import config from "../config.ts";

interface Bucket {
    count: number;
    resetAt: number;
}

const buckets = new Map<string, Bucket>();
let sweepCounter = 0;

function maybeSweep() {
    if (++sweepCounter < 1000) return;
    sweepCounter = 0;
    const now = Date.now();
    for (const [key, bucket] of buckets) {
        if (now > bucket.resetAt) buckets.delete(key);
    }
}

export function checkRateLimit(
    ip: string | null,
    maxRequests: number,
    windowMs: number,
): boolean {
    if (config.RATE_LIMIT_DISABLED || !ip) return true;
    const now = Date.now();
    const bucket = buckets.get(ip);
    if (!bucket || now > bucket.resetAt) {
        buckets.set(ip, { count: 1, resetAt: now + windowMs });
        maybeSweep();
        return true;
    }
    if (bucket.count >= maxRequests) return false;
    bucket.count++;
    return true;
}

export function getClientIp(
    request: Request,
    server: Bun.Server<unknown> | null,
): string | null {
    if (config.TRUSTED_PROXY) {
        return (
            request.headers.get("x-forwarded-for")?.split(",")[0]?.trim() ??
            null
        );
    }
    return server?.requestIP(request)?.address ?? null;
}