なんかもうめっちゃ変えた

packages/backend/src/server/api/RateLimiterService.ts

@@ -0,0 +1,89 @@
+import { Inject, Injectable } from '@nestjs/common';
+import Limiter from 'ratelimiter';
+import Redis from 'ioredis';
+import { DI } from '@/di-symbols.js';
+import Logger from '@/logger.js';
+import type { IEndpointMeta } from './endpoints.js';
+
+const logger = new Logger('limiter');
+
+@Injectable()
+export class RateLimiterService {
+	constructor(
+		@Inject(DI.redis)
+		private redisClient: Redis.Redis,
+	) {
+	}
+
+	public limit(limitation: IEndpointMeta['limit'] & { key: NonNullable<string> }, actor: string) {
+		return new Promise<void>((ok, reject) => {
+			if (process.env.NODE_ENV === 'test') ok();
+			
+			// Short-term limit
+			const min = (): void => {
+				const minIntervalLimiter = new Limiter({
+					id: `${actor}:${limitation.key}:min`,
+					duration: limitation.minInterval,
+					max: 1,
+					db: this.redisClient,
+				});
+		
+				minIntervalLimiter.get((err, info) => {
+					if (err) {
+						return reject('ERR');
+					}
+		
+					logger.debug(`${actor} ${limitation.key} min remaining: ${info.remaining}`);
+		
+					if (info.remaining === 0) {
+						reject('BRIEF_REQUEST_INTERVAL');
+					} else {
+						if (hasLongTermLimit) {
+							max();
+						} else {
+							ok();
+						}
+					}
+				});
+			};
+		
+			// Long term limit
+			const max = (): void => {
+				const limiter = new Limiter({
+					id: `${actor}:${limitation.key}`,
+					duration: limitation.duration,
+					max: limitation.max,
+					db: this.redisClient,
+				});
+		
+				limiter.get((err, info) => {
+					if (err) {
+						return reject('ERR');
+					}
+		
+					logger.debug(`${actor} ${limitation.key} max remaining: ${info.remaining}`);
+		
+					if (info.remaining === 0) {
+						reject('RATE_LIMIT_EXCEEDED');
+					} else {
+						ok();
+					}
+				});
+			};
+		
+			const hasShortTermLimit = typeof limitation.minInterval === 'number';
+		
+			const hasLongTermLimit =
+				typeof limitation.duration === 'number' &&
+				typeof limitation.max === 'number';
+		
+			if (hasShortTermLimit) {
+				min();
+			} else if (hasLongTermLimit) {
+				max();
+			} else {
+				ok();
+			}
+		});
+	}
+}