// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http.Formatting.Parsers;
using System.Net.Http.Headers;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.TestCommon;
using Moq;

namespace System.Net.Http
{
    public class HttpContentMultipartExtensionsTests
    {
        private const string ValidBoundary = "-A-";
        private const string DefaultContentType = "text/plain";
        private const string DefaultContentDisposition = "form-data";
        private const string ExceptionStreamProviderMessage = "Bad Stream Provider!";
        private const string ExceptionSyncStreamMessage = "Bad Sync Stream!";
        private const string ExceptionAsyncStreamMessage = "Bad Async Stream!";

        public static TheoryDataSet<string, bool, string, bool> IsMimeMultipartContentTestData
        {
            get
            {
                return new TheoryDataSet<string, bool, string, bool>
                {
                    { "text/plain", false, "plain", false },
                    { "application/*", false, "related", false },
                    { "*/*", false, "related", false },
                    { "multipart/form-data", false, "form-data", false },
                    { "multipart/form-data; boundary=1234", true, "related", false },
                    { "multipart/form-data; boundary=1234; charset=utf-8", true, "form-data", true },
                    { "Multipart/Related; boundary=example-1; start=\"<950120.aaCC@XIson.com>\"; type=\"Application/X-FixedRecord\"; start-info=\"-o ps\"", true, "related", true },
                };
            }
        }

        public static TheoryDataSet<string, bool> IsMimeMultipartContentTestData_NoSubType
        {
            get
            {
                var dataSet = new TheoryDataSet<string, bool>();
                foreach (var item in IsMimeMultipartContentTestData)
                {
                    dataSet.Add((string)item[0], (bool)item[1]);
                }

                return dataSet;
            }
        }

        private static HttpContent CreateContent(string boundary, params string[] bodyEntity)
        {
            return CreateContentWithContentType(boundary, DefaultContentType, bodyEntity);
        }

        private static HttpContent CreateContentWithContentType(string boundary, string partContentType, params string[] bodyEntity)
        {
            List<string> entities = new List<string>();
            int cnt = 0;
            foreach (var body in bodyEntity)
            {
                byte[] header = InternetMessageFormatHeaderParserTests.CreateBuffer(
                    String.Format("N{0}: V{0}", cnt),
                    String.Format("Content-Type: {0}", partContentType),
                    String.Format("Content-Disposition: {0}; FileName=\"N{1}\"", DefaultContentDisposition, cnt));
                entities.Add(Encoding.UTF8.GetString(header) + body);
                cnt++;
            }

            byte[] message = MimeMultipartParserTests.CreateBuffer(boundary, entities.ToArray());
            HttpContent result = new ByteArrayContent(message);
            var contentType = new MediaTypeHeaderValue("multipart/form-data");
            contentType.Parameters.Add(new NameValueHeaderValue("boundary", String.Format("\"{0}\"", boundary)));
            result.Headers.ContentType = contentType;
            return result;
        }

        private static async Task ValidateContentsAsync(IEnumerable<HttpContent> contents)
        {
            int cnt = 0;
            foreach (var content in contents)
            {
                Assert.NotNull(content);
                Assert.NotNull(content.Headers);
                Assert.Equal(4, content.Headers.Count());

                IEnumerable<string> parsedValues = content.Headers.GetValues(String.Format("N{0}", cnt));
                string parsedValue = Assert.Single(parsedValues);
                Assert.Equal(String.Format("V{0}", cnt), parsedValue);

                Assert.Equal(DefaultContentType, content.Headers.ContentType.MediaType);

                Assert.Equal(DefaultContentDisposition, content.Headers.ContentDisposition.DispositionType);
                Assert.Equal(String.Format("\"N{0}\"", cnt), content.Headers.ContentDisposition.FileName);

                await AssertContentLengthHeaderValueAsync(content);

                cnt++;
            }
        }

        private static async Task AssertContentLengthHeaderValueAsync(HttpContent content)
        {
            long contentLength = (await content.ReadAsByteArrayAsync()).LongLength;
            long contentLengthHeaderValue = content.Headers.ContentLength.GetValueOrDefault();
            Assert.Equal(contentLength, contentLengthHeaderValue);
        }

        [Fact]
        public void IsMimeMultipartContent_ThrowsOnNullContent()
        {
            Assert.ThrowsArgumentNull(() => HttpContentMultipartExtensions.IsMimeMultipartContent(null), "content");
        }

        [Fact]
        public void IsMimeMultipartContent_ThrowsOnNullSubType()
        {
            StringContent content = new StringContent(String.Empty);
            Assert.ThrowsArgumentNull(() => HttpContentMultipartExtensions.IsMimeMultipartContent(content, null), "subtype");
        }

        [Theory]
        [PropertyData("IsMimeMultipartContentTestData")]
        public void IsMimeMultipartContent_ReturnsCorrectValue(string mediaType, bool isMultipart, string subtype, bool hasSubtype)
        {
            StringContent content = new StringContent(String.Empty);
            content.Headers.ContentType = MediaTypeHeaderValue.Parse(mediaType);

            Assert.Equal(isMultipart, content.IsMimeMultipartContent());
            Assert.Equal(hasSubtype, content.IsMimeMultipartContent(subtype));
        }

        [Fact]
        public Task ReadAsMultipartAsync_ThrowsOnNullStreamProvider()
        {
            HttpContent content = CreateContent(ValidBoundary);
            return Assert.ThrowsArgumentNullAsync(() => content.ReadAsMultipartAsync((MultipartStreamProvider)null), "streamProvider");
        }

        [Fact]
        public Task ReadAsMultipartAsync_ThrowsOnInvalidBufferSize()
        {
            HttpContent content = CreateContent(ValidBoundary);
            return Assert.ThrowsArgumentGreaterThanOrEqualToAsync(
                () => content.ReadAsMultipartAsync(new MultipartMemoryStreamProvider(), ParserData.MinBufferSize - 1),
                "bufferSize", ParserData.MinBufferSize.ToString(), ParserData.MinBufferSize - 1);
        }

        [Theory]
        [PropertyData("IsMimeMultipartContentTestData_NoSubType")]
        public async Task ReadAsMultipartAsync_DetectsNonMultipartContent(string mediaType, bool isMultipart)
        {
            StringContent content = new StringContent(String.Empty);
            content.Headers.ContentType = MediaTypeHeaderValue.Parse(mediaType);
            if (!isMultipart)
            {
                await Assert.ThrowsArgumentAsync(() => content.ReadAsMultipartAsync(), "content");
            }
        }

        [Theory]
        [TestDataSet(typeof(MimeMultipartParserTests), "Boundaries")]
        public async Task ReadAsMultipartAsync_ParsesContent(string boundary)
        {
            HttpContent successContent;
            MultipartMemoryStreamProvider result;

            successContent = CreateContent(boundary, "A", "B", "C");
            result = await successContent.ReadAsMultipartAsync();
            Assert.Equal(3, result.Contents.Count);

            successContent = CreateContent(boundary, "A", "B", "C");
            result = await successContent.ReadAsMultipartAsync(new MultipartMemoryStreamProvider());
            Assert.Equal(3, result.Contents.Count);

            successContent = CreateContent(boundary, "A", "B", "C");
            result = await successContent.ReadAsMultipartAsync(new MultipartMemoryStreamProvider(), 1024);
            Assert.Equal(3, result.Contents.Count);
        }

        [Fact]
        public async Task ReadAsMultipartAsync_SkipsHeaderValidation()
        {
            // Arrange
            var content = CreateContentWithContentType("--boundary", "invalid", "SomeContent");

            // Act
            var result = await content.ReadAsMultipartAsync(CancellationToken.None);

            // Assert
            var bodyPart = Assert.Single(result.Contents);
            Assert.Null(bodyPart.Headers.ContentType);
            Assert.Equal("invalid", Assert.Single(bodyPart.Headers.GetValues("Content-Type")));
        }

        [Fact]
        public async Task ReadAsMultipartAsync_SetsStronglyTypedHeader_WhenHeaderIsValid()
        {
            // Arrange
            var content = CreateContentWithContentType("--boundary", "application/json", "SomeContent");

            // Act
            var result = await content.ReadAsMultipartAsync(CancellationToken.None);

            // Assert
            var bodyPart = Assert.Single(result.Contents);
            Assert.NotNull(bodyPart.Headers.ContentType);
            Assert.Equal("application/json", bodyPart.Headers.ContentType.MediaType);
        }

        [Theory]
        [TestDataSet(typeof(MimeMultipartParserTests), "Boundaries")]
        public async Task ReadAsMultipartAsync_ParsesEmptyContent(string boundary)
        {
            HttpContent content = CreateContent(boundary);
            MultipartMemoryStreamProvider result = await content.ReadAsMultipartAsync();
            Assert.Empty(result.Contents);
        }

        [Fact]
        public async Task ReadAsMultipartAsync_ThrowsOnBadStreamProvider()
        {
            HttpContent content = CreateContent(ValidBoundary, "A", "B", "C");
            IOException exception = await Assert.ThrowsAsync<IOException>(() => content.ReadAsMultipartAsync(new BadStreamProvider()));
            InvalidOperationException invalidOperationException = exception.InnerException as InvalidOperationException;
            Assert.NotNull(invalidOperationException);
            Assert.NotNull(invalidOperationException.InnerException);
            Assert.Equal(ExceptionStreamProviderMessage, invalidOperationException.InnerException.Message);
        }

        [Fact]
        public async Task ReadAsMultipartAsync_ThrowsOnNullProvider()
        {
            HttpContent content = CreateContent(ValidBoundary, "A", "B", "C");
            IOException exception = await Assert.ThrowsAsync<IOException>(() => content.ReadAsMultipartAsync(new NullProvider()));
            Assert.IsType<InvalidOperationException>(exception.InnerException);
        }

        [Fact]
        public async Task ReadAsMultipartAsync_ThrowsOnReadOnlyStream()
        {
            HttpContent content = CreateContent(ValidBoundary, "A", "B", "C");
            IOException exception = await Assert.ThrowsAsync<IOException>(() => content.ReadAsMultipartAsync(new ReadOnlyStreamProvider()));
            Assert.IsType<InvalidOperationException>(exception.InnerException);
        }

        [Fact]
        public Task ReadAsMultipartAsync_ThrowsOnPrematureEndOfStream()
        {
            HttpContent content = new StreamContent(Stream.Null);
            string mediaType = String.Format("multipart/form-data; boundary=\"{0}\"", ValidBoundary);
            content.Headers.ContentType = MediaTypeHeaderValue.Parse(mediaType);
            return Assert.ThrowsAsync<IOException>(() => content.ReadAsMultipartAsync());
        }

        [Fact]
        public async Task ReadAsMultipartAsync_ThrowsOnReadError()
        {
            HttpContent content = new StreamContent(new ReadErrorStream());
            string mediaType = String.Format("multipart/form-data; boundary=\"{0}\"", ValidBoundary);
            content.Headers.ContentType = MediaTypeHeaderValue.Parse(mediaType);
            IOException exception = await Assert.ThrowsAsync<IOException>(() => content.ReadAsMultipartAsync());
            Assert.NotNull(exception.InnerException);
            Assert.Equal(ExceptionAsyncStreamMessage, exception.InnerException.Message);
        }

        [Fact]
        public async Task ReadAsMultipartAsync_ThrowsOnWriteError()
        {
            HttpContent content = CreateContent(ValidBoundary, "A", "B", "C");
            IOException exception = await Assert.ThrowsAsync<IOException>(() => content.ReadAsMultipartAsync(new WriteErrorStreamProvider()));
            Assert.NotNull(exception.InnerException);
            Assert.Equal(ExceptionAsyncStreamMessage, exception.InnerException.Message);
        }

        [Theory]
        [TestDataSet(typeof(MimeMultipartParserTests), "Boundaries", typeof(MimeMultipartParserTests), "SingleShortBodies")]
        public async Task ReadAsMultipartAsync_SingleShortBodyPart(string boundary, string singleShortBody)
        {
            HttpContent content = CreateContent(boundary, singleShortBody);

            MultipartMemoryStreamProvider result = await content.ReadAsMultipartAsync();
            HttpContent resultContent = Assert.Single(result.Contents);
            Assert.Equal(singleShortBody, await resultContent.ReadAsStringAsync());
            await ValidateContentsAsync(result.Contents);
        }

        [Fact]
        public async Task ReadAsMultipartAsync_WithHugeBody_AvoidStackOverflow()
        {
            // Arrange
            var fiftyMegs = 1024 * 1024 * 50;
            HttpContent content = CreateContent("---3123---", new string('x', fiftyMegs));

            // Act
            MultipartMemoryStreamProvider result = await content.ReadAsMultipartAsync(new MultipartMemoryStreamProvider(), 256);

            // Assert
            // this is for sanity. The actual test here is that the Act part did not cause a stack overflow
            Assert.Equal(fiftyMegs, (await result.Contents[0].ReadAsStringAsync()).Length);
            await ValidateContentsAsync(result.Contents);
        }

        [Theory]
        [TestDataSet(typeof(MimeMultipartParserTests), "Boundaries", typeof(MimeMultipartParserTests), "MultipleShortBodies")]
        public async Task ReadAsMultipartAsync_MultipleShortBodyParts(string boundary, string[] multipleShortBodies)
        {
            HttpContent content = CreateContent(boundary, multipleShortBodies);
            MultipartMemoryStreamProvider result = await content.ReadAsMultipartAsync();
            Assert.Equal(multipleShortBodies.Length, result.Contents.Count);
            for (var check = 0; check < multipleShortBodies.Length; check++)
            {
                Assert.Equal(multipleShortBodies[check], await result.Contents[check].ReadAsStringAsync());
            }

            await ValidateContentsAsync(result.Contents);
        }

        [Theory]
        [TestDataSet(typeof(MimeMultipartParserTests), "Boundaries", typeof(MimeMultipartParserTests), "SingleLongBodies")]
        public async Task ReadAsMultipartAsync_SingleLongBodyPart(string boundary, string singleLongBody)
        {
            HttpContent content = CreateContent(boundary, singleLongBody);

            MultipartMemoryStreamProvider result = await content.ReadAsMultipartAsync();
            HttpContent resultContent = Assert.Single(result.Contents);
            Assert.Equal(singleLongBody, await resultContent.ReadAsStringAsync());
            await ValidateContentsAsync(result.Contents);
        }

        [Theory]
        [TestDataSet(typeof(MimeMultipartParserTests), "Boundaries", typeof(MimeMultipartParserTests), "MultipleLongBodies")]
        public async Task ReadAsMultipartAsync_MultipleLongBodyParts(string boundary, string[] multipleLongBodies)
        {
            HttpContent content = CreateContent(boundary, multipleLongBodies);
            MultipartMemoryStreamProvider result = await content.ReadAsMultipartAsync(new MultipartMemoryStreamProvider(), ParserData.MinBufferSize);
            Assert.Equal(multipleLongBodies.Length, result.Contents.Count);
            for (var check = 0; check < multipleLongBodies.Length; check++)
            {
                Assert.Equal(multipleLongBodies[check], await result.Contents[check].ReadAsStringAsync());
            }

            await ValidateContentsAsync(result.Contents);
        }

        [Theory]
        [TestDataSet(typeof(MimeMultipartParserTests), "Boundaries")]
        public async Task ReadAsMultipartAsync_UsingMultipartContent(string boundary)
        {
            MultipartContent content = new MultipartContent("mixed", boundary);
            content.Add(new StringContent("A"));
            content.Add(new StringContent("B"));
            content.Add(new StringContent("C"));

            MemoryStream memStream = new MemoryStream();
            await content.CopyToAsync(memStream);
            memStream.Position = 0;
            byte[] data = memStream.ToArray();
            var byteContent = new ByteArrayContent(data);
            byteContent.Headers.ContentType = content.Headers.ContentType;

            MultipartMemoryStreamProvider result = await byteContent.ReadAsMultipartAsync();
            Assert.Equal(3, result.Contents.Count);
            Assert.Equal("A", await result.Contents[0].ReadAsStringAsync());
            Assert.Equal("B", await result.Contents[1].ReadAsStringAsync());
            Assert.Equal("C", await result.Contents[2].ReadAsStringAsync());
        }

        [Theory]
        [TestDataSet(typeof(MimeMultipartParserTests), "Boundaries")]
        public async Task ReadAsMultipartAsync_NestedMultipartContent(string boundary)
        {
            const int nesting = 10;
            const string innerText = "Content";

            MultipartContent innerContent = new MultipartContent("mixed", boundary);
            innerContent.Add(new StringContent(innerText));
            for (var cnt = 0; cnt < nesting; cnt++)
            {
                string outerBoundary = String.Format("{0}_{1}", boundary, cnt);
                MultipartContent outerContent = new MultipartContent("mixed", outerBoundary);
                outerContent.Add(innerContent);
                innerContent = outerContent;
            }

            MemoryStream memStream = new MemoryStream();
            await innerContent.CopyToAsync(memStream);
            memStream.Position = 0;
            byte[] data = memStream.ToArray();
            HttpContent content = new ByteArrayContent(data);
            content.Headers.ContentType = innerContent.Headers.ContentType;

            for (var cnt = 0; cnt < nesting + 1; cnt++)
            {
                MultipartMemoryStreamProvider result = await content.ReadAsMultipartAsync();
                content = Assert.Single(result.Contents);
                Assert.NotNull(content);
            }

            string text = await content.ReadAsStringAsync();
            Assert.Equal(innerText, text);
        }

        [Fact]
        public async Task ReadAsMultipartAsyncOfT_PassesCancellationToken()
        {
            CancellationToken token = new CancellationToken();
            HttpContent content = CreateContent("boundary");
            Mock<MultipartStreamProvider> provider = new Mock<MultipartStreamProvider>();
            provider.Setup(p => p.ExecutePostProcessingAsync(token))
                .Returns(Task.FromResult(42))
                .Verifiable();

            await content.ReadAsMultipartAsync<MultipartStreamProvider>(provider.Object, token);

            provider.Verify();
        }

        public class ReadOnlyStream : MemoryStream
        {
            public override bool CanWrite
            {
                get
                {
                    return false;
                }
            }
        }

        public class ReadErrorStream : MemoryStream
        {
            public override int Read(byte[] buffer, int offset, int count)
            {
                throw new IOException(ExceptionSyncStreamMessage);
            }
            public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
            {
                throw new IOException(ExceptionAsyncStreamMessage);
            }

#if !NETFX_CORE // BeginX and EndX not supported on Streams in portable libraries
            public override IAsyncResult BeginRead(byte[] buffer, int offset, int count, AsyncCallback callback, object state)
            {
                throw new IOException(ExceptionAsyncStreamMessage);
            }
#endif
        }

        public class WriteErrorStream : MemoryStream
        {
            public override void Write(byte[] buffer, int offset, int count)
            {
                throw new IOException(ExceptionSyncStreamMessage);
            }

            public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
            {
                throw new IOException(ExceptionAsyncStreamMessage);
            }

#if !NETFX_CORE // BeginX and EndX not supported on Streams in portable libraries
            public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback callback, object state)
            {
                throw new IOException(ExceptionAsyncStreamMessage);
            }
#endif
        }

        public class BadStreamProvider : MultipartStreamProvider
        {
            public override Stream GetStream(HttpContent parent, HttpContentHeaders headers)
            {
                throw new Exception(ExceptionStreamProviderMessage);
            }
        }

        public class NullProvider : MultipartStreamProvider
        {
            public override Stream GetStream(HttpContent parent, HttpContentHeaders headers)
            {
                return null;
            }
        }

        public class ReadOnlyStreamProvider : MultipartStreamProvider
        {
            public override Stream GetStream(HttpContent parent, HttpContentHeaders headers)
            {
                return new ReadOnlyStream();
            }
        }

        public class WriteErrorStreamProvider : MultipartStreamProvider
        {
            public override Stream GetStream(HttpContent parent, HttpContentHeaders headers)
            {
                return new WriteErrorStream();
            }
        }
    }
}