/*
  Welcome to ArduinoOS v1.0 Serial Editon by @bockring.
  This is a operating system for Arduino devices.
  Please use Arduino Mega 2560 or Arduino Due.
  If you use this software, please read all the "README.docx".

  You will needs:
   Arduino Mega 2560 or Arduino Due x1
   USB connector(USB Host) x1
   USB to Serial transfer PCB x1
   D.C. jack(5.5mm φ2.1mm) x1
   A.C. adaptor(Recomend:12V 1.5A) x1
   Box(can include device) x1
   Some wires
   Arduino IDE installed PC x1(This software need to connect PC)
   USB cabel x1

   Command reference
    shutdown //Turn off your computer
*/

char input = ""; //Input and save letters
char output = ""; //Output letters
char command = ""; //Entered command
long cache1 = "";
long cache2 = "";
long cache3 = "";
int login = 0;
char username[16] = "Admin"; //Set your user name here(Up to 16 letters)
char password[32] = "Password"; //Set your password here(Up to 32 letters)

void setup() {
  Serial.begin(9600);
  String password = String(password);

  digitalWrite(13, HIGH);

  Serial.println("      ■■■■■                 ■■■■■"); //Print Arduino logo
  Serial.println("   ■         ■           ■         ■");
  Serial.println(" ■              ■     ■       ■      ■");
  Serial.println("■                 ■ ■         ■       ■");
  Serial.println("■  ■■■■■■■■■■■     ■     ■■■■■■■■■■■  ■");
  Serial.println("■                 ■ ■         ■       ■");
  Serial.println(" ■              ■     ■       ■      ■");
  Serial.println("   ■         ■           ■         ■");
  Serial.println("      ■■■■■                 ■■■■■");

  Serial.println("Now loading the system files...");
  delay(3000);
  Serial.println(" ");
  Serial.println("Welcome to ArduinoOS v1.0 Serial Edition!");

  Serial.println("   ■                ■");
  Serial.println("  ■ ■               ■           ■                   ■■■■    ■■■■");
  Serial.println(" ■   ■              ■                              ■    ■  ■");
  Serial.println("■     ■  ■ ■■■   ■■■■  ■   ■    ■    ■ ■■    ■■■   ■    ■  ■");
  Serial.println("■     ■  ■■     ■   ■  ■   ■    ■    ■■  ■  ■   ■  ■    ■   ■■■");
  Serial.println("■■■■■■■  ■      ■   ■  ■   ■    ■    ■   ■  ■   ■  ■    ■      ■");
  Serial.println("■     ■  ■      ■   ■  ■  ■■    ■    ■   ■  ■   ■  ■    ■      ■");
  Serial.println("■     ■  ■       ■■■■   ■■ ■    ■    ■   ■   ■■■    ■■■■    ■■■");
  Serial.println("");
  delay(500);
}

void loop() {
  //Login process
  if (login == 0) {
    Serial.println("Please enter the password.");
    Serial.print("USERNAME : ");
    Serial.println(username);
    Serial.println("PASSWORD : ");
    login = 1;
  }

  if (Serial.available()) {
    String input = String(Serial.readStringUntil(0x0a));
    if (input == password) {
      Serial.println("Succeed. Now loging in...");
      login = 2;
      goto mainprocess;
    } else {
      login = 0;
    }

    if (input != password & input != ""& login == 0) {
      Serial.println("Failed. Please Try again.");
      Serial.println("");
      Serial.println("PASSWORD : ");
      input = "";
      login = 0;
    }

    if (input == ""& login != 2) {
      login = 1;
      delayMicroseconds(1);
    }


mainprocess: //Main process
    if (login == 2) { //Login checker
      Serial.println("");
      Serial.println("Welcome to ArduinoOS v1 Serial Edition.");
      Serial.println("This software was made by @bockring.");

      for (login = 2; login == 2; login = login + 0) {
        Serial.print(username);
        Serial.print("@ArduinoOS:~$ ");

        if (Serial.available()) {
          String command = String(Serial.readStringUntil(0x0a));
          Serial.println(command);
          //If you want to add commands, please write commands, and features here.
          if (command == "shutdown") {
            Serial.println("Are you sure to turn off this computer?(y/n)");
shutdown:
            input = Serial.readStringUntil(0x0a);
            if (input == "y") {
              Serial.println("Shuting down now...");
              delay(1000);
              Serial.println("If you want to reboot, please press reset buttom.");
              Serial.println("Disconnected");
              Serial.end();
              goto off;
            } else if (input != "n") {
              goto shutdown;
            }
          }
        }
      }
off:
      for (cache1 = 0; cache1 == 0; cache1 = cache1 + 0) {
        delay(1000);
      }
    }
  }
}