// 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;
using System.Globalization;
using System.Linq;
using CsvHelper.Configuration;

namespace CsvHelper.TypeConversion
{
	/// <summary>
	/// Converts a <see cref="double"/> to and from a <see cref="string"/>.
	/// </summary>
	public class DoubleConverter : DefaultTypeConverter
	{
		private Lazy<string> defaultFormat = new Lazy<string>(() => double.TryParse(double.MaxValue.ToString("R"), out var _) ? "R" : "G17");

		/// <summary>
		/// Converts the object to a string.
		/// </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 format = memberMapData.TypeConverterOptions.Formats?.FirstOrDefault() ?? defaultFormat.Value;

			if (value is double d)
			{
				return d.ToString(format, memberMapData.TypeConverterOptions.CultureInfo);
			}

			return base.ConvertToString(value, row, memberMapData);
		}

		/// <summary>
		/// Converts the string to an object.
		/// </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 numberStyle = memberMapData.TypeConverterOptions.NumberStyles ?? NumberStyles.Float | NumberStyles.AllowThousands;

			if (double.TryParse(text, numberStyle, memberMapData.TypeConverterOptions.CultureInfo, out var d))
			{
				return d;
			}

			return base.ConvertFromString(text, row, memberMapData);
		}
	}
}