// 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;
using System.Collections.Generic;
using System.Globalization;
using Microsoft.AspNetCore.Http.Features;
using Microsoft.Extensions.Primitives;
using Xunit;

namespace Microsoft.AspNetCore.Http.Internal
{
    public class DefaultHttpResponseTests
    {
        [Theory]
        [InlineData(0)]
        [InlineData(9001)]
        [InlineData(65535)]
        public void GetContentLength_ReturnsParsedHeader(long value)
        {
            // Arrange
            var response = GetResponseWithContentLength(value.ToString(CultureInfo.InvariantCulture));

            // Act and Assert
            Assert.Equal(value, response.ContentLength);
        }

        [Fact]
        public void GetContentLength_ReturnsNullIfHeaderDoesNotExist()
        {
            // Arrange
            var response = GetResponseWithContentLength(contentLength: null);

            // Act and Assert
            Assert.Null(response.ContentLength);
        }

        [Theory]
        [InlineData("cant-parse-this")]
        [InlineData("-1000")]
        [InlineData("1000.00")]
        [InlineData("100/5")]
        public void GetContentLength_ReturnsNullIfHeaderCannotBeParsed(string contentLength)
        {
            // Arrange
            var response = GetResponseWithContentLength(contentLength);

            // Act and Assert
            Assert.Null(response.ContentLength);
        }

        [Fact]
        public void GetContentType_ReturnsNullIfHeaderDoesNotExist()
        {
            // Arrange
            var response = GetResponseWithContentType(contentType: null);

            // Act and Assert
            Assert.Null(response.ContentType);
        }

        private static HttpResponse CreateResponse(IHeaderDictionary headers)
        {
            var context = new DefaultHttpContext();
            context.Features.Get<IHttpResponseFeature>().Headers = headers;
            return context.Response;
        }

        private static HttpResponse GetResponseWithContentLength(string contentLength = null)
        {
            return GetResponseWithHeader("Content-Length", contentLength);
        }

        private static HttpResponse GetResponseWithContentType(string contentType = null)
        {
            return GetResponseWithHeader("Content-Type", contentType);
        }

        private static HttpResponse GetResponseWithHeader(string headerName, string headerValue)
        {
            var headers = new HeaderDictionary();
            if (headerValue != null)
            {
                headers.Add(headerName, headerValue);
            }

            return CreateResponse(headers);
        }
    }
}