// Copyright (c) Arlo Godfrey. All Rights Reserved.
// Licensed under the GNU Lesser General Public License, Version 3.0 with additional terms.
// See the LICENSE, LICENSE.LESSER and LICENSE.ADDITIONAL files in the project root for more information.

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using OwlCore.Provisos;
using StrixMusic.Sdk.CoreModels;

namespace StrixMusic.Services.CoreManagement
{
    /// <summary>
    /// Manages added and removing core instances.
    /// </summary>
    public interface ICoreManagementService : IAsyncInit
    {
        /// <summary>
        /// Raised when a core is added to the registry.
        /// </summary>
        event EventHandler<CoreInstanceEventArgs>? CoreInstanceRegistered;

        /// <summary>
        /// Raised when a core is removed from the registry.
        /// </summary>
        event EventHandler<CoreInstanceEventArgs>? CoreInstanceUnregistered;

        /// <summary>
        /// Gets a list of all cores that the user has set up and configured.
        /// </summary>
        /// <returns>A <see cref="Task"/> that represents the asynchronous operation.</returns>
        Task<Dictionary<string, CoreMetadata>> GetCoreInstanceRegistryAsync();

        /// <summary>
        /// Gets a sorted list of cores instance IDs that indicate to the user's preferred ranking.
        /// </summary>
        /// <returns>A <see cref="Task"/> that represents the asynchronous operation.</returns>
        public Task<IReadOnlyList<string>> GetCoreInstanceRanking();

        /// <summary>
        /// Registers a new core instance.
        /// </summary>
        /// <param name="coreMetadata">The metadata for the core being registered.</param>
        /// <returns>A <see cref="Task"/> representing the asynchronous operation. Value is the <see cref="ICore.InstanceId"/> used to uniquely identify the core instance.</returns>
        Task<string> RegisterCoreInstanceAsync(CoreMetadata coreMetadata);

        /// <summary>
        /// Unregisters an existing core instance.
        /// </summary>
        /// <param name="instanceId">The ID of the core to remove.</param>
        /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
        Task UnregisterCoreInstanceAsync(string instanceId);

        /// <summary>
        /// Given a core instance, return the <see cref="CoreMetadata"/> that was used to create it.
        /// </summary>
        /// <param name="core">The core instance to check.</param>
        /// <returns>The metadata used to create the given <paramref name="core"/>.</returns>
        CoreMetadata GetCoreMetadata(ICore core);
    }
}