Threads reloaded

[FedorLap2006]

So, seeing still ongoing problem with lack of threads implementation, I decided to make my own PR on them.
This PR should include everything that's on threads currently.

This PR also includes some code from #982 and #922 (it is meant to be continuation of those two, but written from scratch). So credits to the authors.

The roadmap

• Gateway
• REST
• State
  • CRUD
  • Membership

[FedorLap2006]

🚧 This is still under development

[FedorLap2006]

Woah, that went pretty fast. Anyways, should be everything now.

[FedorLap2006]

@CarsonHoffman Take a look

[orakaro]

Huge ++ to this work, and I would love to have Thread support on DiscordGo also. Appreciate if @CarsonHoffman could make this happen.

[orakaro]

Bumped! Thanks for your work and how is this going? I am looking forward to have Thread supported any time soon!

[FedorLap2006]

Bumped! Thanks for your work and how is this going? I am looking forward to have Thread supported any time soon!

Well, I think by now everything is finished, just waiting when @CarsonHoffman does review on this.

[trag-stripe]

@CarsonHoffman and @FedorLap2006 👋 - checking in if this pull is ready to go?
Thanks for building this project for the community and making all our lives easier!

[FedorLap2006]

@CarsonHoffman and @FedorLap2006 wave - checking in if this pull is ready to go? Thanks for building this project for the community and making all our lives easier!

Almost. If I didn't forget anything then it's gonna be only the LastMessageID thing and that will be it.

[omegasome]

So we're just waiting for @CarsonHoffman to provide their input on the LastMessageID thing?

[FedorLap2006]

So we're just waiting for @CarsonHoffman to provide their input on the LastMessageID thing?

Yes.

[srikanthrc]

This would be really cool extension to what the library already allows for. Would love to see this land sooner than later. @CarsonHoffman any chance we can bump this up in the queue of things to get to? thanks in advance,

[FedorLap2006]

@CarsonHoffman I think it's ready for the final review.

[shrapx]

@FedorLap2006 I found a missing threadID assignment intended here:
https://github.com/FedorLap2006/discordgo/blob/threads/restapi.go#L2223

(added snippet)

func (s *Session) WebhookThreadExecute(webhookID, token string, wait bool, threadID string, data *WebhookParams) (st *Message, err error) {
  return s.webhookExecute(webhookID, token, wait, "", data)
}

[FedorLap2006]

After deeper reading of Discord's documentation and our current source code, I've come to the conclusion that Carson with right, about LastMessageID and it should not be changed. On other hand I will open a PR so it would be easier to work this out

[FedorLap2006]

There are a couple of problems (it deletes some threads rest methods) with merge of master.
I'm going to resolve them in a couple of hours.
Please don't update the branch until I fix these issues, they will break your code.