LeagueARAMTracker/LeagueAPI/CachingHttpClient.cs

namespace LeagueAPI;

public class HttpCache : Dictionary<string, InvalidatableCacheObject<string>> { }
public record struct InvalidatableCacheObject<T>(
    T Value,
    DateTime? InvalidateTime = null
    )
{
    public readonly bool IsValid()
    {
        return !InvalidateTime.HasValue || InvalidateTime < DateTime.UtcNow;
    }
}

public class CachingHttpClient : IDisposable
{
    private bool _isDisposed;
    private readonly HttpCache _cache = ResourceService.GetHttpCache() ?? [];
    private readonly HttpClient _client = new();

    public CachingHttpClient(bool insecure = false)
    {
        if (insecure)
        {
            HttpClientHandler handler = new()
            {
                ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator
            };
            _client = new(handler);
        }
        else
        {
            _client = new();
        }
    }

    public async Task<string> GetStringAsync(string requestUri, TimeSpan? invalidateAfter = null)
    {
        if (_cache.TryGetValue(requestUri, out InvalidatableCacheObject<string> response) && response.IsValid())
        {
            return response.Value;
        }
        string result = await _client.GetStringAsync(requestUri);
        if (invalidateAfter is not null && invalidateAfter > TimeSpan.Zero)
        {
            _cache[requestUri] = new(result, DateTime.UtcNow + invalidateAfter);
        }
        else
        {
            _cache[requestUri] = new(result);
        }
        return result;
    }

    #region IDisposable
    protected virtual void Dispose(bool disposing)
    {
        if (!_isDisposed)
        {
            if (disposing)
            {
                _client?.Dispose();
            }

            _cache?.Clear();
            _isDisposed = true;
        }
    }

    public void Dispose()
    {
        // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
        Dispose(disposing: true);
        GC.SuppressFinalize(this);
    }
    #endregion
}