Topic                                         QualityOfService      Callback   
    __________________________________________    ________________    _____________

    "channels/1393455/subscribe/fields/field2"           0            "showmessage"

on_connect: This function is called when the MQTT mqttclient receives a CONNACK = connection acknowledged.
on_subscribe: This function is called when the mqttclient receives a SUBACK = subscription has 
            been successfully completed.
on_message: This function is called when the mqttclient receives a PUBLISH message from the MQTT server. 
            Whenever the MQTT server publishes a message, based on the subscriptions for the mqttclient, 
            this function will be called.
The...
*/



// --------------------  mqtt reconnect  --------------------------------
void reconnect() {
  while (!mqttclient.connected()) {                     // Loop until we're reconnected
    // String client_id = mqtt_username;
    // client_id += String(WiFi.macAddress());
    Serial.print (client_id); Serial.print(" Attempting MQTT connection  ...");
    // Serial.printf("The mqttclient %s connects to the MQTT broker\n", client_id);
    // if (mqttclient.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
    if (mqttclient.connect(mqtt_username)) {
      Serial.println("connected");                     // connection existent
      // Subscribe
      mqttclient.subscribe(topic);                     // topic selection = subscribe
    } else {
      Serial.print("failed, rc=");
      Serial.print(mqttclient.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}



void farbpixel () {
  //  Farbpixel random am gesamten Bildschirm
  
  int ROT = 255, GRUEN = 255, BLAU = 255;
  tft.fillScreen(ILI9341_BLACK);
  for  (int i = 0; i < 7000; i ++)
  {
    int PixelX = random(1, tft.width());
    int PixelY = random(1, tft.height());
    tft.drawPixel(PixelX, PixelY, tft.color565(random(ROT),random(GRUEN),random(BLAU)));
    delay(5);
  }
  delay(2000);
}



// ---------  diverses -----------
void diverses (void) {
  int i, j=1;

  tft.fillScreen(ILI9341_BLACK);
  tft.setCursor(rand, 120);
  tft.setTextColor(ILI9341_RED);
  tft.setTextSize(3);
  tft.println("Hello ESP32");

  tft.setCursor(rand, 160);
  tft.setTextColor(ILI9341_GREEN);
  tft.setTextSize(2);
  tft.println("I can do SPI :-)");
  delay(2000);

  //  Textsize ---------------------------
  tft.fillScreen(ILI9341_BLACK);
  tft.setTextColor(ILI9341_WHITE);
  tft.setCursor(0,rand);
  for (i=0;i<6;i++) {
    // tft.setCursor(0,i);
    tft.setTextSize(i);

    tft.print("textsize ");
    tft.println(i);

    delay(2000);
  }

  //  display size -----------------------
  tft.setTextSize(1);
  tft.fillScreen(ILI9341_YELLOW);
  tft.setTextColor(ILI9341_BLUE);
  tft.println(String(tft.width()));
  tft.println(String(tft.height()));
  delay(2000);
}



// Aufbau der Bildschirmmaske -------------
void maske (void)
{
  int i, dicke=4;

  tft.setRotation(1);
  tft.fillScreen(ILI9341_CYAN);
  tft.setTextColor(ILI9341_MAGENTA);
  for (i=1;i<dicke;i++) {
  tft.drawRoundRect(rand+i, rand+i, (tft.width()-2*rand)-2*i, (tft.height()-2*rand)-2*i, rand/2, ILI9341_RED);
  tft.drawRoundRect(2*rand+i, 2*rand+i, (tft.width()-4*rand)-2*i, (tft.height()-4*rand)-2*i, rand/2, ILI9341_BLACK);
  }
  tft.setTextSize(3);
  tft.setCursor(30,35);
  tft.println("Parameter");
  tft.setCursor(30,60);
  tft.println("der Hauptmaske:");
  for (i=1;i<dicke;i++)
    tft.drawLine(20, 100+i, tft.width()-20, 100+i, ILI9341_BLACK);
  tft.setTextSize(2);
  tft.setCursor(4*rand,120);
  tft.println("Temperatur:");
  tft.setCursor(4*rand,150);
  tft.println("Luftfeuchte:");
  tft.setCursor(4*rand,180);
  tft.print("Luftdruck:");
  
}


// void temperature (int);
// void humidity (int);