/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <log4cxx/writerappender.h>
#include <log4cxx/helpers/loglog.h>
#include <log4cxx/helpers/synchronized.h>
#include <log4cxx/layout.h>
#include <log4cxx/helpers/stringhelper.h>

using namespace log4cxx;
using namespace log4cxx::helpers;
using namespace log4cxx::spi;

IMPLEMENT_LOG4CXX_OBJECT(WriterAppender)

WriterAppender::WriterAppender() {
   synchronized sync(mutex);
   immediateFlush = true;
}

WriterAppender::WriterAppender(const LayoutPtr& layout1,
               log4cxx::helpers::WriterPtr& writer1)
    : AppenderSkeleton(layout1), writer(writer1) {
      Pool p;
      synchronized sync(mutex);
      immediateFlush = true;
      activateOptions(p);
}

WriterAppender::WriterAppender(const LayoutPtr& layout1)
    : AppenderSkeleton(layout1) {
    synchronized sync(mutex);
    immediateFlush = true;
}


WriterAppender::~WriterAppender()
{
    finalize();
}

void WriterAppender::activateOptions(Pool& p)
{
        int errors = 0;
        if(layout == 0) {
                errorHandler->error(
                        ((LogString) LOG4CXX_STR("No layout set for the appender named ["))
                        + name+ LOG4CXX_STR("]."));
                errors++;
        }

        if(writer == 0) {
          errorHandler->error(
                  ((LogString) LOG4CXX_STR("No writer set for the appender named ["))
                  + name+ LOG4CXX_STR("]."));
          errors++;
        }

        if (errors == 0) {
           AppenderSkeleton::activateOptions(p);
        }
}



void WriterAppender::append(const spi::LoggingEventPtr& event, Pool& pool1)
{

        if(!checkEntryConditions())
        {
                return;
        }

        subAppend(event, pool1);
}

/**
   This method determines if there is a sense in attempting to append.

   <p>It checks whether there is a set output target and also if
   there is a set layout. If these checks fail, then the boolean
   value <code>false</code> is returned. */
bool WriterAppender::checkEntryConditions() const {
  static bool warnedClosed = false;
  static bool warnedNoWriter = false;
  if (closed) {
    if(!warnedClosed) {
      LogLog::warn(LOG4CXX_STR("Not allowed to write to a closed appender."));
      warnedClosed = true;
    }
    return false;
  }

  if (writer == 0) {
    if (warnedNoWriter) {
        errorHandler->error(
            LogString(LOG4CXX_STR("No output stream or file set for the appender named [")) +
               name + LOG4CXX_STR("]."));
        warnedNoWriter = true;
    }

    return false;
  }
  
  if (layout == 0) {
    errorHandler->error(
            LogString(LOG4CXX_STR("No layout set for the appender named [")) +
               name + LOG4CXX_STR("]."));
    return false;
  }

  return true;
}




/**
   Close this appender instance. The underlying stream or writer is
   also closed.

   <p>Closed appenders cannot be reused.

   @see #setWriter
   */
void WriterAppender::close()
{
        synchronized sync(mutex);

        if(closed)
        {
                return;
        }

        closed = true;
        closeWriter();
}

/**
 * Close the underlying {@link java.io.Writer}.
 * */
void WriterAppender::closeWriter() {
  if (writer != NULL) {
    try {
      // before closing we have to output out layout's footer
      //
      //   Using the object's pool since this is a one-shot operation
      //    and pool is likely to be reclaimed soon when appender is destructed.
      //
      writeFooter(pool);
      writer->close(pool);
      writer = 0;
    } catch (IOException& e) {
      LogLog::error(LogString(LOG4CXX_STR("Could not close writer for WriterAppender named "))+name, e);
    }
  }

}

/**
   Returns an OutputStreamWriter when passed an OutputStream.  The
   encoding used will depend on the value of the
   <code>encoding</code> property.  If the encoding value is
   specified incorrectly the writer will be opened using the default
   system encoding (an error message will be printed to the loglog.  */
WriterPtr WriterAppender::createWriter(OutputStreamPtr& os) {

  LogString enc(getEncoding());

  CharsetEncoderPtr encoder;
  if (enc.empty()) {
    encoder = CharsetEncoder::getDefaultEncoder();
  } else {
    if(StringHelper::equalsIgnoreCase(enc,
        LOG4CXX_STR("utf-16"), LOG4CXX_STR("UTF-16"))) {
      encoder = CharsetEncoder::getEncoder(LOG4CXX_STR("UTF-16BE"));
    } else {
      encoder = CharsetEncoder::getEncoder(enc);
    }
    if (encoder == NULL) {
      encoder = CharsetEncoder::getDefaultEncoder();
      LogLog::warn(LOG4CXX_STR("Error initializing output writer."));
      LogLog::warn(LOG4CXX_STR("Unsupported encoding?"));
    }
  }

  return new OutputStreamWriter(os, encoder);
}

LogString WriterAppender::getEncoding() const {
  return encoding;
}

void WriterAppender::setEncoding(const LogString& enc) {
  encoding = enc;
}

void WriterAppender::subAppend(const spi::LoggingEventPtr& event, Pool& p)
{
        LogString msg;
        layout->format(msg, event, p);
        {
           synchronized sync(mutex);
         if (writer != NULL) {
           writer->write(msg, p);
              if (immediateFlush) {
               writer->flush(p);
              }
         }
        }
}


void WriterAppender::writeFooter(Pool& p)
{
        if (layout != NULL) {
          LogString foot;
          layout->appendFooter(foot, p);
          synchronized sync(mutex);
          writer->write(foot, p);
        }
}

void WriterAppender::writeHeader(Pool& p)
{
        if(layout != NULL) {
          LogString header;
          layout->appendHeader(header, p);
          synchronized sync(mutex);
          writer->write(header, p);
        }
}


void WriterAppender::setWriter(const WriterPtr& newWriter) {
   synchronized sync(mutex);
   writer = newWriter;
}


bool WriterAppender::requiresLayout() const {
   return true;
}

void WriterAppender::setOption(const LogString& option, const LogString& value) {
    if(StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("ENCODING"), LOG4CXX_STR("encoding"))) {
       setEncoding(value);
    } else {
      AppenderSkeleton::setOption(option, value);
    }
}


void WriterAppender::setImmediateFlush(bool value) { 
    synchronized sync(mutex);
    immediateFlush = value; 
}