@using System.Net
@using System.Net.Http
@using Microsoft.AspNetCore.Blazor.Browser.Http
@inject HttpClient Http

<h1>HTTP request tester</h1>

<p>
    <div>URI:</div>
    <input id="request-uri" bind="@uri" size="60"/>
</p>

<p>
    <div>Method:</div>
    <select id="request-method" bind="@method">
        <option value="GET">GET</option>
        <option value="POST">POST</option>
        <option value="PUT">PUT</option>
        <option value="DELETE">DELETE</option>
    </select>
</p>

<p>
    <div>Request body:</div>
    <textarea id="request-body" bind="@requestBody"></textarea>
</p>

<p>
    <div>Request headers:</div>
    @foreach (var header in requestHeaders)
    {
        <div class="header-entry">
            Name: <input bind="@header.Name" />
            Value: <input bind="@header.Value" />
            [<a href="#" onclick="@(e => RemoveHeader(header))">remove</a>]
        </div>
    }
    <button id="add-header" onclick="@AddHeader">Add</button>
</p>

<p>
    <div>Request referrer:</div>
    <input id="request-referrer" type="text" bind=@requestReferrer />
</p>

<button id="send-request" onclick="@DoRequest">Request</button>

@if (responseStatusCode.HasValue)
{
    <h2>Response</h2>
    <p><div>Status:</div><span id="response-status">@responseStatusCode</span></p>
    <p><div>Body:</div><textarea id="response-body" readonly>@responseBody</textarea></p>
    <p><div>Headers:</div><textarea id="response-headers" readonly>@responseHeaders</textarea></p>
}

<style type="text/css">
    textarea {
        width: 100%;
        height: 60px;
    }
</style>

@functions {
    string uri = "http://api.icndb.com/jokes/random";
    string method = "GET";
    string requestBody = "";
    List<RequestHeader> requestHeaders = new List<RequestHeader>();
    string requestReferrer = "";

    HttpStatusCode? responseStatusCode;
    string responseBody;
    string responseHeaders;

    async void DoRequest()
    {
        responseStatusCode = null;

        try
        {
            var requestMessage = new HttpRequestMessage()
            {
                Method = new HttpMethod(method),
                RequestUri = new Uri(uri),
                Content = string.IsNullOrEmpty(requestBody)
                    ? null
                    : new StringContent(requestBody)
            };

            foreach (var header in requestHeaders)
            {
                // StringContent automatically adds its own Content-Type header with default value "text/plain"
                // If the developer is trying to specify a content type explicitly, we need to replace the default value,
                // rather than adding a second Content-Type header.
                if (header.Name.Equals("Content-Type", StringComparison.OrdinalIgnoreCase) && requestMessage.Content != null)
                {
                    requestMessage.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue(header.Value);
                    continue;
                }

                if (!requestMessage.Headers.TryAddWithoutValidation(header.Name, header.Value))
                {
                    requestMessage.Content?.Headers.TryAddWithoutValidation(header.Name, header.Value);
                }
            }

            if (!string.IsNullOrEmpty(requestReferrer))
            {
                requestMessage.Properties[BrowserHttpMessageHandler.FetchArgs] = new
                {
                    referrer = requestReferrer
                };
            }

            var response = await Http.SendAsync(requestMessage);
            responseStatusCode = response.StatusCode;
            responseBody = await response.Content.ReadAsStringAsync();
            var allHeaders = response.Headers.Concat(response.Content?.Headers
                ?? Enumerable.Empty<KeyValuePair<string, IEnumerable<string>>>());
            responseHeaders = string.Join(
                Environment.NewLine,
                allHeaders.Select(pair => $"{pair.Key}: {pair.Value.First()}").ToArray());
        }
        catch (Exception ex)
        {
            if (ex is AggregateException)
            {
                ex = ex.InnerException;
            }
            responseStatusCode = HttpStatusCode.SeeOther;
            responseBody = ex.Message + Environment.NewLine + ex.StackTrace;
        }

        StateHasChanged();
    }

    void AddHeader()
        => requestHeaders.Add(new RequestHeader());

    void RemoveHeader(RequestHeader header)
        => requestHeaders.Remove(header);

    class RequestHeader
    {
        public string Name { get; set; }
        public string Value { get; set; }
    }
}