// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics.Metrics;
using Microsoft.Extensions.Diagnostics.Metrics;
 
namespace Microsoft.AspNetCore.InternalTesting;
 
internal sealed class TestMeterFactory : IMeterFactory
{
    private readonly Lock _lock = new();
 
    public List<Meter> Meters { get; } = new List<Meter>();
 
    public Meter Create(MeterOptions options)
    {
        lock (_lock)
        {
            // Simulate DefaultMeterFactory behavior of returning the same meter instance for the same name/version.
            if (Meters.FirstOrDefault(m => m.Name == options.Name && m.Version == options.Version) is { } existingMeter)
            {
                return existingMeter;
            }
 
            var meter = new Meter(options.Name, options.Version, Array.Empty<KeyValuePair<string, object>>(), scope: this);
            Meters.Add(meter);
            return meter;
        }
    }
 
    public void Dispose()
    {
        foreach (var meter in Meters)
        {
            meter.Dispose();
        }
 
        Meters.Clear();
    }
}