// sw.js — debug-friendly service worker
// Replace your existing worker with this (or merge the relevant parts).
importScripts('https://cdn.jsdelivr.net/npm/localforage@1.10.0/dist/localforage.min.js');

const THREADS_KEY = 'threads_v1';
const TARGET_SUBSTRING = 'openrouter.ai/api/v1/chat/completions'; // keep your real target here
const LOG = (...a) => { console.log('[sw-debug]', ...a) };

const gid = () => Math.random().toString(36).slice(2,9) + '-' + Date.now().toString(36);

// ---------- small idb helpers using localforage ----------
async function readThreads() {
  try { const v = await localforage.getItem(THREADS_KEY); return Array.isArray(v) ? v : []; }
  catch (e) { LOG('readThreads err', e); return []; }
}
async function writeThreads(arr) {
  try { await localforage.setItem(THREADS_KEY, arr); }
  catch (e) { LOG('writeThreads err', e); throw e; }
}
function pickThread(threads) {
  if (!threads || !threads.length) return null;
  // prefer newest updatedAt
  threads.sort((a,b) => (b.updatedAt||0) - (a.updatedAt||0));
  return threads[0];
}
async function upsertStreamMessage(streamId, text, meta = {}) {
  const threads = await readThreads();
  let th = pickThread(threads);
  const now = Date.now();
  if (!th) {
    th = { id: 'sw-' + gid(), title: 'Missed while backgrounded', pinned: false, updatedAt: now, messages: [] };
    threads.unshift(th);
  }
  let msgIndex = -1;
  for (let i = th.messages.length - 1; i >= 0; i--) {
    if (th.messages[i] && th.messages[i].sw_streamId === streamId) { msgIndex = i; break; }
  }
  const contentParts = [{ type: 'text', text }];
  if (msgIndex >= 0) {
    const ex = th.messages[msgIndex];
    ex.content = text;
    ex.contentParts = contentParts;
    ex.updatedAt = now;
    ex._sw_lastSave = now;
    ex._sw_meta = Object.assign({}, ex._sw_meta || {}, meta);
  } else {
    th.messages.push({
      id: 'swmsg-' + gid(),
      role: 'assistant',
      content: text,
      contentParts,
      kind: 'assistant',
      sw_saved: true,
      sw_streamId: streamId,
      createdAt: now,
      updatedAt: now,
      _sw_meta: meta
    });
  }
  th.updatedAt = now;
  await writeThreads(threads);
  return { threadId: th.id };
}
async function finalizeStream(streamId, meta = {}) {
  const threads = await readThreads();
  const th = pickThread(threads);
  if (!th) return;
  for (let i = th.messages.length - 1; i >= 0; i--) {
    const m = th.messages[i];
    if (m && m.sw_streamId === streamId) {
      m._sw_meta = Object.assign({}, m._sw_meta || {}, meta, { completeAt: Date.now() });
      m.updatedAt = Date.now();
      th.updatedAt = Date.now();
      break;
    }
  }
  await writeThreads(threads);
  // notify clients
  const clientsList = await self.clients.matchAll({ includeUncontrolled: true, type: 'window' });
  for (const c of clientsList) {
    try { c.postMessage({ type: 'stream-saved', streamId, meta }); } catch(e) {}
  }
}

// ---------- helpers ----------
async function listSwStreams() {
  const threads = await readThreads();
  const found = [];
  for (const t of (threads || [])) {
    for (const m of (t.messages || [])) {
      if (m && m.sw_streamId) found.push({
        threadId: t.id,
        threadTitle: t.title,
        messageId: m.id,
        sw_streamId: m.sw_streamId,
        snippet: (m.content||'').slice(0,200),
        updatedAt: m.updatedAt
      });
    }
  }
  return found;
}
async function notifyClients(msg) {
  try {
    const list = await self.clients.matchAll({ includeUncontrolled: true, type: 'window' });
    for (const c of list) {
      try { c.postMessage(msg); } catch(e) {}
    }
  } catch(e) { LOG('notifyClients err', e); }
}

// ---------- install/activate ----------
self.addEventListener('install', e => { self.skipWaiting(); });
self.addEventListener('activate', e => { e.waitUntil(self.clients.claim()); });

// ---------- fetch: keep existing behavior for your real target, plus a debug probe ----------
self.addEventListener('fetch', event => {
  const reqUrl = event.request.url || '';
  // debug probe route — the sune will call /__sw_tee_test to force a tee test:
  if (new URL(reqUrl).pathname === '/__sw_tee_test') {
    event.respondWith((async () => {
      const probeId = new URL(reqUrl).searchParams.get('probeId') || gid();
      LOG('Received tee-test probe', probeId);

      // create a simulated streaming source inside the SW
      const encoder = new TextEncoder();
      const stream = new ReadableStream({
        start(ctrl) {
          let count = 0;
          const id = setInterval(() => {
            count++;
            const chunk = `probe(${probeId}) chunk ${count}\n`;
            ctrl.enqueue(encoder.encode(chunk));
            // after 6 chunks stop
            if (count >= 6) { clearInterval(id); ctrl.close(); }
          }, 300);
        }
      });

      // tee the generated stream: one branch to client, one branch for SW consumption/save
      const [clientBranch, swBranch] = stream.tee();

      // in SW consume swBranch and write to localforage
      (async () => {
        try {
          const reader = swBranch.getReader();
          const dec = new TextDecoder('utf-8');
          let collected = '';
          let bytes = 0;
          while (true) {
            const { value, done } = await reader.read();
            if (done) break;
            const chunkText = dec.decode(value, { stream: true });
            collected += chunkText;
            bytes += (value && value.byteLength) ? value.byteLength : chunkText.length;
            // periodic save: write the collected so far into threads_v1 under probe stream id
            await upsertStreamMessage('probe-' + probeId, collected, { probeId, bytesSoFar: bytes });
            // notify clients incrementally
            await notifyClients({ type: 'tee-probe-chunk', probeId, bytes, snippet: chunkText.slice(0,200) });
          }
          await finalizeStream('probe-' + probeId, { totalBytes: bytes, probeId });
          LOG('tee-probe: save complete', probeId, 'bytes', bytes);
          await notifyClients({ type: 'tee-probe-complete', probeId, totalBytes: bytes });
        } catch (err) {
          LOG('tee-probe save error', err);
          await notifyClients({ type: 'tee-probe-error', probeId, error: String(err) });
        }
      })();

      // return the client branch as a streaming response
      return new Response(clientBranch, { status: 200, headers: { 'Content-Type': 'text/plain; charset=utf-8' } });
    })());
    return;
  }

  // your production streaming intercept — minimal example:
  if (reqUrl.includes(TARGET_SUBSTRING)) {
    // let your existing logic run — simple pass-through or tee logic you already had
    // For demonstration, do a straight throughfetch (or optionally tee/save like earlier example)
    event.respondWith(fetch(event.request));
    return;
  }

  // not handled by SW: let it go
});

// ---------- message handling: richer PING/DIAG ----------
self.addEventListener('message', event => {
  const data = event.data || {};
  try {
    if (data && data.type === 'PING') {
      // reply with diagnostic info (prefer port)
      (async () => {
        const streams = await listSwStreams();
        const info = {
          type: 'PONG',
          ts: Date.now(),
          ok: true,
          canTeeProbe: true,
          savedStreamCount: streams.length,
          lastSaved: streams[0] || null
        };
        if (event.ports && event.ports[0]) {
          event.ports[0].postMessage(info);
        } else if (event.source && typeof event.source.postMessage === 'function') {
          event.source.postMessage(info);
        } else {
          await notifyClients(info);
        }
      })();
      return;
    }

    if (data && data.type === 'list-sw-streams') {
      (async () => {
        const streams = await listSwStreams();
        const payload = { type: 'sw-streams-list', streams };
        if (event.ports && event.ports[0]) event.ports[0].postMessage(payload);
        else if (event.source && typeof event.source.postMessage === 'function') event.source.postMessage(payload);
        else await notifyClients(payload);
      })();
      return;
    }

    // allow direct command to run a tee probe from client (alternative path)
    if (data && data.type === 'run-tee-probe' && data.probeId) {
      // reply that probe will be run — the fetch handler will simulate the stream
      (async () => {
        try {
          const probeUrl = '/__sw_tee_test?probeId=' + encodeURIComponent(data.probeId);
          // perform fetch from SW to itself to cause internal handling (not required — client can call the endpoint)
          // but we simply reply OK and let the client hit the endpoint so the client receives the response body
          if (event.ports && event.ports[0]) event.ports[0].postMessage({ type:'run-tee-probe-ok', probeId: data.probeId, probeUrl });
          else if (event.source && typeof event.source.postMessage === 'function') event.source.postMessage({ type:'run-tee-probe-ok', probeId: data.probeId, probeUrl });
        } catch (e) {
          if (event.ports && event.ports[0]) event.ports[0].postMessage({ type:'run-tee-probe-error', error: String(e) });
        }
      })();
      return;
    }

  } catch (err) {
    LOG('message handler error', err);
  }
});