/*
  Copyright (c) 2012 Boris Moiseev (cyberbobs at gmail dot com)

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License version 2.1
  as published by the Free Software Foundation and appearing in the file
  LICENSE.LGPL included in the packaging of this file.

  This program 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 Lesser General Public License for more details.
*/
#ifndef LOGGER_H
#define LOGGER_H

// Qt
#include <QString>
#include <QDebug>
#include <QDateTime>
#include <QElapsedTimer>

// Local
#include "CuteLogger_global.h"
class AbstractAppender;


class Logger;
CUTELOGGERSHARED_EXPORT Logger* cuteLoggerInstance();
#define cuteLogger cuteLoggerInstance()


#define LOG_TRACE            CuteMessageLogger(cuteLoggerInstance(), Logger::Trace,   __FILE__, __LINE__, Q_FUNC_INFO).write
#define LOG_DEBUG            CuteMessageLogger(cuteLoggerInstance(), Logger::Debug,   __FILE__, __LINE__, Q_FUNC_INFO).write
#define LOG_INFO             CuteMessageLogger(cuteLoggerInstance(), Logger::Info,    __FILE__, __LINE__, Q_FUNC_INFO).write
#define LOG_WARNING          CuteMessageLogger(cuteLoggerInstance(), Logger::Warning, __FILE__, __LINE__, Q_FUNC_INFO).write
#define LOG_ERROR            CuteMessageLogger(cuteLoggerInstance(), Logger::Error,   __FILE__, __LINE__, Q_FUNC_INFO).write
#define LOG_FATAL            CuteMessageLogger(cuteLoggerInstance(), Logger::Fatal,   __FILE__, __LINE__, Q_FUNC_INFO).write

#define LOG_CTRACE(category)   CuteMessageLogger(cuteLoggerInstance(), Logger::Trace,   __FILE__, __LINE__, Q_FUNC_INFO, category).write()
#define LOG_CDEBUG(category)   CuteMessageLogger(cuteLoggerInstance(), Logger::Debug,   __FILE__, __LINE__, Q_FUNC_INFO, category).write()
#define LOG_CINFO(category)    CuteMessageLogger(cuteLoggerInstance(), Logger::Info,    __FILE__, __LINE__, Q_FUNC_INFO, category).write()
#define LOG_CWARNING(category) CuteMessageLogger(cuteLoggerInstance(), Logger::Warning, __FILE__, __LINE__, Q_FUNC_INFO, category).write()
#define LOG_CERROR(category)   CuteMessageLogger(cuteLoggerInstance(), Logger::Error,   __FILE__, __LINE__, Q_FUNC_INFO, category).write()
#define LOG_CFATAL(category)   CuteMessageLogger(cuteLoggerInstance(), Logger::Fatal,   __FILE__, __LINE__, Q_FUNC_INFO, category).write()

#define LOG_TRACE_TIME  LoggerTimingHelper loggerTimingHelper(cuteLoggerInstance(), Logger::Trace, __FILE__, __LINE__, Q_FUNC_INFO); loggerTimingHelper.start
#define LOG_DEBUG_TIME  LoggerTimingHelper loggerTimingHelper(cuteLoggerInstance(), Logger::Debug, __FILE__, __LINE__, Q_FUNC_INFO); loggerTimingHelper.start
#define LOG_INFO_TIME   LoggerTimingHelper loggerTimingHelper(cuteLoggerInstance(), Logger::Info,  __FILE__, __LINE__, Q_FUNC_INFO); loggerTimingHelper.start

#define LOG_ASSERT(cond)        ((!(cond)) ? cuteLoggerInstance()->writeAssert(__FILE__, __LINE__, Q_FUNC_INFO, #cond) : qt_noop())
#define LOG_ASSERT_X(cond, msg) ((!(cond)) ? cuteLoggerInstance()->writeAssert(__FILE__, __LINE__, Q_FUNC_INFO, msg) : qt_noop())

#if (__cplusplus >= 201103L)
#include <functional>

#define LOG_CATEGORY(category) \
  Logger customCuteLoggerInstance{category};\
  std::function<Logger*()> cuteLoggerInstance = [&customCuteLoggerInstance]() {\
    return &customCuteLoggerInstance;\
  };\

#define LOG_GLOBAL_CATEGORY(category) \
  Logger customCuteLoggerInstance{category, true};\
  std::function<Logger*()> cuteLoggerInstance = [&customCuteLoggerInstance]() {\
    return &customCuteLoggerInstance;\
  };\

#else

#define LOG_CATEGORY(category) \
    Logger* cuteLoggerInstance()\
    {\
      static Logger customCuteLoggerInstance(category);\
      return &customCuteLoggerInstance;\
    }\

#define LOG_GLOBAL_CATEGORY(category) \
    Logger* cuteLoggerInstance()\
    {\
      static Logger customCuteLoggerInstance(category);\
      customCuteLoggerInstance.logToGlobalInstance(category, true);\
      return &customCuteLoggerInstance;\
    }\

#endif


class LoggerPrivate;
class CUTELOGGERSHARED_EXPORT Logger
{
  Q_DISABLE_COPY(Logger)

  public:
    Logger();
    Logger(const QString& defaultCategory, bool writeToGlobalInstance = false);
    ~Logger();

    //! Describes the possible severity levels of the log records
    enum LogLevel
    {
      Trace,   //!< Trace level. Can be used for mostly unneeded records used for internal code tracing.
      Debug,   //!< Debug level. Useful for non-necessary records used for the debugging of the software.
      Info,    //!< Info level. Can be used for informational records, which may be interesting for not only developers.
      Warning, //!< Warning. May be used to log some non-fatal warnings detected by your application.
      Error,   //!< Error. May be used for a big problems making your application work wrong but not crashing.
      Fatal    //!< Fatal. Used for unrecoverable errors, crashes the application right after the log record is written.
    };

    //! Sets the timing display mode for the LOG_TRACE_TIME, LOG_DEBUG_TIME and LOG_INFO_TIME macros
    enum TimingMode
    {
      TimingAuto, //!< Show time in seconds, if it exceeds 10s (default)
      TimingMs    //!< Always use milliseconds to display
    };

    static QString levelToString(LogLevel logLevel);
    static LogLevel levelFromString(const QString& s);

    static Logger* globalInstance();

    void registerAppender(AbstractAppender* appender);
    void registerCategoryAppender(const QString& category, AbstractAppender* appender);

    void removeAppender(AbstractAppender* appender);

    void logToGlobalInstance(const QString& category, bool logToGlobal = false);

    void setDefaultCategory(const QString& category);
    QString defaultCategory() const;

    void write(const QDateTime& timeStamp, LogLevel logLevel, const char* file, int line, const char* function, const char* category,
               const QString& message);
    void write(LogLevel logLevel, const char* file, int line, const char* function, const char* category, const QString& message);

    void writeAssert(const char* file, int line, const char* function, const char* condition);

  private:
    void write(const QDateTime& timeStamp, LogLevel logLevel, const char* file, int line, const char* function, const char* category,
               const QString& message, bool fromLocalInstance);
    Q_DECLARE_PRIVATE(Logger)
    LoggerPrivate* d_ptr;
};


class CUTELOGGERSHARED_EXPORT CuteMessageLogger
{
  Q_DISABLE_COPY(CuteMessageLogger)

  public:
    CuteMessageLogger(Logger* l, Logger::LogLevel level, const char* file, int line, const char* function)
        : m_l(l),
          m_level(level),
          m_file(file),
          m_line(line),
          m_function(function),
          m_category(nullptr)
    {}

    CuteMessageLogger(Logger* l, Logger::LogLevel level, const char* file, int line, const char* function, const char* category)
        : m_l(l),
          m_level(level),
          m_file(file),
          m_line(line),
          m_function(function),
          m_category(category)
    {}

    ~CuteMessageLogger();

    void write(const char* msg, ...)
#if defined(Q_CC_GNU) && !defined(__INSURE__)
#  if defined(Q_CC_MINGW) && !defined(Q_CC_CLANG)
    __attribute__ ((format (gnu_printf, 2, 3)))
#  else
    __attribute__ ((format (printf, 2, 3)))
#  endif
#endif
    ;

    void write(const QString& msg);

    QDebug write();

  private:
    Logger* m_l;
    Logger::LogLevel m_level;
    const char* m_file;
    int m_line;
    const char* m_function;
    const char* m_category;
    QString m_message;
};


class CUTELOGGERSHARED_EXPORT LoggerTimingHelper
{
  Q_DISABLE_COPY(LoggerTimingHelper)

  public:
    inline explicit LoggerTimingHelper(Logger* l, Logger::LogLevel logLevel, const char* file, int line,
                                       const char* function)
      : m_logger(l),
        m_logLevel(logLevel),
        m_timingMode(Logger::TimingAuto),
        m_file(file),
        m_line(line),
        m_function(function)
    {}

    void start(const char* msg, ...)
#if defined(Q_CC_GNU) && !defined(__INSURE__)
  #  if defined(Q_CC_MINGW) && !defined(Q_CC_CLANG)
    __attribute__ ((format (gnu_printf, 2, 3)))
  #  else
    __attribute__ ((format (printf, 2, 3)))
  #  endif
#endif
        ;

    void start(const QString& msg = QString());
    void start(Logger::TimingMode mode, const QString& msg);

    ~LoggerTimingHelper();

  private:
    Logger* m_logger;
    QElapsedTimer m_time;
    Logger::LogLevel m_logLevel;
    Logger::TimingMode m_timingMode;
    const char* m_file;
    int m_line;
    const char* m_function;
    QString m_block;
};


#endif // LOGGER_H