// (c) Copyright Ascensio System SIA 2010-2022
//
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// 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.
//
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// of MERCHANTABILITY or FITNESS FOR A PARTICULAR  PURPOSE. For details, see
// the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
//
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//
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// display Appropriate Legal Notices, as required under Section 5 of the GNU AGPL version 3.
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// 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.Core.Caching;

[Singletone]
class AzServiceCache
{
    internal readonly ICache Cache;
    internal readonly ICacheNotify<AzRecordCache> CacheNotify;

    public AzServiceCache(ICacheNotify<AzRecordCache> cacheNotify, ICache cache)
    {
        CacheNotify = cacheNotify;
        Cache = cache;

        cacheNotify.Subscribe((r) => UpdateCache(r, true), CacheNotifyAction.Remove);
        cacheNotify.Subscribe((r) => UpdateCache(r, false), CacheNotifyAction.InsertOrUpdate);
    }

    private void UpdateCache(AzRecord r, bool remove)
    {
        var aces = Cache.Get<AzRecordStore>(GetKey(r.Tenant));
        if (aces != null)
        {
            lock (aces)
            {
                if (remove)
                {
                    aces.Remove(r);
                }
                else
                {
                    aces.Add(r);
                }
            }
        }
    }

    public static string GetKey(int tenant)
    {
        return "acl" + tenant.ToString();
    }
}

[Scope]
class CachedAzService : IAzService
{
    private readonly IAzService _service;
    private readonly ICacheNotify<AzRecordCache> _cacheNotify;
    private readonly ICache _cache;
    private readonly TimeSpan _cacheExpiration;

    public CachedAzService(DbAzService service, AzServiceCache azServiceCache)
    {
        _service = service ?? throw new ArgumentNullException(nameof(service));
        _cache = azServiceCache.Cache;
        _cacheNotify = azServiceCache.CacheNotify;
        _cacheExpiration = TimeSpan.FromMinutes(10);
    }

    public IEnumerable<AzRecord> GetAces(int tenant, DateTime from)
    {
        var key = AzServiceCache.GetKey(tenant);
        var aces = _cache.Get<AzRecordStore>(key);
        if (aces == null)
        {
            var records = _service.GetAces(tenant, default);
            aces = new AzRecordStore(records);
            _cache.Insert(key, aces, DateTime.UtcNow.Add(_cacheExpiration));
        }

        return aces;
    }

    public AzRecord SaveAce(int tenant, AzRecord r)
    {
        r = _service.SaveAce(tenant, r);
        _cacheNotify.Publish((AzRecordCache)r, CacheNotifyAction.InsertOrUpdate);

        return r;
    }

    public void RemoveAce(int tenant, AzRecord r)
    {
        _service.RemoveAce(tenant, r);
        _cacheNotify.Publish((AzRecordCache)r, CacheNotifyAction.Remove);
    }
}