// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Collections.Concurrent;
using Microsoft.CodeAnalysis.Internal.Log;

namespace Microsoft.CodeAnalysis.Storage;

internal sealed class StorageDatabaseLogger
{
    private const string Kind = nameof(Kind);
    private const string Reason = nameof(Reason);

    private static readonly StorageDatabaseLogger Instance = new();

#pragma warning disable IDE0052 // Remove unread private members - hold onto last exception to make investigation easier
    private Exception? _reportedException;
    private string? _reportedExceptionMessage;
#pragma warning restore IDE0052 // Remove unread private members

    private readonly ConcurrentDictionary<Type, Exception> _set = new(concurrencyLevel: 2, capacity: 10);

    internal static void LogException(Exception ex)
        => Instance.LogExceptionWorker(ex);

    private void LogExceptionWorker(Exception ex)
    {
        // hold onto last exception to make investigation easier
        _reportedException = ex;
        _reportedExceptionMessage = ex.ToString();

        // we already reported about this exception. also don't hold onto too many exceptions.
        if (_set.Count > 10 || !_set.TryAdd(ex.GetType(), ex))
        {
            return;
        }

        Logger.Log(FunctionId.StorageDatabase_Exceptions, KeyValueLogMessage.Create(static (m, ex) =>
        {
            // this is okay since it is our exception
            m[Kind] = ex.GetType().ToString();
            m[Reason] = ex.ToString();
        }, ex));
    }
}