// 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 Xunit;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace CsvHelper.Tests.Async
{
	
	public class WritingTests
	{
		[Fact]
		public async Task WritingTest()
		{
			using (var stream = new MemoryStream())
			using (var reader = new StreamReader(stream))
			using (var writer = new StreamWriter(stream))
			using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
			{
				var records = new List<Simple>
				{
					new Simple { Id = 1, Name = "one" },
					new Simple { Id = 2, Name = "two" },
				};
				csv.WriteHeader<Simple>();
				await csv.NextRecordAsync();
				foreach (var record in records)
				{
					csv.WriteRecord(record);
					await csv.NextRecordAsync();
				}

				writer.Flush();
				stream.Position = 0;

				var expected = new TestStringBuilder(csv.Configuration.NewLine);
				expected.AppendLine("Id,Name");
				expected.AppendLine("1,one");
				expected.AppendLine("2,two");

				Assert.Equal(expected.ToString(), reader.ReadToEnd());
			}
		}

		[Fact]
		public async Task WriteRecordsTest()
		{
			using (var stream = new MemoryStream())
			using (var reader = new StreamReader(stream))
			using (var writer = new StreamWriter(stream))
			using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
			{
				var records = new List<Simple>
				{
					new Simple { Id = 1, Name = "one" },
					new Simple { Id = 2, Name = "two" },
				};
				await csv.WriteRecordsAsync(records);

				writer.Flush();
				stream.Position = 0;

				var expected = new TestStringBuilder(csv.Configuration.NewLine);
				expected.AppendLine("Id,Name");
				expected.AppendLine("1,one");
				expected.AppendLine("2,two");

				Assert.Equal(expected.ToString(), reader.ReadToEnd());
			}
		}

		[Fact]
		public async Task WriteRecordsTestCanceled()
		{
			using (var source = new CancellationTokenSource())
			using (var stream = new MemoryStream())
			using (var reader = new StreamReader(stream))
			using (var writer = new StreamWriter(stream))
			using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture))
			{
				var records = new List<Simple>
				{
					new Simple { Id = 1, Name = "one" },
					new Simple { Id = 2, Name = "two" },
					new Simple { Id = 3, Name = "three" },
				};
				source.Cancel();

				try
				{
					await csv.WriteRecordsAsync(records, source.Token);
				}
				catch (WriterException ex)
				{
					if (ex.InnerException is OperationCanceledException || ex.InnerException is TaskCanceledException)
					{
						return;
					}
				}

				throw new XUnitException("Did not throw exception");
			}
		}

		private class Simple
		{
			public int Id { get; set; }

			public string Name { get; set; }
		}
	}
}