/* -*- C++ -*- */
// $Id$

// ============================================================================
//
// = LIBRARY
//    ace
//
// = FILENAME
//    Registry.h
//
// = AUTHOR
//    Irfan Pyarali (irfan@cs.wustl.edu)
//
// ============================================================================

#ifndef ACE_REGISTRY_H
#define ACE_REGISTRY_H

#include "ace/OS.h"

#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */

#if defined (ACE_WIN32)
// This only works on Win32 platforms

#include "ace/Containers.h"
#include "ace/SString.h"

class ACE_Export ACE_Registry
{
  // = TITLE
  //     A Name Server implementation
  //
  // = DESCRIPTION
  //     The registry interface is inspired by the interface
  //     specified in the CORBA Naming Service Specification.
  //     The implementation is done through Win32 <Reg*> functions.
  //     Other than providing an OO wrapper for the Win32 <Reg*>
  //     functions, ACE_Registry provides an abstraction for iteration
  //     over the elements of the Registry.
public:

// International string
#if defined (UNICODE)
  typedef ACE_WString Istring;
#else
  typedef ACE_CString Istring;
#endif /* UNICODE */

  struct ACE_Export Name_Component
  {
    Istring id_;
    Istring kind_;

    int operator== (const Name_Component &rhs) const;
    int operator!= (const Name_Component &rhs) const;
    // Comparison
  };
  // The <id_> field is used,
  // but the <kind_> field is currently ignored

  // A Name is an ordered collections of components (ids)
  typedef ACE_Unbounded_Set<Name_Component> Name;

  static LPCTSTR STRING_SEPARATOR;
  // Separator for components in a name

  static Istring make_string (const Name &name);
  // Convert a <name> to a <string>

  static Name make_name (const Istring &string);
  // Convert a <string> to a <name>

  enum Binding_Type {INVALID, OBJECT, CONTEXT};
  // There are two types of bindings

  struct ACE_Export Binding
  {
    Binding (void);
    // Empty (default) constructor

    Binding (const Name &binding_name,
             Binding_Type binding_type);
    // Constructor
    // (Name version)

    Binding (const Istring &binding_name,
             Binding_Type binding_type);
    // Constructor
    // (String version)

    int operator== (const Binding &rhs) const;
    int operator!= (const Binding &rhs) const;
    // Comparison

    void name (Name &name);
    // Name accessor
    // (Name version)

    void name (Istring &name);
    Istring name (void);
    // Name accessors
    // (String version)

    Binding_Type type (void);
    // Type accessor

  private:
    Istring name_;
    Binding_Type type_;
    // A binding has a name and a type
  };

  // A list of bindings
  typedef ACE_Unbounded_Set<Binding> Binding_List;

  class Binding_Iterator;
  // Forward declaration of iterator

  class ACE_Export Object
  {
    // = TITLE
    //     An object representation
    //
    // = DESCRIPTION
    //     In CORBA, all objects inherit from (CORBA::Object).
    //     For the registry, this is used as a wrapper for an
    //     instance of a built-in data type.
    //     Think about an object as being similar to a file
    //     in a file system.
  public:
    Object (void *data = 0,
            u_long size = 0,
            u_long type = REG_NONE);
    // Default constructor

    void data (void *data);
    void *data (void) const;
    // Set/Get data

    void size (u_long size);
    u_long size (void) const;
    // Set/Get size

    void type (u_long type);
    u_long type (void) const;
    // Set/Get type

  private:
    void *data_;
    // Pointer to data

    u_long size_;
    // Size of the data

    u_long type_;
    // Type of data
  };

  class ACE_Export Naming_Context
  {
    // = TITLE
    //     An context representation
    //
    // = DESCRIPTION
    //     Think about a context as being similar to a directory
    //     in a file system.
  public:
    friend class ACE_Predefined_Naming_Contexts;
    // Friend factory

    enum { MAX_OBJECT_NAME_SIZE = BUFSIZ,
           MAX_CONTEXT_NAME_SIZE = MAXPATHLEN + 1 };
    // Max sizes of names
    // (Not too sure about this value)

    Naming_Context (void);
    // Empty constructor: keys will be NULL

    Naming_Context (const HKEY &key);
    // Constructor: key_ will be set to <key>

    ~Naming_Context (void);
    // Destructor will call <Naming_Context::close>.

    // The following interfaces are for objects

    int bind_new (const Name &name,
                  const Object &object);
    // Insert <object> with <name> into <this> context
    // This will fail if <name> already exists
    // (Name version)

    int bind_new (const Istring &name,
                  const Object &object);
    // Insert <object> with <name> into <this> context
    // This will fail if <name> already exists
    // (String version)

    int bind (const Name &name,
              const Object &object);
    // Insert or update <object> with <name> into <this> context
    // This will not fail if <name> already exists
    // (Name version)

    int bind (const Istring &name,
              const Object &object);
    // Insert or update <object> with <name> into <this> context
    // This will not fail if <name> already exists
    // (String version)

    int rebind (const Name &name,
                const Object &object);
    // Update <object> with <name> in <this> context
    // (Name version)

    int rebind (const Istring &name,
                const Object &object);
    // Update <object> with <name> in <this> context

    int resolve (const Name &name,
                 Object &object);
    // Find <object> with <name> in <this> context
    // (Name version)

    int resolve (const Istring &name,
                 Object &object);
    // Find <object> with <name> in <this> context

    int unbind (const Name &name);
    // Delete object with <name> in <this> context
    // (Name version)

    int unbind (const Istring &name);
    // Delete object with <name> in <this> context


    // The following interfaces are for Naming Context

    int new_context (Naming_Context &naming_context);
    // Create new <naming_context>

    int bind_new_context (const Name &name,
                          Naming_Context &naming_context,
                          u_long persistence = REG_OPTION_NON_VOLATILE,
                          u_long security_access = KEY_ALL_ACCESS,
                          LPSECURITY_ATTRIBUTES security_attributes = 0);
    // Insert <naming_context> with <name> relative to <this> context
    // This will fail if <name> already exists
    // (Name version)

    int bind_new_context (const Istring &name,
                          Naming_Context &naming_context,
                          u_long persistence = REG_OPTION_NON_VOLATILE,
                          u_long security_access = KEY_ALL_ACCESS,
                          LPSECURITY_ATTRIBUTES security_attributes = 0);
    // Insert <naming_context> with <name> relative to <this> context
    // This will fail if <name> already exists

    int bind_context (const Name &name,
                      /* const */ Naming_Context &naming_context,
                      u_long persistence = REG_OPTION_NON_VOLATILE,
                      u_long security_access = KEY_ALL_ACCESS,
                      LPSECURITY_ATTRIBUTES security_attributes = 0);
    // Insert or update <naming_context> with <name> relative to <this> context
    // This will not fail if <name> already exists
    // (Name version)

    int bind_context (const Istring &name,
                      /* const */ Naming_Context &naming_context,
                      u_long persistence = REG_OPTION_NON_VOLATILE,
                      u_long security_access = KEY_ALL_ACCESS,
                      LPSECURITY_ATTRIBUTES security_attributes = 0);
    // Insert or update <naming_context> with <name> relative to <this> context
    // This will not fail if <name> already exists

    int rebind_context (const Name &name,
                        /* const */ Naming_Context &naming_context);
    // Rename <naming_context> to <name>
    // (Name version)

    int rebind_context (const Istring &name,
                        /* const */ Naming_Context &naming_context);
    // Rename <naming_context> to <name>

    int resolve_context (const Name &name,
                         Naming_Context &naming_context,
                         u_long security_access = KEY_ALL_ACCESS);
    // Find <naming_context> with <name> in <this> context
    // (Name version)

    int resolve_context (const Istring &name,
                         Naming_Context &naming_context,
                         u_long security_access = KEY_ALL_ACCESS);
    // Find <naming_context> with <name> in <this> context

    int unbind_context (const Name &name);
    // Remove naming_context with <name> from <this> context
    // (Name version)

    int unbind_context (const Istring &name);
    // Remove naming_context with <name> from <this> context

    int destroy (void);
    // Same as <unbind_context> with <this> as naming_context

    int list (u_long how_many,
              Binding_List &list,
              Binding_Iterator &iterator);
    // listing function: iterator creator
    // This is useful when there are many objects and contexts
    // in <this> context and you only want to look at a few entries
    // at a time

    int list (Binding_List &list);
    // listing function: iterator creator
    // This gives back a listing of all entries in <this> context.


    // Some other necessary functions which are
    // not part of the CORBA interface

    int flush (void);
    // Sync content of context to disk

    int close (void);
    // Close the handle of the context
    // Note: <close> does not call <flush>


    // Accessors

    HKEY key (void);
    // Get key

    // void parent (HKEY parent);
    HKEY parent (void);
    // Get parent

    void name (Name &name);
    // Get name
    // (Name version)

    void name (Istring &name);
    Istring name (void);
    // Get name
    // (String version)

  protected:
    void key (HKEY key);
    // Set key

    void parent (HKEY parent);
    // Set parent

    void name (const Name &name);
    // Set name
    // (Name version)

    void name (const Istring &name);
    // Set name
    // (String version)

  private:
    Naming_Context (const Naming_Context &rhs);
    // Disallow copy constructors

    const Naming_Context &operator= (const Naming_Context &rhs);
    // Disallow assignment

    HKEY key_;
    // Key for self

    HKEY parent_key_;
    // Key for parent

    Istring name_;
    // Name of self
  };

  class ACE_Export Binding_Iterator
  {
    // = TITLE
    //     An iterator
    //
    // = DESCRIPTION
    //     Useful when iteratorating over a few entries at a time
  public:
    friend class Naming_Context;
    // Friend factory

    Binding_Iterator (void);
    // Default constructor

    int next_one (Binding &binding);
    // Next entry

    int next_n (u_long how_many,
                Binding_List &list);
    // Next <how_many> entries

    int destroy (void);
    // Cleanup

    void reset (void);
    // Reset the internal state of the iterator

    Naming_Context &naming_context (void);
    // Get naming_context that the iterator is iterating over

  private:

    void naming_context (Naming_Context& naming_context);
    // Set naming_context that the iterator is iterating over

    Naming_Context *naming_context_;
    // Reference to context

  public:
    // This should really be private
    // But the compiler is broken

    class ACE_Export Iteration_State
      // Base class for state
      {
      public:
        Iteration_State (Binding_Iterator &iterator);

        virtual int next_n (u_long how_many,
                            Binding_List &list) = 0;
        // Next <how_many> entries

        void reset (void);
        // Reset state

      protected:
        Binding_Iterator *parent_;
        // Pointer to parent iterator

        u_long index_;
      };

  private:
    class ACE_Export Object_Iteration : public Iteration_State
      {
      public:
        Object_Iteration (Binding_Iterator &iterator);

        int next_n (u_long how_many,
                    Binding_List &list);
        // Next <how_many> entries
      };

    class ACE_Export Context_Iteration : public Iteration_State
      {
      public:
        Context_Iteration (Binding_Iterator &iterator);

        int next_n (u_long how_many,
                    Binding_List &list);
        // Next <how_many> entries
      };

    class ACE_Export Iteration_Complete : public Iteration_State
      {
      public:
        Iteration_Complete (Binding_Iterator &iterator);

        int next_n (u_long how_many,
                    Binding_List &list);
        // Next <how_many> entries
      };

    friend class Iteration_State;
    friend class Object_Iteration;
    friend class Context_Iteration;
    friend class Iteration_Complete;
    // Friend states

    Object_Iteration object_iteration_;
    Context_Iteration context_iteration_;
    Iteration_Complete iteration_complete_;
    // Instances of all states

    Iteration_State *current_enumeration_;
    // Pointer to current state

    void current_enumeration (Iteration_State& current_enumeration);
    Iteration_State &current_enumeration (void);
    // Set/Get current_enumeration
  };
};

class ACE_Export ACE_Predefined_Naming_Contexts
{
  // = TITLE
  //     A factory for predefined registries, which exist by default
  //     on Win32 platforms
  //
  // = DESCRIPTION
  //     This factory can connect to both local and remote
  //     predefined registries.
public:
  static int connect (ACE_Registry::Naming_Context &naming_context,
                      HKEY predefined = HKEY_LOCAL_MACHINE,
                      LPCTSTR machine_name = 0);
  // Factory method for connecting to predefined registries.  This
  // method works for both remote and local machines.  However, for
  // remote machines, HKEY_CLASSES_ROOT and HKEY_CURRENT_USER types
  // are not allowed

private:
  static int is_local_host (LPCTSTR machine_name);
  // Check if <machine_name> is the local host
};

// Fix me!  Shouldn't have to define this stuff

#if defined (ACE_HAS_BROKEN_NESTED_TEMPLATES)
  typedef ACE_Registry::Name_Component Name_Component;
  typedef ACE_Registry::Binding Binding;
#endif /* ACE_HAS_BROKEN_NESTED_TEMPLATES */

#endif /* ACE_WIN32 */
#endif /* ACE_REGISTRY_H */