nexus/server/src/routes/puter-proxy.ts

import { Router } from "express";
import type { Db } from "@paperclipai/db";
import { assertBoard, assertCompanyAccess } from "./authz.js";
import { puterProxyService } from "../services/puter-proxy.js";
import { badRequest } from "../errors.js";

export function puterProxyRoutes(db: Db): Router {
  const router = Router();

  // POST /puter-proxy/token — store or rotate Puter auth token
  router.post("/puter-proxy/token", async (req, res) => {
    assertBoard(req);
    const { companyId, token } = req.body;

    if (!companyId || typeof companyId !== "string") {
      throw badRequest("companyId is required");
    }
    if (!token || typeof token !== "string") {
      throw badRequest("token is required");
    }

    assertCompanyAccess(req, companyId);

    await puterProxyService(db).storeToken(companyId, token);
    res.json({ ok: true });
  });

  // POST /puter-proxy/chat — stream AI chat via Puter proxy
  router.post("/puter-proxy/chat", async (req, res) => {
    assertBoard(req);
    const { companyId, agentId, messages, model } = req.body;

    if (!companyId || typeof companyId !== "string") {
      res.status(400).json({ error: "companyId is required" });
      return;
    }
    if (!Array.isArray(messages) || messages.length === 0) {
      res.status(400).json({ error: "messages must be a non-empty array" });
      return;
    }

    assertCompanyAccess(req, companyId);

    // Set SSE headers and flush immediately (same pattern as chat.ts)
    res.setHeader("Content-Type", "text/event-stream");
    res.setHeader("Cache-Control", "no-cache");
    res.setHeader("Connection", "keep-alive");
    res.setHeader("X-Accel-Buffering", "no");
    res.flushHeaders();
    res.write(":ok\n\n");

    const abort = new AbortController();
    req.on("close", () => abort.abort());

    try {
      const svc = puterProxyService(db);
      // agentId is optional — pass through as-is (string or undefined)
      for await (const chunk of svc.chatStream(
        companyId,
        agentId as string | undefined,
        messages,
        model as string | undefined,
        abort.signal,
      )) {
        if (!res.writable) break;
        res.write(`data: ${JSON.stringify({ token: chunk })}\n\n`);
      }
      if (res.writable && !abort.signal.aborted) {
        res.write(`data: ${JSON.stringify({ done: true })}\n\n`);
      }
    } catch (err) {
      if (res.writable) {
        res.write(`data: ${JSON.stringify({ error: "Puter stream error" })}\n\n`);
      }
    } finally {
      res.end();
    }
  });

  return router;
}