meeting-assistant/MeetingAssistant/Recording/MicrophoneDeviceSelection.cs

namespace MeetingAssistant.Recording;

public sealed class MicrophoneDeviceSelection
{
    private readonly object sync = new();
    private string? selectedDeviceId;

    public string? SelectedDeviceId
    {
        get
        {
            lock (sync)
            {
                return selectedDeviceId;
            }
        }
    }

    public void Select(string deviceId)
    {
        lock (sync)
        {
            selectedDeviceId = string.IsNullOrWhiteSpace(deviceId)
                ? null
                : deviceId.Trim();
        }
    }

    public MicrophoneDevice? Resolve(
        string? configuredDeviceId,
        MicrophoneDevice? defaultDevice,
        IReadOnlyList<MicrophoneDevice> availableDevices)
    {
        var selected = SelectedDeviceId;
        return FindById(availableDevices, selected) ??
            FindById(availableDevices, configuredDeviceId) ??
            FindById(availableDevices, defaultDevice?.Id) ??
            availableDevices.FirstOrDefault() ??
            defaultDevice;
    }

    private static MicrophoneDevice? FindById(
        IReadOnlyList<MicrophoneDevice> devices,
        string? id)
    {
        if (string.IsNullOrWhiteSpace(id))
        {
            return null;
        }

        return devices.FirstOrDefault(device => string.Equals(
            device.Id,
            id.Trim(),
            StringComparison.OrdinalIgnoreCase));
    }
}