/** \file BufferedLogCallback.cxx
 * Buffer certain log messages permanently for later retrieval and display
 */

// Copyright (C) 2013  James Turner  zakalawe@mac.com
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
 
#include <simgear_config.h>
#include <simgear/debug/BufferedLogCallback.hxx>
     
#include <boost/foreach.hpp>
     
#include <simgear/sg_inlines.h>
#include <simgear/threads/SGThread.hxx>
#include <simgear/threads/SGGuard.hxx>

#include <cstdlib> // for malloc
     
namespace simgear
{

class BufferedLogCallback::BufferedLogCallbackPrivate
{
public:
    SGMutex m_mutex;
    vector_cstring m_buffer;
    unsigned int m_stamp;
    unsigned int m_maxLength;
};
   
BufferedLogCallback::BufferedLogCallback(sgDebugClass c, sgDebugPriority p) :
	simgear::LogCallback(c,p),
    d(new BufferedLogCallbackPrivate)
{
    d->m_stamp = 0;
    d->m_maxLength = 0xffff;
}

BufferedLogCallback::~BufferedLogCallback()
{
    for (unsigned char* msg : d->m_buffer) {
        free(msg);
    }
}
    
void BufferedLogCallback::operator()(sgDebugClass c, sgDebugPriority p, 
        const char* file, int line, const std::string& aMessage)
{
    SG_UNUSED(file);
    SG_UNUSED(line);
    
    if (!shouldLog(c, p)) return;
    
    vector_cstring::value_type msg;
    if (aMessage.size() >= d->m_maxLength) {
        msg = (vector_cstring::value_type) malloc(d->m_maxLength);
        strncpy((char*) msg, aMessage.c_str(), d->m_maxLength - 1);
        msg[d->m_maxLength - 1] = 0; // add final NULL byte
    } else {
        msg = (vector_cstring::value_type) strdup(aMessage.c_str());
    }
    
    SGGuard<SGMutex> g(d->m_mutex);
    d->m_buffer.push_back(msg);
    d->m_stamp++;
}
 
unsigned int BufferedLogCallback::stamp() const
{
    return d->m_stamp;
}
 
unsigned int BufferedLogCallback::threadsafeCopy(vector_cstring& aOutput)
{
    SGGuard<SGMutex> g(d->m_mutex);
    size_t sz = d->m_buffer.size();
    aOutput.resize(sz);
    memcpy(aOutput.data(), d->m_buffer.data(), sz * sizeof(vector_cstring::value_type));
    return d->m_stamp;
} 
 
void BufferedLogCallback::truncateAt(unsigned int t)
{
    d->m_maxLength = t;
}
 
} // of namespace simgear