/*
 * 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/logstring.h>
#include <log4cxx/fileappender.h>
#include <log4cxx/helpers/stringhelper.h>
#include <log4cxx/helpers/loglog.h>
#include <log4cxx/helpers/optionconverter.h>
#include <log4cxx/helpers/synchronized.h>
#include <log4cxx/helpers/pool.h>
#include <log4cxx/helpers/fileoutputstream.h>
#include <log4cxx/helpers/outputstreamwriter.h>
#include <log4cxx/helpers/bufferedwriter.h>
#include <log4cxx/helpers/bytebuffer.h>
#include <log4cxx/helpers/synchronized.h>

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

IMPLEMENT_LOG4CXX_OBJECT(FileAppender)


FileAppender::FileAppender()
{
    LOCK_W sync(mutex);
    fileAppend = true;
    bufferedIO = false;
    bufferSize = 8 * 1024;
}

FileAppender::FileAppender(const LayoutPtr& layout1, const LogString& fileName1,
                           bool append1, bool bufferedIO1, int bufferSize1)
    : WriterAppender(layout1)
{
    {
        LOCK_W sync(mutex);
        fileAppend = append1;
        fileName = fileName1;
        bufferedIO = bufferedIO1;
        bufferSize = bufferSize1;
    }
    Pool p;
    activateOptions(p);
}

FileAppender::FileAppender(const LayoutPtr& layout1, const LogString& fileName1,
                           bool append1)
    : WriterAppender(layout1)
{
    {
        LOCK_W sync(mutex);
        fileAppend = append1;
        fileName = fileName1;
        bufferedIO = false;
        bufferSize = 8 * 1024;
    }
    Pool p;
    activateOptions(p);
}

FileAppender::FileAppender(const LayoutPtr& layout1, const LogString& fileName1)
    : WriterAppender(layout1)
{
    {
        LOCK_W sync(mutex);
        fileAppend = true;
        fileName = fileName1;
        bufferedIO = false;
        bufferSize = 8 * 1024;
    }
    Pool p;
    activateOptions(p);
}

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

void FileAppender::setAppend(bool fileAppend1)
{
    LOCK_W sync(mutex);
    this->fileAppend = fileAppend1;
}

void FileAppender::setFile(const LogString& file)
{
    LOCK_W sync(mutex);
    fileName = file;
}


void FileAppender::setBufferedIO(bool bufferedIO1)
{
    LOCK_W sync(mutex);
    this->bufferedIO = bufferedIO1;

    if (bufferedIO1)
    {
        setImmediateFlush(false);
    }
}

void FileAppender::setOption(const LogString& option,
                             const LogString& value)
{
    if (StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("FILE"), LOG4CXX_STR("file"))
            || StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("FILENAME"), LOG4CXX_STR("filename")))
    {
        LOCK_W sync(mutex);
        fileName = stripDuplicateBackslashes(value);
    }
    else if (StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("APPEND"), LOG4CXX_STR("append")))
    {
        LOCK_W sync(mutex);
        fileAppend = OptionConverter::toBoolean(value, true);
    }
    else if (StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("BUFFEREDIO"), LOG4CXX_STR("bufferedio")))
    {
        LOCK_W sync(mutex);
        bufferedIO = OptionConverter::toBoolean(value, true);
    }
    else if (StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("IMMEDIATEFLUSH"), LOG4CXX_STR("immediateflush")))
    {
        LOCK_W sync(mutex);
        bufferedIO = !OptionConverter::toBoolean(value, false);
    }
    else if (StringHelper::equalsIgnoreCase(option, LOG4CXX_STR("BUFFERSIZE"), LOG4CXX_STR("buffersize")))
    {
        LOCK_W sync(mutex);
        bufferSize = OptionConverter::toFileSize(value, 8 * 1024);
    }
    else
    {
        WriterAppender::setOption(option, value);
    }
}

void FileAppender::activateOptions(Pool& p)
{
    LOCK_W sync(mutex);
    int errors = 0;

    if (!fileName.empty())
    {
        try
        {
            setFile(fileName, fileAppend, bufferedIO, bufferSize, p);
        }
        catch (IOException& e)
        {
            errors++;
            LogString msg(LOG4CXX_STR("setFile("));
            msg.append(fileName);
            msg.append(1, (logchar) 0x2C /* ',' */);
            StringHelper::toString(fileAppend, msg);
            msg.append(LOG4CXX_STR(") call failed."));
            errorHandler->error(msg, e, ErrorCode::FILE_OPEN_FAILURE);
        }
    }
    else
    {
        errors++;
        LogLog::error(LogString(LOG4CXX_STR("File option not set for appender ["))
                      +  name + LOG4CXX_STR("]."));
        LogLog::warn(LOG4CXX_STR("Are you using FileAppender instead of ConsoleAppender?"));
    }

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


/**
 * Replaces double backslashes (except the leading doubles of UNC's)
 * with single backslashes for compatibility with existing path
 * specifications that were working around use of
 * OptionConverter::convertSpecialChars in XML configuration files.
 *
 * @param src source string
 * @return modified string
 *
 *
 */
LogString FileAppender::stripDuplicateBackslashes(const LogString& src)
{
    logchar backslash = 0x5C; // '\\'
    LogString::size_type i = src.find_last_of(backslash);

    if (i != LogString::npos)
    {
        LogString tmp(src);

        for (;
                i != LogString::npos && i > 0;
                i = tmp.find_last_of(backslash, i - 1))
        {
            //
            //   if the preceding character is a slash then
            //      remove the preceding character
            //      and continue processing
            if (tmp[i - 1] == backslash)
            {
                tmp.erase(i, 1);
                i--;

                if (i == 0)
                {
                    break;
                }
            }
            else
            {
                //
                //  if there an odd number of slashes
                //     the string wasn't trying to work around
                //     OptionConverter::convertSpecialChars
                return src;
            }
        }

        return tmp;
    }

    return src;
}

/**
  <p>Sets and <i>opens</i> the file where the log output will
  go. The specified file must be writable.

  <p>If there was already an opened file, then the previous file
  is closed first.

  <p><b>Do not use this method directly. To configure a FileAppender
  or one of its subclasses, set its properties one by one and then
  call activateOptions.</b>

  @param filename The path to the log file.
  @param append   If true will append to fileName. Otherwise will
      truncate fileName.
  @param bufferedIO
  @param bufferSize

  @throws IOException

 */
void FileAppender::setFile(
    const LogString& filename,
    bool append1,
    bool bufferedIO1,
    size_t bufferSize1,
    Pool& p)
{
    LOCK_W sync(mutex);

    // It does not make sense to have immediate flush and bufferedIO.
    if (bufferedIO1)
    {
        setImmediateFlush(false);
    }

    closeWriter();

    bool writeBOM = false;

    if (StringHelper::equalsIgnoreCase(getEncoding(),
                                       LOG4CXX_STR("utf-16"), LOG4CXX_STR("UTF-16")))
    {
        //
        //    don't want to write a byte order mark if the file exists
        //
        if (append1)
        {
            File outFile;
            outFile.setPath(filename);
            writeBOM = !outFile.exists(p);
        }
        else
        {
            writeBOM = true;
        }
    }

    OutputStreamPtr outStream;

    try
    {
        outStream = new FileOutputStream(filename, append1);
    }
    catch (IOException& ex)
    {
        LogString parentName = File().setPath(filename).getParent(p);

        if (!parentName.empty())
        {
            File parentDir;
            parentDir.setPath(parentName);

            if (!parentDir.exists(p) && parentDir.mkdirs(p))
            {
                outStream = new FileOutputStream(filename, append1);
            }
            else
            {
                throw;
            }
        }
        else
        {
            throw;
        }
    }


    //
    //   if a new file and UTF-16, then write a BOM
    //
    if (writeBOM)
    {
        char bom[] = { (char) 0xFE, (char) 0xFF };
        ByteBuffer buf(bom, 2);
        outStream->write(buf, p);
    }

    WriterPtr newWriter(createWriter(outStream));

    if (bufferedIO1)
    {
        newWriter = new BufferedWriter(newWriter, bufferSize1);
    }

    setWriter(newWriter);

    this->fileAppend = append1;
    this->bufferedIO = bufferedIO1;
    this->fileName = filename;
    this->bufferSize = bufferSize1;
    writeHeader(p);

}