Extract Links From Google Document

Program.cs

using System.Collections.Generic;
using Google.Apis.Docs;
using Google.Apis.Docs.v1;
using Google.Apis.Docs.v1.Data;

using System.Data.Common;
using System.Xml.Linq;
using Newtonsoft.Json;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Util.Store;
using Google.Apis.Requests;


IEnumerable<IDirectResponseSchema> GenerateLinksFromParagraph(Document document, Paragraph paragraph)
{
    return paragraph.Elements.SelectMany(element => {
        if (element.TextRun?.TextStyle?.Link is not null)
        {
            return new IDirectResponseSchema[] { element.TextRun.TextStyle.Link };
        }
        if (element.RichLink is not null)
        {
            return new IDirectResponseSchema[] { element.RichLink };
        }
        if (element.FootnoteReference is not null)
        {
            var footnote = document.Footnotes[element.FootnoteReference.FootnoteId];
            return footnote.Content.SelectMany(structuralElement => GenerateLinksFromStructuralElement(document, structuralElement));
        }
        return Enumerable.Empty<IDirectResponseSchema>();
    });
}

IEnumerable<IDirectResponseSchema> GenerateLinksFromTable(Document document, Table table) {
    return table.TableRows.SelectMany(tableRow => tableRow.TableCells.SelectMany(tableCell => tableCell.Content.SelectMany(structuralElement => GenerateLinksFromStructuralElement(document, structuralElement))));
}

 IEnumerable<IDirectResponseSchema> GenerateLinksFromStructuralElement(Document document, StructuralElement element) {
    if (element.Paragraph is not null)
    {
        return GenerateLinksFromParagraph(document, element.Paragraph);
    }
    if (element.Table is not null)
    {
        return GenerateLinksFromTable(document, element.Table);
    }
    return Enumerable.Empty<IDirectResponseSchema>();
    
}

IEnumerable<IDirectResponseSchema> GenerateLinksFromDocument(Document document)
{
    return document.Body.Content.SelectMany(structuralElement => GenerateLinksFromStructuralElement(document, structuralElement));

}


async Task TextShowDocumentLinks(CancellationToken cancellationToken = default)
{
    var docId = Environment.GetEnvironmentVariable("GOOGLE_DOCUMENT_ID");
    var clientSecretFilePath = Environment.GetEnvironmentVariable("GOOGLE_CLIENT_SECRET_FILE_PATH");
    var user = Environment.GetEnvironmentVariable("GOOGLE_USER"); 
    UserCredential credential;
    using (var stream = new FileStream(clientSecretFilePath, FileMode.Open, FileAccess.Read))
    {
        credential = await GoogleWebAuthorizationBroker.AuthorizeAsync(
            GoogleClientSecrets.FromStream(stream).Secrets,
            new[] { DocsService.Scope.Documents },
            user,
            cancellationToken);
    }
    var initializer = new DocsService.Initializer
    {
        ApplicationName = "Links Replacer",
        // ApiKey = apiKey,
        HttpClientInitializer = credential
    };

    var docsService = new DocsService(initializer);
    

    var doc = await docsService.Documents.Get(docId).ExecuteAsync();
     
    foreach (var item in GenerateLinksFromDocument(doc))
    {
        if (item is RichLink richLink)
        {
            Console.WriteLine($"Title={richLink.RichLinkProperties.Title} Uri={richLink.RichLinkProperties.Uri}");
        }
        else if (item is Link link)
        {
            Console.WriteLine($"Uri={link.Url}");
        }
    }
    
}

await TextShowDocumentLinks();

project.json

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net7.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Google.Apis.Docs.v1" Version="1.57.0.2833" />
  </ItemGroup>

</Project>