const http = require("http");
const Redis = require("ioredis");

const REDIS_HOST = process.env.REDIS_HOST || "data_jobs";
const REDIS_PORT = Number(process.env.REDIS_PORT || 6379);
const JOB_QUEUE  = process.env.JOB_QUEUE  || "grist:jobs";
const RES_QUEUE  = process.env.RESULT_QUEUE || "grist:results";

const redis = new Redis({ host: REDIS_HOST, port: REDIS_PORT });

function cors(res){
  res.setHeader("Access-Control-Allow-Origin","*");
  res.setHeader("Access-Control-Allow-Methods","GET, POST, OPTIONS");
  res.setHeader("Access-Control-Allow-Headers","*");
}

const server = http.createServer(async (req, res) => {
  cors(res);
  if (req.method === "OPTIONS") { res.writeHead(204); return res.end(); }
  const path = req.url.split("?")[0];

  if (req.method === "GET" && path === "/health") {
    res.writeHead(200, {"content-type":"text/plain"}); return res.end("ok");
  }

  if (req.method === "GET" && (path === "/places" || path === "/api/places")) {
    try {
      await redis.lpush(JOB_QUEUE, "places");
      const reply = await redis.blpop(RES_QUEUE, 8);
      if (!reply) {
        res.writeHead(202, {"content-type":"application/json"});
        return res.end('{"ok":false,"status":"queued-or-timeout"}');
      }
      const [, value] = reply;
      res.writeHead(200, {"content-type":"application/json"});
      return res.end(JSON.stringify({ ok:true, raw:value }));
    } catch (e) {
      res.writeHead(500, {"content-type":"application/json"});
      return res.end(JSON.stringify({ ok:false, error:e.message }));
    }
  }

  res.writeHead(404, {"content-type":"application/json"});
  res.end('{"error":"not found"}');
});

server.listen(8080, "0.0.0.0", () => console.log("[gateway] listening 8080"));