// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using Xunit;

namespace Microsoft.Extensions.Logging.AzureAppServices.Test
{
    public class AzureAppendBlobTests
    {
        public string _containerUrl = "https://host/container?query=1";
        public string _blobName = "blob/path";

        [Fact]
        public async Task SendsDataAsStream()
        {
            var testMessageHandler = new TestMessageHandler(async message =>
            {
                Assert.Equal(HttpMethod.Put, message.Method);
                Assert.Equal("https://host/container/blob/path?query=1&comp=appendblock", message.RequestUri.ToString());
                Assert.Equal(new byte[] { 0, 2, 3 }, await message.Content.ReadAsByteArrayAsync());
                AssertDefaultHeaders(message);

                return new HttpResponseMessage(HttpStatusCode.OK);
            });

            var blob = new BlobAppendReferenceWrapper(_containerUrl, _blobName, new HttpClient(testMessageHandler));
            await blob.AppendAsync(new ArraySegment<byte>(new byte[] { 0, 2, 3 }), CancellationToken.None);
        }

        private static void AssertDefaultHeaders(HttpRequestMessage message)
        {
            Assert.Equal(new[] {"AppendBlob"}, message.Headers.GetValues("x-ms-blob-type"));
            Assert.Equal(new[] {"2016-05-31"}, message.Headers.GetValues("x-ms-version"));
            Assert.NotNull(message.Headers.Date);
        }

        [Theory]
        [InlineData(HttpStatusCode.Created)]
        [InlineData(HttpStatusCode.PreconditionFailed)]
        public async Task CreatesBlobIfNotExist(HttpStatusCode createStatusCode)
        {
            var stage = 0;
            var testMessageHandler = new TestMessageHandler(async message =>
            {
                // First PUT request
                if (stage == 0)
                {
                    Assert.Equal(HttpMethod.Put, message.Method);
                    Assert.Equal("https://host/container/blob/path?query=1&comp=appendblock", message.RequestUri.ToString());
                    Assert.Equal(new byte[] { 0, 2, 3 }, await message.Content.ReadAsByteArrayAsync());
                    Assert.Equal(3, message.Content.Headers.ContentLength);

                    AssertDefaultHeaders(message);

                    stage++;
                    return new HttpResponseMessage(HttpStatusCode.NotFound);
                }
                // Create request
                if (stage == 1)
                {
                    Assert.Equal(HttpMethod.Put, message.Method);
                    Assert.Equal("https://host/container/blob/path?query=1", message.RequestUri.ToString());
                    Assert.Equal(0, message.Content.Headers.ContentLength);
                    Assert.Equal(new[] { "*" }, message.Headers.GetValues("If-None-Match"));

                    AssertDefaultHeaders(message);

                    stage++;
                    return new HttpResponseMessage(createStatusCode);
                }
                // First PUT request
                if (stage == 2)
                {
                    Assert.Equal(HttpMethod.Put, message.Method);
                    Assert.Equal("https://host/container/blob/path?query=1&comp=appendblock", message.RequestUri.ToString());
                    Assert.Equal(new byte[] { 0, 2, 3 }, await message.Content.ReadAsByteArrayAsync());
                    Assert.Equal(3, message.Content.Headers.ContentLength);

                    AssertDefaultHeaders(message);

                    stage++;
                    return new HttpResponseMessage(HttpStatusCode.Created);
                }
                throw new NotImplementedException();
            });

            var blob = new BlobAppendReferenceWrapper(_containerUrl, _blobName, new HttpClient(testMessageHandler));
            await blob.AppendAsync(new ArraySegment<byte>(new byte[] { 0, 2, 3 }), CancellationToken.None);

            Assert.Equal(3, stage);
        }

        [Fact]
        public async Task ThrowsForUnknownStatus()
        {
            var stage = 0;
            var testMessageHandler = new TestMessageHandler(async message =>
            {
                // First PUT request
                if (stage == 0)
                {
                    Assert.Equal(HttpMethod.Put, message.Method);
                    Assert.Equal("https://host/container/blob/path?query=1&comp=appendblock", message.RequestUri.ToString());
                    Assert.Equal(new byte[] { 0, 2, 3 }, await message.Content.ReadAsByteArrayAsync());
                    Assert.Equal(3, message.Content.Headers.ContentLength);

                    AssertDefaultHeaders(message);

                    stage++;
                    return new HttpResponseMessage(HttpStatusCode.InternalServerError);
                }

                throw new NotImplementedException();
            });

            var blob = new BlobAppendReferenceWrapper(_containerUrl, _blobName, new HttpClient(testMessageHandler));
            await Assert.ThrowsAsync<HttpRequestException>(() => blob.AppendAsync(new ArraySegment<byte>(new byte[] { 0, 2, 3 }), CancellationToken.None));

            Assert.Equal(1, stage);
        }

        [Fact]
        public async Task ThrowsForUnknownStatusDuringCreation()
        {
            var stage = 0;
            var testMessageHandler = new TestMessageHandler(async message =>
            {
                // First PUT request
                if (stage == 0)
                {
                    Assert.Equal(HttpMethod.Put, message.Method);
                    Assert.Equal("https://host/container/blob/path?query=1&comp=appendblock", message.RequestUri.ToString());
                    Assert.Equal(new byte[] { 0, 2, 3 }, await message.Content.ReadAsByteArrayAsync());
                    Assert.Equal(3, message.Content.Headers.ContentLength);

                    AssertDefaultHeaders(message);

                    stage++;
                    return new HttpResponseMessage(HttpStatusCode.NotFound);
                }
                // Create request
                if (stage == 1)
                {
                    Assert.Equal(HttpMethod.Put, message.Method);
                    Assert.Equal("https://host/container/blob/path?query=1", message.RequestUri.ToString());
                    Assert.Equal(0, message.Content.Headers.ContentLength);
                    Assert.Equal(new[] { "*" }, message.Headers.GetValues("If-None-Match"));

                    AssertDefaultHeaders(message);

                    stage++;
                    return new HttpResponseMessage(HttpStatusCode.InternalServerError);
                }

                throw new NotImplementedException();
            });

            var blob = new BlobAppendReferenceWrapper(_containerUrl, _blobName, new HttpClient(testMessageHandler));
            await Assert.ThrowsAsync<HttpRequestException>(() => blob.AppendAsync(new ArraySegment<byte>(new byte[] { 0, 2, 3 }), CancellationToken.None));

            Assert.Equal(2, stage);
        }


        private class TestMessageHandler : HttpMessageHandler
        {
            private readonly Func<HttpRequestMessage, Task<HttpResponseMessage>> _callback;

            public TestMessageHandler(Func<HttpRequestMessage, Task<HttpResponseMessage>> callback)
            {
                _callback = callback;
            }

            protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
            {
                return await _callback(request);
            }
        }
    }
}