cordis/client/webapp/auto-verifier-with-args.ts

// Intended to be used with message lists

import { stringify } from "querystring";
import { AutoVerifier, AutoVerifierChangesType } from "./auto-verifier";
import { Changes, WithEquals } from "./data-types";

export interface PartialMessageListQuery {
	channelId: string;
	messageId: string | null;
	number: number;
}

export interface IDQuery {
	id: string;
}

export class AutoVerifierWithArg<T, K> {
	private tokenAutoVerifiers = new Map<string, AutoVerifier<T>>();
	private tokenQueries = new Map<string, K>();

	// TODO: Clear out old autoverifiers that haven't been used for a while.

	constructor(
		private tokenizer: (query: K) => string, // must be one-to-one mapping
		private primaryFunc: (query: K) => Promise<T | null>,
		private trustedFunc: (query: K) => Promise<T | null>,
		private verifyFunc: (query: K, primaryResult: T | null, trustedResult: T | null) => Promise<void>
	) {}

	static createStandardPartialMessageListAutoVerifier<T extends WithEquals<T> & { id: string }>(
		primaryFunc: (query: PartialMessageListQuery) => Promise<T[] | null>,
		trustedFunc: (query: PartialMessageListQuery) => Promise<T[] | null>,
		changesFunc: (query: PartialMessageListQuery, changesType: AutoVerifierChangesType, changes: Changes<T>) => Promise<void>
	) {
		return new AutoVerifierWithArg<T[], PartialMessageListQuery>(
			query => `ch#${query.channelId} m#${query.messageId}->${query.number}`,
			query => primaryFunc(query),
			query => trustedFunc(query),
			async (query: PartialMessageListQuery, primaryResult: T[] | null, trustedResult: T[] | null) => {
				let changes = AutoVerifier.getChanges<T>(primaryResult, trustedResult);
				let changesType = AutoVerifier.getListChangesType<T>(primaryResult, trustedResult, changes);
				await changesFunc(query, changesType, changes);
			}
		);
	}

	static createStandardIDQueriedSingleAutoVerifier<T extends WithEquals<T> & { id: string }>(
		primaryFunc: (query: IDQuery) => Promise<T | null>,
		trustedFunc: (query: IDQuery) => Promise<T | null>,
		changesFunc: (query: IDQuery, changesType: AutoVerifierChangesType, primaryResult: T | null, trustedResult: T | null) => Promise<void>
	) {
		return new AutoVerifierWithArg<T, IDQuery>(
			query => `id#${query.id}`,
			query => primaryFunc(query),
			query => trustedFunc(query),
			async (query: IDQuery, primaryResult: T | null, trustedResult: T | null) => {
				let changesType = AutoVerifier.getSingleChangesType<T>(primaryResult, trustedResult);
				await changesFunc(query, changesType, primaryResult, trustedResult);
			}
		);
	}

	unverifyAll(): void {
		for (let autoVerifier of this.tokenAutoVerifiers.values()) {
			autoVerifier.unverify();
		}
		this.tokenAutoVerifiers.clear();
		this.tokenQueries.clear();
	}

	unverifySome(toUnverifyFilter: (query: K) => boolean) {
		let tokensToUnverify = Array.from(this.tokenQueries.values())
			.filter(toUnverifyFilter)
			.map(query => this.tokenizer(query));
		for (let token of tokensToUnverify) {
			this.tokenAutoVerifiers.get(token)?.unverify();
			this.tokenAutoVerifiers.delete(token);
			this.tokenQueries.delete(token);
		}
	}

	async fetchAndVerifyIfNeded(query: K): Promise<T | null> {
		let token = this.tokenizer(query);
		this.tokenQueries.set(token, query);
		let autoVerifier = this.tokenAutoVerifiers.get(token);
		if (!autoVerifier) {
			autoVerifier = new AutoVerifier<T>(
				async () => await this.primaryFunc(query),
				async () => await this.trustedFunc(query),
				async (primaryResult: T | null, trustedResult: T | null) => await this.verifyFunc(query, primaryResult, trustedResult),
			);
			this.tokenAutoVerifiers.set(token, autoVerifier);
		}
		return await autoVerifier.fetchAndVerifyIfNeeded();
	}
}