import type { Context } from "jsr:@hono/hono@4";
import { rateLimitWrapper } from "./ratelimit.ts";
import { getAuthenticatedUser } from "./auth-session.ts";

// Middleware helper to get IP address
export function getClientIp(c: Context): string {
  // Check for X-Real-IP first
  const realIp = c.req.header("x-real-ip");
  if (realIp) {
    return realIp.trim();
  }

  // Fallback to X-Forwarded-For, bounded to prevent memory exhaustion
  let forwardedFor = c.req.header("x-forwarded-for");
  if (forwardedFor) {
    // Truncate to a max of 256 characters
    if (forwardedFor.length > 256) {
      forwardedFor = forwardedFor.substring(0, 256);
    }
    const parts = forwardedFor.split(",");
    // Extract the last untrusted hop (right-most IP)
    return parts[parts.length - 1].trim();
  }
  // Fallback (might not be accurate behind proxy without X-Forwarded-For)
  return "unknown-ip";
}

export const publicRateLimiter = async (
  c: Context,
  next: () => Promise<void>,
) => {
  const ip = getClientIp(c);
  const key = `ratelimit:public:${ip}`;
  const allowed = await rateLimitWrapper.checkRateLimit(key, 10, 60000);
  if (!allowed) {
    return c.json({ error: "Too Many Requests" }, 429);
  }
  await next();
};

export const adminRateLimiter = async (
  c: Context,
  next: () => Promise<void>,
) => {
  const auth = await getAuthenticatedUser(c);
  if (!auth) {
    return c.json({ error: "Missing or invalid session" }, 401);
  }

  const key = `ratelimit:admin:${auth.userId}`;
  const allowed = await rateLimitWrapper.checkRateLimit(key, 60, 60000);
  if (!allowed) {
    return c.json({ error: "Too Many Requests" }, 429);
  }

  // Stash userId in context so downstream routes can use it
  c.set("userId", auth.userId);
  await next();
};

// Also apply requireAdmin logic on the admin route by chaining it or exporting it.
// We'll export requireAdmin here or use it directly in the admin routes.