const CH = "chat-stream-v1";
let bc, streams = /* @__PURE__ */ new Map();
self.addEventListener("install", (e) => self.skipWaiting());
self.addEventListener("activate", (e) => e.waitUntil(self.clients.claim()));
function send(m) {
  try {
    bc || (bc = new BroadcastChannel(CH));
    bc.postMessage(m);
  } catch {
  }
}
function hint(x) {
  x = String(x || "");
  if (/401|unauthorized/i.test(x)) return "Unauthorized (check API key).";
  if (/429|rate/i.test(x)) return "Rate limited (slow down or upgrade).";
  if (/403|forbidden|access/i.test(x)) return "Forbidden (model or key scope).";
  return "Request failed.";
}
async function start(id, p) {
  bc || (bc = new BroadcastChannel(CH));
  const body = typeof p.body === "string" ? p.body : JSON.stringify(p.body || {}), ctrl = new AbortController();
  let done = false, buf = "";
  streams.set(id, { ctrl, buf: () => buf, done: () => done });
  try {
    const r = await fetch(p.url, { method: "POST", headers: p.headers || {}, body, signal: ctrl.signal });
    if (!r.ok) throw new Error(await r.text().catch(() => "") || "HTTP " + r.status);
    const rd = r.body.getReader(), dc = new TextDecoder("utf-8");
    let acc = "";
    const doneOnce = () => {
      if (done) return;
      done = true;
      send({ t: "done", id });
    };
    for (; ; ) {
      const { value, done: d } = await rd.read();
      if (d) break;
      acc += dc.decode(value, { stream: true });
      let i;
      while ((i = acc.indexOf("\n\n")) !== -1) {
        const raw = acc.slice(0, i).trim();
        acc = acc.slice(i + 2);
        if (!raw || !raw.startsWith("data:")) continue;
        const data = raw.slice(5).trim();
        if (data === "[DONE]") {
          doneOnce();
          continue;
        }
        try {
          const j = JSON.parse(data);
          const delta = j.choices?.[0]?.delta?.content ?? "";
          if (delta) {
            buf += delta;
            send({ t: "delta", id, data: delta });
          }
          const fin = j.choices?.[0]?.finish_reason;
          if (fin) doneOnce();
        } catch {
        }
      }
    }
    doneOnce();
  } catch (e) {
    const aborted = e?.name === "AbortError" || /abort/i.test(String(e?.message || ""));
    if (aborted) send({ t: "done", id, aborted: true });
    else send({ t: "error", id, hint: hint(e?.message) });
  } finally {
    streams.delete(id);
  }
}
function stop(id) {
  const s = streams.get(id);
  if (!s) return;
  try {
    s.ctrl.abort();
  } catch {
  } finally {
    streams.delete(id);
  }
}
function replay(id, offset = 0) {
  const s = streams.get(id);
  if (!s) return;
  const cur = s.buf(), remain = cur.slice(Math.max(0, offset));
  if (remain) send({ t: "delta", id, data: remain });
  if (s.done()) send({ t: "done", id });
}
bc = new BroadcastChannel(CH);
bc.onmessage = (e) => {
  const m = e.data || {};
  if (m.t === "hello") send({ t: "hello-ack" });
  else if (m.t === "start" && m.id && m.payload) start(m.id, m.payload);
  else if (m.t === "stop" && m.id) stop(m.id);
  else if (m.t === "replay" && m.id) replay(m.id, m.offset | 0);
};