"""M12/Node - HearthNode composition root.

Spec: docs/M12-cli.md §5 (node.start 15-step sequence)
Impl-ref: impl_ref.md §17 (node.py, ManifestPublisher)

Wires all services together. The 15-step startup lives in node.start().
"""

from __future__ import annotations

import asyncio
import contextlib
import logging
import time
from dataclasses import dataclass
from pathlib import Path
from typing import Any

from hearthnet.bus import CapabilityBus, InMemoryTransport
from hearthnet.discovery import PeerRecord, PeerRegistry
from hearthnet.emergency.detector import Detector
from hearthnet.emergency.state import StateBus
from hearthnet.facades import ChatFacade, MarketplaceFacade, RagFacade
from hearthnet.services import ChatService, LlmService, MarketplaceService, RagService
from hearthnet.services.files import FileService
from hearthnet.services.moe import MoeService
from hearthnet.services.tools import PlantIdentificationService
from hearthnet.types import CommunityID, Endpoint, NodeID, Profile

_log = logging.getLogger(__name__)

# Gossip-sync period in seconds
_GOSSIP_INTERVAL_SECONDS = 30


class _HttpxSyncClient:
    """Minimal httpx adapter for :class:`SyncClient`.

    SyncClient treats a dict response as already-parsed JSON, so we return the
    decoded body directly from ``get``/``post`` (avoiding SyncClient's
    aiohttp-style ``await resp.json()`` path). Degrades to a no-op when httpx is
    not installed.
    """

    def __init__(self) -> None:
        self._client: Any = None
        self.unavailable = False
        try:
            import httpx

            self._client = httpx.AsyncClient(timeout=30.0)
        except ImportError:
            self.unavailable = True

    async def get(self, url: str) -> dict[str, Any]:
        resp = await self._client.get(url)
        resp.raise_for_status()
        return resp.json()

    async def post(
        self, url: str, *, data: Any = None, headers: dict[str, str] | None = None
    ) -> dict[str, Any]:
        resp = await self._client.post(url, content=data, headers=headers)
        resp.raise_for_status()
        return resp.json()

    async def aclose(self) -> None:
        if self._client is not None:
            with contextlib.suppress(Exception):
                await self._client.aclose()


@dataclass
class NodeManifest:
    node_id: NodeID
    display_name: str
    community_id: CommunityID
    profile: Profile
    capabilities: list[dict[str, Any]]

    def as_dict(self) -> dict[str, Any]:
        return {
            "version": 1,
            "contract_version": "1.0",
            "node_id": self.node_id,
            "display_name": self.display_name,
            "community_id": self.community_id,
            "profile": self.profile,
            "capabilities": self.capabilities,
        }


class HearthNode:
    def __init__(
        self,
        node_id: NodeID,
        display_name: str,
        community_id: CommunityID,
        *,
        transport: InMemoryTransport | None = None,
        profile: Profile = "hearth",
    ) -> None:
        self.node_id = node_id
        self.display_name = display_name
        self.community_id = community_id
        self.profile: Profile = profile
        # Default to the HTTP-capable transport so a standalone node can reach
        # remote peers over the network (e.g. the public HF Space). The
        # in-process InMemoryNetwork still passes a shared InMemoryTransport.
        # CompositeTransport is a drop-in superset of HttpBusTransport that also
        # accepts pluggable delivery strategies (relay/WebRTC/tunnel) — relay is
        # attached only on demand via join_relay(), keeping nodes local-first.
        if transport is None:
            from hearthnet.bus.transport import CompositeTransport

            transport = CompositeTransport()
        self.bus = CapabilityBus(node_id, community_id, transport)
        self.peers = PeerRegistry(node_id, community_id)
        self.state_bus = StateBus()
        self.detector = Detector(self.bus, self.state_bus, self.peers)
        self.rag = RagFacade(self.bus)
        self.chat = ChatFacade(self.bus)
        self.marketplace = MarketplaceFacade(self.bus)

        # Manual peer bridging (discovery.peer.add / discovery.peers) — enables
        # cross-network peering where mDNS/UDP multicast cannot reach.
        from hearthnet.discovery.service import DiscoveryService

        self.bus.register_service(DiscoveryService(self.bus, self.peers))

        # mesh.join — redeem an invite/relay code into all-to-all relay membership.
        from hearthnet.transport.mesh_service import MeshService

        self.bus.register_service(MeshService(self))

        # Populated by start()
        self._http_server: Any = None
        self._event_log: Any = None
        self._replay_engine: Any = None
        self._mdns_announcer: Any = None
        self._mdns_browser: Any = None
        self._udp_announcer: Any = None
        self._udp_listener: Any = None
        self._gossip_task: asyncio.Task | None = None
        self._emergency_task: asyncio.Task | None = None
        self._pubsub_task: asyncio.Task | None = None
        self._replicator_task: asyncio.Task | None = None
        self._replicator: Any = None
        self._rag_service: Any = None
        self._started: bool = False
        self._relay_client: Any = None

    # ------------------------------------------------------------------
    # Relay mesh (opt-in, NAT-safe all-to-all over a public hub)
    # ------------------------------------------------------------------

    async def join_relay(
        self, relay_url: str, *, token: str | None = None
    ) -> dict[str, Any]:
        """Join a relay hub so this node meshes all-to-all with NAT-bound peers.

        Opt-in only — a node stays purely local until this is called (e.g. from a
        redeemed invite or the ``mesh up`` launcher). Registers the relay roster's
        capabilities locally and attaches a :class:`RelayStrategy` to the bus
        transport so calls to those peers are delivered through the hub.

        Returns the hub's join response (current roster + ttl). Raises if the bus
        transport is not relay-capable (i.e. not a CompositeTransport).
        """
        from hearthnet.bus.transport import CompositeTransport
        from hearthnet.transport.relay_client import RelayClient, RelayStrategy

        if not isinstance(self.bus.transport, CompositeTransport):
            raise RuntimeError("relay requires a CompositeTransport bus transport")

        if self._relay_client is not None:
            await self._relay_client.close()
            self.bus.transport.remove_strategy("relay")

        client = RelayClient(
            relay_url,
            node_id=self.node_id,
            display_name=self.display_name,
            community_id=self.community_id,
            bus=self.bus,
            peers=self.peers,
            token=token,
        )
        result = await client.join()
        self.bus.transport.add_strategy(RelayStrategy(client))
        self._relay_client = client
        return result

    async def leave_relay(self) -> None:
        if self._relay_client is not None:
            from hearthnet.bus.transport import CompositeTransport

            await self._relay_client.close()
            if isinstance(self.bus.transport, CompositeTransport):
                self.bus.transport.remove_strategy("relay")
            self._relay_client = None

    # ------------------------------------------------------------------
    # Service installation
    # ------------------------------------------------------------------

    def install_demo_services(self, *, internet_llm: bool = False, corpus: str = "demo") -> None:
        """FOR TESTS ONLY — install echo-LLM + in-memory services (no disk I/O, fast).

        Production code should call install_services() which auto-discovers real backends.
        """
        # Use demo- prefixed model name so LlmService creates _EchoBackend (test path)
        from hearthnet.services.demo import (
            LlmService as DemoLlm,
        )
        from hearthnet.services.demo import (
            MarketplaceService as DemoMarket,
        )
        from hearthnet.services.demo import (
            RagService as DemoRag,
        )

        model_name = "demo-remote" if internet_llm else "demo-local"
        services = [
            DemoLlm(model=model_name, requires_internet=internet_llm),
            DemoRag(
                corpus=corpus,
                documents=[
                    {
                        "id": "seed",
                        "title": "Water",
                        "text": "Store clean water and boil rainwater.",
                    }
                ],
            ),
            DemoMarket(),
            ChatService(self.node_id, bus=self.bus),
            FileService(),
            MoeService(bus=self.bus),
            PlantIdentificationService(bus=self.bus),
        ]
        # ModelDistributionService also needed in tests; use a temp BlobStore
        import tempfile

        from hearthnet.blobs.store import BlobStore
        from hearthnet.services.llm.model_distribution import ModelDistributionService
        from hearthnet.services.protocol import ProtocolService
        from hearthnet.services.rag.federated import FederatedRagService

        tmp_store = BlobStore(Path(tempfile.mkdtemp()) / "blobs")
        services.append(ModelDistributionService(store=tmp_store, models_dir=None, bus=self.bus))
        services.append(ProtocolService(node=self))
        services.append(FederatedRagService(self.bus, corpus=corpus))
        for service in services:
            self.bus.register_service(service)

    def install_services(
        self,
        *,
        corpus: str = "community",
        models_dir=None,
        blob_store=None,
    ) -> None:
        """Install real services with auto-discovered LLM backends.

        Backend discovery order (local-first, no internet unless explicitly enabled):
          1. OllamaBackend  — if ollama is running on localhost
          2. LlamaCppBackend — if llama.cpp HTTP server is running on localhost
          3. HfLocalBackend  — if transformers is installed (loads on first call)
          4. _UnavailableBackend — fallback: returns a clear error, not a silent echo

        Also installs ModelDistributionService so peers can pull model weights.
        """
        import os

        from hearthnet.services.llm.backends.hf_local import HfLocalBackend
        from hearthnet.services.llm.backends.modal_backend import ModalBackend
        from hearthnet.services.llm.backends.nemotron import NemotronBackend
        from hearthnet.services.llm.backends.ollama import OllamaBackend
        from hearthnet.services.llm.backends.openai_compat import OpenAICompatBackend
        from hearthnet.services.llm.backends.openbmb import OpenBmbBackend
        from hearthnet.services.llm.model_distribution import ModelDistributionService
        from hearthnet.services.protocol import ProtocolService

        backends = []

        # 1. Ollama (best quality, zero-config local)
        ollama = OllamaBackend()
        if ollama.is_available():
            backends.append(ollama)

        # 2. llama.cpp HTTP server on default port
        llama_http = OpenAICompatBackend(
            base_url="http://localhost:8080/v1",
            api_key_env="",
            model="local",
        )
        if llama_http.is_available():
            backends.append(llama_http)

        # 3. MiniCPM local server (OpenBMB prize track)
        if os.getenv("MINICPM_URL"):
            minicpm = OpenBmbBackend(base_url=os.getenv("MINICPM_URL", "http://localhost:8000"))
            if minicpm.is_available():
                backends.append(minicpm)
                _log.info("MiniCPM backend registered from MINICPM_URL")

        # 4. NVIDIA Nemotron (cloud NIM or local; NVIDIA prize track)
        if os.getenv("NVIDIA_API_KEY"):
            nemotron = NemotronBackend(api_key_env="NVIDIA_API_KEY")
            backends.append(nemotron)  # cloud — no local check needed
            _log.info("Nemotron backend registered (NVIDIA_API_KEY set)")
        elif os.getenv("NEMOTRON_URL"):
            nemotron_local = NemotronBackend(
                base_url=os.getenv("NEMOTRON_URL", "http://localhost:8001"),
                local=True,
            )
            if nemotron_local.is_available():
                backends.append(nemotron_local)
                _log.info("Nemotron local backend registered from NEMOTRON_URL")

        # 5. Modal serverless GPU (Modal prize track)
        if os.getenv("MODAL_ENDPOINT"):
            modal_b = ModalBackend()
            if modal_b.is_available():
                backends.append(modal_b)
                _log.info("Modal backend registered from MODAL_ENDPOINT")

        # 6. HF Transformers local (always available if transformers installed)
        hf = HfLocalBackend()
        if hf.is_available():
            backends.append(hf)

        from hearthnet.services.rag.federated import FederatedRagService

        services = [
            LlmService(backends=backends or None),  # _UnavailableBackend if none found
            # RagService receives blob_store now; event_log is injected in start()
            # after the EventLog is open (it's a lazy reference via _rag_service).
            RagService(corpus=corpus, blob_store=blob_store),
            FederatedRagService(self.bus, corpus=corpus),
            MarketplaceService(),
            ChatService(self.node_id, bus=self.bus),
            FileService(),
            MoeService(bus=self.bus),
            PlantIdentificationService(bus=self.bus),
            ProtocolService(node=self),
        ]
        # Keep a reference so start() can inject the event_log later.
        self._rag_service = services[1]

        # Model weight distribution (BitTorrent-style M07/M26)
        # Use provided blob_store or auto-create a persistent one in ~/.hearthnet/blobs
        if blob_store is None:
            from hearthnet.blobs.store import BlobStore

            blob_store = BlobStore(Path.home() / ".hearthnet" / "blobs")

        model_svc = ModelDistributionService(
            store=blob_store,
            models_dir=models_dir,
            bus=self.bus,
        )
        services.append(model_svc)

        for service in services:
            self.bus.register_service(service)

        # Register the real auxiliary services (embed/rerank/ocr/translation/
        # speech/image). Phase-3 research services stay off unless opted in.
        self.install_extended_services(research=False)

    def install_extended_services(
        self,
        *,
        research: bool = False,
        embed_model: str = "BAAI/bge-small-en-v1.5",
    ) -> None:
        """Register the real auxiliary services beyond the core set.

        Always (each degrades gracefully to an "unavailable" response when its
        optional backend/model is missing — never a mock):
          M11 EmbeddingService   embed.text      (real semantic vectors when
                                                  sentence-transformers present)
          M24 RerankService      rerank.text
          M17 OcrService         ocr.image / ocr.pdf
          M18 TranslationService trans.text
          M19 Stt/TtsService     stt.transcribe / tts.speak
          M20 Image services     image.describe / image.generate

        When ``research=True`` (opt-in; the demo Space enables it), also registers
        the real Phase-3 services:
          M30 EvidenceService      evidence.claim.*
          M31 CivilDefenseService  civdef.*

        Every registration is wrapped so a missing optional dependency can never
        break node startup.
        """

        def _register(svc: Any) -> None:
            if hasattr(svc, "capabilities"):
                self.bus.register_service(svc)
            elif hasattr(svc, "register"):
                svc.register(self.bus)

        # ── M11 Embedding (core for real RAG) ──────────────────────────────
        try:
            import importlib.util

            from hearthnet.services.embedding.service import EmbeddingService

            backend = None
            if importlib.util.find_spec("sentence_transformers") is not None:
                from hearthnet.services.embedding.backends import (
                    SentenceTransformerBackend,
                )

                backend = SentenceTransformerBackend(model=embed_model)
            _register(EmbeddingService(backend=backend))
        except Exception as exc:
            _log.warning("EmbeddingService registration skipped: %s", exc)

        # ── Remaining always-on auxiliary services ─────────────────────────
        _aux: list[tuple[str, Any]] = []
        try:
            from hearthnet.services.rerank.service import RerankService

            _aux.append(("rerank", RerankService()))
        except Exception as exc:
            _log.debug("RerankService unavailable: %s", exc)
        try:
            from hearthnet.services.ocr.service import OcrService

            _aux.append(("ocr", OcrService()))
        except Exception as exc:
            _log.debug("OcrService unavailable: %s", exc)
        try:
            from hearthnet.services.translation.service import TranslationService

            _aux.append(("translation", TranslationService()))
        except Exception as exc:
            _log.debug("TranslationService unavailable: %s", exc)
        try:
            from hearthnet.services.speech.stt_service import SttService
            from hearthnet.services.speech.tts_service import TtsService

            _aux.append(("stt", SttService()))
            _aux.append(("tts", TtsService()))
        except Exception as exc:
            _log.debug("Speech services unavailable: %s", exc)
        try:
            from hearthnet.services.image.describe_service import ImageDescribeService

            _aux.append(("image.describe", ImageDescribeService()))
        except Exception as exc:
            _log.debug("ImageDescribeService unavailable: %s", exc)
        try:
            from hearthnet.services.image.generate_service import ImageGenerateService

            _aux.append(("image.generate", ImageGenerateService()))
        except Exception as exc:
            _log.debug("ImageGenerateService unavailable: %s", exc)

        for label, svc in _aux:
            try:
                _register(svc)
            except Exception as exc:
                _log.warning("%s registration skipped: %s", label, exc)

        if not research:
            return

        # ── Phase-3 research services (opt-in only) ────────────────────────
        try:
            from hearthnet.evidence.service import EvidenceService

            _register(EvidenceService(community_id=self.community_id))
        except Exception as exc:
            _log.warning("EvidenceService registration skipped: %s", exc)
        try:
            from hearthnet.civdef.service import CivilDefenseService

            _register(CivilDefenseService())
        except Exception as exc:
            _log.warning("CivilDefenseService registration skipped: %s", exc)

    async def start(
        self,
        *,
        host: str = "0.0.0.0",  # nosec B104
        port: int = 7080,
        data_dir: Path | str | None = None,
        gossip_interval: int = _GOSSIP_INTERVAL_SECONDS,
    ) -> None:
        """Start the node — wires all subsystems.

        Steps:
         1-2. Already done: node_id + bus created in __init__
           3. Start mDNS + UDP peer discovery
           4. Load config (external; this method receives data_dir)
           5. Services already registered by caller via install_services()
           6. (LLM warmup deferred to first call)
           7. (RAG warmup deferred to first call)
           8. Start Detector (emergency probe loop)
           9. Start EventLog + ReplayEngine
          10. Start FastAPI HttpServer (X01)
          11. Publish manifest (mDNS)
          12. (Community join via invite; deferred to CLI/UI)
          13. Start observability
          14. (Federation; deferred)
          15. Signal ready
        """
        if self._started:
            return

        _log.info("HearthNode.start() node_id=%s port=%d", self.node_id, port)
        data_dir_path = (
            Path(data_dir) if data_dir else Path.home() / ".hearthnet" / "nodes" / self.node_id[:16]
        )
        data_dir_path.mkdir(parents=True, exist_ok=True)

        # ── Step 9: Event log + replay engine ─────────────────────────
        try:
            from hearthnet.events import EventLog, ReplayEngine

            self._event_log = EventLog(data_dir_path / "events.db", self.community_id, self.node_id)
            self._replay_engine = ReplayEngine(self._event_log)
            _log.debug("EventLog opened at %s", data_dir_path / "events.db")
        except Exception as exc:
            _log.warning("EventLog init failed (non-fatal): %s", exc)

        # ── Step 3: Peer discovery (mDNS + UDP) ───────────────────────
        caps = [e.descriptor.name for e in self.bus.registry.all_local()]
        try:
            from hearthnet.discovery.mdns import MdnsAnnouncer, MdnsBrowser
            from hearthnet.discovery.udp import UdpAnnouncer, UdpListener

            self._mdns_announcer = MdnsAnnouncer(
                self.peers,
                self.node_id,
                self.display_name,
                port=port,
                properties={"profile": self.profile, "caps": caps},
            )
            self._mdns_browser = MdnsBrowser(self.peers, self.community_id)
            self._udp_announcer = UdpAnnouncer(
                self.peers, self.node_id, self.community_id, port=port, caps=caps
            )
            self._udp_listener = UdpListener(self.peers, self.community_id)

            await self._mdns_announcer.start()
            await self._mdns_browser.start()
            await self._udp_announcer.start()
            await self._udp_listener.start()
            _log.debug("mDNS + UDP discovery started on port %d", port)
        except Exception as exc:
            _log.warning("Discovery init failed (non-fatal): %s", exc)

        # ── Step 8: Emergency detector ────────────────────────────────
        try:
            await self.detector.start()
        except Exception as exc:
            _log.warning("Emergency detector start failed (non-fatal): %s", exc)

        # ── Step 10: HTTP server (X01) + WebSocket pubsub (X06) ───────
        try:
            from hearthnet.events.sync import SyncServer
            from hearthnet.transport.server import HttpServer

            sync_server = SyncServer(self._event_log) if self._event_log else None
            self._http_server = HttpServer(
                bus=self.bus,
                node_manifest_fn=lambda: self.manifest().as_dict(),
                sync_server=sync_server,
                host=host,
                port=port,
            )
            self._http_server.build_app()
            await self._http_server.start()
            _log.info("HTTP server listening on %s:%d", host, port)

            # Wire StateBus -> WebSocket pubsub (X06)
            if self._http_server._ws_pubsub is not None:
                self._pubsub_task = asyncio.create_task(
                    self._state_bus_to_pubsub(), name="state-pubsub"
                )
        except Exception as exc:
            _log.warning("HTTP server start failed (non-fatal): %s", exc)

        # ── Gossip sync loop (X02) ────────────────────────────────────
        if self._event_log is not None:
            self._gossip_task = asyncio.create_task(
                self._gossip_loop(gossip_interval), name="gossip-sync"
            )

        # -- Corpus replicator (Phase 2: BitTorrent-style RAG sync) ----------
        if self._event_log is not None:
            try:
                from hearthnet.blobs.store import BlobStore
                from hearthnet.blobs.transfer import TransferManager
                from hearthnet.services.rag.replication import CorpusReplicator
                from hearthnet.services.rag.store import CorpusStore

                # Inject event_log into the RagService now that EventLog is open.
                if self._rag_service is not None:
                    self._rag_service._event_log = self._event_log

                repl_blob_store = BlobStore(data_dir_path / "repl_blobs")
                transfer = TransferManager(repl_blob_store, http_client=None)

                def _corpus_store_fn(corpus: str) -> CorpusStore:
                    return CorpusStore(data_dir_path / "corpora", corpus)

                self._replicator = CorpusReplicator(
                    bus=self.bus,
                    event_log=self._event_log,
                    transfer=transfer,
                    peers=self.peers,
                    local_node_id=self.node_id,
                    corpus_store_fn=_corpus_store_fn,
                )
                self._replicator_task = self._replicator.start()
                _log.info("CorpusReplicator started")
            except Exception as exc:
                _log.warning("CorpusReplicator init failed (non-fatal): %s", exc)

        _log.info("HearthNode ready: %s", self.node_id)

    async def stop(self) -> None:
        """Gracefully stop all background tasks and subsystems."""
        if not self._started:
            return

        _log.info("HearthNode.stop() node_id=%s", self.node_id)
        self._started = False

        # Leave relay mesh (stops poll loop, closes client)
        with contextlib.suppress(Exception):
            await self.leave_relay()

        # Close event log
        if self._event_log is not None:
            with contextlib.suppress(Exception):
                self._event_log.close()
            self._event_log = None

        # Stop emergency detector
        with contextlib.suppress(Exception):
            await self.detector.stop()

        # Cancel background tasks
        for task_attr in ("_gossip_task", "_pubsub_task", "_replicator_task"):
            task = getattr(self, task_attr, None)
            if task and not task.done():
                task.cancel()
                with contextlib.suppress(asyncio.CancelledError, Exception):
                    await task
            setattr(self, task_attr, None)

        # Stop discovery
        for attr in ("_udp_announcer", "_udp_listener", "_mdns_announcer"):
            obj = getattr(self, attr, None)
            if obj:
                with contextlib.suppress(Exception):
                    await obj.stop()
        if self._mdns_browser:
            try:
                if hasattr(self._mdns_browser, "stop"):
                    await self._mdns_browser.stop()
            except Exception:
                pass

        # Stop HTTP server
        if self._http_server:
            with contextlib.suppress(Exception):
                await self._http_server.shutdown()
            self._http_server = None

    # ------------------------------------------------------------------
    # Background tasks
    # ------------------------------------------------------------------

    async def _gossip_loop(self, interval: int) -> None:
        """Periodically sync event log with all known peers (X02 gossip)."""
        from hearthnet.events.sync import SyncClient

        http_client = _HttpxSyncClient()
        if http_client.unavailable:
            _log.info("Gossip sync disabled: httpx not installed")
            return
        sync_client = SyncClient(self._event_log, http_client)

        try:
            while True:
                await asyncio.sleep(interval)
                for peer in self.peers.all():
                    if not peer.endpoints:
                        continue
                    ep = peer.endpoints[0]
                    if ep.transport == "memory":
                        continue  # in-process; no HTTP needed
                    peer_url = f"http://{ep.host}:{ep.port}"
                    try:
                        result = await sync_client.sync_with(peer_url, self.community_id)
                        if result.received_count or result.sent_count:
                            _log.debug(
                                "Gossip with %s: sent=%d recv=%d ms=%d",
                                peer.display_name,
                                result.sent_count,
                                result.received_count,
                                result.duration_ms,
                            )
                    except Exception as exc:
                        _log.debug("Gossip sync with %s failed: %s", peer.display_name, exc)
        finally:
            await http_client.aclose()

    async def _state_bus_to_pubsub(self) -> None:
        """Forward StateBus state changes to the WebSocket pubsub (X06)."""
        try:
            async for state in self.state_bus.subscribe():
                if self._http_server is None:
                    break
                await self._http_server.publish_event(
                    topic="emergency.mode.changed",
                    event="emergency.mode.changed",
                    data={
                        "mode": state.mode,
                        "mode_label": state.mode_label,
                        "changed_at": state.changed_at,
                        "probe_results": state.probe_results,
                        "consecutive_fails": state.consecutive_fails,
                    },
                )
        except asyncio.CancelledError:
            pass
        except Exception as exc:
            _log.warning("state_bus_to_pubsub error: %s", exc)

    # ------------------------------------------------------------------
    # Introspection
    # ------------------------------------------------------------------

    def manifest(self) -> NodeManifest:
        capabilities = [
            {
                "name": entry.descriptor.name,
                "version": entry.descriptor.version_str,
                "stability": entry.descriptor.stability,
                "schema_hash": entry.descriptor.schema_hash(),
                "params": dict(entry.descriptor.params),
                "max_concurrent": entry.descriptor.max_concurrent,
            }
            for entry in self.bus.registry.all_local()
        ]
        return NodeManifest(
            self.node_id, self.display_name, self.community_id, self.profile, capabilities
        )

    def discover(self, other: HearthNode) -> None:
        record = PeerRecord(
            node_id_full=other.node_id,
            display_name=other.display_name,
            community_id=other.community_id,
            profile=other.profile,
            endpoints=[Endpoint("memory", other.node_id, 0)],
            manifest=other.manifest().as_dict(),
            last_seen=time.monotonic(),
        )
        if self.peers.upsert(record):
            self.bus.registry.update_from_peer_manifest(record, record.manifest or {})

    def snapshot(self) -> dict[str, Any]:
        topology = self.bus.topology_snapshot([peer.as_view() for peer in self.peers.all()])
        return {
            "node": {
                "node_id": self.node_id,
                "display_name": self.display_name,
                "community_id": self.community_id,
                "profile": self.profile,
            },
            "emergency": self.state_bus.current(),
            "topology": topology,
            "started": self._started,
            "event_log_head": self._event_log.head() if self._event_log else None,
        }


class InMemoryNetwork:
    def __init__(self) -> None:
        self.transport = InMemoryTransport()
        self.nodes: list[HearthNode] = []

    def add_node(
        self, node_id: NodeID, display_name: str, community_id: CommunityID = "ed25519:community"
    ) -> HearthNode:
        node = HearthNode(node_id, display_name, community_id, transport=self.transport)
        self.nodes.append(node)
        return node

    def mesh_discover(self) -> None:
        for node in self.nodes:
            for other in self.nodes:
                if node is not other:
                    node.discover(other)


# ---------------------------------------------------------------------------
# PeriodicTask — generic async interval runner (M12 §5)
# ---------------------------------------------------------------------------


class PeriodicTask:
    """Run *fn* every *interval_seconds* until cancelled.

    Usage::

        task = PeriodicTask(my_async_fn, interval_seconds=60)
        asyncio.create_task(task.run())
    """

    def __init__(self, fn, interval_seconds: int) -> None:
        self._fn = fn
        self._interval = interval_seconds

    async def run(self) -> None:
        while True:
            await asyncio.sleep(self._interval)
            try:
                await self._fn()
            except asyncio.CancelledError:
                raise
            except Exception as exc:
                _log.debug("PeriodicTask %s error: %s", self._fn, exc)


# ---------------------------------------------------------------------------
# ManifestPublisher — republishes node manifest to mDNS + UDP (M12 §5)
# ---------------------------------------------------------------------------

_MANIFEST_REPUBLISH_INTERVAL_SECONDS = 300  # 5 minutes default


class ManifestPublisher:
    """Periodically re-publishes the node manifest to mDNS + UDP announcer.

    Also triggered when the bus registry changes (capability added/removed).
    """

    def __init__(
        self,
        bus,
        peer_registry,
        mdns_announcer=None,
        udp_announcer=None,
        node_manifest_fn=None,
        interval_seconds: int = _MANIFEST_REPUBLISH_INTERVAL_SECONDS,
    ) -> None:
        self._bus = bus
        self._peer_registry = peer_registry
        self._mdns_announcer = mdns_announcer
        self._udp_announcer = udp_announcer
        self._node_manifest_fn = node_manifest_fn
        self._interval = interval_seconds
        self._task: asyncio.Task | None = None

    async def run(self) -> None:
        """Publish immediately then republish every *interval_seconds*."""
        while True:
            await self._publish()
            await asyncio.sleep(self._interval)

    async def _publish(self) -> None:
        try:
            manifest = self._node_manifest_fn() if self._node_manifest_fn else {}
            caps = [c.get("name") for c in manifest.get("capabilities", [])]
            if self._mdns_announcer and hasattr(self._mdns_announcer, "republish"):
                await self._mdns_announcer.republish(caps)
            if self._udp_announcer and hasattr(self._udp_announcer, "republish"):
                await self._udp_announcer.republish()
        except Exception as exc:
            _log.debug("ManifestPublisher._publish error: %s", exc)