server/extra/admin-api/Utilities/Spacebar.Client/Pages/Channels/GuildChannel.razor

@page "/channels/{GuildId:long}/{ChannelId:long}"
@page "/channels/{GuildId:long}/{ChannelId:long}/{MessageId:long}"
@using System.Collections.ObjectModel
@using ArcaneLibs.Blazor.Components.Services
@using ArcaneLibs.Extensions
@using Spacebar.Client.Components
@using Spacebar.Models.Gateway
@using Spacebar.Models.Generic
@inject JsConsoleService jsConsole

<style>@_guildCss</style>
<ChannelMessageList Messages="@_messages"></ChannelMessageList>

@code {

    private ObservableCollection<Message> _messages { get; set; } = [];
    private string _guildCss = "";

    [Parameter]
    public long GuildId { get; set; }

    [Parameter]
    public long ChannelId { get; set; }

    [Parameter]
    public long? MessageId { get; set; }

    protected override async Task OnInitializedAsync() {
        var cid = ChannelId;
        Console.WriteLine($"OIA GuildChannel(g={GuildId},c={ChannelId},m={MessageId})");
        await (App.ClientManager.ClientAvailable ?? Task.CompletedTask);
        if (MessageId is null) {
            App.ClientManager.Client?.Gateway.OnceGatewayMessage.Add(async evt => {
                if (evt is { Opcode: GatewayOpcode.S2CDispatch, DispatchEventType: "MESSAGE_CREATE" }) {
                    if (evt.EventData["channel_id"].GetValue<string>() != ChannelId.ToString()) return false;
                    await jsConsole.Info("Current channel message:", evt);
                    var msg = evt.GetData<Message>();
                    await jsConsole.Info("... typed:", msg);
                    _messages.Add(msg);
                    StateHasChanged();
                }

                return cid != ChannelId;
            });
            await (App.ClientManager.ClientReady ?? Task.CompletedTask);
            _messages = new ObservableCollection<Message>(Enumerable.Reverse(await App.ClientManager.Client.GetChannel(ChannelId).GetMessagesAsync(
                before: App.ClientManager.ClientState.Guilds[GuildId].Channels.First(x => x.Id == ChannelId).LastMessageId + 1,
                limit: 100
            )));

            // build role color css...
            _guildCss = "";
            foreach (var role in App.ClientManager.ClientState.Guilds[GuildId].Roles) {
                _guildCss += $$"""
                               .role_{{role.Id}} {
                                 color: #{{role.Colors.PrimaryColor.ToString("X6")}};
                               }

                               """;
            }
        }
    }

    public override async Task SetParametersAsync(ParameterView parameters) {
        bool reset = false;
        if (parameters.GetValueOrDefault<long>("ChannelId") != ChannelId) reset = true;

        await base.SetParametersAsync(parameters);
        if (reset) await OnInitializedAsync();
    }

}