sdk: add support to NIP17 relay list

[yukibtc]

When gossip option is enabled, automatically get NIP17 relay list for sending private DMs.

[reyamir]

I think we can support NIP17 relay list for fetching the gift wrap event too

[reyamir]

Hi @yukibtc , I wonder are you working on it? I will try implement it on tomorrow and submit a PR

[yukibtc]

Hi @yukibtc , I wonder are you working on it? I will try implement it on tomorrow and submit a PR

I'm working on it right now

[yukibtc]

Currently, when gossip is enabled, the events are sent to the INBOX and OUTBOX relays, but also to the WRITE ones (the manually added with Client::add_relay or Client::add_write_relay). In your opinion this should happen also with the NIP17?

[reyamir]

I think we should skip the WRITE relays, only send to NIP17 relays. Unlike normal event, dm event should pretty strict where to stored.

Some clients are social media + direct message both, the WRITE relays maybe isn't related to store dms.

[yukibtc]

I think we can support NIP17 relay list for fetching the gift wrap event too

I think I'll always use NIP17 + NIP65 relays to fetch events with gossip enabled. The alternative is to check if exists a Kind::GiftWrap in the Filter, but this will create issues when requesting all events of a public key or getting event by IDs without including the Kind (DMs from NIP17 relays will not be returned).

[yukibtc]

I opened the PR #642
I haven't tested it yet. If you have the chance, let me know if you notice any issues.