// 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.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Reflection;
using System.Threading;
 
namespace Microsoft.Extensions.DependencyInjection.ServiceLookup
{
    internal static class ServiceLookupHelpers
    {
        private const BindingFlags LookupFlags = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance;
        private static readonly MethodInfo ArrayEmptyMethodInfo = typeof(Array).GetMethod(nameof(Array.Empty))!;
 
        internal static readonly MethodInfo InvokeFactoryMethodInfo = typeof(Func<IServiceProvider, object>)
            .GetMethod(nameof(Func<IServiceProvider, object>.Invoke), LookupFlags)!;
 
        internal static readonly MethodInfo CaptureDisposableMethodInfo = typeof(ServiceProviderEngineScope)
            .GetMethod(nameof(ServiceProviderEngineScope.CaptureDisposable), LookupFlags)!;
 
        internal static readonly MethodInfo TryGetValueMethodInfo = typeof(IDictionary<ServiceCacheKey, object>)
            .GetMethod(nameof(IDictionary<ServiceCacheKey, object>.TryGetValue), LookupFlags)!;
 
        internal static readonly MethodInfo ResolveCallSiteAndScopeMethodInfo = typeof(CallSiteRuntimeResolver)
            .GetMethod(nameof(CallSiteRuntimeResolver.Resolve), LookupFlags)!;
 
        internal static readonly MethodInfo AddMethodInfo = typeof(IDictionary<ServiceCacheKey, object>)
            .GetMethod(nameof(IDictionary<ServiceCacheKey, object>.Add), LookupFlags)!;
 
        internal static readonly MethodInfo MonitorEnterMethodInfo = typeof(Monitor)
            .GetMethod(nameof(Monitor.Enter), BindingFlags.Public | BindingFlags.Static, null, new Type[] { typeof(object), typeof(bool).MakeByRefType() }, null)!;
        internal static readonly MethodInfo MonitorExitMethodInfo = typeof(Monitor)
            .GetMethod(nameof(Monitor.Exit), BindingFlags.Public | BindingFlags.Static, null, new Type[] { typeof(object) }, null)!;
 
        [RequiresDynamicCode("The code for an array of the specified type might not be available.")]
        [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2060:MakeGenericMethod",
            Justification = "Calling Array.Empty<T>() is safe since the T doesn't have trimming annotations.")]
        internal static MethodInfo GetArrayEmptyMethodInfo(Type itemType) =>
            ArrayEmptyMethodInfo.MakeGenericMethod(itemType);
    }
}