// Copyright (c) 2005-2024 Jay Berkenbilt
//
// This file is part of qpdf.
//
// Licensed 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.
//
// Versions of qpdf prior to version 7 were released under the terms of version 2.0 of the Artistic
// License. At your option, you may continue to consider qpdf to be licensed under those terms.
// Please see the manual for additional information.

#ifndef QPDFANNOTATIONOBJECTHELPER_HH
#define QPDFANNOTATIONOBJECTHELPER_HH

#include <qpdf/Constants.h>
#include <qpdf/QPDFObjectHelper.hh>

#include <qpdf/DLL.h>

class QPDFAnnotationObjectHelper: public QPDFObjectHelper
{
  public:
    QPDF_DLL
    QPDFAnnotationObjectHelper(QPDFObjectHandle);
    QPDF_DLL
    ~QPDFAnnotationObjectHelper() override = default;

    // This class provides helper methods for annotations. More functionality will likely be added
    // in the future.

    // Some functionality for annotations is also implemented in QPDFAcroFormDocumentHelper and
    // QPDFFormFieldObjectHelper. In some cases, functions defined there work for other annotations
    // besides widget annotations, but they are implemented with form fields so that they can
    // properly handle form fields when needed.

    // Return the subtype of the annotation as a string (e.g. "/Widget"). Returns an empty string
    // if the subtype (which is required by the spec) is missing.
    QPDF_DLL
    std::string getSubtype();

    QPDF_DLL
    QPDFObjectHandle::Rectangle getRect();

    QPDF_DLL
    QPDFObjectHandle getAppearanceDictionary();

    // Return the appearance state as given in "/AS", or an empty string if none is given.
    QPDF_DLL
    std::string getAppearanceState();

    // Return flags from "/F". The value is a logical or of pdf_annotation_flag_e as defined in
    // qpdf/Constants.h.
    QPDF_DLL
    int getFlags();

    // Return a specific stream. "which" may be one of "/N", "/R", or "/D" to indicate the normal,
    // rollover, or down appearance stream. (Any value may be passed to "which"; if an appearance
    // stream of that name exists, it will be returned.) If the value associated with "which" in the
    // appearance dictionary is a subdictionary, an appearance state may be specified to select
    // which appearance stream is desired. If not specified, the appearance state in "/AS" will
    // used.
    QPDF_DLL
    QPDFObjectHandle getAppearanceStream(std::string const& which, std::string const& state = "");

    // Generate text suitable for addition to the containing page's content stream that draws this
    // annotation's appearance stream as a form XObject. The value "name" is the resource name that
    // will be used to refer to the form xobject. The value "rotate" should be set to the page's
    // /Rotate value or 0 if none. The values of required_flags and forbidden_flags are constructed
    // by logically "or"ing annotation flags of type pdf_annotation_flag_e defined in
    // qpdf/Constants.h. Content will be returned only if all required_flags are set and no
    // forbidden_flags are set. For example, including an_no_view in forbidden_flags could be useful
    // for creating an on-screen view, and including an_print to required_flags could be useful if
    // preparing to print.
    QPDF_DLL
    std::string getPageContentForAppearance(
        std::string const& name,
        int rotate,
        int required_flags = 0,
        int forbidden_flags = an_invisible | an_hidden);

  private:
    class Members
    {
        friend class QPDFAnnotationObjectHelper;

      public:
        QPDF_DLL
        ~Members() = default;

      private:
        Members() = default;
        Members(Members const&) = delete;
    };

    std::shared_ptr<Members> m;
};

#endif // QPDFANNOTATIONOBJECTHELPER_HH
