//! Copyright (C) 2013 Roland Winklmeier
//! This Source Code Form is subject to the terms of the Mozilla Public
//! License, v. 2.0. If a copy of the MPL was not distributed with this
//! file, You can obtain one at http://mozilla.org/MPL/2.0/

#ifndef BLACKMISC_LOG_H
#define BLACKMISC_LOG_H

#include <QMutex>
#include <QList>
#include <QString>
#include <QDateTime>

namespace BlackMisc
{

    class ILogDisplay;
    class IContext;

    //! Logging class
    /*! This class implements the logging of the library. It holds a list of displays
        takes care of any additional information needed, e.g. timestamps, filename etc.
        To use the logging use the default displayer or implement your own one and
        register it with this class.
    */
    class CLog
    {
    public:
        //! Logging type.
        /*! This enum holds all different available log types. */
        enum TLogType
        {
            eOff = 0,
            eError,
            eWarning,
            eInfo,
            eDebug,
            eLast
        };

        //! SLogParameter
        /*!
          This structs capsulates all information needed to output a log line.
        */
        struct SLogInformation
        {
            SLogInformation() : m_dateTime(), m_logType(CLog::eOff), m_applicationName(), m_threadId(0), m_sourceFile(NULL), m_line(-1), m_methodName(NULL) {}
            QDateTime           m_dateTime;
            TLogType            m_logType;
            QString             m_applicationName;
            quint32             m_threadId;
            const char         *m_sourceFile;
            qint32              m_line;
            const char         *m_methodName;
        };

        CLog(IContext &context, TLogType logType = eOff);

        //! CLog destructor.
        virtual ~CLog(void);

        /*!
         * Display
         */

        //! This method adds a Displayer to the Log object
        /*! CLog does not own the pointer. It is the callers responsibility
            to allocate the displayer and remove it after using. */
        /*!
          \param display A pointer to a display.
          \sa ILogDisplay
        */
        void attachDisplay(BlackMisc::ILogDisplay *display);

        //! This method returns the pointer to a registered display.
        /*!
          \return display A pointer to a display.
        */
        ILogDisplay *getDisplay(const QString &displayName);

        //! Removes a display
        /*!
          \param logDisplay Pointer to the display.
        */
        void dettachDisplay(ILogDisplay *logDisplay);

        //! Removes a display by its name.
        /*!
          \param displayName Name of the display.
        */
        void dettachDisplay(const QString &displayName);

        //! Checks if the displayer is added
        /*!
          \param logDisplay Pointer to a display.
          \return Returns true if display is attached, otherwise false.
        */
        bool isAttached(ILogDisplay *logDisplay) const;

        //! Checks if the object has any attached displays
        /*!
          \return Returns true if no display is attached, otherwise false.
        */
        bool hasNoDisplays() const { return m_logDisplays.empty(); }

        //! Sets any additional information as prefix to the log message
        /*!
          \param fileName This is the name of the corresponding source file.
          \param methodName This is the name of calling method.
        */
        void setLogInformation(int line, const char *fileName, const char *methodName = NULL);

        //! Prints the message and adds an new line character at the end
        /*!
          \param message Message string, which has to be logged
        */
        void printWithNewLine(QString &message);

        //! Prints the message as is and appends no additional characters
        /*!
          \param message Message string, which has to be logged
        */
        void print(QString &message);

        void printString(QString &message);

    protected:

        /// Display a string in decorated form to all attached displayers.
        void displayString(const char *str);

        /// Symetric to setPosition(). Automatically called by display...(). Do not call if noDisplayer().
        void resetLogInformation();

        //! Context
        IContext                             &m_context;

        //! Logging Type.
        /*!
          Specifies which logging type should be used.
          Possible are: Error, Warning, Info, Debug and Assert.
        */
        TLogType                              m_logType;

        //! Source file name.
        /*!
          Specifies the name of the source file, log message was called from.
        */
        const char                           *m_sourceFile;

        //! Code line.
        /*!
          Specifies the line in the source file, log message was called from.
        */
        qint32                                m_line;

        //! Method name.
        /*!
          Specifies the method in the source file, log message was called from.
        */
        const char                           *m_methodName;

        /*!
          \typedef TLogDisplayerMap
          QList container holding pointers to ILogDisplay objects
          \sa ArrayList::GetEnumerator, \sa List::GetEnumerator
        */
        typedef QList<ILogDisplay *>          TLogDisplayList;

        //! List of all attached displays.
        TLogDisplayList                       m_logDisplays;

        //! Mutex object
        /*!
          This makes our class thread safe.
        */
        QMutex                                m_mutex;

        //! Position
        quint32                               m_posSet;

        //! Log message string
        /*!
          This variable is used, if a log line consists of two or more
          calls. The first ones are then stored temporary in this variable
          until one message ends with a line feed.
        */
        QString                              m_logLine;
        SLogInformation                      m_logInformation;
    };

} // namespace BlackMisc

#endif //BLACKMISC_LOG_H