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 Locale[] locations;           // An uninitialized array of type Locale. See init() for initialization.
    public static int[][]  nav;                 // An uninitialized array of type int int.
    public static int moves = 0;                // Counter of the player's moves.
    public static int score = 0;                // Tracker of the player's score.

    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 it was provided as a command line parameter.
        if (args.length > 0) {
            int startLocation = Integer.parseInt(args[0]);    // TODO We need to catch a possible exception here.
            // Check that the passed-in value for startLocation is within the range of actual locations.
            if ( startLocation >= 0 && startLocation <= MAX_LOCALES) {
                currentLocale = startLocation;
            }
        }

        // Get the game started.
        init();
        updateDisplay();

        // Game Loop
        while (stillPlaying) {
            getCommand();
            navigate();
            updateDisplay();
        }

        // We're done. Thank the player and exit.
        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 instances of the Locale class.
        Locale loc0 = new Locale(0);
        loc0.setName("The Lab");
        loc0.setDesc("You are in a shiny new lab.");

        Locale loc1 = new Locale(1);
        loc1.setName("Dungeon");
        loc1.setDesc("This is a dark and smelly place.");

        Locale loc2 = new Locale(2);
        loc2.setName("TARDIS");
        loc2.setDesc("It seems larger on the inside.");

        // Set up the location array.
        locations = new Locale[3];
        locations[2] = loc2; // "TARDIS";   //  ^
        locations[0] = loc0; // "The Lab";  //  N
        locations[1] = loc1; // "Dungeon";  //  |

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

        // Set up the navigation matrix.
        nav = new int[][] {
                                 /* N   S   E   W */
                                 /* 0   1   2   3 */
         /* 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].getName());
        System.out.println(locations[currentLocale].getDesc());
    }

    private static void getCommand() {
        System.out.print("[" + moves + " moves, score " + score + "] ");
        Scanner inputReader = new Scanner(System.in);
        command = inputReader.nextLine();  // command is global.
    }

    private static void navigate() {
        final int INVALID = -1;
        int dir = INVALID;  // This will get set to a value > 0 if a direction command was entered.

        if (        command.equalsIgnoreCase("north") || command.equalsIgnoreCase("n") ) {
            dir = 0;
        } else if ( command.equalsIgnoreCase("south") || command.equalsIgnoreCase("s") ) {
            dir = 1;
        } else if ( command.equalsIgnoreCase("east")  || command.equalsIgnoreCase("e") ) {
            dir = 2;
        } else if ( command.equalsIgnoreCase("west")  || command.equalsIgnoreCase("w") ) {
            dir = 3;

        } else if ( command.equalsIgnoreCase("quit")  || command.equalsIgnoreCase("q")) {
            quit();
        } else if ( command.equalsIgnoreCase("help")  || command.equalsIgnoreCase("h")) {
            help();
        };

        if (dir > -1) {   // This means a dir was set.
            int newLocation = nav[currentLocale][dir];
            if (newLocation == INVALID) {
                System.out.println("You cannot go that way.");
            } else {
                currentLocale = newLocation;
                moves = moves + 1;
                // TODO: Deal with hasVisited and the score here.
            }
        }
    }

    private static void help() {
        System.out.println("The commands are as follows:");
        System.out.println("   n/north");
        System.out.println("   s/south");
        System.out.println("   q/quit");
    }

    private static void quit() {
        stillPlaying = false;
    }
}