// ============================================================================
//
// = LIBRARY
//    ULib - c++ library
//
// = FILENAME
//    client_rdb.h
//
// = AUTHOR
//    Stefano Casazza
//
// ============================================================================

#ifndef U_RDB_CLIENT_H
#define U_RDB_CLIENT_H 1

#include <ulib/db/rdb.h>
#include <ulib/net/rpc/rpc.h>
#include <ulib/net/client/client.h>

/**
 * @class URDBClient_Base
 *
 * @brief Creates and manages a client connection with a RDB server
 */

typedef void (*vPFprpr)(UStringRep*, UStringRep*);

class U_EXPORT URDBClient_Base : public UClient_Base {
public:

   // SERVICES

   void reset()
      {
      U_TRACE(0, "URDBClient_Base::reset()")

      URPC::resetInfo();
      }

   bool isOK()
      {
      U_TRACE(0, "URDBClient_Base::isOK()")

      U_RETURN(nResponseCode == 200);
      }

   bool readResponse();
   bool processRequest(const char* token);

   // Combines the old cdb file and the diffs in a new cdb file

   bool closeReorganize();

   // ------------------------------------------------------
   // Write a key/value pair to a reliable database.
   // ------------------------------------------------------
   // RETURN VALUE
   // ------------------------------------------------------
   //  0: Everything was OK.
   // -1: flags was RDB_INSERT and this key already existed.
   // -3: disk full writing to the journal file
   // ------------------------------------------------------

   int store(const UString& key, const UString& data, int flag = RDB_INSERT);

   // ---------------------------------------------------------
   // Mark a key/value as deleted.
   // ---------------------------------------------------------
   // RETURN VALUE
   // ---------------------------------------------------------
   //  0: Everything was OK.
   // -1: The entry was not in the database
   // -2: The entry was already marked deleted in the hash-tree
   // -3: disk full writing to the journal file
   // ---------------------------------------------------------

   int remove(const UString& key);

   // ----------------------------------------------------------
   // Substitute a key/value with a new key/value (remove+store)
   // ----------------------------------------------------------
   // RETURN VALUE
   // ----------------------------------------------------------
   //  0: Everything was OK
   // -1: The entry was not in the database
   // -2: The entry was marked deleted in the hash-tree
   // -3: disk full writing to the journal file
   // -4: flag was RDB_INSERT and the new key already existed
   // ----------------------------------------------------------

   int substitute(const UString& key, const UString& new_key, const UString& data, int flag = RDB_INSERT);

   // operator []

   UString operator[](const UString& key);

   // TRANSACTION

   bool  beginTransaction();
   bool  abortTransaction();
   bool commitTransaction();

   // Call function for all entry

   void callForAllEntry(      vPFprpr function) { _callForAllEntry(function, false); }
   void callForAllEntrySorted(vPFprpr function) { _callForAllEntry(function, true); }

   // DEBUG

#if defined(U_STDCPP_ENABLE) && defined(DEBUG)
   const char* dump(bool reset) const;
#endif

protected:
   int nResponseCode;

   // Costruttori

   URDBClient_Base(UFileConfig* _cfg) : UClient_Base(_cfg)
      {
      U_TRACE_REGISTER_OBJECT(0, URDBClient_Base, "%p", _cfg)

      URPC::allocate();

      nResponseCode = 0;
      }

   ~URDBClient_Base()
      {
      U_TRACE_UNREGISTER_OBJECT(0, URDBClient_Base)

      delete URPC::rpc_info;
      }

   // Call function for all entry

   void _callForAllEntry(vPFprpr function, bool sorted);

private:
   void setStatus() U_NO_EXPORT;

#ifdef U_COMPILER_DELETE_MEMBERS
   URDBClient_Base(const URDBClient_Base&) = delete;
   URDBClient_Base& operator=(const URDBClient_Base&) = delete;
#else
   URDBClient_Base(const URDBClient_Base&) : UClient_Base(0) {}
   URDBClient_Base& operator=(const URDBClient_Base&)        { return *this; }
#endif
};

template <class Socket> class U_EXPORT URDBClient : public URDBClient_Base {
public:

   // COSTRUTTORI

   URDBClient(UFileConfig* _cfg) : URDBClient_Base(_cfg)
      {
      U_TRACE_REGISTER_OBJECT(0, URDBClient, "%p", _cfg)

      UClient_Base::socket = U_NEW(Socket(UClient_Base::bIPv6));
      }

   ~URDBClient()
      {
      U_TRACE_UNREGISTER_OBJECT(0, URDBClient)
      }

   // DEBUG

#if defined(U_STDCPP_ENABLE) && defined(DEBUG)
   const char* dump(bool _reset) const { return URDBClient_Base::dump(_reset); }
#endif

private:
#ifdef U_COMPILER_DELETE_MEMBERS
   URDBClient(const URDBClient&) = delete;
   URDBClient& operator=(const URDBClient&) = delete;
#else
   URDBClient(const URDBClient&) : URDBClient_Base(0) {}
   URDBClient& operator=(const URDBClient&)           { return *this; }
#endif
};

#endif