HubIdentifier.cs

using System;
using System.Threading.Tasks;

namespace SlackNet.Bot;

[Obsolete("Use ConversationIdentifier instead")]
public abstract class HubIdentifier
{
    public abstract Task<string> HubId(ISlackBot bot);
        
    public static implicit operator HubIdentifier(string name) => 
        name?[0] == '@' ? new ImByName(name)
        : name?[0] == '#' ? (HubIdentifier)new ChannelByName(name)
        : new GroupByName(name);

    public static implicit operator HubIdentifier(Hub hub) => new HubByRef(hub);
        
    public static implicit operator HubIdentifier(Conversation conversation) => new HubByConversationIdentifier(conversation);
    public static implicit operator HubIdentifier(ConversationIdentifier conversationIdentifier) => new HubByConversationIdentifier(conversationIdentifier);
}

[Obsolete("Use ConversationByRef instead")]
public class HubByRef : HubIdentifier
{
    private readonly Hub _hub;
    public HubByRef(Hub hub) => _hub = hub;

    public override Task<string> HubId(ISlackBot bot) => Task.FromResult(_hub.Id);
}

[Obsolete("Use ConversationByName instead")]
public class ChannelByName : HubIdentifier
{
    private readonly string _name;
    public ChannelByName(string name) => _name = name;
        
    public override Task<string> HubId(ISlackBot bot) => Task.FromResult(_name);
}

[Obsolete("Use ConversationByName instead")]
public class GroupByName : HubIdentifier
{
    private readonly string _name;
    public GroupByName(string name) => _name = name;
        
    public override Task<string> HubId(ISlackBot bot) => Task.FromResult(_name);
}

[Obsolete("Use ConversationByName instead")]
public class ImByName : HubIdentifier
{
    private readonly string _name;
    public ImByName(string name) => _name = name;

    public override async Task<string> HubId(ISlackBot bot) => (await bot.GetImByName(_name.Substring(1)).ConfigureAwait(false)).Id;
}

class HubByConversationIdentifier : HubIdentifier
{
    private readonly ConversationIdentifier _conversationIdentifier;
    public HubByConversationIdentifier(ConversationIdentifier conversationIdentifier) => _conversationIdentifier = conversationIdentifier;
        
    public override Task<string> HubId(ISlackBot bot) => _conversationIdentifier.ConversationId(bot);
}