import java.util.Scanner;

public class Game {

   // Globals
   public static final int MAX_LOCALES = 2;   // Total number of rooms/locations we have in the game.
   public static int currentLocale = 0;       // Player starts in locale 0.
   public static String command;              // What the player types as he or she plays the game.
   public static boolean stillPlaying = true; // Controls the game loop.
   public static String[] locations;          // An uninitialized array of type String. See init() for initialization.

   public static void main(String[] args) {
      // Display the command line args.
      System.out.println("Starting with args:");
      for (int i = 0; i < args.length; i++) {
         System.out.println(i + ":" + args[i]);
      }

      // Set starting locale, if any.
      // TODO: What happens is there are no args given when the game is invoked? Fix that.
      int startLocation = Integer.parseInt(args[0]);
      if ( startLocation >= 0 && startLocation <= MAX_LOCALES) {
         currentLocale = startLocation;
      }

      init();
      updateDisplay();

      // Game Loop
      while (stillPlaying) {
         getCommand();
         navigate();
         updateDisplay();
      }
      System.out.println("Thank you for playing.");
   }

   private static void init() {
      // Initialize any uninitialized globals.
      command = new String();
      stillPlaying = true;   // TODO: Do we need this?

      // Set up the location list.
      locations = new String[3];
      locations[2] = "TARDIS";   //  ^
      locations[0] = "The Lab";  //  N
      locations[1] = "Dungeon";  //  |

      System.out.println("All game locations:");
      for (int i = 0; i < locations.length; ++i) {
         System.out.println(i + ":" + locations[i]);
      }

      // Set up the navigation matrix.
      int[][] nav = new int[][]
      {                         /* N   S   E   W */
        /* nav[0] for loc 0 */  {  2,  1, -1, -1 },
        /* nav[1] for loc 1 */  {  0, -1, -1, -1 },
        /* nav[2] for loc 2 */  { -1,  0, -1, -1 }
      };
   }

  private static void updateDisplay() {
     System.out.println(locations[currentLocale]);
  }

   private static void getCommand() {
      Scanner inputReader = new Scanner(System.in);
      command = inputReader.nextLine();  // command is global.
   }

   private static void navigate() {
      // TODO Separate directional navigation (n, s, e, w) from other commands (like quit).
      // TODO Refactor this part code to use the nav[][] matrix.
      if ( command.equals("north") || command.equals("n") ) {
         // We are going NORTH. But from where...?
         if (currentLocale == 1) {
            currentLocale = 0;
         } else if (currentLocale == 0) {
            currentLocale = 2;
         }

      } else if ( command.equals("south") || command.equals("s") ) {
         // We are going SOUTH. But from where...?
         if (currentLocale == 2) {
            currentLocale = 0;
         } else if (currentLocale == 0) {
            currentLocale = 1;
         }

      } else if ( command.equals("quit") ) {
         stillPlaying = false;
      }
   }

}