// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Runtime.CompilerServices;
using CultureInfo = System.Globalization.CultureInfo;
 
namespace System.Reflection.Emit
{
    internal sealed class RuntimeFieldBuilder : FieldBuilder
    {
        #region Private Data Members
        private readonly int m_fieldTok;
        private readonly RuntimeTypeBuilder m_typeBuilder;
        private readonly string m_fieldName;
        private readonly FieldAttributes m_Attributes;
        private readonly Type m_fieldType;
        #endregion
 
        #region Constructor
        internal RuntimeFieldBuilder(RuntimeTypeBuilder typeBuilder, string fieldName, Type type,
            Type[]? requiredCustomModifiers, Type[]? optionalCustomModifiers, FieldAttributes attributes)
        {
            if (fieldName[0] == '\0')
                throw new ArgumentException(SR.Argument_IllegalName, nameof(fieldName));
 
            if (type == typeof(void))
                throw new ArgumentException(SR.Argument_BadFieldType);
 
            m_fieldName = fieldName;
            m_typeBuilder = typeBuilder;
            m_fieldType = type;
            m_Attributes = attributes & ~FieldAttributes.ReservedMask;
 
            SignatureHelper sigHelp = SignatureHelper.GetFieldSigHelper(m_typeBuilder.Module);
            sigHelp.AddArgument(type, requiredCustomModifiers, optionalCustomModifiers);
 
            byte[] signature = sigHelp.InternalGetSignature(out int sigLength);
 
            RuntimeModuleBuilder module = m_typeBuilder.GetModuleBuilder();
            m_fieldTok = RuntimeTypeBuilder.DefineField(new QCallModule(ref module),
                typeBuilder.TypeToken, fieldName, signature, sigLength, m_Attributes);
        }
 
        #endregion
 
        #region Internal Members
        internal void SetData(byte[]? data, int size)
        {
            RuntimeModuleBuilder module = m_typeBuilder.GetModuleBuilder();
            RuntimeModuleBuilder.SetFieldRVAContent(new QCallModule(ref module), m_fieldTok, data, size);
        }
        #endregion
 
        #region MemberInfo Overrides
        public override int MetadataToken => m_fieldTok;
 
        public override Module Module => m_typeBuilder.Module;
 
        public override string Name => m_fieldName;
 
        public override Type? DeclaringType
        {
            get
            {
                if (m_typeBuilder.m_isHiddenGlobalType)
                    return null;
 
                return m_typeBuilder;
            }
        }
 
        public override Type? ReflectedType
        {
            get
            {
                if (m_typeBuilder.m_isHiddenGlobalType)
                    return null;
 
                return m_typeBuilder;
            }
        }
 
        #endregion
 
        #region FieldInfo Overrides
        public override Type FieldType => m_fieldType;
 
        public override object? GetValue(object? obj)
        {
            // NOTE!!  If this is implemented, make sure that this throws
            // a NotSupportedException for Save-only dynamic assemblies.
            // Otherwise, it could cause the .cctor to be executed.
 
            throw new NotSupportedException(SR.NotSupported_DynamicModule);
        }
 
        public override void SetValue(object? obj, object? val, BindingFlags invokeAttr, Binder? binder, CultureInfo? culture)
        {
            // NOTE!!  If this is implemented, make sure that this throws
            // a NotSupportedException for Save-only dynamic assemblies.
            // Otherwise, it could cause the .cctor to be executed.
 
            throw new NotSupportedException(SR.NotSupported_DynamicModule);
        }
 
        public override RuntimeFieldHandle FieldHandle => throw new NotSupportedException(SR.NotSupported_DynamicModule);
 
        public override FieldAttributes Attributes => m_Attributes;
 
        #endregion
 
        #region ICustomAttributeProvider Implementation
        public override object[] GetCustomAttributes(bool inherit)
        {
            throw new NotSupportedException(SR.NotSupported_DynamicModule);
        }
 
        public override object[] GetCustomAttributes(Type attributeType, bool inherit)
        {
            throw new NotSupportedException(SR.NotSupported_DynamicModule);
        }
 
        public override bool IsDefined(Type attributeType, bool inherit)
        {
            throw new NotSupportedException(SR.NotSupported_DynamicModule);
        }
 
        #endregion
 
        #region Protected Members Overrides
        protected override void SetOffsetCore(int iOffset)
        {
            m_typeBuilder.ThrowIfCreated();
 
            RuntimeModuleBuilder module = m_typeBuilder.GetModuleBuilder();
            RuntimeTypeBuilder.SetFieldLayoutOffset(new QCallModule(ref module), m_fieldTok, iOffset);
        }
 
        protected override void SetConstantCore(object? defaultValue)
        {
            m_typeBuilder.ThrowIfCreated();
 
            if (defaultValue == null && m_fieldType.IsValueType)
            {
                // nullable types can hold null value.
                if (!(m_fieldType.IsGenericType && m_fieldType.GetGenericTypeDefinition() == typeof(Nullable<>)))
                    throw new ArgumentException(SR.Argument_ConstantNull);
            }
 
            RuntimeTypeBuilder.SetConstantValue(m_typeBuilder.GetModuleBuilder(), m_fieldTok, m_fieldType, defaultValue);
        }
 
        protected override void SetCustomAttributeCore(ConstructorInfo con, ReadOnlySpan<byte> binaryAttribute)
        {
            RuntimeModuleBuilder moduleBuilder = (RuntimeModuleBuilder)m_typeBuilder.Module;
 
            m_typeBuilder.ThrowIfCreated();
 
            RuntimeTypeBuilder.DefineCustomAttribute(moduleBuilder,
                m_fieldTok, moduleBuilder.GetMethodMetadataToken(con), binaryAttribute);
        }
 
        #endregion
    }
}