//----------------------------------------------------------------------------
//  EgalTech    2013-2023
//----------------------------------------------------------------------------
// File : EgtLogger.h      Data : 15.12.23          Versione : 2.5l3
// Contenuto : Classi per logger.
//
//
//
// Modifiche : 06.12.13 DS Creazione modulo.
//             15.12.23 DS Ora default è thread safe.
//
//----------------------------------------------------------------------------

#pragma once

#include "/EgtDev/Include/EgtILogger.h"
#include <iostream>
#include <vector>
#define NOMINMAX
#include <Windows.h>
#include <time.h>

//----------------------------------------------------------------------------
namespace egtlogger
{
   //----------------------------------------------------------------------------
   class IntraProcessLock
   {
      public :
         IntraProcessLock( bool bThreadSafe)
            : m_bThreadSafe( bThreadSafe)
         {
            if ( m_bThreadSafe)
               InitializeCriticalSection( &m_cs) ;
         }
         
         ~IntraProcessLock( void)
         {
            if ( m_bThreadSafe)
               DeleteCriticalSection( &m_cs) ;
         }

         void Lock( void)
         {
            if ( m_bThreadSafe)
               EnterCriticalSection( &m_cs) ;
         }

         void Unlock( void)
         {
            if ( m_bThreadSafe)
               LeaveCriticalSection( &m_cs) ;
         }

      private :
         bool             m_bThreadSafe ;
         CRITICAL_SECTION m_cs ;
   } ;

   //----------------------------------------------------------------------------
   class Logger : public ILogger
   {
      private :
         struct StreamInfo
         {
            std::ostream* pStream ;
            bool bOwned ;
            LogLevel nLevel ;

            StreamInfo( std::ostream* pStream, bool bOwned, LogLevel nLevel)
            {
               this->pStream = pStream ;
               this->bOwned = bOwned ;
               this->nLevel = nLevel ;
            }
         } ;

      public :
         Logger( LogLevel nLevel, const char* szName, bool bThreadSafe = true,
                 int nLoggableItems = LI_DATETIME | LI_LOGGERNAME | LI_LOGGERLEVEL | LI_FUNCTION | LI_LINENUMBER) 
            : m_nLevel( nLevel), m_name( szName), m_threadProtect( bThreadSafe), m_loggableItem( nLoggableItems)
         {}

         ~Logger( void)
         {
            ClearOutputStreams() ;
         }

         void AddOutputStream( std::ostream& os, bool bOwn, LogLevel nLevel)
         {
            AddOutputStream( &os, bOwn, nLevel) ;
         }

         void AddOutputStream( std::ostream& os, bool bOwn)
         {
            AddOutputStream( os, bOwn, m_nLevel) ;
         }

         void AddOutputStream( std::ostream* os, bool bOwn)
         {
            AddOutputStream( os, bOwn, m_nLevel) ;
         }

         void AddOutputStream( std::ostream* os, bool bOwn, LogLevel nLevel)
         {
            StreamInfo si( os, bOwn, nLevel) ;
            m_outputStreams.push_back( si) ;
         }
         
         void ClearOutputStreams( void)
         {
            for ( auto iter = m_outputStreams.cbegin() ; iter < m_outputStreams.cend() ; ++iter) {
               if ( iter->bOwned)
                  delete iter->pStream ;
            }

            m_outputStreams.clear() ;
         }

         void Log( LogLevel nLevel, const char* szFile, int nLine, const char* szFunc, const char* szText)
         {
            Log( nLevel, m_loggableItem, szFile, nLine, szFunc, szText) ;
         }

         void Log( LogLevel nLevel, int nItem, const char* szFile, int nLine, const char* szFunc, const char* szText)
         {
            m_threadProtect.Lock() ;

            for ( auto iter = m_outputStreams.cbegin() ; iter < m_outputStreams.cend() ; ++iter) {
               if ( nLevel < iter->nLevel)
                  continue ;

               bool bWritten = false ;
               std::ostream* pStream = iter->pStream ;
               if ( pStream == nullptr)
                  continue ;
            
               if ( nItem &  LI_DATETIME)
                  bWritten = write_datetime( bWritten, pStream) ;
            
               if ( nItem & LI_THREADID)
                  bWritten = write<int>( GetCurrentThreadId(), bWritten, pStream) ;

               if ( nItem & LI_LOGGERNAME)
                  bWritten = write<const char*>( m_name.c_str(), bWritten, pStream) ;

               if ( nItem & LI_LOGGERLEVEL) {
                  char strLevel[4] ;
                  LogLevelToString( nLevel, strLevel) ;
                  bWritten = write<const char*>( strLevel, bWritten, pStream) ;
               }

               if ( nItem & LI_FUNCTION)
                  bWritten = write<const char*>( szFunc, bWritten, pStream) ;

               if ( nItem & LI_FILENAME)
                  bWritten = write<const char*>( szFile, bWritten, pStream) ;

               if ( nItem & LI_LINENUMBER)
                  bWritten = write<int>( nLine, bWritten, pStream) ;
                        
               bWritten = write<const char*>( szText, bWritten, pStream) ;

               if ( bWritten) {
                  (*pStream) << std::endl ;
                  pStream->flush() ;
               }
            }

            m_threadProtect.Unlock() ;
         }

      private :
         int                      m_loggableItem ;
         LogLevel                 m_nLevel ;
         std::string              m_name ; 
         std::vector<StreamInfo>  m_outputStreams ;
         IntraProcessLock         m_threadProtect ;
   
         template <class T>
         bool write( T data, bool bWritten, std::ostream* strm)
         {
            if ( bWritten)
               (*strm) << " " ;
            (*strm) << data ;
            return true ;
         }

         bool write_datetime( bool bWritten, std::ostream* strm)
         {
            if ( bWritten)
               (*strm) << " " ;

           // seconds elapsed since midnight, January 1, 1970
            time_t _time ;
            time( &_time) ;
           // structured time
            tm _tm ;
            if ( localtime_s( &_tm, &_time) != 0)
               (*strm) << "time/date error" ;
           // string format
            const int DT_LEN = 24 ;
            char szDateTime[DT_LEN] = { '\0'} ;
            strftime( szDateTime, DT_LEN, "%Y/%m/%d %H:%M:%S", &_tm) ;
           // output
            (*strm) << szDateTime ;

            return true ;
         }

         void LogLevelToString( LogLevel nLevel, char* strLevel)
         {
            switch ( nLevel) {
            case LL_ERROR :
               strcpy_s( strLevel, 4, "ERR") ;
               break ;
            case LL_WARN :
               strcpy_s( strLevel, 4, "WRN") ;
               break ;
            case LL_INFO :
               strcpy_s( strLevel, 4, "INF") ;
               break ;
            case LL_DEBUG :
               strcpy_s( strLevel, 4, "DBG") ;
               break ;
            }
         }
   } ;
}