/*

 * 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 <iostream>   // for `cout`, `endl`

#include <cstdlib>    // for `exit()`, `EXIT_FAILURE`

#include <unistd.h>   // for `readlink`, `chdir`

#include <libgen.h>   // for `dirname`

#include <limits.h>   // for `PATH_MAX`

#include <iomanip>    // for `put_time()`

#include <ctime>    // for `time()`

#include <fuzzer/FuzzedDataProvider.h>

#include <log4cxx/propertyconfigurator.h>

#include <log4cxx/appenderskeleton.h>

using namespace LOG4CXX_NS;

namespace LOG4CXX_NS::fuzzer {

/**

 * Appender encoding incoming log events using the provided layout.

 * It is intended for appender-agnostic fuzzing.

 */

class EncodingAppender : public AppenderSkeleton {

public:

  DECLARE_LOG4CXX_OBJECT(EncodingAppender)

  BEGIN_LOG4CXX_CAST_MAP()

  LOG4CXX_CAST_ENTRY(EncodingAppender)

  LOG4CXX_CAST_ENTRY_CHAIN(AppenderSkeleton)

  END_LOG4CXX_CAST_MAP()

  EncodingAppender() : AppenderSkeleton() {}

  EncodingAppender(const LayoutPtr& layout) : AppenderSkeleton(layout) {}

  void close() override {}

  bool requiresLayout() const override {

    return true;

  }

  void append(const spi::LoggingEventPtr& event, helpers::Pool& pool) override {

    LogString msg;

    getLayout()->format(msg, event, pool);

  }

  void setOption(const LogString& option, const LogString& value) override {}

}; // class

IMPLEMENT_LOG4CXX_OBJECT(EncodingAppender)

LOG4CXX_PTR_DEF(EncodingAppender);

} // namespace

static std::time_t logTime;

static std::tm* logTimeBuffer;

#define LOG(stream) \

  logTime = std::time(nullptr); \

  logTimeBuffer = std::localtime(&logTime); \

  stream << std::put_time(logTimeBuffer, "%Y-%m-%d %H:%M:%S") << " [" << __FILE_NAME__ << ":" << __LINE__ << "] "

static void findExecutablePath(char* buffer) {

    ssize_t length = readlink("/proc/self/exe", buffer, PATH_MAX);

    if (length == -1) {

      LOG(std::cerr) << "ERROR: Failed to find the executable path" << std::endl;

    exit(EXIT_FAILURE);

  }

  buffer[length] = '\0';

}

static void chdirExecutableHome() {

    char executablePath[PATH_MAX];

    findExecutablePath(executablePath);

    char* executableHome = dirname(executablePath);

  if (chdir(executableHome) != 0) {

    LOG(std::cerr) << "DEBUG: Executable path: " << executablePath << std::endl;

    LOG(std::cerr) << "DEBUG: Executable home: " << executableHome << std::endl;

    LOG(std::cerr) << "ERROR: Failed to `chdir()` the executable path" << std::endl;

  }

}

static int INITIALIZED = 0;

static void init() {

  if (INITIALIZED != 0) {

    return;

  }

  LOG(std::cout) << "INFO: Produced using the Git commit ID: " << GIT_COMMIT_ID << std::endl;

  chdirExecutableHome();

  PropertyConfigurator::configure("PatternLayoutFuzzer.properties");

  INITIALIZED = 1;

}

#define MAX_STRING_LENGTH 512

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

  init();

  LoggerPtr logger = Logger::getRootLogger();

    FuzzedDataProvider dataProvider(data, size);

    while (dataProvider.remaining_bytes() > 0) {

      std::string message = dataProvider.ConsumeRandomLengthString(MAX_STRING_LENGTH);

      LOG4CXX_INFO(logger, message);

    }

    return 0;

}