#region Copyright notice and license
 
// Copyright 2019 The gRPC Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#endregion
 
using System.Diagnostics.CodeAnalysis;
using Grpc.AspNetCore.Server;
using Grpc.Core;
using Microsoft.AspNetCore.Http;
 
namespace Grpc.Shared.Server;
 
/// <summary>
/// Server method invoker base type.
/// </summary>
/// <typeparam name="TService">Service type for this method.</typeparam>
/// <typeparam name="TRequest">Request message type for this method.</typeparam>
/// <typeparam name="TResponse">Response message type for this method.</typeparam>
internal abstract class ServerMethodInvokerBase<[DynamicallyAccessedMembers(ServerDynamicAccessConstants.ServiceAccessibility)] TService, TRequest, TResponse>
    where TRequest : class
    where TResponse : class
    where TService : class
{
    /// <summary>
    /// Gets the description of the gRPC method.
    /// </summary>
    public Method<TRequest, TResponse> Method { get; }
 
    /// <summary>
    /// Gets the options used to execute the method.
    /// </summary>
    public MethodOptions Options { get; }
 
    /// <summary>
    /// Gets the service activator used to create service instances.
    /// </summary>
    public IGrpcServiceActivator<TService> ServiceActivator { get; }
 
    /// <summary>
    /// Creates a new instance of <see cref="ServerMethodInvokerBase{TService, TRequest, TResponse}"/>.
    /// </summary>
    /// <param name="method">The description of the gRPC method.</param>
    /// <param name="options">The options used to execute the method.</param>
    /// <param name="serviceActivator">The service activator used to create service instances.</param>
    private protected ServerMethodInvokerBase(
        Method<TRequest, TResponse> method,
        MethodOptions options,
        IGrpcServiceActivator<TService> serviceActivator)
    {
        Method = method;
        Options = options;
        ServiceActivator = serviceActivator;
    }
 
    protected GrpcActivatorHandle<TService> CreateServiceHandle(ServerCallContext context)
    {
        return CreateServiceHandle(context.GetHttpContext());
    }
 
    protected GrpcActivatorHandle<TService> CreateServiceHandle(HttpContext httpContext)
    {
        if (!Options.SuppressCreatingService)
        {
            return ServiceActivator.Create(httpContext.RequestServices);
        }
 
        return default;
    }
}