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

namespace CsvHelper.Configuration
{
	/// <summary>
	/// The configured data for the member map.
	/// </summary>
	public class MemberMapData
	{
		/// <summary>
		/// Gets the member type.
		/// </summary>
		public virtual Type Type
		{
			get
			{
				if (Member != null)
				{
					return Member.MemberType();
				}

				if (IsConstantSet)
				{
					return Constant?.GetType() ?? typeof(string);
				}

				if (IsDefaultSet)
				{
					return Default?.GetType() ?? typeof(string);
				}

				return typeof(string);
			}
		}

		/// <summary>
		/// Gets the <see cref="MemberInfo"/> that the data
		/// is associated with.
		/// </summary>
		public virtual MemberInfo? Member { get; private set; }

		/// <summary>
		/// Gets the list of column names.
		/// </summary>
		public virtual MemberNameCollection Names { get; } = new MemberNameCollection();

		/// <summary>
		/// Gets or sets the index of the name.
		/// This is used if there are multiple
		/// columns with the same names.
		/// </summary>
		public virtual int NameIndex { get; set; }

		/// <summary>
		/// Gets or sets a value indicating if the name was
		/// explicitly set. True if it was explicitly set,
		/// otherwise false.
		/// </summary>
		public virtual bool IsNameSet { get; set; }

		/// <summary>
		/// Gets or sets the column index.
		/// </summary>
		public virtual int Index { get; set; } = -1;

		/// <summary>
		/// Gets or sets the index end. The Index end is used to specify a range for use
		/// with a collection member. Index is used as the start of the range, and IndexEnd
		/// is the end of the range.
		/// </summary>
		public virtual int IndexEnd { get; set; } = -1;

		/// <summary>
		/// Gets or sets a value indicating if the index was
		/// explicitly set. True if it was explicitly set,
		/// otherwise false.
		/// </summary>
		public virtual bool IsIndexSet { get; set; }

		/// <summary>
		/// Gets or sets the type converter.
		/// </summary>
		public virtual ITypeConverter? TypeConverter { get; set; }

		/// <summary>
		/// Gets or sets the type converter options.
		/// </summary>
		public virtual TypeConverterOptions TypeConverterOptions { get; set; } = new TypeConverterOptions();

		/// <summary>
		/// Gets or sets a value indicating whether the field should be ignored.
		/// </summary>
		public virtual bool Ignore { get; set; }

		/// <summary>
		/// Gets or sets the default value used when a CSV field is empty.
		/// </summary>
		public virtual object? Default { get; set; }

		/// <summary>
		/// Gets or sets a value indicating whether this instance is default value set.
		/// the default value was explicitly set. True if it was
		/// explicitly set, otherwise false.
		/// </summary>
		public virtual bool IsDefaultSet { get; set; }

		/// <summary>
		/// Gets or setse a value indicating if the default value should be used when
		/// a type conversion failure happens. <c>true</c> to use the default, otherwise
		/// <c>false</c>.
		/// </summary>
		public virtual bool UseDefaultOnConversionFailure { get; set; }

		/// <summary>
		/// Gets or sets the constant value used for every record.
		/// </summary>
		public virtual object? Constant { get; set; }

		/// <summary>
		/// Gets or sets a value indicating if a constant was explicitly set.
		/// </summary>
		public virtual bool IsConstantSet { get; set; }

		/// <summary>
		/// Gets or sets the expression used to convert data in the
		/// row to the member.
		/// </summary>
		public virtual Expression ReadingConvertExpression { get; set; }

		/// <summary>
		/// Gets or sets the expression to be used to convert the object
		/// to a field.
		/// </summary>
		public virtual Expression WritingConvertExpression { get; set; }

		/// <summary>
		/// Gets or sets the expression use to validate a field.
		/// </summary>
		public virtual Expression ValidateExpression { get; set; }

		/// <summary>
		/// Gets or sets the expression used to get the validation message when validation fails.
		/// </summary>
		public virtual Expression ValidateMessageExpression { get; set; }

		/// <summary>
		/// Gets or sets a value indicating if a field is optional.
		/// </summary>
		public virtual bool IsOptional { get; set; }

        /// <summary>
		/// Initializes a new instance of the <see cref="MemberMapData"/> class.
		/// </summary>
		/// <param name="member">The member.</param>
		public MemberMapData(MemberInfo? member)
		{
			Member = member;
		}
	}
}