/* -*- 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 .

 */

#ifndef INCLUDED_SDEXT_SOURCE_PDFIMPORT_INC_PDFPARSE_HXX

#define INCLUDED_SDEXT_SOURCE_PDFIMPORT_INC_PDFPARSE_HXX

#include <sal/types.h>

#include <rtl/ustring.hxx>

#include <rtl/string.hxx>

#include <string_view>

#include <unordered_map>

#include <utility>

#include <vector>

#include <memory>

namespace pdfparse

{

struct EmitImplData;

struct PDFContainer;

class EmitContext

{

public:

    virtual bool write( const void* pBuf, unsigned int nLen ) = 0;

    virtual unsigned int getCurPos() = 0;

    virtual bool copyOrigBytes( unsigned int nOrigOffset, unsigned int nLen ) = 0;

    virtual unsigned int readOrigBytes( unsigned int nOrigOffset, unsigned int nLen, void* pBuf ) = 0;

    explicit EmitContext( const PDFContainer* pTop = nullptr );

    virtual ~EmitContext();

    // set this to deflate contained streams

    bool m_bDeflate;

    // set this to decrypt the PDF file

    bool m_bDecrypt;

private:

    friend struct PDFEntry;

    std::unique_ptr<EmitImplData> m_pImplData;

};

struct PDFEntry

{

    PDFEntry() {}

    virtual ~PDFEntry();

    virtual bool emit( EmitContext& rWriteContext ) const = 0;

    virtual PDFEntry* clone() const = 0;

protected:

    static EmitImplData* getEmitData( EmitContext const & rContext );

    static void setEmitData( EmitContext& rContext, EmitImplData* pNewEmitData );

};

struct PDFComment final : public PDFEntry

{

    OString  m_aComment;

    explicit PDFComment( OString aComment )

    : PDFEntry(), m_aComment(std::move( aComment )) {}

    virtual ~PDFComment() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

};

struct PDFValue : public PDFEntry

{

    // abstract base class for simple values

    PDFValue() : PDFEntry() {}

    virtual ~PDFValue() override;

};

struct PDFName final : public PDFValue

{

    OString  m_aName;

    explicit PDFName( OString aName )

    : PDFValue(), m_aName(std::move( aName )) {}

    virtual ~PDFName() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

    OUString getFilteredName() const;

};

struct PDFString final : public PDFValue

{

    OString  m_aString;

    explicit PDFString( OString aString )

    : PDFValue(), m_aString(std::move( aString )) {}

    virtual ~PDFString() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

    OString getFilteredString() const;

};

struct PDFNumber final : public PDFValue

{

    double m_fValue;

    explicit PDFNumber( double fVal )

    : PDFValue(), m_fValue( fVal ) {}

    virtual ~PDFNumber() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

};

struct PDFBool final : public PDFValue

{

    bool m_bValue;

    explicit PDFBool( bool bVal )

    : PDFValue(), m_bValue( bVal ) {}

    virtual ~PDFBool() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

};

struct PDFObjectRef final : public PDFValue

{

    unsigned int    m_nNumber;

    unsigned int    m_nGeneration;

    PDFObjectRef( unsigned int nNr, unsigned int nGen )

    : PDFValue(), m_nNumber( nNr ), m_nGeneration( nGen ) {}

    virtual ~PDFObjectRef() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

};

struct PDFNull final : public PDFValue

{

    PDFNull() {}

    virtual ~PDFNull() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

};

struct PDFObject;

struct PDFContainer : public PDFEntry

{

    sal_Int32              m_nOffset;

    std::vector<std::unique_ptr<PDFEntry>> m_aSubElements;

    // this is an abstract base class for identifying

    // entries that can contain sub elements besides comments

    PDFContainer() : PDFEntry(), m_nOffset( 0 ) {}

    virtual ~PDFContainer() override;

    bool emitSubElements( EmitContext& rWriteContext ) const;

    void cloneSubElements( std::vector<std::unique_ptr<PDFEntry>>& rNewSubElements ) const;

    PDFObject* findObject( unsigned int nNumber, unsigned int nGeneration ) const;

    PDFObject* findObject( PDFObjectRef const * pRef ) const

    { return findObject( pRef->m_nNumber, pRef->m_nGeneration ); }

};

struct PDFArray final : public PDFContainer

{

    PDFArray() {}

    virtual ~PDFArray() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

};

struct PDFDict final : public PDFContainer

{

    typedef std::unordered_map<OString,PDFEntry*> Map;

    Map m_aMap;

    PDFDict() {}

    virtual ~PDFDict() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

    // inserting a value of NULL will remove rName and the previous value

    // from the dictionary

    void insertValue( const OString& rName, std::unique_ptr<PDFEntry> pValue );

    // removes a name/value pair from the dict

    void eraseValue( std::string_view rName );

    // builds new map as of sub elements

    // returns NULL if successful, else the first offending element

    PDFEntry* buildMap();

};

struct PDFStream final : public PDFEntry

{

    unsigned int    m_nBeginOffset;

    unsigned int    m_nEndOffset; // offset of the byte after the stream

    PDFDict*        m_pDict;

    PDFStream( unsigned int nBegin, unsigned int nEnd, PDFDict* pStreamDict )

    : PDFEntry(), m_nBeginOffset( nBegin ), m_nEndOffset( nEnd ), m_pDict( pStreamDict ) {}

    virtual ~PDFStream() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

    unsigned int getDictLength( const PDFContainer* pObjectContainer ) const; // get contents of the "Length" entry of the dict

};

struct PDFTrailer final : public PDFContainer

{

    PDFDict*        m_pDict;

    PDFTrailer() : PDFContainer(), m_pDict( nullptr ) {}

    virtual ~PDFTrailer() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

};

struct PDFFileImplData;

struct PDFFile final : public PDFContainer

{

private:

    mutable std::unique_ptr<PDFFileImplData> m_pData;

    PDFFileImplData*            impl_getData() const;

public:

    unsigned int        m_nMajor;           // PDF major

    unsigned int        m_nMinor;           // PDF minor

    PDFFile();

    virtual ~PDFFile() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

    bool isEncrypted() const;

    bool usesSupportedEncryptionFormat() const;

    // this method checks whether rPwd is compatible with

    // either user or owner password and sets up decrypt data in that case

    // returns true if decryption can be done

    bool setupDecryptionData( const OString& rPwd ) const;

    bool decrypt( const sal_uInt8* pInBuffer, sal_uInt32 nLen,

                  sal_uInt8* pOutBuffer,

                  unsigned int nObject, unsigned int nGeneration ) const;

};

struct PDFObject final : public PDFContainer

{

    PDFEntry*       m_pObject;

    PDFStream*      m_pStream;

    unsigned int    m_nNumber;

    unsigned int    m_nGeneration;

    PDFObject( unsigned int nNr, unsigned int nGen )

    : m_pObject( nullptr ), m_pStream( nullptr ), m_nNumber( nNr ), m_nGeneration( nGen ) {}

    virtual ~PDFObject() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

    // writes only the contained stream, deflated if necessary

    void writeStream( EmitContext& rContext, const PDFFile* pPDFFile ) const;

private:

    // returns true if stream is deflated

    // fills *ppStream and *pBytes with start of stream and count of bytes

    // memory returned in *ppStream must be freed with std::free afterwards

    // fills in NULL and 0 in case of error

    bool getDeflatedStream( std::unique_ptr<char[]>& rpStream, unsigned int* pBytes, const PDFContainer* pObjectContainer, EmitContext& rContext ) const;

};

struct PDFPart final : public PDFContainer

{

    PDFPart() : PDFContainer() {}

    virtual ~PDFPart() override;

    virtual bool emit( EmitContext& rWriteContext ) const override;

    virtual PDFEntry* clone() const override;

};

struct PDFReader

{

    PDFReader() = delete;

    static std::unique_ptr<PDFEntry> read(std::u16string_view aFileName);

};

} // namespace

#endif

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