DocSpace-buildtools/web/ASC.Web.Core/Utility/UrlShortener.cs

// (c) Copyright Ascensio System SIA 2010-2022
//
// This program is a free software product.
// You can redistribute it and/or modify it under the terms
// of the GNU Affero General Public License (AGPL) version 3 as published by the Free Software
// Foundation. In accordance with Section 7(a) of the GNU AGPL its Section 15 shall be amended
// to the effect that Ascensio System SIA expressly excludes the warranty of non-infringement of
// any third-party rights.
//
// This program is distributed WITHOUT ANY WARRANTY, without even the implied warranty
// of MERCHANTABILITY or FITNESS FOR A PARTICULAR  PURPOSE. For details, see
// the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
//
// You can contact Ascensio System SIA at Lubanas st. 125a-25, Riga, Latvia, EU, LV-1021.
//
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// display Appropriate Legal Notices, as required under Section 5 of the GNU AGPL version 3.
//
// Pursuant to Section 7(b) of the License you must retain the original Product logo when
// distributing the program. Pursuant to Section 7(e) we decline to grant you any rights under
// trademark law for use of our trademarks.
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// All the Product's GUI elements, including illustrations and icon sets, as well as technical writing
// content are licensed under the terms of the Creative Commons Attribution-ShareAlike 4.0
// International. See the License terms at http://creativecommons.org/licenses/by-sa/4.0/legalcode

namespace ASC.Web.Core.Utility;

[Scope(Additional = typeof(UrlShortenerExtension))]
public interface IUrlShortener
{
    Task<string> GetShortenLinkAsync(string shareLink);
}

[Scope]
public class BaseUrlShortener: IUrlShortener
{
    private readonly ConsumerFactory _consumerFactory;
    private readonly IServiceProvider _serviceProvider;

    public BaseUrlShortener(
        ConsumerFactory consumerFactory,
        IServiceProvider serviceProvider)
    {
        _consumerFactory = consumerFactory;
        _serviceProvider = serviceProvider;
    }

    public Task<string> GetShortenLinkAsync(string shareLink)
    {
        IUrlShortener shortener;
        if (_consumerFactory.Get<BitlyLoginProvider>().Enabled)
        {
            shortener = _serviceProvider.GetRequiredService<BitLyShortener>();
        }
        else
        {
            shortener = _serviceProvider.GetRequiredService<OnlyoShortener>();
        }

        return shortener.GetShortenLinkAsync(shareLink);
    }
}

[Scope]
public class BitLyShortener : IUrlShortener
{
    public BitLyShortener(ConsumerFactory consumerFactory)
    {
        ConsumerFactory = consumerFactory;
    }

    private ConsumerFactory ConsumerFactory { get; }

    public Task<string> GetShortenLinkAsync(string shareLink)
    {
        return Task.FromResult(ConsumerFactory.Get<BitlyLoginProvider>().GetShortenLink(shareLink));
    }
}

[Scope]
public class OnlyoShortener : IUrlShortener
{
    private readonly IDbContextFactory<UrlShortenerDbContext> _contextFactory;
    private readonly CommonLinkUtility _commonLinkUtility;
    private readonly TenantManager _tenantManager;
    public OnlyoShortener(IDbContextFactory<UrlShortenerDbContext> contextFactory,
        CommonLinkUtility commonLinkUtility,
        TenantManager tenantManager)
    {
        _contextFactory = contextFactory;
        _commonLinkUtility = commonLinkUtility;
        _tenantManager = tenantManager;
    }

    public async Task<string> GetShortenLinkAsync(string shareLink)
    {
        if (Uri.IsWellFormedUriString(shareLink, UriKind.Absolute))
        {
            var context = _contextFactory.CreateDbContext();
            var link = await context.ShortLinks.FirstOrDefaultAsync(q=> q.Link == shareLink);
            if (link != null)
            {
                return _commonLinkUtility.GetFullAbsolutePath(UrlShortRewriter.BasePath + link.Short);
            }
            else
            {
                while (true)
                {
                    var key = ShortUrl.GenerateRandomKey();
                    var id = ShortUrl.Decode(key);
                    var existId = await context.ShortLinks.AnyAsync(q => q.Id == id);
                    if (!existId)
                    {
                        var newShortLink = new ShortLink()
                        {
                            Id = id,
                            Link = shareLink,
                            Short = key,
                            TenantId = (await _tenantManager.GetCurrentTenantAsync()).Id
                        };
                        await context.ShortLinks.AddAsync(newShortLink);
                        await context.SaveChangesAsync();
                        return _commonLinkUtility.GetFullAbsolutePath(UrlShortRewriter.BasePath + key);
                    }
                }
            }
        }
        else
        {
            return shareLink;
        }
    }
}

public static class ShortUrl
{
    private const string Alphabet = "5XzpDt6wZRdsTrJkSY_cgPyxN4j-fnb9WKBF8vh3GH72QqmLVCM";
    private static readonly int _base = Alphabet.Length;

    public static string GenerateRandomKey()
    {
        var rand = new Random();
        var length = 15;
        var result = "";
        for (var i = 0; i < length; i++)
        {
            var x = rand.Next(0, 51);
            result += Alphabet.ElementAt(x);
        }
        return result;
    }

    public static ulong Decode(string str)
    {
        ulong num = 0;
        for (var i = 0; i < str.Length; i++)
        {
            num = num * (ulong)_base + (ulong)Alphabet.IndexOf(str.ElementAt(i));
        }
        return num;
    }
}

public static class UrlShortenerExtension
{
    public static void Register(DIHelper dIHelper)
    {
        dIHelper.TryAdd<IUrlShortener, BaseUrlShortener>();
        dIHelper.TryAdd<BitLyShortener>();
        dIHelper.TryAdd<OnlyoShortener>();
    }
}