// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Diagnostics.CodeAnalysis;
using Microsoft.Extensions.Http.Resilience.Internal;
using Microsoft.Shared.Diagnostics;
using Polly.DependencyInjection;
 
namespace Microsoft.Extensions.Http.Resilience;
 
/// <summary>
/// The context used when building a resilience pipeline HTTP handler.
/// </summary>
public sealed class ResilienceHandlerContext
{
    private readonly AddResiliencePipelineContext<HttpKey> _context;
 
    internal ResilienceHandlerContext(AddResiliencePipelineContext<HttpKey> context)
    {
        _context = context;
    }
 
    /// <summary>
    /// Gets the service provider.
    /// </summary>
    public IServiceProvider ServiceProvider => _context.ServiceProvider;
 
    /// <summary>
    /// Gets the name of the builder being built.
    /// </summary>
    public string BuilderName => _context.PipelineKey.Name;
 
    /// <summary>
    /// Gets the instance name of resilience pipeline being built.
    /// </summary>
    public string InstanceName => _context.PipelineKey.InstanceName;
 
    /// <summary>
    /// Enables dynamic reloading of the resilience pipeline whenever the <typeparamref name="TOptions"/> options are changed.
    /// </summary>
    /// <typeparam name="TOptions">The options type to listen to.</typeparam>
    /// <param name="name">The named options, if any.</param>
    /// <remarks>
    /// You can decide based on the <paramref name="name"/> to listen for changes in global options or named options.
    /// If <paramref name="name"/> is <see langword="null"/> then the global options are listened to.
    /// By default, the <paramref name="name"/> parameter is <see langword="null"/>.
    /// <para>
    /// You can listen for changes only for single options. If you call this method multiple times, the preceding calls are ignored and only the last one wins.
    /// </para>
    /// </remarks>
    public void EnableReloads<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)] TOptions>(string? name = null) => _context.EnableReloads<TOptions>(name);
 
    /// <summary>
    /// Gets the options identified by <paramref name="name"/>.
    /// </summary>
    /// <typeparam name="TOptions">The options type.</typeparam>
    /// <param name="name">The options name, if any.</param>
    /// <returns>The options instance.</returns>
    /// <remarks>
    /// If <paramref name="name"/> is <see langword="null"/> then the global options are returned.
    /// By default, the <paramref name="name"/> parameter is <see langword="null"/>.
    /// </remarks>
    public TOptions GetOptions<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)] TOptions>(string? name = null) => _context.GetOptions<TOptions>(name);
 
    /// <summary>
    /// Registers a callback that is called when the pipeline instance being configured is disposed.
    /// </summary>
    /// <param name="callback">The callback delegate.</param>
    public void OnPipelineDisposed(Action callback) => _context.OnPipelineDisposed(Throw.IfNull(callback));
}