//------------DEFINITIONS------------
// Libaries
#ifdef ESP32
  #include <WiFi.h>
#else
  #include <ESP8266WiFi.h>
#endif
#include <WiFiClientSecure.h>
#include <UniversalTelegramBot.h>   // Universal Telegram Bot Library written by Brian Lough: https://github.com/witnessmenow/Universal-Arduino-Telegram-Bot
#include <ArduinoJson.h>

// Replace with your network credentials
//const char* ssid = "S10";
//const char* password = "aUjK67$2";
const char* ssid = "SchneckenAufPasta";
const char* password = "hf8CnyjPwrhc";


// Initialize Telegram BOT
#define BOTtoken "5094918649:AAFPjufh6NMhPtwWeMwRAZMygFaDyMoRfXk"  // your Bot Token (Get from Botfather)
#ifdef ESP8266
  X509List cert(TELEGRAM_CERTIFICATE_ROOT);
#endif
WiFiClientSecure client;
UniversalTelegramBot bot(BOTtoken, client);


// Variables
const int powerPin = D1;
const int powerStateReadPin = A0;
bool powerState = HIGH; //LOW = of
int t1, t2, t3, t4, t5, avg;
uint8_t newMACAddress[] = {0x32, 0xAE, 0xA4, 0x07, 0x0D, 0x66};


// Tweaks & Settings
int botRequestDelay = 5000;
const int powerStateThreshhold = 470; //min 0=0V, max 1023=3.3V, 470=1.5V
const int maxCycles = 40; //c.a. 1.5s per cycle




//------------FUNCTIONS------------
// Check current power-state
void checkPowerState() {
  // Do multiple measurements to catch blinking led
  t1 = analogRead(powerStateReadPin);
  //delay(120);
  t2 = analogRead(powerStateReadPin);
  //delay(150);
  t3 = analogRead(powerStateReadPin);
  //delay(180);
  t4 = analogRead(powerStateReadPin);
  //delay(50);
  t5 = analogRead(powerStateReadPin);
  avg = (t1+t2+t3+t4+t5)/5;

  // Interprete Result
  if (avg > powerStateThreshhold) {
    powerState = HIGH;
  }
  else {
    powerState = LOW;
  }
}

// Switch power state
void switchPowerState(bool desiredPowerState) {
  // Simulate press of power-button
  digitalWrite(powerPin, LOW);
  delay(200);
  digitalWrite(powerPin, HIGH);

  // Give the server time to boot
  // My server does a double or tripple boot sometimes, so in this case, i wait for 2min
  delay(60000);

  // Check PowerState
  int i = 0;
  Serial.print("Waiting for power change");
  while (powerState != desiredPowerState)
  {
    checkPowerState();
    i = i+1;
    delay(1000);
    Serial.print(".");
    if (i == 36); //6min
    {
      break;  
    } 
  }
  Serial.println("[OK]");
}

// Handle new messages
void handleNewMessages(int numNewMessages) {
  Serial.println("handleNewMessages");
  Serial.println(String(numNewMessages));

  // Fetch Message details
  for (int i=0; i<numNewMessages; i++) {
    // Chat id of the requester
    String chat_id = String(bot.messages[i].chat_id);
    
    // Print the received message
    String text = bot.messages[i].text;
    Serial.println(text);

    // Handling Start/Help
    String from_name = bot.messages[i].from_name;
    if (text == "/start" || text == "/help") {
      String welcome = "Welcome, " + from_name + ".\n";
      welcome += "Use the following commands to control your outputs.\n\n";
      welcome += "/state to request current server state \n";
      welcome += "/on to boot server \n";  
      welcome += "/off to shutdown server \n";
      bot.sendMessage(chat_id, welcome, "");
    }
    // Handling turn-on
    else if (text == "/on" and powerState == LOW) {
      bot.sendMessage(chat_id, "Booting Server..." "");
      switchPowerState(HIGH);
      if (powerState = HIGH) {
        bot.sendMessage(chat_id, "Bootup succeded" "");
      }
      else
      {
        bot.sendMessage(chat_id, "[WARNING]: Bootup failed" "");
      }
    }
    // Handling turn-off
    else if (text == "/off" and powerState == HIGH) {
      bot.sendMessage(chat_id, "Shutting down Server..." "");
      switchPowerState(LOW);
      if (powerState = LOW) {
        bot.sendMessage(chat_id, "Shutdown succeded" "");
      }
      else
      {
        bot.sendMessage(chat_id, "[WARNING]: Shutdown failed" "");
      }
    }
    // Handling unnessassary turn-on
    else if (text == "/on" and powerState == HIGH) {
      bot.sendMessage(chat_id, "Server is already online" "");
    }
    // Handling unnessassary turn-off
    else if (text == "/off" and powerState == LOW) {
      bot.sendMessage(chat_id, "Server is already offline" "");
    }
    // Waiting for change in power-state  
    else if (text == "/state") {
      checkPowerState();
      if (powerState == HIGH) {
        bot.sendMessage(chat_id, "Server is online" "");
      }
      else {
        bot.sendMessage(chat_id, "Server is offline" "");
      }
    }
  }
}




//------------SETUP------------
void setup() {
  Serial.begin(9600);

  // Telegram Certification
  #ifdef ESP8266
    configTime(0, 0, "pool.ntp.org");      // get UTC time via NTP
    client.setTrustAnchors(&cert);         // Add root certificate for api.telegram.org
  #endif

  // GPIO-Initialisation
  pinMode(powerPin, OUTPUT);
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(powerPin, powerState);

  // Changing Mac-Address
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  Serial.print("Old MacAdress: ");
  Serial.println(WiFi.macAddress());
  wifi_set_macaddr(0, &newMACAddress[0]);
  Serial.print("New MacAdress: ");
  Serial.println(WiFi.macAddress());
  
  // Connect to WiFi
  #ifdef ESP32
    client.setCACert(TELEGRAM_CERTIFICATE_ROOT); // Add root certificate for api.telegram.org
  #endif
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi..");
  }
  Serial.println(WiFi.localIP());
}




//------------LOOP------------
void loop() {  
  // Checking power-state
  checkPowerState();

  // Signal Activity
  digitalWrite(LED_BUILTIN, LOW);
  
  // Handling Messages
  Serial.println("Checking for messages...");
  int numNewMessages = bot.getUpdates(bot.last_message_received + 1);
  while(numNewMessages) {
    Serial.println("got response");
    handleNewMessages(numNewMessages);
    numNewMessages = bot.getUpdates(bot.last_message_received + 1);
  }

  // Signal Activity
  digitalWrite(LED_BUILTIN, HIGH);

  // Delay
  delay(botRequestDelay);
}