// 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.

#if DNX451

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNet.Http;
using Microsoft.AspNet.Http.Internal;
using Microsoft.AspNet.Mvc.ModelBinding.Validation;
using Microsoft.Net.Http.Headers;
using Moq;
using Xunit;

namespace Microsoft.AspNet.Mvc.ModelBinding
{
    public class FormFileModelBinderTest
    {
        [Fact]
        public async Task FormFileModelBinder_SuppressesValidation()
        {
            // Arrange
            var formFiles = new FormFileCollection();
            formFiles.Add(GetMockFormFile("file", "file1.txt"));
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));
            var bindingContext = GetBindingContext(typeof(IEnumerable<IFormFile>), httpContext);
            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            Assert.True(result.IsModelSet);

            var entry = bindingContext.ValidationState[result.Model];
            Assert.True(entry.SuppressValidation);
            Assert.Null(entry.Key);
            Assert.Null(entry.Metadata);
        }

        [Fact]
        public async Task FormFileModelBinder_ExpectMultipleFiles_BindSuccessful()
        {
            // Arrange
            var formFiles = new FormFileCollection();
            formFiles.Add(GetMockFormFile("file", "file1.txt"));
            formFiles.Add(GetMockFormFile("file", "file2.txt"));
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));
            var bindingContext = GetBindingContext(typeof(IEnumerable<IFormFile>), httpContext);
            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            Assert.True(result.IsModelSet);

            var entry = bindingContext.ValidationState[result.Model];
            Assert.True(entry.SuppressValidation);
            Assert.Null(entry.Key);
            Assert.Null(entry.Metadata);

            var files = Assert.IsAssignableFrom<IList<IFormFile>>(result.Model);
            Assert.Equal(2, files.Count);
        }

        [Fact]
        public async Task FormFileModelBinder_FilesWithQuotedContentDisposition_BindSuccessful()
        {
            // Arrange
            var formFiles = new FormFileCollection();
            formFiles.Add(GetMockFormFileWithQuotedContentDisposition("file", "file1.txt"));
            formFiles.Add(GetMockFormFileWithQuotedContentDisposition("file", "file2.txt"));
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));
            var bindingContext = GetBindingContext(typeof(IEnumerable<IFormFile>), httpContext);
            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            var files = Assert.IsAssignableFrom<IList<IFormFile>>(result.Model);
            Assert.Equal(2, files.Count);
        }

        [Fact]
        public async Task FormFileModelBinder_ExpectSingleFile_BindFirstFile()
        {
            // Arrange
            var formFiles = new FormFileCollection();
            formFiles.Add(GetMockFormFile("file", "file1.txt"));
            formFiles.Add(GetMockFormFile("file", "file2.txt"));
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));
            var bindingContext = GetBindingContext(typeof(IFormFile), httpContext);
            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            var file = Assert.IsAssignableFrom<IFormFile>(result.Model);
            Assert.Equal("form-data; name=file; filename=file1.txt",
                         file.ContentDisposition);
        }

        [Fact]
        public async Task FormFileModelBinder_ReturnsNoResult_WhenNoFilePosted()
        {
            // Arrange
            var formFiles = new FormFileCollection();
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));
            var bindingContext = GetBindingContext(typeof(IFormFile), httpContext);
            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            Assert.Null(result.Model);
        }

        [Fact]
        public async Task FormFileModelBinder_ReturnsNoResult_WhenNamesDontMatch()
        {
            // Arrange
            var formFiles = new FormFileCollection();
            formFiles.Add(GetMockFormFile("different name", "file1.txt"));
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));
            var bindingContext = GetBindingContext(typeof(IFormFile), httpContext);
            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            Assert.Null(result.Model);
        }

        [Theory]
        [InlineData(true, "FieldName")]
        [InlineData(false, "ModelName")]
        public async Task FormFileModelBinder_UsesFieldNameForTopLevelObject(bool isTopLevel, string expected)
        {
            // Arrange
            var formFiles = new FormFileCollection();
            formFiles.Add(GetMockFormFile("FieldName", "file1.txt"));
            formFiles.Add(GetMockFormFile("ModelName", "file1.txt"));
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));

            var bindingContext = GetBindingContext(typeof(IFormFile), httpContext);
            bindingContext.IsTopLevelObject = isTopLevel;
            bindingContext.FieldName = "FieldName";
            bindingContext.ModelName = "ModelName";

            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            Assert.True(result.IsModelSet);
            var file = Assert.IsAssignableFrom<IFormFile>(result.Model);
            
            ContentDispositionHeaderValue contentDisposition;
            ContentDispositionHeaderValue.TryParse(file.ContentDisposition, out contentDisposition);
            Assert.Equal(expected, contentDisposition.Name);
        }

        [Fact]
        public async Task FormFileModelBinder_ReturnsNoResult_WithEmptyContentDisposition()
        {
            // Arrange
            var formFiles = new FormFileCollection();
            formFiles.Add(new Mock<IFormFile>().Object);
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));
            var bindingContext = GetBindingContext(typeof(IFormFile), httpContext);
            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            Assert.Null(result.Model);
        }

        [Fact]
        public async Task FormFileModelBinder_ReturnsNoResult_WithNoFileNameAndZeroLength()
        {
            // Arrange
            var formFiles = new FormFileCollection();
            formFiles.Add(GetMockFormFile("file", ""));
            var httpContext = GetMockHttpContext(GetMockFormCollection(formFiles));
            var bindingContext = GetBindingContext(typeof(IFormFile), httpContext);
            var binder = new FormFileModelBinder();

            // Act
            var result = await binder.BindModelAsync(bindingContext);

            // Assert
            Assert.NotEqual(ModelBindingResult.NoResult, result);
            Assert.Null(result.Model);
        }

        private static ModelBindingContext GetBindingContext(Type modelType, HttpContext httpContext)
        {
            var metadataProvider = new EmptyModelMetadataProvider();
            var bindingContext = new ModelBindingContext
            {
                ModelMetadata = metadataProvider.GetMetadataForType(modelType),
                ModelName = "file",
                ModelState = new ModelStateDictionary(),
                OperationBindingContext = new OperationBindingContext
                {
                    ActionContext = new ActionContext()
                    {
                        HttpContext = httpContext,
                    },
                    ModelBinder = new FormFileModelBinder(),
                    MetadataProvider = metadataProvider,
                },
                ValidationState = new ValidationStateDictionary(),
            };

            return bindingContext;
        }

        private static HttpContext GetMockHttpContext(IFormCollection formCollection)
        {
            var httpContext = new Mock<HttpContext>();
            httpContext.Setup(h => h.Request.ReadFormAsync(It.IsAny<CancellationToken>()))
                .Returns(Task.FromResult(formCollection));
            httpContext.Setup(h => h.Request.HasFormContentType).Returns(true);
            return httpContext.Object;
        }

        private static IFormCollection GetMockFormCollection(FormFileCollection formFiles)
        {
            var formCollection = new Mock<IFormCollection>();
            formCollection.Setup(f => f.Files).Returns(formFiles);
            return formCollection.Object;
        }

        private static IFormFile GetMockFormFile(string modelName, string filename)
        {
            var formFile = new Mock<IFormFile>();
            formFile.Setup(f => f.ContentDisposition)
                .Returns(string.Format("form-data; name={0}; filename={1}", modelName, filename));
            return formFile.Object;
        }

        private static IFormFile GetMockFormFileWithQuotedContentDisposition(string modelName, string filename)
        {
            var formFile = new Mock<IFormFile>();
            formFile.Setup(f => f.ContentDisposition)
                .Returns(string.Format("form-data; name=\"{0}\"; filename=\"{1}\"", modelName, filename));
            return formFile.Object;
        }
    }
}

#endif