Game.java

import java.util.Stack;
/**
 *  This class is the main class of the "World of Zuul" application. 
 *  "World of Zuul" is a very simple, text based adventure game.  Users 
 *  can walk around some scenery. That's all. It should really be extended 
 *  to make it more interesting!
 * 
 *  To play this game, create an instance of this class and call the "play"
 *  method.
 * 
 *  This main class creates and initialises all the others: it creates all
 *  rooms, creates the parser and starts the game.  It also evaluates and
 *  executes the commands that the parser returns.
 * 
 * @author  Michael Kölling and David J. Barnes
 * @version 2016.02.29
 */

public class Game 
{
    private Parser parser;
    private Room currentRoom;
    private Stack <Room> history;
    
    /**
     * Create the game and initialise its internal map.
     */
    public Game() 
    {
        createRooms();
        parser = new Parser();
        history = new Stack<>();
    }

    /**
     * Create all the rooms and link their exits together.
     */
    private void createRooms()
    {
        Room cubby, workingArea, toiletRoom, cafeteria, kitchen, lobby,
             directorsRoom, meetingRoom, reception, exit;
      
        // create the rooms
        kitchen = new Room("in the kitchen");
        cafeteria = new Room("in the cafeteria");
        workingArea = new Room("in a giant working area of an office");
        cubby = new Room("in a cubby.");
        toiletRoom = new Room("in the toilet room of the office");
        lobby = new Room ("in the lobby");
        directorsRoom = new Room ("in the director's Room");
        meetingRoom = new Room ("in the meeting Room");
        reception = new Room ("in the office's reception");
        exit = new Room ("at the exit", true);
        
        // initialise room exits
        kitchen.setExits("north", cafeteria);
        
        cafeteria.setExits("south", kitchen);
        cafeteria.setExits("north", workingArea);
        
        workingArea.setExits("south", cafeteria);
        workingArea.setExits("west", toiletRoom);
        workingArea.setExits("east", cubby);
        workingArea.setExits("north", lobby);
        
        cubby.setExits("west", workingArea);
        
        toiletRoom.setExits("east", workingArea);
        
        lobby.setExits("south", workingArea);
        lobby.setExits("west", directorsRoom);
        lobby.setExits("east", meetingRoom);
        lobby.setExits("north", reception);
        
        directorsRoom.setExits("west", lobby);
        
        meetingRoom.setExits("east", lobby);
        
        reception.setExits("south", lobby);
        reception.setExits("north", exit);
        
        // Set up Items
        cafeteria.addItem(new Item("coffee", "A tasty cup of coffee that restores your health", 0));
        kitchen.addItem(new Item("spoon", "A shiny silver spoon", 150));
        workingArea.addItem(new Item("stapler", "A stapler (sponsored by Staples)", 200));
        directorsRoom.addItem(new Item("bat", "A wooden baseball bat signed by Derek Jeter", 2000));
        directorsRoom.addItem(new Item("printer", "A laser printer", 15000));
        meetingRoom.addItem(new Item("shredder", "A shredder", 2000));
        toiletRoom.addItem(new Item("window", "A very small, very dirty window", -1));
        reception.addItem(new Item("pencil", "A very pointy-looking pencil", 100));
        
        currentRoom = cubby;  // start game in a cubby
    }

    /**
     *  Main play routine.  Loops until end of play.
     */
    public void play() 
    {            
        printWelcome();

        // Enter the main command loop.  Here we repeatedly read commands and
        // execute them until the game is over.
                
        boolean finished = false;
        while (! finished) {
            Command command = parser.getCommand();
            finished = processCommand(command);
        }
        System.out.println("Thank you for playing.  Good bye.");
    }

    /**
     * Print out the opening message for the player.
     */
    private void printWelcome()
    {
        System.out.println();
        System.out.println("Welcome to the World of Zuul!");
        System.out.println("World of Zuul is a new, incredibly boring adventure game.");
        System.out.println("Type 'help' if you need help.");
        System.out.println();
        printLocationInfo();
    }

    /**
     * Given a command, process (that is: execute) the command.
     * @param command The command to be processed.
     * @return true If the command ends the game, false otherwise.
     */
    private boolean processCommand(Command command) 
    {
        boolean wantToQuit = false;

        if(command.isUnknown()) {
            System.out.println("I don't know what you mean...");
            return false;
        }

        String commandWord = command.getCommandWord();
        if (commandWord.equals("help")) {
            printHelp();
        }
        else if (commandWord.equals("go")) {
            wantToQuit = goRoom(command);
        }
        else if (commandWord.equals("quit")) {
            wantToQuit = quit(command);
        }
        else if (commandWord.equals("look")) {
            look();
        }
        else if (commandWord.equals("drink")) {
            drink();
        }
        else if (commandWord.equals("scream")) {
            scream();
        }
        else if (commandWord.equals("info")) {
            info(command);
        }
        else if (commandWord.equals("back")) {
            goBack();
        }
        return wantToQuit;
    }

    // implementations of user commands:

    /**
     * Print out some help information.
     * Here we print some stupid, cryptic message and a list of the 
     * command words.
     */
    private void printHelp() 
    {
        System.out.println("You are lost. You are alone. You wander");
        System.out.println("around at the university.");
        System.out.println();
        System.out.println("Your command words are:");
        parser.showCommands();
    }

    /** 
     * Try to go in one direction. If there is an exit, enter
     * the new room, otherwise print an error message.
     */
    private boolean goRoom(Command command) 
    {
        if(!command.hasSecondWord()) {
            // if there is no second word, we don't know where to go...
            System.out.println("Go where?");
            return false;
        }

        String direction = command.getSecondWord();

        // Try to leave current room.
        Room nextRoom = null;
        nextRoom = currentRoom.getExit(direction);

        if (nextRoom == null) {
            System.out.println("There is no door!");
        }
        else {
            history.push(currentRoom);
            currentRoom = nextRoom;
            printLocationInfo();
        }
        
        return currentRoom.isExit();
    }

    /** 
     * "Quit" was entered. Check the rest of the command to see
     * whether we really quit the game.
     * @return true, if this command quits the game, false otherwise.
     */
    private boolean quit(Command command) 
    {
        if(command.hasSecondWord()) {
            System.out.println("Quit what?");
            return false;
        }
        else {
            return true;  // signal that we want to quit
        }
    }
    
    private void look ()
    {
        System.out.println(currentRoom.getLongDescription());
    }
    
    private void drink ()
    {
      int bottle = 1;
      if(bottle > 0) {
        System.out.println("You drank your last bottle of water. Hurry up now!");
        bottle--;
      }
    }
    
    private void scream ()
    {
        System.out.println("Your voice won't be heard");
    }
    
    private void printLocationInfo ()
    {
        System.out.println(currentRoom.getLongDescription());
    }
    
    private void info(Command command){
        if(!command.hasSecondWord()) {
            // if there is no second word, we don't know where to go...
            System.out.println("Which item?");
            return;
        }
        String itemName = command.getSecondWord();
        Item item = currentRoom.getItem(itemName);
        if(item != null){
            System.out.println(item.getDescription());
        }else{
            System.out.println("There is no such item here!");
        }
    }
    private void goBack(){
        if(history.size() == 0){
            System.out.println("You are at start!");
            return;
        }
        
        currentRoom = history.pop();
        printLocationInfo();
    }
    
    
}