src/lib/agentLoop/codeRunner.ts

/**
 * codeRunner.ts — Code runner tools
 *
 * Contiene: runCodeSandbox, runViaPyodideWorker, Pyodide worker via WorkerManager,
 * tool implementations: run_code, execute_shell, pip_install, run_python,
 * zip_project, profile_code, read_pdf, send_notification
 *
 * S135 — Integrazione runtime/WorkerManager per py worker:
 *   - WorkerManager gestisce lifecycle completo: spawn, ping/pong health check (60s),
 *     auto-respawn dopo 3 ping falliti, idle-terminate
 *   - codeRunner.ts gestisce message routing via _pyListeners Map
 *   - WorkerManager usa w.onmessage internamente (ping/pong) —
 *     codeRunner usa addEventListener per coesistere senza conflitti
 *   - onStatusChange subscription: re-attacca handler dopo ogni respawn
 *     senza che codeRunner.ts gestisca alcun lifecycle manuale
 *   - pyodideReady in RuntimeDiagnosticsPanel ora riporta stato reale
 */

import { vfsAsync } from "../vfsDb";
import { vfs } from "../vfs";
import { debugLoop } from "../debugLoop";
import { agentMemory } from "../agentMemory";
import { adaptiveSolver } from "../adaptiveSolver";
import { recordOutcomeAsync } from "../selfLearningAsync"; // FIX22: S649 — era dynamic import+sync (blocca UI ~200ms iPhone)
import { usePythonVarsStore } from "@/store/pythonVarsStore";
import type { PythonVar } from "@/store/pythonVarsStore";
import { workerManager, WorkerManager } from "../runtime/WorkerManager";
import type { WorkerLike } from "../runtime/WorkerManager";
import { eventRuntime } from "@/core/events"; // S768: partial_output event

// ─── Tool dispatcher ──────────────────────────────────────────────────────────

export async function tryExecute(name: string, args: Record<string, unknown>, signal?: AbortSignal): Promise<string | null> {
  if (name === "run_code") {
    const { code, language, _retry = false } = args as { code: string; language?: string; _retry?: boolean };
    // S74: Python/bash/ts → usa exec backend HF Space /api/exec se disponibile
    const _lang = (language ?? "javascript").toLowerCase();
    if (!["javascript", "js"].includes(_lang)) {
      const { backend } = await import("../backendClient");
      if (backend.isExecAvailable()) {
        // P1: Pre-exec Python dep detection — installa moduli non-stdlib prima dell'esecuzione
        // Elimina l'iterazione sprecata su ModuleNotFoundError
        if (_lang === "python" || _lang === "py") {
          const _PYLIB = new Set(["os","sys","json","re","math","datetime","collections","itertools",
            "functools","pathlib","typing","abc","io","time","random","hashlib","urllib","http",
            "threading","subprocess","traceback","inspect","copy","string","struct","base64",
            "contextlib","dataclasses","enum","logging","tempfile","shutil","glob","csv","xml",
            "html","email","socket","ssl","unittest","gc","weakref","queue","heapq","bisect",
            "builtins","operator","textwrap","warnings","keyword","ast","types","decimal",
            "statistics","cmath","numbers","array","zlib","pickle","shelve","sqlite3",
            "configparser","argparse","platform","signal","mimetypes","calendar",
            "__future__","typing_extensions","dataclasses","pprint","reprlib"]);
          const _pyPkgs = Array.from(new Set(
            (code.match(/^(?:import|from)\s+(\w+)/gm) ?? [])
              .map((m: string) => m.split(/\s+/)[1])
              .filter((mod: string) => mod && !_PYLIB.has(mod))
          ));
          if (_pyPkgs.length) {
            try { await backend.execCode(`pip install ${_pyPkgs.join(" ")} -q 2>&1 | tail -1`, "bash"); } catch { /* best-effort — non-blocking */ }
          }
        }
        try {
          const r = await backend.execCode(code, _lang);
          // S768: partial output — emetti evento
          // S769: persist al VFS per ispezione post-chip
          if (r.partial) {
            const _partialSnip = (r.stdout ?? "").slice(0, 300);
            try { eventRuntime.emit({ kind: "partial_output", tool: "run_code", partialOut: _partialSnip }); } catch { /* non-blocking */ }
            const _ts = Date.now();
            vfsAsync.write(
              `.partial_out_${_ts}.txt`,
              `[S769] tool: run_code\ntime: ${new Date(_ts).toISOString()}\n\n${r.stdout ?? ""}`,
            ).catch(() => {});
          }
          const out = [r.stdout, r.stderr].filter(Boolean).join("\n").trim();
          return out || `[OK (exit ${r.exit_code}) — ${_lang}]`;
        } catch { /* fallback a browser sandbox */ }
      }
    }
    const result = await runCodeSandbox(code);
    if (result.startsWith("❌") && !_retry) {
      // RT-10: se il segnale è già abortito, non avviare auto-fix + secondo sandbox —
      // evita esecuzione fantasma di 70s in background dopo che il timeout esterno (65s)
      // ha già restituito "❌ [TIMEOUT]" al loop.
      if (signal?.aborted) return result;
      const taskId = crypto.randomUUID().slice(0, 8);
      const fixed = await debugLoop._askLLMFix(code, result.replace("❌ ", ""), "javascript", taskId);
      if (fixed && fixed.trim() !== code.trim()) {
        // RT-10: secondo check prima del secondo runCodeSandbox
        if (signal?.aborted) return result;
        const retryResult = await runCodeSandbox(fixed);
        if (!retryResult.startsWith("❌")) return `[auto-fix]→${retryResult}`;
        const solved = await adaptiveSolver.solve(retryResult, fixed, "run_code");
        if (solved.success) {
          // S350: impara dai fix riusciti — pattern salvato per sessioni future
          try { recordOutcomeAsync({ task: `run_code:${solved.strategy}`, output: solved.output.slice(0, 300), success: true, confidence: 0.85, toolsUsed: ["run_code"] }); } catch { /* non-blocking */ } // FIX22
          return `[adaptive-solver: ${solved.strategy}] ${solved.description}\n${solved.output}`;
        }
        return `${result}\n\n⚠️ Auto-fix tentato ma ancora in errore:\n${retryResult}\n\n💡 ${solved.description}`;
      }
      const solved = await adaptiveSolver.solve(result, code, "run_code");
      if (solved.success) {
        // S350: impara dai fix riusciti — pattern salvato per sessioni future
        try { recordOutcomeAsync({ task: `run_code:${solved.strategy}`, output: solved.output.slice(0, 300), success: true, confidence: 0.85, toolsUsed: ["run_code"] }); } catch { /* non-blocking */ } // FIX22
        return `[adaptive-solver: ${solved.strategy}] ${solved.description}\n${solved.output}`;
      }
    }
    return result;
  }

  if (name === "execute_shell") {
    const { command, timeout = 15, session_id } = args as { command: string; timeout?: number; session_id?: string };
    const { backend } = await import("../backendClient");

    // S144-Fix5: messaggio contestuale quando nessun backend è configurato.
    // EXEC_BACKEND fa già fallback su BACKEND (VITE_BACKEND_URL), quindi
    // isExecAvailable() è false SOLO se entrambe le env var sono vuote.
    if (!backend.isExecAvailable()) {
      const isPyCmd = /^\s*(python3?|pip3?)\s/.test(command);
      if (isPyCmd) return "💡 Backend non configurato. Per eseguire Python usa il tool **run_python** — funziona anche offline via Pyodide.";
      return "❌ execute_shell: nessun backend configurato. Imposta **VITE_BACKEND_URL** nelle env Vercel puntando all\'HF Space.";
    }

    try {
      // S694-persist: session_id da args (npm_install/npm_run propagano) o getExecSessionId() internamente
      // Cap 300s: npm install/build richiedono fino a 120s; il server HF Space ha i propri resource limits
      const r = await backend.executeShell(command, Math.min(Number(timeout) || 15, 300), session_id);
      // S768: partial output — emetti evento
      // S769: persist al VFS
      if (r.partial) {
        const _partialSnip = (r.stdout ?? "").slice(0, 300);
        try { eventRuntime.emit({ kind: "partial_output", tool: "execute_shell", partialOut: _partialSnip }); } catch { /* non-blocking */ }
        const _ts = Date.now();
        vfsAsync.write(
          `.partial_out_${_ts}.txt`,
          `[S769] tool: execute_shell\ntime: ${new Date(_ts).toISOString()}\n\n${r.stdout ?? ""}`,
        ).catch(() => {});
      }
      let out = "```\n";
      if (r.stdout) out += r.stdout;
      if (r.stderr) out += `\n[stderr] ${r.stderr}`;
      out += `\n[exit ${r.exit_code}]` + "\n```";
      return out;
    } catch (e) {
      const errMsg = e instanceof Error ? e.message : String(e);

      // S144-Fix5: se il backend HF Space non ha /api/execute-shell (404/405),
      // re-routing automatico per comandi Python via Pyodide.
      if (/404|405|not.?found|method.?not.?allowed/i.test(errMsg)) {
        // Caso: python3 -c "codice" → esegui via run_python
        const pyInlineMatch = command.match(/python3?\s+-c\s+["'\`]([\s\S]+)["'\`]/);
        if (pyInlineMatch) {
          return runViaPyodideWorker(pyInlineMatch[1]);
        }
        // Caso: comando shell generico non supportato
        return "❌ execute_shell: il backend HF Space non supporta comandi shell diretti. Usa **run_python** per codice Python, oppure configura un Exec Engine dedicato (VITE_EXEC_BACKEND_URL).";
      }

      return `❌ execute_shell: ${errMsg}`;
    }
  }

  if (name === "pip_install") {
    const { packages } = args as { packages: string[] };
    if (!Array.isArray(packages) || packages.length === 0) return "❌ pip_install: fornisci almeno un pacchetto.";
    const { backend } = await import("../backendClient");

    // S144-Fix5: suggerisci micropip (Pyodide) se nessun backend disponibile
    const _micropipHint = (pkgs: string[]) =>
      `💡 pip_install non disponibile senza backend. In Pyodide usa micropip:\n\`\`\`python\nimport micropip\nawait micropip.install([${pkgs.map(p => `"${p}"`).join(", ")}])\n\`\`\``;

    if (!backend.isExecAvailable()) return _micropipHint(packages);

    try {
      const r = await backend.pipInstall(packages);
      if (r.exit_code === 0) return `✅ Installati: ${(r.installed ?? packages).join(", ")}`;
      return `❌ pip install fallito (exit ${r.exit_code}):\n${r.stderr ?? r.error ?? "errore sconosciuto"}`;
    } catch (e) {
      const errMsg = e instanceof Error ? e.message : String(e);
      // S144-Fix5: 404 sul backend → suggerisci micropip
      if (/404|405|not.?found/i.test(errMsg)) return _micropipHint(packages);
      return `❌ pip_install: ${errMsg}`;
    }
  }

  if (name === "run_python") {
    const { code, packages = [] } = args as { code: string; packages?: string[] };
    return await runViaPyodideWorker(code, packages, signal);
  }

  if (name === "zip_project") {
    const { paths, filename = "project.zip" } = args as { paths?: string[]; filename?: string };
    const allFiles = await vfsAsync.list() as Array<{ path: string }>;
    const targets = paths && paths.length > 0
      ? allFiles.filter(f => paths.some(p => f.path.startsWith(p) || f.path === p))
      : allFiles;
    if (targets.length === 0) return "❌ zip_project: nessun file nel VFS da zippare.";
    const fileContentsRaw = await Promise.all(targets.map(async f => ({ path: f.path, content: await vfsAsync.read(f.path) })));
    const fileContents = fileContentsRaw.filter((f): f is { path: string; content: string } => f.content !== null);
    const zipCode = `
const JSZip = (await importModule('jszip')).default;
const zip = new JSZip();
const files = ${JSON.stringify(fileContents)};
for (const f of files) zip.file(f.path.replace(/^\\//, ''), f.content);
const blob = await zip.generateAsync({ type: 'blob', compression: 'DEFLATE' });
const url = URL.createObjectURL(blob);
const a = document.createElement('a'); a.href = url; a.download = ${JSON.stringify(filename)}; a.click();
setTimeout(() => URL.revokeObjectURL(url), 5000);
console.log('📦 ZIP scaricato: ${filename} (' + files.length + ' file)'); // check-console-log: ok
`;
    return await runCodeSandbox(zipCode.trim());
  }

  if (name === "profile_code") {
    const { code, iterations = 100, warmup = 10 } = args as { code: string; iterations?: number; warmup?: number };
    const iters = Math.min(Number(iterations) || 100, 10000);
    const warmupN = Math.min(Number(warmup) || 10, 100);
    const profileCode = `
${code}

if (typeof main !== 'function') { console.log('❌ Definisci una funzione main() nel codice da profilare.'); } // check-console-log: ok
else {
  const WARMUP = ${warmupN};
  const ITERS = ${iters};
  // Warmup
  for (let i = 0; i < WARMUP; i++) await main();
  // Measure
  const times = [];
  for (let i = 0; i < ITERS; i++) {
    const t0 = performance.now();
    await main();
    times.push(performance.now() - t0);
  }
  times.sort((a,b) => a-b);
  const sum = times.reduce((a,b)=>a+b,0);
  const avg = sum/times.length;
  const min = times[0];
  const max = times[times.length-1];
  const p50 = times[Math.floor(times.length*0.5)];
  const p95 = times[Math.floor(times.length*0.95)];
  const p99 = times[Math.floor(times.length*0.99)];
  const opsPerSec = avg > 0 ? (1000/avg).toFixed(0) : '∞';
  console.log('⚡ Profiler Results (' + ITERS + ' iterazioni, ' + WARMUP + ' warmup)'); // check-console-log: ok
  console.log('avg:  ' + avg.toFixed(4) + ' ms'); // check-console-log: ok
  console.log('min:  ' + min.toFixed(4) + ' ms'); // check-console-log: ok
  console.log('max:  ' + max.toFixed(4) + ' ms'); // check-console-log: ok
  console.log('p50:  ' + p50.toFixed(4) + ' ms'); // check-console-log: ok
  console.log('p95:  ' + p95.toFixed(4) + ' ms'); // check-console-log: ok
  console.log('p99:  ' + p99.toFixed(4) + ' ms'); // check-console-log: ok
  console.log('ops/s: ' + opsPerSec); // check-console-log: ok
}
`;
    return await runCodeSandbox(profileCode.trim());
  }

  if (name === "read_pdf") {
    const { url, max_pages = 10 } = args as { url: string; max_pages?: number };
    const maxP = Math.min(Number(max_pages) || 10, 30);
    const pdfCode = `
const pdfjsLib = await importModule('pdfjs-dist/legacy/build/pdf');
pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://cdnjs.cloudflare.com/ajax/libs/pdf.js/4.10.38/pdf.worker.min.mjs';
const pdf = await pdfjsLib.getDocument(${JSON.stringify(url)}).promise;
const numPages = Math.min(pdf.numPages, ${maxP});
const pages = [];
for (let i = 1; i <= numPages; i++) {
  const page = await pdf.getPage(i);
  const content = await page.getTextContent();
  const text = content.items.map(item => ('str' in item ? item.str : '')).join(' ').trim();
  if (text) pages.push('--- Pagina ' + i + ' ---\\n' + text);
}
if (!pages.length) { console.log('❌ Nessun testo estraibile (PDF scansionato o protetto).'); } // check-console-log: ok
else { console.log('📄 PDF: ' + pdf.numPages + ' pagine totali, estratte: ' + numPages + '\\n\\n' + pages.join('\\n\\n').slice(0, 8000)); } // check-console-log: ok
`;
    return await runCodeSandbox(pdfCode.trim());
  }

  return null;
}

// ─── Code Sandbox ─────────────────────────────────────────────────────────────

export async function runCodeSandbox(code: string): Promise<string> {
  const logs: string[] = [];
  const logFn = (...a: unknown[]) => logs.push(a.map(x => typeof x === "string" ? x : JSON.stringify(x, null, 2)).join(" "));

  const downloadFn = (content: string, filename = "file.txt", mimeType = "text/plain") => {
    const blob = new Blob([content], { type: mimeType });
    const url = URL.createObjectURL(blob);
    const a = document.createElement("a");
    a.href = url; a.download = filename; a.click();
    setTimeout(() => URL.revokeObjectURL(url), 5000);
    logs.push(`📁 Download avviato: ${filename}`);
  };

  // I-a fix S178: generatePDF scaricava HTML rinominato .pdf — ora apre finestra stampa
  // (browser → Stampa → "Salva come PDF" = vero PDF) e scarica anche l'HTML come fallback
  const generatePDF = async (html: string, filename = "documento.pdf") => {
    const fullHtml = `<!DOCTYPE html><html><head><title>${filename}</title><style>
      body{font-family:sans-serif;max-width:800px;margin:2rem auto;line-height:1.6}
      @media print{body{margin:0}button{display:none}}
    </style></head><body>
      <button onclick="window.print()" style="margin-bottom:1rem;padding:.5rem 1rem;cursor:pointer">🖨️ Stampa / Salva come PDF</button>
      ${html}
    </body></html>`;
    const blob = new Blob([fullHtml], { type: "text/html" });
    const url = URL.createObjectURL(blob);
    const win = window.open(url, "_blank");
    if (win) { setTimeout(() => win.print(), 800); }
    else {
      const a = document.createElement("a"); a.href = url; a.download = filename.replace(/\.pdf$/i, ".html"); a.click();
      logs.push(`⚠️ generatePDF: popup bloccato — scaricato HTML (${filename.replace(/\.pdf$/i,".html")}). Apri il file e usa Stampa → Salva come PDF.`);
    }
    setTimeout(() => URL.revokeObjectURL(url), 30000);
    logs.push(`🖨️ PDF-print: "${filename}" — finestra stampa aperta. Scegli "Salva come PDF" nel dialogo.`);
  };

  const globals: Record<string, unknown> = {
    console: { log: logFn, warn: logFn, error: logFn, info: logFn },
    fetch, vfs, memory: agentMemory,
    download: downloadFn, generatePDF,
    uuid: () => crypto.randomUUID(),
    hash: async (s: string, algo = "SHA-256") => {
      const buf = await crypto.subtle.digest(algo, new TextEncoder().encode(s));
      return Array.from(new Uint8Array(buf)).map(b => b.toString(16).padStart(2, "0")).join("");
    },
    b64encode: (s: string) => btoa(unescape(encodeURIComponent(s))),
    b64decode: (s: string) => decodeURIComponent(escape(atob(s))),
    csvParse: (t: string) => t.trim().split(/\r?\n/).map(l => {
      const r: string[] = []; let f = "", q = false;
      for (const c of l) {
        if (c === '"') q = !q;
        else if (c === ',' && !q) { r.push(f); f = ""; }
        else f += c;
      }
      r.push(f); return r;
    }),
    importModule: (spec: string) => import(/* @vite-ignore */ `https://esm.sh/${spec}`),
    // OPT: require polyfill — redirige al sistema esm.sh con messaggio utile
    // Evita ReferenceError generico "require is not defined" che confonde l'LLM
    require: (spec: string) => {
      throw new Error(
        `require("${spec}") non disponibile nel browser sandbox.\n` +
        `Usa invece: const mod = await importModule("${spec}");`
      );
    },
    chart: (type: string, labels: string[], values: number[], title?: string) => { logs.push(`📊 Chart[${type}] "${title ?? ""}" — ${labels.slice(0,4).join(", ")}…`); },
    sleep: (ms: number) => new Promise<void>(r => setTimeout(r, ms)),
    atob, btoa, URL, Promise, JSON, Math, Date, Object, Array, String, Number, Boolean,
    parseInt, parseFloat, isNaN, isFinite, encodeURIComponent, decodeURIComponent,
    setTimeout, clearTimeout, setInterval, clearInterval, TextEncoder, TextDecoder,
    crypto, Blob, ArrayBuffer, Uint8Array, Int8Array, Float32Array, Float64Array,
  };

  try {
    const AsyncFunction = Object.getPrototypeOf(async function () { }).constructor as new (...args: string[]) => (...args: unknown[]) => Promise<unknown>;
    const fn = new AsyncFunction(...Object.keys(globals), `"use strict";\n${code}`);
    const timeoutP = new Promise<void>((_, rej) => setTimeout(() => rej(new Error("Sandbox timeout (30s)")), 30_000));
    await Promise.race([fn(...Object.values(globals)), timeoutP]);
    const out = logs.join("\n") || "(nessun output)";
    return out.length > 4000 ? out.slice(0, 4000) + "\n...(troncato)" : out;
  } catch (err) {
    return `❌ ${err instanceof Error ? `${err.name}: ${err.message}` : String(err)}`;
  }
}

// ─── Pyodide Worker via runtime/WorkerManager ─────────────────────────────────
//
// S135: WorkerManager (runtime/WorkerManager.ts) gestisce il lifecycle completo:
//   • Spawn lazy alla prima run_python
//   • Ping/pong health check ogni 60s
//   • Auto-respawn automatico dopo 3 ping falliti (Safari iOS silent kill)
//   • Idle auto-terminate dopo 60s di inattività
//   • Status reporting per RuntimeDiagnosticsPanel (pyodideReady ora reale)
//
// Coesistenza con WorkerManager.onmessage:
//   WorkerManager usa w.onmessage = ... per ping/pong (ready/pong).
//   codeRunner usa w.addEventListener("message", ...) per coesistere senza
//   sovrascrivere l'handler interno. Entrambi i listener ricevono tutti i
//   messaggi; _pyMessageHandler ignora ready/pong, WorkerManager ignora il resto.
//
// Respawn handling:
//   onStatusChange subscription (module-level, registrata una volta):
//   - health "dead"  → pulisce _pyWorkerRef e pending _pyListeners
//   - health "alive" → riattacca _pyMessageHandler al nuovo worker
//
// _pyStatus è settato da agentLoop via setPyodideStatus() prima di ogni runAgentLoop.

type _PyWorkerMsg = {
  type: string;
  id?: string;
  text?: string;
  message?: string;
  exitCode?: number;
  progress?: number;
  vars?: PythonVar[];
};

let _pyStatus: ((s: string) => void) | null = null;
const _pyListeners = new Map<string, (_msg: _PyWorkerMsg) => void>();

/** Riferimento al worker attivo corrente — null se non ancora spawned o dopo terminate. */
let _pyWorkerRef: WorkerLike | null = null; // S143-Bug4: tipo allineato a WorkerLike

// ─── Message handler ──────────────────────────────────────────────────────────
// Funzione named e stabile — addEventListener/removeEventListener richiedono
// la stessa referenza. Non deve essere ricreata tra respawn.

function _pyMessageHandler(e: MessageEvent<_PyWorkerMsg>): void {
  const msg = e.data;

  if (msg.type === "loading") {
    const pct = (msg as { type: string; progress?: number }).progress ?? 0;
    if (_pyStatus) {
      if (pct <= 0)      _pyStatus("🐍 Avvio Python…");
      else if (pct < 60) _pyStatus("🐍 Caricamento Python…");
      else               _pyStatus("🐍 Python quasi pronto…");
    }
    return;
  }

  // "ready" e "pong" sono gestiti da WorkerManager.onmessage internamente —
  // questo handler li ignora per evitare doppia elaborazione.
  if (msg.type === "ready" || msg.type === "pong") return;

  // S71: variabili Python estratte post-run → aggiorna store
  if (msg.type === "vars" && (msg as { type: string; vars?: PythonVar[] }).vars?.length) {
    usePythonVarsStore.getState().updateVars(
      (msg as { type: string; vars: PythonVar[] }).vars,
    );
    return;
  }

  // Messaggi per-esecuzione → routing per id
  if (msg.id) _pyListeners.get(msg.id)?.(msg);
}

// ─── Attacca handler al worker (idempotente) ──────────────────────────────────
// Usa addEventListener → coesiste con WorkerManager.onmessage senza sovrascriverlo.
// removeEventListener prima di add → garantisce unicità anche su chiamate ripetute.

// S143-Bug4: WorkerLike ora include addEventListener/removeEventListener.
// Rimosso il cast fragile "as Worker" — wl è già tipato correttamente.
function _attachPyHandler(wl: WorkerLike): void {
  wl.removeEventListener("message", _pyMessageHandler);
  wl.addEventListener("message", _pyMessageHandler);
  _pyWorkerRef = wl;
}

// ─── Subscription unica ai lifecycle events del worker ───────────────────────
// Registrata a module load — non in una funzione — così esiste per tutta
// la vita dell'app e sopravvive a respawn multipli.

workerManager.onStatusChange((status) => {
  if (status.type !== "py") return;

  if (status.health === "dead") {
    // Worker morto (crash o idle terminate) → pulisci riferimento
    _pyWorkerRef = null;
    for (const [, cb] of _pyListeners) {
      cb({ type: "error", message: "Worker Pyodide terminato — riprova" });
    }
    _pyListeners.clear();
    return;
  }

  if (status.health === "alive") {
    // Worker spawned o respawned → riattacca handler se cambiato
    try {
      const wl = workerManager.ensureSpawned("py");
      if (wl !== _pyWorkerRef) {
        _attachPyHandler(wl);
      }
    } catch { /* non-fatal: _getPyWorker lo ritenterà */ }
  }
});

/** Chiamato da agentLoop.ts per agganciare onStatus al bridge Pyodide. */
export function setPyodideStatus(fn: ((s: string) => void) | null): void {
  _pyStatus = fn;
}

/**
 * Ritorna il worker Pyodide attivo, spawnandolo se necessario.
 * WorkerManager gestisce health check e respawn: questa funzione si
 * limita a ottenere il worker live e garantire che l'handler sia attaccato.
 */
function _getPyWorker(): WorkerLike | null {
  if (!WorkerManager.isWorkerSupported()) return null;
  try {
    const wl = workerManager.ensureSpawned("py");
    // Attacca handler se non ancora fatto (prima use) o dopo respawn via onStatusChange
    if (wl !== _pyWorkerRef) {
      _attachPyHandler(wl);
    }
    return _pyWorkerRef;
  } catch {
    return null;
  }
}

// ─── Helper: Pyodide worker bridge (run_python tool) ─────────────────────────
// S139-Fix3 — Safari iOS detection: module workers non supportati in modo affidabile.
// Fallback trasparente su backend HF Space (già configurato come EXEC_BACKEND).
function _isSafariIOS(): boolean {
  if (typeof navigator === "undefined") return false;
  return /iPad|iPhone|iPod/.test(navigator.userAgent) &&
    !(window as unknown as Record<string, unknown>).MSStream;
}

/**
 * runViaPyodideWorker — entry point pubblico.
 * Su Safari iOS: delega l'esecuzione Python al backend HF Space (exec engine).
 * Su altri browser: usa il worker Pyodide locale.
 */
function runViaPyodideWorker(code: string, packages: string[] = [], signal?: AbortSignal): Promise<string> {
  if (_isSafariIOS()) {
    return import("../backendClient").then(({ backend }) => {
      if (backend.isExecAvailable()) {
        const fullCode = packages.length > 0
          ? `import subprocess\nsubprocess.run(["pip","install","-q",${packages.map(p => JSON.stringify(p)).join(",")}], capture_output=True)\n` + code
          : code;
        return backend.execCode(fullCode, "python", 30)
          .then(r => {
            // S768: partial output — emetti evento
            // S769: persist al VFS
            if (r.partial) {
              const _partialSnip = (r.stdout ?? "").slice(0, 300);
              try { eventRuntime.emit({ kind: "partial_output", tool: "run_python", partialOut: _partialSnip }); } catch { /* non-blocking */ }
              const _ts = Date.now();
              vfsAsync.write(
                `.partial_out_${_ts}.txt`,
                `[S769] tool: run_python\ntime: ${new Date(_ts).toISOString()}\n\n${r.stdout ?? ""}`,
              ).catch(() => {});
            }
            const out = [r.stdout, r.stderr ? `[stderr] ${r.stderr}` : ""].filter(Boolean).join("\n").trim();
            return out || "(nessun output)";
          })
          .catch((e: Error) => `❌ Python (server): ${e.message}`);
      }
      // Backend non disponibile: tenta comunque il worker (Safari 16.4+ lo supporta parzialmente)
      return _runViaPyodideWorkerInternal(code, packages, signal);
    });
  }
  return _runViaPyodideWorkerInternal(code, packages, signal);
}

function _runViaPyodideWorkerInternal(code: string, packages: string[] = [], signal?: AbortSignal): Promise<string> {
  return new Promise<string>((resolve) => {
    const worker = _getPyWorker();
    if (!worker) {
      resolve("❌ Worker Pyodide non disponibile (Safari iOS potrebbe non supportare module workers — prova Chrome/Firefox)");
      return;
    }

    let stdout = "";
    let stderr = "";
    const id = crypto.randomUUID();

    const cleanup = () => {
      clearTimeout(timer);
      _pyListeners.delete(id);
      signal?.removeEventListener("abort", abortHandler);
    };

    // RT-3: abort propagation — risolve immediatamente senza aspettare i 32s di timeout
    const abortHandler = () => {
      cleanup();
      const partial = [stdout, stderr ? `[stderr] ${stderr}` : ""].filter(Boolean).join("\n");
      resolve(`❌ [ABORT] Esecuzione Python interrotta dall'utente.${partial ? "\nOutput parziale:\n" + partial : ""}`);
    };
    if (signal?.aborted) { resolve("❌ [ABORT] Esecuzione Python interrotta dall'utente."); return; }
    if (signal) signal.addEventListener("abort", abortHandler, { once: true });

    const timer = setTimeout(() => {
      cleanup();
      const partial = [stdout, stderr ? `[stderr] ${stderr}` : ""].filter(Boolean).join("\n");
      resolve(`❌ Python timeout (30s)${partial ? "\nOutput parziale:\n" + partial : ""}`);
    }, 32_000);

    _pyListeners.set(id, (msg: _PyWorkerMsg) => {
      if (msg.type === "stdout") {
        const text = msg.text ?? "";
        if (text.startsWith("[pip]")) {
          // S70: messaggi install → feedback live via onStatus
          const label = text.replace("[pip]", "").replace(/\n$/, "").trim();
          if (label && _pyStatus) {
            if (label.startsWith("✓")) _pyStatus(`✅ Python: ${label.slice(1).trim()}`);
            else                        _pyStatus(`📦 ${label}`);
          }
          stdout += text;
        } else {
          stdout += text;
        }
      } else if (msg.type === "stderr") {
        stderr += msg.text ?? "";
      } else if (msg.type === "done" || msg.type === "error") {
        cleanup();
        const exitCode = msg.type === "done" ? (msg.exitCode ?? 0) : 1;
        // Rimuovi linee [pip] dall'output finale — l'utente le ha già viste live
        const cleanStdout = stdout
          .split("\n")
          .filter(l => !l.startsWith("[pip]"))
          .join("\n")
          .trim();
        const out = [cleanStdout, stderr ? `[stderr] ${stderr.trim()}` : ""]
          .filter(Boolean)
          .join("\n") || "(nessun output)";
        resolve(exitCode === 0 ? out : `❌ Python error (exit ${exitCode}):\n${out}`);
      }
    });

    worker.postMessage({ type: "run", id, code, packages });
  });
}