// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
 
namespace System.Text.Json.Serialization.Converters
{
    [RequiresDynamicCode(JsonSerializer.SerializationRequiresDynamicCodeMessage)]
    internal sealed class EnumConverterFactory : JsonConverterFactory
    {
        public EnumConverterFactory()
        {
        }
 
        public override bool CanConvert(Type type)
        {
            return type.IsEnum;
        }
 
        public override JsonConverter CreateConverter(Type type, JsonSerializerOptions options)
        {
            Debug.Assert(CanConvert(type));
            return Create(type, EnumConverterOptions.AllowNumbers, namingPolicy: null, options);
        }
 
        internal static JsonConverter Create(Type enumType, EnumConverterOptions converterOptions, JsonNamingPolicy? namingPolicy, JsonSerializerOptions options)
        {
            return (JsonConverter)Activator.CreateInstance(
                GetEnumConverterType(enumType),
                new object?[] { converterOptions, namingPolicy, options })!;
        }
 
        [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2070:UnrecognizedReflectionPattern",
            Justification = "'EnumConverter<T> where T : struct' implies 'T : new()', so the trimmer is warning calling MakeGenericType here because enumType's constructors are not annotated. " +
            "But EnumConverter doesn't call new T(), so this is safe.")]
        [return: DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)]
        private static Type GetEnumConverterType(Type enumType) => typeof(EnumConverter<>).MakeGenericType(enumType);
    }
}