import { Injectable } from '@nestjs/common';

const WINDOW_MS = 60_000;
const MAX_PER_WINDOW = 10;

@Injectable()
export class RegistrationRateLimitService {
  private hits: Map<string, number[]> = new Map();

  isAllowed(ip: string, now: number = Date.now()): boolean {
    const arr = (this.hits.get(ip) ?? []).filter((t) => now - t < WINDOW_MS);
    this.hits.set(ip, arr);
    return arr.length < MAX_PER_WINDOW;
  }

  record(ip: string, now: number = Date.now()): void {
    const arr = (this.hits.get(ip) ?? []).filter((t) => now - t < WINDOW_MS);
    arr.push(now);
    this.hits.set(ip, arr);
  }

  tryConsume(ip: string, now: number = Date.now()): boolean {
    const arr = (this.hits.get(ip) ?? []).filter((t) => now - t < WINDOW_MS);
    if (arr.length >= MAX_PER_WINDOW) {
      this.hits.set(ip, arr);
      return false;
    }
    arr.push(now);
    this.hits.set(ip, arr);
    return true;
  }
}