// 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.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using FormatterWebSite;
using Newtonsoft.Json;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.FunctionalTests
{
    public class JsonPatchSampleTest : IClassFixture<MvcTestFixture<Startup>>
    {
        public JsonPatchSampleTest(MvcTestFixture<Startup> fixture)
        {
            Client = fixture.Client;
        }

        public HttpClient Client { get; }

        [Fact]
        public async Task AddOperation_Works()
        {
            // Arrange
            var input = "[{ 'op': 'add', 'path': 'Reviews/-', 'value': { 'Rating': 3.5 }}]".Replace("'", "\"");
            var request = GetPatchRequest(input);

            // Act
            var response = await Client.SendAsync(request);

            // Assert
            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
            var body = await response.Content.ReadAsStringAsync();
            var product = JsonConvert.DeserializeObject<Product>(body);
            Assert.NotNull(product);
            Assert.NotNull(product.Reviews);
            Assert.Equal(3, product.Reviews.Count);
            Assert.Equal(3.5, product.Reviews[2].Rating);
        }

        [Fact]
        public async Task ReplaceOperation_Works()
        {
            // Arrange
            var input = "[{ 'op': 'replace', 'path': 'Reviews/0/Rating', 'value': 5 }]".Replace("'", "\"");
            var request = GetPatchRequest(input);

            // Act
            var response = await Client.SendAsync(request);

            // Assert
            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
            var body = await response.Content.ReadAsStringAsync();
            var product = JsonConvert.DeserializeObject<Product>(body);
            Assert.NotNull(product);
            Assert.NotNull(product.Reviews);
            Assert.Equal(2, product.Reviews.Count);
            Assert.Equal(5, product.Reviews[0].Rating);
        }

        [Fact]
        public async Task CopyOperation_Works()
        {
            // Arrange
            var input = "[{ 'op': 'copy', 'path': 'Reviews/1/Rating', 'from': 'Reviews/0/Rating'}]".Replace("'", "\"");
            var request = GetPatchRequest(input);

            // Act
            var response = await Client.SendAsync(request);

            // Assert
            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
            var body = await response.Content.ReadAsStringAsync();
            var product = JsonConvert.DeserializeObject<Product>(body);
            Assert.NotNull(product);
            Assert.NotNull(product.Reviews);
            Assert.Equal(2, product.Reviews.Count);
            Assert.Equal(4, product.Reviews[1].Rating);
            Assert.Equal(4, product.Reviews[0].Rating);
        }

        [Fact]
        public async Task MoveOperation_Works()
        {
            // Arrange
            var input = "[{ 'op': 'move', 'path': 'Reviews/1/Rating', 'from': 'Reviews/0/Rating'}]".Replace("'", "\"");
            var request = GetPatchRequest(input);

            // Act
            var response = await Client.SendAsync(request);

            // Assert
            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
            var body = await response.Content.ReadAsStringAsync();
            var product = JsonConvert.DeserializeObject<Product>(body);
            Assert.NotNull(product);
            Assert.NotNull(product.Reviews);
            Assert.Equal(2, product.Reviews.Count);
            Assert.Equal(4, product.Reviews[1].Rating);
            Assert.Equal(0, product.Reviews[0].Rating);
        }

        [Fact]
        public async Task RemoveOperation_Works()
        {
            // Arrange
            var input = "[{ 'op': 'remove', 'path': 'Reviews/0/Rating'}]".Replace("'", "\"");
            var request = GetPatchRequest(input);

            // Act
            var response = await Client.SendAsync(request);

            // Assert
            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
            var body = await response.Content.ReadAsStringAsync();
            var product = JsonConvert.DeserializeObject<Product>(body);
            Assert.NotNull(product);
            Assert.NotNull(product.Reviews);
            Assert.Equal(2, product.Reviews.Count);
            Assert.Equal(0, product.Reviews[0].Rating);
        }

        [Fact]
        public async Task AddOperation_InvalidValueForProperty_AddsErrorToModelState()
        {
            // Arrange
            var input = "[{ 'op': 'add', 'path': 'Reviews/-', 'value': { 'Rating': 'not-a-double' }}]".Replace("'", "\"");
            var request = GetPatchRequest(input);

            // Act
            var response = await Client.SendAsync(request);

            // Assert
            Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
        }

        [Fact]
        public async Task InvalidOperation_AddsErrorToModelState()
        {
            // Arrange
            var input = "[{ 'op': 'invalid', 'path': 'Reviews/1/Rating', 'from': 'Reviews/0/Rating'}]".Replace("'", "\"");
            var request = GetPatchRequest(input);

            // Act
            var response = await Client.SendAsync(request);

            // Assert
            Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
        }

        private HttpRequestMessage GetPatchRequest(string body)
        {
            return new HttpRequestMessage
            {
                Content = new StringContent(body, Encoding.UTF8, "application/json-patch+json"),
                Method = new HttpMethod("PATCH"),
                RequestUri = new Uri("http://localhost/jsonpatch/PatchProduct")
            };
        }
    }
}