/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * 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/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   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 .
 */

#include <sal/config.h>
#include <sal/log.hxx>

#include "methodguard.hxx"
#include "loghandler.hxx"

#include <com/sun/star/logging/XLogHandler.hpp>
#include <com/sun/star/lang/XServiceInfo.hpp>
#include <com/sun/star/lang/IllegalArgumentException.hpp>
#include <com/sun/star/util/PathSubstitution.hpp>
#include <com/sun/star/util/XStringSubstitution.hpp>

#include <comphelper/diagnose_ex.hxx>

#include <cppuhelper/compbase.hxx>
#include <cppuhelper/basemutex.hxx>
#include <cppuhelper/supportsservice.hxx>

#include <osl/file.hxx>

#include <memory>

namespace logging
{
    using ::com::sun::star::uno::Reference;
    using ::com::sun::star::logging::LogRecord;
    using ::com::sun::star::logging::XLogFormatter;
    using ::com::sun::star::uno::Sequence;
    using ::com::sun::star::uno::XInterface;
    using ::com::sun::star::uno::XComponentContext;
    using ::com::sun::star::logging::XLogHandler;
    using ::com::sun::star::lang::XServiceInfo;
    using ::com::sun::star::uno::Exception;
    using ::com::sun::star::lang::IllegalArgumentException;
    using ::com::sun::star::util::PathSubstitution;
    using ::com::sun::star::util::XStringSubstitution;
    using ::com::sun::star::beans::NamedValue;

    typedef ::cppu::WeakComponentImplHelper    <   XLogHandler
                                                ,   XServiceInfo
                                                >   FileHandler_Base;

    namespace {

    class FileHandler   :public ::cppu::BaseMutex
                        ,public FileHandler_Base
    {
    private:
        enum FileValidity
        {
            /// never attempted to open the file
            eUnknown,
            /// file is valid
            eValid,
            /// file is invalid
            eInvalid
        };

        Reference<XComponentContext>    m_xContext;
        LogHandlerHelper                m_aHandlerHelper;
        OUString                 m_sFileURL;
        std::unique_ptr< ::osl::File >  m_pFile;
        FileValidity                    m_eFileValidity;

    public:
        FileHandler(const css::uno::Reference<XComponentContext> &context,
                const css::uno::Sequence<css::uno::Any> &arguments);
        virtual ~FileHandler() override;

    private:
        // XLogHandler
        virtual OUString SAL_CALL getEncoding() override;
        virtual void SAL_CALL setEncoding( const OUString& _encoding ) override;
        virtual Reference< XLogFormatter > SAL_CALL getFormatter() override;
        virtual void SAL_CALL setFormatter( const Reference< XLogFormatter >& _formatter ) override;
        virtual ::sal_Int32 SAL_CALL getLevel() override;
        virtual void SAL_CALL setLevel( ::sal_Int32 _level ) override;
        virtual void SAL_CALL flush(  ) override;
        virtual sal_Bool SAL_CALL publish( const LogRecord& Record ) override;

        // XServiceInfo
        virtual OUString SAL_CALL getImplementationName() override;
        virtual sal_Bool SAL_CALL supportsService( const OUString& _rServiceName ) override;
        virtual Sequence< OUString > SAL_CALL getSupportedServiceNames() override;

        // OComponentHelper
        virtual void SAL_CALL disposing() override;

    public:
        typedef ComponentMethodGuard< FileHandler > MethodGuard;
        void    enterMethod( MethodGuard::Access );
        void    leaveMethod( MethodGuard::Access );

    private:
        /** prepares our output file for writing
        */
        bool    impl_prepareFile_nothrow();

        /// writes the given string to our file
        void    impl_writeString_nothrow( const OString& _rEntry );

        /** does string substitution on a (usually externally provided) file url
        */
        void    impl_doStringsubstitution_nothrow( OUString& _inout_rURL );
    };

    }

    FileHandler::FileHandler(const css::uno::Reference<XComponentContext> &context,
            const css::uno::Sequence<css::uno::Any> &arguments)
        :FileHandler_Base( m_aMutex )
        ,m_xContext( context )
        ,m_aHandlerHelper( context, m_aMutex, rBHelper )
        ,m_eFileValidity( eUnknown )
    {
        ::osl::MutexGuard aGuard( m_aMutex );

        if ( arguments.getLength() != 1 )
            throw IllegalArgumentException( OUString(), *this, 1 );

        Sequence< NamedValue > aSettings;
        if ( arguments[0] >>= m_sFileURL )
        {
            // create( [in] string URL );
            impl_doStringsubstitution_nothrow( m_sFileURL );
        }
        else if ( arguments[0] >>= aSettings )
        {
            // createWithSettings( [in] sequence< css::beans::NamedValue > Settings )
            ::comphelper::NamedValueCollection aTypedSettings( aSettings );
            m_aHandlerHelper.initFromSettings( aTypedSettings );

            if ( aTypedSettings.get_ensureType( u"FileURL"_ustr, m_sFileURL ) )
                impl_doStringsubstitution_nothrow( m_sFileURL );
        }
        else
            throw IllegalArgumentException( OUString(), *this, 1 );

        m_aHandlerHelper.setIsInitialized();
    }

    FileHandler::~FileHandler()
    {
        if ( !rBHelper.bDisposed )
        {
            acquire();
            dispose();
        }
    }


    bool FileHandler::impl_prepareFile_nothrow()
    {
        if ( m_eFileValidity == eUnknown )
        {
            m_pFile.reset( new ::osl::File( m_sFileURL ) );
            // check whether the log file already exists
            ::osl::DirectoryItem aFileItem;
            if (osl::FileBase::E_None == ::osl::DirectoryItem::get(m_sFileURL, aFileItem))
            {
                ::osl::FileStatus aStatus(osl_FileStatus_Mask_Validate);
                if (::osl::FileBase::E_None == aFileItem.getFileStatus(aStatus))
                    ::osl::File::remove(m_sFileURL);
            }

            ::osl::FileBase::RC res = m_pFile->open( osl_File_OpenFlag_Write | osl_File_OpenFlag_Create );
            m_eFileValidity =   res == ::osl::FileBase::E_None
                            ?   eValid
                            :   eInvalid;
        #if OSL_DEBUG_LEVEL > 0
            if ( m_eFileValidity == eInvalid )
            {
                SAL_WARN( "extensions.logging", "FileHandler::impl_prepareFile_nothrow: could not open the designated log file:"
                            "\nURL: " << m_sFileURL
                            << "\nerror code: " << static_cast<sal_Int32>(res) );
            }
        #endif
            if ( m_eFileValidity == eValid )
            {
                OString sHead;
                if ( m_aHandlerHelper.getEncodedHead( sHead ) )
                    impl_writeString_nothrow( sHead );
            }
        }

        return m_eFileValidity == eValid;
    }


    void FileHandler::impl_writeString_nothrow( const OString& _rEntry )
    {
        OSL_PRECOND(m_pFile, "FileHandler::impl_writeString_nothrow: no file!");

        sal_uInt64 nBytesToWrite( _rEntry.getLength() );
        sal_uInt64 nBytesWritten( 0 );
        ::osl::FileBase::RC res =
              m_pFile->write( _rEntry.getStr(), nBytesToWrite, nBytesWritten );
        OSL_ENSURE( ( res == ::osl::FileBase::E_None ) && ( nBytesWritten == nBytesToWrite ),
            "FileHandler::impl_writeString_nothrow: could not write the log entry!" );
    }


    void FileHandler::impl_doStringsubstitution_nothrow( OUString& _inout_rURL )
    {
        try
        {
            Reference< XStringSubstitution > xStringSubst(PathSubstitution::create(m_xContext));
            _inout_rURL = xStringSubst->substituteVariables( _inout_rURL, true );
        }
        catch( const Exception& )
        {
            DBG_UNHANDLED_EXCEPTION("extensions.logging");
        }
    }


    void SAL_CALL FileHandler::disposing()
    {
        if ( m_eFileValidity == eValid )
        {
            OString sTail;
            if ( m_aHandlerHelper.getEncodedTail( sTail ) )
                impl_writeString_nothrow( sTail );
        }

        m_pFile.reset();
        m_aHandlerHelper.setFormatter( nullptr );
    }


    void FileHandler::enterMethod( MethodGuard::Access )
    {
        m_aHandlerHelper.enterMethod();
    }


    void FileHandler::leaveMethod( MethodGuard::Access )
    {
        m_aMutex.release();
    }


    OUString SAL_CALL FileHandler::getEncoding()
    {
        MethodGuard aGuard( *this );
        OUString sEncoding;
        OSL_VERIFY( m_aHandlerHelper.getEncoding( sEncoding ) );
        return sEncoding;
    }


    void SAL_CALL FileHandler::setEncoding( const OUString& _rEncoding )
    {
        MethodGuard aGuard( *this );
        OSL_VERIFY( m_aHandlerHelper.setEncoding( _rEncoding ) );
    }


    Reference< XLogFormatter > SAL_CALL FileHandler::getFormatter()
    {
        MethodGuard aGuard( *this );
        return m_aHandlerHelper.getFormatter();
    }


    void SAL_CALL FileHandler::setFormatter( const Reference< XLogFormatter >& _rxFormatter )
    {
        MethodGuard aGuard( *this );
        m_aHandlerHelper.setFormatter( _rxFormatter );
    }


    ::sal_Int32 SAL_CALL FileHandler::getLevel()
    {
        MethodGuard aGuard( *this );
        return m_aHandlerHelper.getLevel();
    }


    void SAL_CALL FileHandler::setLevel( ::sal_Int32 _nLevel )
    {
        MethodGuard aGuard( *this );
        m_aHandlerHelper.setLevel( _nLevel );
    }


    void SAL_CALL FileHandler::flush(  )
    {
        MethodGuard aGuard( *this );
        if (!m_pFile)
        {
            OSL_PRECOND(false, "FileHandler::flush: no file!");
            return;
        }
        ::osl::FileBase::RC res = m_pFile->sync();
        OSL_ENSURE(res == ::osl::FileBase::E_None, "FileHandler::flush: Could not sync logfile to filesystem.");
    }


    sal_Bool SAL_CALL FileHandler::publish( const LogRecord& _rRecord )
    {
        MethodGuard aGuard( *this );

        if ( !impl_prepareFile_nothrow() )
            return false;

        OString sEntry;
        if ( !m_aHandlerHelper.formatForPublishing( _rRecord, sEntry ) )
            return false;

        impl_writeString_nothrow( sEntry );
        return true;
    }

    OUString SAL_CALL FileHandler::getImplementationName()
    {
        return u"com.sun.star.comp.extensions.FileHandler"_ustr;
    }

    sal_Bool SAL_CALL FileHandler::supportsService( const OUString& _rServiceName )
    {
        return cppu::supportsService(this, _rServiceName);
    }

    Sequence< OUString > SAL_CALL FileHandler::getSupportedServiceNames()
    {
        return { u"com.sun.star.logging.FileHandler"_ustr };
    }

} // namespace logging

extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface *
com_sun_star_comp_extensions_FileHandler(
    css::uno::XComponentContext *context,
    css::uno::Sequence<css::uno::Any> const &arguments)
{
    return cppu::acquire(new logging::FileHandler(context, arguments));
}

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