indiekit-endpoint-activitypub/lib/mastodon/router.js

/**
 * Mastodon Client API — main router.
 *
 * Combines all sub-routers, applies CORS and error handling middleware.
 * Mounted at "/" via Indiekit.addEndpoint() so Mastodon clients can access
 * /api/v1/*, /api/v2/*, /oauth/* at the domain root.
 */
import express from "express";
import rateLimit from "express-rate-limit";
import { corsMiddleware } from "./middleware/cors.js";
import { tokenRequired, optionalToken } from "./middleware/token-required.js";
import { errorHandler, notImplementedHandler } from "./middleware/error-handler.js";

// Route modules
import oauthRouter from "./routes/oauth.js";
import instanceRouter from "./routes/instance.js";
import accountsRouter from "./routes/accounts.js";
import statusesRouter from "./routes/statuses.js";
import timelinesRouter from "./routes/timelines.js";
import notificationsRouter from "./routes/notifications.js";
import searchRouter from "./routes/search.js";
import mediaRouter from "./routes/media.js";
import stubsRouter from "./routes/stubs.js";

// Rate limiters for different endpoint categories
const apiLimiter = rateLimit({
  windowMs: 5 * 60 * 1000, // 5 minutes
  max: 300,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: "Too many requests, please try again later" },
});

const authLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 30,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: "Too many authentication attempts" },
});

const appRegistrationLimiter = rateLimit({
  windowMs: 60 * 60 * 1000, // 1 hour
  max: 25,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: "Too many app registrations" },
});

/**
 * Create the combined Mastodon API router.
 *
 * @param {object} options
 * @param {object} options.collections - MongoDB collections object
 * @param {object} [options.pluginOptions] - Plugin options (handle, etc.)
 * @returns {import("express").Router} Express router
 */
export function createMastodonRouter({ collections, pluginOptions = {} }) {
  const router = express.Router(); // eslint-disable-line new-cap

  // ─── Body parsers ───────────────────────────────────────────────────────
  // Mastodon clients send JSON, form-urlencoded, and occasionally text/plain.
  // These must be applied before route handlers.
  router.use("/api", express.json());
  router.use("/api", express.urlencoded({ extended: true }));
  router.use("/oauth", express.json());
  router.use("/oauth", express.urlencoded({ extended: true }));

  // ─── CORS ───────────────────────────────────────────────────────────────
  router.use("/api", corsMiddleware);
  router.use("/oauth/token", corsMiddleware);
  router.use("/oauth/revoke", corsMiddleware);
  router.use("/.well-known/oauth-authorization-server", corsMiddleware);

  // ─── Rate limiting ─────────────────────────────────────────────────────
  router.use("/api", apiLimiter);
  router.use("/oauth/token", authLimiter);
  router.use("/api/v1/apps", appRegistrationLimiter);

  // ─── Inject collections + plugin options into req ───────────────────────
  router.use("/api", (req, res, next) => {
    req.app.locals.mastodonCollections = collections;
    req.app.locals.mastodonPluginOptions = pluginOptions;
    next();
  });
  router.use("/oauth", (req, res, next) => {
    req.app.locals.mastodonCollections = collections;
    req.app.locals.mastodonPluginOptions = pluginOptions;
    next();
  });
  router.use("/.well-known/oauth-authorization-server", (req, res, next) => {
    req.app.locals.mastodonCollections = collections;
    req.app.locals.mastodonPluginOptions = pluginOptions;
    next();
  });

  // ─── Token resolution ───────────────────────────────────────────────────
  // Apply optional token resolution to all API routes so handlers can check
  // req.mastodonToken. Specific routes that require auth use tokenRequired.
  router.use("/api", optionalToken);

  // ─── OAuth routes (no token required for most) ──────────────────────────
  router.use(oauthRouter);

  // ─── Public API routes (no auth required) ───────────────────────────────
  router.use(instanceRouter);

  // ─── Authenticated API routes ───────────────────────────────────────────
  router.use(accountsRouter);
  router.use(statusesRouter);
  router.use(timelinesRouter);
  router.use(notificationsRouter);
  router.use(searchRouter);
  router.use(mediaRouter);
  router.use(stubsRouter);

  // ─── Catch-all for unimplemented endpoints ──────────────────────────────
  // Express 5 path-to-regexp v8: use {*name} for wildcard
  router.all("/api/v1/{*rest}", notImplementedHandler);
  router.all("/api/v2/{*rest}", notImplementedHandler);

  // ─── Error handler ──────────────────────────────────────────────────────
  router.use("/api", errorHandler);
  router.use("/oauth", errorHandler);

  return router;
}