#ifndef PLUGINS_STDPHYSLAYER_NUMREG_H
#define PLUGINS_STDPHYSLAYER_NUMREG_H

#include "cstypes.h"
#include "csutil/hash.h"

#include "physicallayer/numreg.h"

class csString;

/**
 * This class stores a list of Objects and assignes a unique ID to them
 *  Note: This class does nearly no error checking  and should be used with
 *  care
 */
class NumRegLists : public iNumReg
{
public:
  /** 
   *  Constructor, limit is the maximum size this array will grow,
   *   freelistsize is the size of the list holding last freed items (the
   *   bigger this list is the better your performance if you remove/add new
   *   elements often.
   *   startsize is the initial size of the array
   */
  NumRegLists(int limit=100000, int freelistsize=100, int startsize=300);
  /// The destructor frees all memory
  virtual ~NumRegLists();

  SCF_DECLARE_IBASE;

  /** 
   *  Registers an object in the registry and returns the new ID, in error
   * case ID 0 is returned
   */
  virtual uint Register (void* obj);
  /**
   *  Registers an object in the registry with an ID. You shouldn't use this
   * function with this implementation. It should work though, but slow.
   */
  virtual void RegisterWithID (void* obj, uint id);
  /** Removes an registered object from registry */
  virtual bool Remove (uint id);
  /** Removes an registered object from registry (Note: this is slow you
   * should use Remove(id) if possible
   */
  virtual bool Remove (void* obj);
  
  /** Removes all objects from the list */
  virtual void Clear();

  /** Returns the object with ID id from the list */
  virtual void* Get(uint id)
  { 
    if (id>=listsize)
      return 0;
    
    return list[id];
  }

  // Returns the size of the buffer (This is NOT the count of objects in the
  // registry)
  virtual size_t Length()
  {
    return listsize;
  }
  
protected:
  inline uint intern_Register(void* obj);
  
  void** list;
  size_t* freelist;
  size_t listsize;
  uint limit;
  size_t freelistend;
  size_t freelistsize;
};

/**
 * Another implementation of iNumReg. You should use it for client 
 * applications when IDs are allocated on server.
 */
class NumRegHash : public iNumReg
{
public:
  NumRegHash(int limit);
  virtual ~NumRegHash();

  SCF_DECLARE_IBASE;

  virtual uint Register(void* obj);
  virtual void RegisterWithID(void* obj, uint id);
  
  virtual bool Remove(uint id);
  virtual bool Remove(void* obj);

  virtual void Clear();

  virtual void* Get(uint id);
  virtual size_t Length();

private:
  csHash<void*,uint> reg;
  uint current_id;
  uint limit;
};


/**
 * Main registry that can be composed of more than one NumReg. Each NumReg 
 * represents a different scope. The first numreg is the default one, that will
 * be used for example by iPcRegion to create its dummy entities.
 */
class celIDRegistry
{
private:
  struct part
  {
    iNumReg* numreg;
    uint start;
    uint end;
  };
  csArray<struct part> regs;

private:
  size_t GetScopeOfID (uint id);

public:
  celIDRegistry ();
  ~celIDRegistry ();

  /**
   * Add a new ID scope to the registry. 
   * size is the number of IDs in the scope. 
   * 
   * This function returns the index of the scope (to use with Register)
   *
   * impl is the implementation of the numreg choosed:
   *  cel.numreg.lists or cel.numreg.hash
   */
  size_t AddScope (csString impl, int size);

  /**
   * Register an object in the given scope. Error case return 0
   */
  uint Register (void* obj, size_t scope);

  /**
   * Register an object with the provided ID.
   */
  void RegisterWithID (void* obj, uint id);

  /**
   * Remove an object
   */
  bool Remove (uint id);

  /**
   * Remove an object (slow)
   */
  bool Remove (void* obj);

  /**
   * Remove all objects, doesn't remove scopes.
   */
  void Clear ();

  /**
   * Get an object from its id.
   */
  void* Get (uint id);

  // Default scope. 
  size_t DefaultScope;
};

#endif