/**************************************************************
 * 
 * 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.
 * 
 *************************************************************/



// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_sd.hxx"

#include "SlsCacheCompactor.hxx"

#include "SlsBitmapCompressor.hxx"
#include "SlsBitmapCache.hxx"
#include "SlsCacheCompactor.hxx"
#include "SlsCacheConfiguration.hxx"

#include <rtl/ustring.hxx>
#include <com/sun/star/uno/Any.hxx>
#include <set>

using namespace ::com::sun::star::uno;

// Uncomment the definition of VERBOSE to get some more OSL_TRACE messages.
#ifdef DEBUG
//#define VERBOSE
#endif

namespace {

/** This is a trivial implementation of the CacheCompactor interface class.
    It ignores calls to RequestCompaction() and thus will never decrease the
    total size of off-screen preview bitmaps.
*/
class NoCacheCompaction
    : public ::sd::slidesorter::cache::CacheCompactor
{
public:
    NoCacheCompaction (
        ::sd::slidesorter::cache::BitmapCache& rCache,
        sal_Int32 nMaximalCacheSize)
        : CacheCompactor(rCache, nMaximalCacheSize)
    {}

    virtual void RequestCompaction (void) { /* Ignored */ };

protected:
    virtual void Run (void) { /* Do nothing */ };
};




/** This implementation of the CacheCompactor interface class uses one of
    several bitmap compression algorithms to reduce the number of the bytes
    of the off-screen previews in the bitmap cache.  See the documentation
    of CacheCompactor::Create() for more details on configuration properties
    that control the choice of compression algorithm.
*/
class CacheCompactionByCompression
    : public ::sd::slidesorter::cache::CacheCompactor
{
public:
    CacheCompactionByCompression (
        ::sd::slidesorter::cache::BitmapCache& rCache,
        sal_Int32 nMaximalCacheSize,
        const ::boost::shared_ptr< ::sd::slidesorter::cache::BitmapCompressor>& rpCompressor);

protected:
    virtual void Run (void);

private:
    ::boost::shared_ptr< ::sd::slidesorter::cache::BitmapCompressor>  mpCompressor;
};


} // end of anonymous namespace

namespace sd { namespace slidesorter { namespace cache {


::std::auto_ptr<CacheCompactor> CacheCompactor::Create (
    BitmapCache& rCache,
    sal_Int32 nMaximalCacheSize)
{
    static const ::rtl::OUString sNone (RTL_CONSTASCII_USTRINGPARAM("None"));
    static const ::rtl::OUString sCompress (RTL_CONSTASCII_USTRINGPARAM("Compress"));
    static const ::rtl::OUString sErase (RTL_CONSTASCII_USTRINGPARAM("Erase"));
    static const ::rtl::OUString sResolution (RTL_CONSTASCII_USTRINGPARAM("ResolutionReduction"));
    static const ::rtl::OUString sPNGCompression (RTL_CONSTASCII_USTRINGPARAM("PNGCompression"));
    
    ::boost::shared_ptr<BitmapCompressor> pCompressor;
    ::rtl::OUString sCompressionPolicy(sPNGCompression);
    Any aCompressionPolicy (CacheConfiguration::Instance()->GetValue(
        ::rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("CompressionPolicy"))));
    if (aCompressionPolicy.has<rtl::OUString>())
        aCompressionPolicy >>= sCompressionPolicy;
    if (sCompressionPolicy == sNone)
        pCompressor.reset(new NoBitmapCompression());
    else if (sCompressionPolicy == sErase)
        pCompressor.reset(new CompressionByDeletion());
    else if (sCompressionPolicy == sResolution)
        pCompressor.reset(new ResolutionReduction());
    else
        pCompressor.reset(new PngCompression());
    
    ::std::auto_ptr<CacheCompactor> pCompactor (NULL);
    ::rtl::OUString sCompactionPolicy(sCompress);
    Any aCompactionPolicy (CacheConfiguration::Instance()->GetValue(
        ::rtl::OUString(RTL_CONSTASCII_USTRINGPARAM("CompactionPolicy"))));
    if (aCompactionPolicy.has<rtl::OUString>())
        aCompactionPolicy >>= sCompactionPolicy;
    if (sCompactionPolicy == sNone)
        pCompactor.reset(new NoCacheCompaction(rCache,nMaximalCacheSize));
    else
        pCompactor.reset(new CacheCompactionByCompression(rCache,nMaximalCacheSize,pCompressor));

    return pCompactor;
}




void CacheCompactor::RequestCompaction (void)
{
    if ( ! mbIsCompactionRunning && ! maCompactionTimer.IsActive())
        maCompactionTimer.Start();
}




CacheCompactor::CacheCompactor(
    BitmapCache& rCache,
    sal_Int32 nMaximalCacheSize)
    : mrCache(rCache),
      mnMaximalCacheSize(nMaximalCacheSize),
      mbIsCompactionRunning(false)
{
    maCompactionTimer.SetTimeout(100 /*ms*/);
    maCompactionTimer.SetTimeoutHdl(LINK(this,CacheCompactor,CompactionCallback));

}




IMPL_LINK(CacheCompactor, CompactionCallback, Timer*, EMPTYARG)
{
    mbIsCompactionRunning = true;
    
    try
    {
        Run();
    }
    catch(::com::sun::star::uno::RuntimeException e) { }
    catch(::com::sun::star::uno::Exception e) { }
    
    mbIsCompactionRunning = false;
    return 1;
}




} } } // end of namespace ::sd::slidesorter::cache




namespace {

//===== CacheCompactionByCompression ==========================================

CacheCompactionByCompression::CacheCompactionByCompression (
    ::sd::slidesorter::cache::BitmapCache& rCache,
    sal_Int32 nMaximalCacheSize,
    const ::boost::shared_ptr< ::sd::slidesorter::cache::BitmapCompressor>& rpCompressor)
    : CacheCompactor(rCache,nMaximalCacheSize),
      mpCompressor(rpCompressor)
{
}




void CacheCompactionByCompression::Run (void)
{
    if (mrCache.GetSize() > mnMaximalCacheSize)
    {
#ifdef VERBOSE
		OSL_TRACE ("bitmap cache uses to much space: %d > %d",
            mrCache.GetSize(), mnMaximalCacheSize);
#endif

        ::std::auto_ptr< ::sd::slidesorter::cache::BitmapCache::CacheIndex> pIndex (
            mrCache.GetCacheIndex(false,false));
        ::sd::slidesorter::cache::BitmapCache::CacheIndex::iterator iIndex;
        for (iIndex=pIndex->begin(); iIndex!=pIndex->end(); ++iIndex)
        {
            if (*iIndex == NULL)
                continue;

            mrCache.Compress(*iIndex, mpCompressor);
            if (mrCache.GetSize() < mnMaximalCacheSize)
                break;
        }
        mrCache.ReCalculateTotalCacheSize();
#ifdef VERBOSE
        OSL_TRACE ("    there are now %d bytes occupied", mrCache.GetSize());
#endif
    }
}


} // end of anonymous namespace