server/extra/admin-api/Utilities/Spacebar.AdminApi.TestClient/Pages/UsersDelete.razor

@page "/Users/Delete/{Id}"
@using System.Net.Http.Headers
@using System.Text.Json
@using System.Text.Json.Nodes
@using ArcaneLibs.Extensions
@using Spacebar.AdminApi.Models
@using Spacebar.AdminApi.TestClient.Services
@inject Config Config
<h3>UsersDelete - @Id</h3>

Deleted @ChannelDeleteProgress.Sum(x=>x.Value.Deleted) messages so far!
@foreach (var (channel, progress) in ChannelDeleteProgress.Where(x=>x.Value.Deleted != x.Value.Total).OrderByDescending(x=>x.Value.Progress)) {
    <div>@channel: @progress.Total total, @progress.Deleted deleted</div>
    <progress max="@progress.Total" value="@progress.Deleted"></progress>
}

@if (Done) {
    <h1>Done!</h1>
}

@code {

    [Parameter]
    public required string Id { get; set; }

    private Dictionary<string, DeleteProgress> ChannelDeleteProgress { get; set; } = new();
    
    private bool Done { get; set; }

    protected override async Task OnInitializedAsync() {
        var hc = new StreamingHttpClient();
        hc.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", Config.AccessToken);
        var response = await hc.GetAsync(Config.AdminUrl + $"/_spacebar/admin/Users/{Id}/delete?messageDeleteChunkSize=100");
        if (!response.IsSuccessStatusCode) throw new Exception(await response.Content.ReadAsStringAsync());
        var content = response.Content.ReadFromJsonAsAsyncEnumerable<AsyncActionResult>();
        await foreach (var actionResult in content) {
            Console.WriteLine(actionResult.ToJson(indent: false));
            switch (actionResult.MessageType) {
                case "STATS": {
                    var data = JsonSerializer.Deserialize<JsonObject>(actionResult.Data.ToJson());
                    ChannelDeleteProgress = data!["messages_per_channel"]!
                        .Deserialize<Dictionary<string, int>>()!
                        .ToDictionary(x=>x.Key, x=>new DeleteProgress { Total = x.Value });
                    break;
                }
                case "BULK_DELETED": {
                    var data = JsonSerializer.Deserialize<JsonObject>(actionResult.Data.ToJson());
                    ChannelDeleteProgress[data!["channel_id"]!.ToString()].Deleted += data!["deleted"]!.GetValue<int>();
                    break;
                }
                default: {
                    Console.WriteLine($"Unknown message type: {actionResult.MessageType}");
                    break;
                }
            }
            
            StateHasChanged();
            await Task.Delay(1);
        }

        Done = true;
        StateHasChanged();
    }

    private class DeleteProgress {
        public int Total { get; set; }
        public int Deleted { get; set; } = 0;
        public float Progress => (float)Deleted / Total;
    }
}