// 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.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading;
using System.Threading.Tasks;
using AngleSharp;
using AngleSharp.Dom;
using AngleSharp.Dom.Html;
using AngleSharp.Network;
using AngleSharp.Parser.Html;
using Xunit;

namespace AuthSamples.FunctionalTests
{
    // Merged HtmlAssert + ResponseAssert from Identity functional tests
    public class TestAssert
    {
        public static IHtmlFormElement HasForm(IHtmlDocument document)
        {
            var form = Assert.Single(document.QuerySelectorAll("form"));
            return Assert.IsAssignableFrom<IHtmlFormElement>(form);
        }

        public static IHtmlAnchorElement HasLink(string selector, IHtmlDocument document)
        {
            var element = Assert.Single(document.QuerySelectorAll(selector));
            return Assert.IsAssignableFrom<IHtmlAnchorElement>(element);
        }

        internal static IEnumerable<IHtmlElement> HasElements(string selector, IHtmlDocument document)
        {
            var elements = document
                .QuerySelectorAll(selector)
                .OfType<IHtmlElement>()
                .ToArray();

            Assert.NotEmpty(elements);

            return elements;
        }

        public static IHtmlElement HasElement(string selector, IParentNode document)
        {
            var element = Assert.Single(document.QuerySelectorAll(selector));
            return Assert.IsAssignableFrom<IHtmlElement>(element);
        }

        public static IHtmlFormElement HasForm(string selector, IParentNode document)
        {
            var form = Assert.Single(document.QuerySelectorAll(selector));
            return Assert.IsAssignableFrom<IHtmlFormElement>(form);
        }

        internal static IHtmlHtmlElement IsHtmlFragment(string htmlMessage)
        {
            var synteticNode = $"<div>{htmlMessage}</div>";
            var fragment = Assert.Single(new HtmlParser().ParseFragment(htmlMessage, context: null));
            return Assert.IsAssignableFrom<IHtmlHtmlElement>(fragment);
        }

        public static Uri IsRedirect(HttpResponseMessage responseMessage)
        {
            Assert.Equal(HttpStatusCode.Redirect, responseMessage.StatusCode);
            return responseMessage.Headers.Location;
        }

        public static async Task<IHtmlDocument> IsHtmlDocumentAsync(HttpResponseMessage response)
        {
            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
            Assert.Equal("text/html", response.Content.Headers.ContentType.MediaType);
            var content = await response.Content.ReadAsStringAsync();
            var document = await BrowsingContext.New()
                .OpenAsync(ResponseFactory, CancellationToken.None);
            return Assert.IsAssignableFrom<IHtmlDocument>(document);

            void ResponseFactory(VirtualResponse htmlResponse)
            {
                htmlResponse
                    .Address(response.RequestMessage.RequestUri)
                    .Status(response.StatusCode);

                MapHeaders(response.Headers);
                MapHeaders(response.Content.Headers);

                htmlResponse.Content(content);

                void MapHeaders(HttpHeaders headers)
                {
                    foreach (var header in headers)
                    {
                        foreach (var value in header.Value)
                        {
                            htmlResponse.Header(header.Key, value);
                        }
                    }
                }
            }
        }

        internal static void IsOK(HttpResponseMessage download)
            => Assert.Equal(HttpStatusCode.OK, download.StatusCode);
    }
}