/**
 * @file Common.java
 *
 * @author Christos Choutouridis AEM:8997
 * @email  cchoutou@ece.auth.gr
 */
package net.hoo2.auth.labyrinth;

import java.util.ArrayList;
import java.util.Collections;

/**
 * Class to hold constant values for entire application
 */
class Const {
   static final int maxTileWalls = 2;  /**< Number of maximum walls for each tile on the board */
   static final int noSupply =-1;      /**< Number to indicate the absent of supply */
   static final int noTileId =-1;      /**< Number to indicate wrong tileId */
}
/**
 * Application wide object to hold settings like values for the session.
 */
class Session {
   static int  boardSize = 15;      /**< Default board's size (if no one set it via command line) */
   static int  supplySize = 4;      /**< Default board's supply size (if no one set it via command line) */
   static int  wallSize = 4*15-1;   /**< Default board's wall size (if no one set it via command line) */
}

/**
 * Helper C++-like enumerator class to hold direction
 */
class Direction {
   static final int  UP    =1;   /**< North direction */
   static final int  RIGHT =3;   /**< East direction */
   static final int  DOWN  =5;   /**< South direction */
   static final int  LEFT  =7;   /**< West direction */
   static final int  Begin =1;   /**< Iterator style begin of range direction (starting north) */
   static final int  End   =8;   /**< Iterator style end of range direction (one place after the last) */
   static final int  Step  =2;   /**< Step for iterator style direction */

   /**
    * Utility to get the opposite 
    * @param direction  Input direction
    * @return           The opposite direction
    */
   static int opposite (int direction) { return (direction+4)%End; }
}

/**
 * @brief
 *    An Application wide board position implementation holding just the id coordinate.
 *
 * Position is a helper class to enable us cope with the redundant position data (id and coordinates).
 * This class provide both static conversion functionalities between id and coordinates
 * and data representation in the coordinates system.
 * For clarity we adopt a row-column naming convention.
 */
class Position {

   /**
    * Basic constructor from row-column coordinates
    * @param row     The row coordinate
    * @param col     The column coordinate
    */
   Position(int row, int col) {
      this.id = toID(row, col);
   }

   /**
    * Basic constructor from Id
    * @param tileId  The id of tile
    */
   Position(int tileId) {
      this.id = tileId;
   }

   /**
    * Constructor from row-column coordinates and a direction.
    *
    * This constructor creates a position relative to coordinates.
    *
    * @param row        The row coordinate
    * @param col        The column coordinate
    * @param direction  The direction
    */
   Position(int row, int col, int direction) {
      switch (direction) {
         case Direction.UP:   this.id = toID(row+1, col);   break;
         case Direction.DOWN: this.id = toID(row-1, col);   break;
         case Direction.LEFT: this.id = toID(row, col-1);   break;
         case Direction.RIGHT:this.id = toID(row, col+1);   break;
      }
   }

   /** @name non-static API */
   /** @{ */
   int getRow()  { return toRow(id); }   /**< Read access to virtual row coordinate */
   int getCol()  { return toCol(id); }   /**< Read access to virtual column coordinate */
   int getId()   { return id; }          /**< Read access to id coordinate */
   /** @} */

   /** @name Static convention utilities */
   /** @{ */
   /**
    * Takes row and column coordinates and return the calculated Id coordinate
    * @param row  The row coordinate
    * @param col  The column coordinate
    * @return     The converted value
    */
   static int toID(int row, int col) {
      return row * Session.boardSize + col;
   }

   /**
    * Takes Id coordinate and return the corresponding row coordinate
    * @param id   The id coordinate
    * @return     The row coordinate
    */
   static int toRow(int id){
      return id / Session.boardSize;
   }
   /**
    * Takes Id coordinate and return the corresponding column coordinate
    * @param id   The id coordinate
    * @return     The column coordinate
    */
   static int toCol(int id) {
      return id % Session.boardSize;
   }
   /** @} */

   /** @name private data types */
   /** @{ */
   private int id;    /**< The id coordinate of the constructed Position object */
   /** @} */
}

/**
 * Class to create ranges of numbers
 */
class Range {
   /**
    * Create the range [begin, end)
    * @param begin   The first item on the range
    * @param end     The item after the last on the range
    */
   Range (int begin, int end) {
      numbers = new ArrayList<Integer>();
      init (begin, end, 1);      
   }
   /**
    * Create the range [begin, end) using step as interval between items.
    * @param begin   The first item on the range
    * @param end     The item after the last on the range
    * @param step    The interval between items
    */
   Range(int begin, int end, int step) {
      numbers = new ArrayList<Integer>();
      init (begin, end, step);
   }

   /**
    * Common utility to create the range for all constructors
    */
   private void init (int begin, int end, int step) {
      numbers.clear();
      for (int i=begin ; i<end ; i+=step)
         numbers.add(i);
   }
   /**
    * Extract and return the first item from the range.
    * @return  The first item of the range or Const.noTileId if there is none.
    */
   int get () {
      try {
         return numbers.remove(0);
      }
      catch (IndexOutOfBoundsException e) {
         return Const.noTileId;
      }
   }

   /** @name protected data types */
   /** @{ */
   protected ArrayList<Integer> numbers;  /**< handle to range */
   /** @} */
}

/**
 * Class to create shuffled ranges of numbers
 */
class ShuffledRange extends Range {
   /**
    * Create a shuffled version of range [begin, end)
    * @param begin   The first item on the range
    * @param end     The item after the last on the range
    */
   ShuffledRange(int begin, int end) {
      super(begin, end);         // Delegate
      Collections.shuffle(numbers);
   }
   /**
    * Create a shuffled version of the range [begin, end)
    * using step as interval between items.
    *
    * @param begin   The first item on the range
    * @param end     The item after the last on the range
    * @param step    The interval between items
    */
   ShuffledRange(int begin, int end, int step) {
      super(begin, end, step);   // Delegate
      Collections.shuffle(numbers);
   }
}