//----------------------------------------------------------------------------
//
// TSDuck - The MPEG Transport Stream Toolkit
// Copyright (c) 2005-2025, Thierry Lelegard
// BSD-2-Clause license, see LICENSE.txt file or https://tsduck.io/license
//
//----------------------------------------------------------------------------
//!
//!  @file
//!  Representation of the model of an XML document.
//!
//----------------------------------------------------------------------------

#pragma once
#include "tsxmlDocument.h"

namespace ts::xml {
    //!
    //! Representation of the model of an XML document.
    //! @ingroup libtscore xml
    //!
    //! A model is an XML document which is used to validate another XML document.
    //! This is a minimal mechanism, much less powerful than XML-Schema.
    //! But since we do not support schema, this is a cheap alternative.
    //!
    //! The XML model contains the structure of a valid document, with all possible
    //! elements and attributes. There is no type checking, no cardinality check.
    //! Comments and texts are ignored. The values of attributes are ignored.
    //!
    class TSCOREDLL ModelDocument: public Document
    {
        TS_NOCOPY(ModelDocument);
    public:
        //!
        //! Constructor.
        //! @param [in,out] report Where to report errors.
        //!
        explicit ModelDocument(Report& report = NULLREP);

        //!
        //! Destructor.
        //!
        virtual ~ModelDocument() override;

        //!
        //! Validate an XML document.
        //! @param [in] doc The document to validate according to the model.
        //! @return True if @a doc matches the model in this object, false if it does not.
        //!
        bool validate(const Document& doc) const;

    protected:
        //!
        //! Find a child element by name in an XML model element.
        //! @param [in] elem An XML element in a model document.
        //! @param [in] name Name of the child element to search.
        //! @return Address of the child model or zero if not found.
        //!
        const Element* findModelElement(const Element* elem, const UString& name) const;

    private:
        //!
        //! Validate an XML tree of elements, used by validate().
        //! @param [in] model The model element.
        //! @param [in] doc The element to validate.
        //! @return True if @a doc matches @a model, false if it does not.
        //!
        bool validateElement(const Element* model, const Element* doc) const;
    };
}
