Files
snort/packages/app/src/chat/nip4.ts
2023-09-22 10:26:17 +01:00

108 lines
3.1 KiB
TypeScript

import { ExternalStore, FeedCache } from "@snort/shared";
import {
EventKind,
NostrEvent,
NostrPrefix,
RequestBuilder,
SystemInterface,
TLVEntryType,
encodeTLVEntries,
TaggedNostrEvent,
decodeTLV,
} from "@snort/system";
import { Chat, ChatSystem, ChatType, inChatWith, lastReadInChat } from "chat";
import { debug } from "debug";
export class Nip4ChatSystem extends ExternalStore<Array<Chat>> implements ChatSystem {
#cache: FeedCache<NostrEvent>;
#log = debug("NIP-04");
constructor(cache: FeedCache<NostrEvent>) {
super();
this.#cache = cache;
}
async onEvent(evs: readonly TaggedNostrEvent[]) {
const dms = evs.filter(a => a.kind === EventKind.DirectMessage && a.tags.some(b => b[0] === "p"));
if (dms.length > 0) {
await this.#cache.bulkSet(dms);
this.notifyChange();
}
}
subscription(pk: string) {
const rb = new RequestBuilder(`nip4:${pk.slice(0, 12)}`);
const dms = this.#cache.snapshot();
const dmSince = dms.reduce(
(acc, v) => (v.created_at > acc && v.kind === EventKind.DirectMessage ? (acc = v.created_at) : acc),
0,
);
this.#log("Loading DMS since %s", new Date(dmSince * 1000));
rb.withFilter().authors([pk]).kinds([EventKind.DirectMessage]).since(dmSince);
rb.withFilter().kinds([EventKind.DirectMessage]).tag("p", [pk]).since(dmSince);
return rb;
}
takeSnapshot(p: string) {
return this.listChats(p);
}
listChats(pk: string): Chat[] {
const myDms = this.#nip4Events();
const chats = myDms.reduce(
(acc, v) => {
const chatId = inChatWith(v, pk);
acc[chatId] ??= [];
acc[chatId].push(v);
return acc;
},
{} as Record<string, Array<NostrEvent>>,
);
return [...Object.entries(chats)].map(([k, v]) => Nip4ChatSystem.createChatObj(encodeTLVEntries("chat4" as NostrPrefix, {
type: TLVEntryType.Author,
value: k,
length: 32,
}), v));
}
static createChatObj(id: string, messages: Array<NostrEvent>) {
const last = lastReadInChat(id);
const participants = decodeTLV(id)
.filter(v => v.type === TLVEntryType.Author)
.map(v => ({
type: "pubkey",
id: v.value as string,
}));
return {
type: ChatType.DirectMessage,
id,
unread: messages.reduce((acc, v) => (v.created_at > last ? acc++ : acc), 0),
lastMessage: messages.reduce((acc, v) => (v.created_at > acc ? v.created_at : acc), 0),
participants,
messages: messages.map(m => ({
id: m.id,
created_at: m.created_at,
from: m.pubkey,
tags: m.tags,
content: "",
needsDecryption: true,
decrypt: async pub => {
return await pub.decryptDm(m);
},
})),
createMessage: async (msg, pub) => {
return await Promise.all(participants.map(v => pub.sendDm(msg, v.id)));
},
sendMessage: (ev, system: SystemInterface) => {
ev.forEach(a => system.BroadcastEvent(a));
},
} as Chat;
}
#nip4Events() {
return this.#cache.snapshot().filter(a => a.kind === EventKind.DirectMessage);
}
}