/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

*

*/

#include "CLucene.h"

#include "CLucene/analysis/AnalysisHeader.h"

#include "CLucene/analysis/Analyzers.h"

#include "analyzer.h"

#include "analyzerexp.h"

#include "cpixanalyzer.h"

#include "cluceneext.h"

#include "cpixexc.h"

#include "cpixparsetools.h"

#include "wchar.h"

#include <string>

#include <vector>

#include <sstream>

#include <iostream>

#include "document.h"

#include "indevicecfg.h" 

namespace

{

    const char AGGR_NONFILEREADERPROXY_ERR[] 

    = "Aggregated reader field should be FileReaderProxy instance";

    const char AGGR_STREAMREADER_ERR[] 

    = "Aggregating streamValue-fields not implemented";

}

namespace Cpix {

    AggregateFieldTokenStream::AggregateFieldTokenStream(lucene::analysis::Analyzer& analyzer, 

                                                         DocumentFieldIterator* fields) 

	: stream_(), analyzer_( analyzer ), reader_(), fields_( fields ) {

        getNextStream(); 

    }

    AggregateFieldTokenStream::~AggregateFieldTokenStream() {

        _CLDELETE( stream_ ); 

        delete fields_; 

    }

    bool AggregateFieldTokenStream::next(lucene::analysis::Token* token) {

        while ( stream_ ) {

            if ( stream_->next( token ) ) {

                return true;

            }

            getNextStream();

        }

        return false;

    }

    void AggregateFieldTokenStream::close() {

        if (stream_) stream_->close(); 

        _CLDELETE( stream_ ); 

        _CLDELETE( reader_ ); 

    }

    void AggregateFieldTokenStream::getNextStream()

    {

        using namespace lucene::document;

        using namespace lucene::util; 

        if ( stream_ ) stream_->close(); 

        _CLDELETE( stream_ ); 

        _CLDELETE( reader_ );

        Field* field = 0; 

        while (*fields_ && field == NULL)

            {

                field = (*fields_)++;

                if (!field->isAggregated()) 

                    {

						field = 0;

                    }

            }

        if (field) {

            if (field->stringValue() != NULL)

                {

                    reader_ = _CLNEW CL_NS(util)::StringReader(field->stringValue(),_tcslen(field->stringValue()),false);

                }

            else if (field->native().readerValue() != NULL)

                {

                    Reader* r = field->native().readerValue();

                    FileReaderProxy

                        * frp = 

                        dynamic_cast<FileReaderProxy*>(r);

                    if (frp == NULL)

                        {

                            _CLTHROWA(CL_ERR_IO, AGGR_NONFILEREADERPROXY_ERR);

                        }

                    else

                        {

                            reader_ = frp->clone();

                        }

                }

            else

                {

                    _CLTHROWA(CL_ERR_IO, AGGR_STREAMREADER_ERR);

                }

            stream_ = analyzer_.tokenStream( field->name(), reader_ ); 

        }

    }

    AggregateFieldAnalyzer::AggregateFieldAnalyzer(Cpix::Document& document, 

                                                   lucene::analysis::Analyzer& analyzer) 

	:	analyzer_(analyzer), document_(document)

    {

    }

    lucene::analysis::TokenStream* AggregateFieldAnalyzer::tokenStream(const TCHAR     * fieldName, 

                                                                       lucene::util::Reader * reader) {

        if ( wcscmp( fieldName, LCPIX_DEFAULT_FIELD ) == 0 ) {

            return new AggregateFieldTokenStream( analyzer_, document_.fields()); 

        } else {

            return analyzer_.tokenStream( fieldName, reader ); 

        }

    }

    SystemAnalyzer::SystemAnalyzer(lucene::analysis::Analyzer* analyzer) : analyzer_(analyzer) {} 

    SystemAnalyzer::~SystemAnalyzer() { _CLDELETE(analyzer_); }

    lucene::analysis::TokenStream* SystemAnalyzer::tokenStream(const TCHAR      	* fieldName, 

                                                               lucene::util::Reader * reader) {

        using namespace lucene::analysis; 

        if ( wcscmp( fieldName, LCPIX_DEFAULT_FIELD ) == 0 ) {

            // Use standard analyzer without stop filter for this task

            TokenStream* ret = _CLNEW standard::StandardTokenizer(reader);

            ret = _CLNEW standard::StandardFilter(ret,true);

            ret = _CLNEW LowerCaseFilter(ret,true);

            return ret;

        } else if (wcscmp( fieldName, LCPIX_DOCUID_FIELD) == 0){

            // Use standard analyzer without stop filter for this task

            return  _CLNEW KeywordTokenizer(reader);

        } else if (wcscmp( fieldName, LCPIX_APPCLASS_FIELD )  == 0){

            // Use standard analyzer without stop filter for this task

            TokenStream* ret = _CLNEW WhitespaceTokenizer(reader);

            ret = _CLNEW LowerCaseFilter(ret,true);

            return ret;

        } else if (wcscmp( fieldName, LCPIX_MIMETYPE_FIELD ) == 0) {

            TokenStream* ret = _CLNEW KeywordTokenizer(reader);

            return ret;

        } else {

            return analyzer_->tokenStream( fieldName, reader ); 

        }									 

    }

    //

    // Following sections provide the glue code for connecting the 

    // analyzer definition syntax with analyzer, tokenizers and filter 

    // implementations. 

    //

    // The glue code is template heavy with the indent of providing 

    // automation for associating specific keywords with specific

    // analyzers, tokenizers and filters implementing corresponding 

    // CLucene abstractions. Additional classes are needed only if 

    // filters, tokenizers, etc. accept parameters.

    //

    // NOTE: To understand the analyzers, it is sufficient to understand

    // that an analyzer transforms characters stream into specific token streams 

    // (e.g. character stream 'foobarmetawords' can be transformed into token 

    // stream 'foo', 'bar' 'meta' 'words'). Analysis consist of two main

    // parts which are tokenization and filtering. Tokenization converts

    // the character stream into token stream (e.g. 'FoO bAr' -> 'FoO' 'bAr')

    // and filtering modifies the tokens (e.g. lowercase filtering 'FoO' -> 

    // 'foo', 'bAr' -> 'bar'). Analyzer as an object is responsible for

    // constructing a tokenizer and a sequence of filters to perform

    // these required tasks.  

    // 

    // See the documentation around TokenizerClassEntries and 

    // FilterClassEntries to see how implementations not taking parameters

    // can be easily added.  

    // 

    using namespace Cpix::AnalyzerExp;

    /**

     * Creates token stream for the given reader and fieldName.

     * This class in in many ways similar to CLucene analyzer class 

     * definition.   

     */

    class TokenStreamFactory {

    public: 

        virtual ~TokenStreamFactory(); 

        virtual lucene::analysis::TokenStream* tokenStream(const wchar_t        * fieldName, 

                                                           lucene::util::Reader * reader) = 0;

    };

    TokenStreamFactory::~TokenStreamFactory() {};

    /**

     * Template class used to create CLucene tokenizers. Template

     * parameter T must implement lucene::analysis::Tokenizer abstraction.  

     */    

    template<class T>

    class TokenizerFactory : public TokenStreamFactory 

    {

    public:

        TokenizerFactory(const Invokation& invokation) {

            if (invokation.params().size() > 0) {

                THROW_CPIXEXC(L"Tokenizer %S does not accept parameters",

                              invokation.id().c_str());

            }

        }

        virtual lucene::analysis::TokenStream* tokenStream(const TCHAR          * /*fieldName*/, 

                                                           lucene::util::Reader * reader) {

            return _CLNEW T(reader); 

        }

    };

    /**

     * Template class wrapping CLucene analyzers. Template parameter T must 

     * implement lucene::analysis::Analyzer abstraction.  

     */    

    template<class T>

    class AnalyzerWrap : public TokenStreamFactory 

    {

    public:

        AnalyzerWrap(const Invokation& invokation) : analyzer_() {

            if (invokation.params().size() > 0) {

                THROW_CPIXEXC(L"Tokenizer %S does not accept parameters",

                              invokation.id().c_str());

            }

        }

        virtual lucene::analysis::TokenStream* tokenStream(const TCHAR          * fieldName, 

                                                           lucene::util::Reader * reader) {

            return analyzer_.tokenStream(fieldName, reader); 

        }

    private: 

        T analyzer_;

    };

    /**

     * Template class associated with CLucene filter and a TokenStreamFactory. 

     * Uses TokenStreamFactory to transform given character stream into tokenstream

     * and then applies the given Clucene filter to the token stream. 

     * The template parameter T must implement lucene::analysis::Filter abstraction.     

     */    

    template<class T>

    class FilterFactory : public TokenStreamFactory 

    {

    public:

        FilterFactory(const Invokation& invokation, auto_ptr<TokenStreamFactory> factory) : factory_(factory) {

            if (invokation.params().size() > 0) {

                THROW_CPIXEXC(L"Filter %S does not accept parameters",

                              invokation.id().c_str());

            }

        }

        virtual lucene::analysis::TokenStream* tokenStream(const TCHAR          * fieldName, 

                                                           lucene::util::Reader * reader) {

            return _CLNEW T(factory_->tokenStream(fieldName, reader), true); 

        }

    private: 

        std::auto_ptr<TokenStreamFactory> factory_; 

    };

	/**

	 * Specialized Analyzer wrap for CLucene's PerFieldAnalyzer. Specialized

	 * template is needed because perfield analyzer accepts parameters

	 * (specific analyzers for different field plus default analyzer)

	 */

    template<>

    class AnalyzerWrap<lucene::analysis::PerFieldAnalyzerWrapper> : public TokenStreamFactory {

    public:

        AnalyzerWrap(const Switch& sw) : analyzer_(0) {

            using namespace Cpt::Parser;

            using namespace lucene::analysis;

            analyzer_ = _CLNEW PerFieldAnalyzerWrapper(_CLNEW CustomAnalyzer(sw.def()));

            for (int i = 0; i < sw.cases().size(); i++) {

                const Case& cs = *sw.cases()[i];

                for (int j = 0; j < cs.fields().size(); j++) {

                    analyzer_->addAnalyzer( cs.fields()[j].c_str(), _CLNEW CustomAnalyzer( cs.piping() ) );

                }

            }

        }

        virtual ~AnalyzerWrap() {

            _CLDELETE(analyzer_);

        }

        virtual lucene::analysis::TokenStream* tokenStream(const TCHAR          * fieldName, 

                                                           lucene::util::Reader * reader) {

            return analyzer_->tokenStream(fieldName, reader); 

        }

    private: 

        lucene::analysis::PerFieldAnalyzerWrapper* analyzer_;

    };

	/**

	 * Specialized StopFilter factory. Specialized filter is needed

	 * because StopFilter needs parameters (stop word list or a language) 

	 */

    template<>

    class FilterFactory<lucene::analysis::StopFilter> : public TokenStreamFactory 

    {

    public:

        FilterFactory(const Invokation& invokation,

                      auto_ptr<TokenStreamFactory> factory)

            :words_(0),  ownWords_(0), factory_(factory) {

            using namespace Cpt::Parser;

            if (invokation.params().size() == 1 && dynamic_cast<Identifier*>(invokation.params()[0])) {

                Identifier* id = dynamic_cast<Identifier*>(invokation.params()[0]);

                //cpix_LangCode lang; 

                if (id->id() == CPIX_WLANG_EN) {

                    words_ = lucene::analysis::StopAnalyzer::ENGLISH_STOP_WORDS;

                } else {

                    THROW_CPIXEXC(L"No prepared stopword list for language code '%S'",

                                  id->id().c_str());

                }

            } else {

                ownWords_ = new wchar_t*[invokation.params().size()+1];

                memset(ownWords_, 0, sizeof(wchar_t*)*(invokation.params().size()+1)); 

                // FIXE: args may leak

                for (int i = 0; i < invokation.params().size(); i++) {

                    StringLit* lit = dynamic_cast<StringLit*>(invokation.params()[i]);

                    if (lit) {

                        const wstring& str = lit->text(); 

                        ownWords_[i] = new wchar_t[str.length()+1]; 

                        wcscpy(ownWords_[i], str.c_str());

                    } else {

                        THROW_CPIXEXC(L"StopFilter accepts only language identifer or list of strings as a parameters.");

                    }

                }

            }

        }

        virtual ~FilterFactory() { 

            if (ownWords_) {

                for (int i = 0; ownWords_[i]; i++) {

                    delete[] ownWords_[i]; 

                }

                delete[] ownWords_;

            }

        }

        virtual lucene::analysis::TokenStream* tokenStream(const TCHAR          * fieldName, 

                                                           lucene::util::Reader * reader) {

            return _CLNEW lucene::analysis::StopFilter(factory_->tokenStream(fieldName, reader), true, ownWords_ ? const_cast<const wchar_t**>(ownWords_) : words_); 

        }

    private: 

        const wchar_t **words_;

        wchar_t **ownWords_; // owned

        std::auto_ptr<TokenStreamFactory> factory_; 

    };

    /**

     * Specialized SnowballFilter factory is needed, because SnowballFilter

     * accepts parameters (the language). 

     */

    template<>

    class FilterFactory<lucene::analysis::SnowballFilter> : public TokenStreamFactory 

    {

    public:

        FilterFactory(const Invokation& invokation, 		

                      auto_ptr<TokenStreamFactory> factory)

            : factory_(factory) {

            using namespace Cpt::Parser;

            if (invokation.params().size() != 1 || !dynamic_cast<Identifier*>(invokation.params()[0])) {

                THROW_CPIXEXC(L"Snowball filter takes exactly one identifier as a parameter." );

            }

            Identifier* id = dynamic_cast<Identifier*>(invokation.params()[0]);

            if (id->id() == CPIX_WLANG_EN) {

                lang_ = cpix_LANG_EN; 

            } else {

                THROW_CPIXEXC(L"Language identifier %S is not supported for stemming",

                              id->id().c_str());

            }

        }

        virtual lucene::analysis::TokenStream* tokenStream(const TCHAR          * fieldName, 

                                                           lucene::util::Reader * reader) {

            return _CLNEW lucene::analysis::SnowballFilter(factory_->tokenStream(fieldName, reader), true, lang_); 

        }

    private: 

        cpix_LangCode lang_;

        std::auto_ptr<TokenStreamFactory> factory_; 

    };

    /**

     * Specialized LengthFilter factory is needed, because length filter 

     * accepts parameters (minimum length and maximum length)

     */

    template<>

    class FilterFactory<lucene::analysis::LengthFilter> : public TokenStreamFactory 

    {

    public:

        FilterFactory(const Invokation& invokation, 

                      auto_ptr<TokenStreamFactory> factory) 

            : factory_(factory) {

            using namespace Cpt::Parser;

            if (invokation.params().size() != 2 || 

                !dynamic_cast<IntegerLit*>(invokation.params()[0]) || 

                !dynamic_cast<IntegerLit*>(invokation.params()[1])) {

                THROW_CPIXEXC("Length filter takes exactly two integer parameters");

            }

            min_ = dynamic_cast<IntegerLit*>(invokation.params()[0])->value();

            max_ = dynamic_cast<IntegerLit*>(invokation.params()[1])->value();

        }

        virtual lucene::analysis::TokenStream* tokenStream(const TCHAR          * fieldName, 

                                                           lucene::util::Reader * reader) {

            return _CLNEW lucene::analysis::LengthFilter(factory_->tokenStream(fieldName, reader), true, min_, max_ ); 

        }

    private: 

        int min_, max_;

        std::auto_ptr<TokenStreamFactory> factory_; 

    };

    typedef auto_ptr<TokenStreamFactory> (*TokenizerFactoryCreator)(const Invokation& invokation);

    typedef auto_ptr<TokenStreamFactory> (*FilterFactoryCreator)(const Invokation& invokation, 

                                                                 auto_ptr<TokenStreamFactory> factory);

    /**

     * Sets up a tokenizer factory with given invokation parameters

     */

    template<class T>

    struct TokenizerFactoryCtor

    {

        static auto_ptr<TokenStreamFactory> create(const Invokation& invokation) {

            return auto_ptr<TokenStreamFactory>(new TokenizerFactory<T>(invokation)); 

        }

    };

    /**

     * Sets up an analyzer wrap with given invokation parameters

     */

    template<class T>

    struct AnalyzerWrapCtor