Files
snort/src/Feed/Subscription.ts
2023-01-25 13:54:45 +00:00

139 lines
3.3 KiB
TypeScript

import { useEffect, useMemo, useReducer, useState } from "react";
import { System } from "Nostr/System";
import { TaggedRawEvent } from "Nostr";
import { Subscriptions } from "Nostr/Subscriptions";
import { debounce } from "Util";
export type NoteStore = {
notes: Array<TaggedRawEvent>,
end: boolean
};
export type UseSubscriptionOptions = {
leaveOpen: boolean
}
interface ReducerArg {
type: "END" | "EVENT" | "CLEAR",
ev?: TaggedRawEvent | Array<TaggedRawEvent>,
end?: boolean
}
function notesReducer(state: NoteStore, arg: ReducerArg) {
if (arg.type === "END") {
return {
notes: state.notes,
end: arg.end!
} as NoteStore;
}
if (arg.type === "CLEAR") {
return {
notes: [],
end: state.end,
} as NoteStore;
}
let evs = arg.ev!;
if (!Array.isArray(evs)) {
evs = [evs];
}
let existingIds = new Set(state.notes.map(a => a.id));
evs = evs.filter(a => !existingIds.has(a.id));
if (evs.length === 0) {
return state;
}
return {
notes: [
...state.notes,
...evs
]
} as NoteStore;
}
const initStore: NoteStore = {
notes: [],
end: false
};
export interface UseSubscriptionState {
store: NoteStore,
clear: () => void,
append: (notes: TaggedRawEvent[]) => void
}
/**
* Wait time before returning changed state
*/
const DebounceMs = 200;
/**
*
* @param {Subscriptions} sub
* @param {any} opt
* @returns
*/
export default function useSubscription(sub: Subscriptions | null, options?: UseSubscriptionOptions): UseSubscriptionState {
const [state, dispatch] = useReducer(notesReducer, initStore);
const [debounceOutput, setDebounceOutput] = useState<number>(0);
const [subDebounce, setSubDebounced] = useState<Subscriptions>();
useEffect(() => {
if (sub) {
return debounce(DebounceMs, () => {
setSubDebounced(sub);
});
}
}, [sub, options]);
useEffect(() => {
if (sub) {
sub.OnEvent = (e) => {
dispatch({
type: "EVENT",
ev: e
});
};
sub.OnEnd = (c) => {
if (!(options?.leaveOpen ?? false)) {
c.RemoveSubscription(sub.Id);
if (sub.IsFinished()) {
System.RemoveSubscription(sub.Id);
}
}
dispatch({
type: "END",
end: true
});
};
console.debug("Adding sub: ", sub.ToObject());
System.AddSubscription(sub);
return () => {
console.debug("Removing sub: ", sub.ToObject());
System.RemoveSubscription(sub.Id);
};
}
}, [subDebounce]);
useEffect(() => {
return debounce(DebounceMs, () => {
setDebounceOutput(s => s += 1);
});
}, [state]);
const stateDebounced = useMemo(() => state, [debounceOutput]);
return {
store: stateDebounced,
clear: () => {
dispatch({ type: "CLEAR" });
},
append: (n: TaggedRawEvent[]) => {
dispatch({
type: "EVENT",
ev: n
});
}
}
}