// Copyright 2009-2022 Josh Close
// This file is a part of CsvHelper and is dual licensed under MS-PL and Apache 2.0.
// See LICENSE.txt for details or visit http://www.opensource.org/licenses/ms-pl.html for MS-PL and http://opensource.org/licenses/Apache-2.0 for Apache 2.0.
// https://github.com/JoshClose/CsvHelper
using System.Collections;
using CsvHelper.Configuration;

namespace CsvHelper.TypeConversion
{
	/// <summary>
	/// Throws an exception when used. This is here so that it's apparent
	/// that there is no support for <see cref="IEnumerable"/> type conversion. A custom
	/// converter will need to be created to have a field convert to and
	/// from an IEnumerable.
	/// </summary>
	public class EnumerableConverter : DefaultTypeConverter
	{
		/// <summary>
		/// Throws an exception.
		/// </summary>
		/// <param name="text">The string to convert to an object.</param>
		/// <param name="row">The <see cref="IReaderRow"/> for the current record.</param>
		/// <param name="memberMapData">The <see cref="MemberMapData"/> for the member being created.</param>
		/// <returns>The object created from the string.</returns>
		public override object? ConvertFromString(string? text, IReaderRow row, MemberMapData memberMapData)
		{
			var message = "Converting IEnumerable types is not supported for a single field. " +
						  "If you want to do this, create your own ITypeConverter and register " +
						  "it in the TypeConverterFactory by calling AddConverter.";
			throw new TypeConverterException(this, memberMapData, text, row.Context, message);
		}

		/// <summary>
		/// Throws an exception.
		/// </summary>
		/// <param name="value">The object to convert to a string.</param>
		/// <param name="row">The <see cref="IWriterRow"/> for the current record.</param>
		/// <param name="memberMapData">The <see cref="MemberMapData"/> for the member being written.</param>
		/// <returns>The string representation of the object.</returns>
		public override string? ConvertToString(object? value, IWriterRow row, MemberMapData memberMapData)
		{
			var message = "Converting IEnumerable types is not supported for a single field. " +
						  "If you want to do this, create your own ITypeConverter and register " +
						  "it in the TypeConverterFactory by calling AddConverter.";
			throw new TypeConverterException(this, memberMapData, value, row.Context, message);
		}
	}
}