// 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 CsvHelper.TypeConversion;
using System;
using System.Collections;
using System.Linq.Expressions;
using System.Reflection;

namespace CsvHelper.Configuration
{
	/// <summary>
	/// Mapping info for a member to a CSV field.
	/// </summary>
	public class MemberMap<TClass, TMember> : MemberMap
	{
		/// <summary>
		/// Creates a new <see cref="MemberMap"/> instance using the specified member.
		/// </summary>
		public MemberMap(MemberInfo? member)
		{
			TypeConverterOption = new MemberMapTypeConverterOption(this);

			Data = new MemberMapData(member);
		}

		/// <summary>
		/// When reading, is used to get the field
		/// at the index of the name if there was a
		/// header specified. It will look for the
		/// first name match in the order listed.
		/// When writing, sets the name of the 
		/// field in the header record.
		/// The first name will be used.
		/// </summary>
		/// <param name="names">The possible names of the CSV field.</param>
		public new virtual MemberMap<TClass, TMember> Name(params string[] names)
		{
			if (names == null || names.Length == 0)
			{
				throw new ArgumentNullException(nameof(names));
			}

			Data.Names.Clear();
			Data.Names.AddRange(names);
			Data.IsNameSet = true;

			return this;
		}

		/// <summary>
		/// When reading, is used to get the 
		/// index of the name used when there 
		/// are multiple names that are the same.
		/// </summary>
		/// <param name="index">The index of the name.</param>
		public new virtual MemberMap<TClass, TMember> NameIndex(int index)
		{
			Data.NameIndex = index;

			return this;
		}

		/// <summary>
		/// When reading, is used to get the field at
		/// the given index. When writing, the fields
		/// will be written in the order of the field
		/// indexes.
		/// </summary>
		/// <param name="index">The index of the CSV field.</param>
		/// <param name="indexEnd">The end index used when mapping to an <see cref="IEnumerable"/> member.</param>
		public new virtual MemberMap<TClass, TMember> Index(int index, int indexEnd = -1)
		{
			Data.Index = index;
			Data.IsIndexSet = true;
			Data.IndexEnd = indexEnd;

			return this;
		}

		/// <summary>
		/// Ignore the member when reading and writing.
		/// If this member has already been mapped as a reference
		/// member, either by a class map, or by automapping, calling
		/// this method will not ignore all the child members down the
		/// tree that have already been mapped.
		/// </summary>
		public new virtual MemberMap<TClass, TMember> Ignore()
		{
			Data.Ignore = true;

			return this;
		}

		/// <summary>
		/// Ignore the member when reading and writing.
		/// If this member has already been mapped as a reference
		/// member, either by a class map, or by automapping, calling
		/// this method will not ignore all the child members down the
		/// tree that have already been mapped.
		/// </summary>
		/// <param name="ignore">True to ignore, otherwise false.</param>
		public new virtual MemberMap<TClass, TMember> Ignore(bool ignore)
		{
			Data.Ignore = ignore;

			return this;
		}

		/// <summary>
		/// The default value that will be used when reading when
		/// the CSV field is empty.
		/// </summary>
		/// <param name="defaultValue">The default value.</param>
		/// <param name="useOnConversionFailure">Use default on conversion failure.</param>
		public virtual MemberMap<TClass, TMember> Default(TMember defaultValue, bool useOnConversionFailure = false)
		{
			Data.Default = defaultValue;
			Data.IsDefaultSet = true;
			Data.UseDefaultOnConversionFailure = useOnConversionFailure;

			return this;
		}

		/// <summary>
		/// The default value that will be used when reading when
		/// the CSV field is empty. This value is not type checked
		/// and will use a <see cref="ITypeConverter"/> to convert
		/// the field. This could potentially have runtime errors.
		/// </summary>
		/// <param name="defaultValue">The default value.</param>
		/// <param name="useOnConversionFailure">Use default on conversion failure.</param>
		public virtual MemberMap<TClass, TMember> Default(string defaultValue, bool useOnConversionFailure = false)
		{
			Data.Default = defaultValue;
			Data.IsDefaultSet = true;
			Data.UseDefaultOnConversionFailure = useOnConversionFailure;

			return this;
		}

		/// <summary>
		/// The constant value that will be used for every record when 
		/// reading and writing. This value will always be used no matter 
		/// what other mapping configurations are specified.
		/// </summary>
		/// <param name="constantValue">The constant value.</param>
		public virtual MemberMap<TClass, TMember> Constant(TMember? constantValue)
		{
			Data.Constant = constantValue;
			Data.IsConstantSet = true;

			return this;
		}

		/// <summary>
		/// Specifies the <see cref="TypeConverter"/> to use
		/// when converting the member to and from a CSV field.
		/// </summary>
		/// <param name="typeConverter">The TypeConverter to use.</param>
		public new virtual MemberMap<TClass, TMember> TypeConverter(ITypeConverter typeConverter)
		{
			Data.TypeConverter = typeConverter;

			return this;
		}

		/// <summary>
		/// Specifies the <see cref="TypeConverter"/> to use
		/// when converting the member to and from a CSV field.
		/// </summary>
		/// <typeparam name="TConverter">The <see cref="System.Type"/> of the 
		/// <see cref="TypeConverter"/> to use.</typeparam>
		public new virtual MemberMap<TClass, TMember> TypeConverter<TConverter>() where TConverter : ITypeConverter
		{
			TypeConverter(ObjectResolver.Current.Resolve<TConverter>());

			return this;
		}

		/// <summary>
		/// Specifies an expression to be used to convert data in the
		/// row to the member.
		/// </summary>
		/// <param name="convertFromStringFunction">The convert expression.</param>
		public virtual MemberMap<TClass, TMember> Convert(ConvertFromString<TMember> convertFromStringFunction)
		{
			var instance = convertFromStringFunction.Target != null ? Expression.Constant(convertFromStringFunction.Target) : null;
			var fieldParameter = Expression.Parameter(typeof(ConvertFromStringArgs), "args");
			var methodExpression = Expression.Call
			(
				instance,
				convertFromStringFunction.Method,
				fieldParameter
			);
			var lambdaExpression = Expression.Lambda<ConvertFromString<TMember>>(methodExpression, fieldParameter);

			Data.ReadingConvertExpression = lambdaExpression;

			return this;
		}

		/// <summary>
		/// Specifies an expression to be used to convert the object
		/// to a field.
		/// </summary>
		/// <param name="convertToStringFunction">The convert expression.</param>
		public virtual MemberMap<TClass, TMember> Convert(ConvertToString<TClass> convertToStringFunction)
		{
			var instance = convertToStringFunction.Target != null ? Expression.Constant(convertToStringFunction.Target) : null;
			var fieldParameter = Expression.Parameter(typeof(ConvertToStringArgs<TClass>), "args");
			var methodExpression = Expression.Call
			(
				instance,
				convertToStringFunction.Method,
				fieldParameter
			);
			var lambdaExpression = Expression.Lambda<ConvertToString<TClass>>(methodExpression, fieldParameter);

			Data.WritingConvertExpression = lambdaExpression;

			return this;
		}

		/// <summary>
		/// Ignore the member when reading if no matching field name can be found.
		/// </summary>
		public new virtual MemberMap<TClass, TMember> Optional()
		{
			Data.IsOptional = true;

			return this;
		}

		/// <summary>
		/// Specifies an expression to be used to validate a field when reading.
		/// </summary>
		/// <param name="validateExpression"></param>
		public new virtual MemberMap<TClass, TMember> Validate(Validate validateExpression)
		{
			return Validate(validateExpression, args => $"Field '{args.Field}' is not valid.");
		}

		/// <summary>
		/// Specifies an expression to be used to validate a field when reading along with specified exception message.
		/// </summary>
		/// <param name="validateExpression"></param>
		/// <param name="validateMessageExpression"></param>
		public new virtual MemberMap<TClass, TMember> Validate(Validate validateExpression, ValidateMessage validateMessageExpression)
		{
			var fieldParameter = Expression.Parameter(typeof(ValidateArgs), "args");
			var validateCallExpression = Expression.Call(
				Expression.Constant(validateExpression.Target),
				validateExpression.Method,
				fieldParameter
			);
			var messageCallExpression = Expression.Call(
				Expression.Constant(validateMessageExpression.Target),
				validateMessageExpression.Method,
				fieldParameter
			);

			Data.ValidateExpression = Expression.Lambda<Validate>(validateCallExpression, fieldParameter);
			Data.ValidateMessageExpression = Expression.Lambda<ValidateMessage>(messageCallExpression, fieldParameter);

			return this;
		}
	}
}