"""Dashboard process-hygiene helpers — extracted from ``hermes_cli/main.py``.

Helpers that STAY in ``hermes_cli.main`` are reached through the lazy ``_m()``
reference so monkeypatches on ``hermes_cli.main.<name>`` keep working and
imports stay one-way (main.py imports this module, never the reverse).
"""

import os
import subprocess
import sys
from pathlib import Path

# Cmdline substrings identifying the long-lived server. ``hermes serve`` is the
# same server under the headless name the desktop app spawns; it is reaped on
# update for the same frontend/backend-mismatch reason as ``dashboard``.
_DASHBOARD_PATTERNS = tuple(
    f"{launcher} {cmd}"
    for cmd in ("dashboard", "serve")
    for launcher in ("hermes", "hermes_cli.main", "hermes_cli/main.py")
)


def _m():
    """Lazy ``hermes_cli.main`` reference (call-time; keeps patches working)."""
    from hermes_cli import main

    return main


def _empty_result() -> dict[str, list]:
    return {"matched": [], "killed": [], "failed": []}


def _scan_dashboard_processes(*, exclude_pids: set[int] | None = None) -> list[tuple[int, str]]:
    """Return matching ``dashboard``/``serve`` processes with their cmdlines.

    ``hermes update`` swaps files on disk while a forgotten dashboard keeps the
    old Python backend in memory against the new JS bundle — a silent mismatch
    (new auth headers → every API call 401s). *exclude_pids* must never be
    returned: Hermes Desktop sets ``HERMES_DESKTOP_CHILD_PID`` on the backend
    it spawns so an auto-update never kills the backend it manages itself.

    Returns an empty list on any scan error (missing ps/wmic, timeout, etc.).
    """
    self_pid = os.getpid()
    found: list[tuple[int, str]] = []

    def _consider(pid: int, command: str) -> None:
        if pid != self_pid and any(p in command for p in _DASHBOARD_PATTERNS):
            found.append((pid, command))

    try:
        if sys.platform == "win32":
            # errors="ignore": wmic may emit the system code page; a decode
            # error would leave stdout=None. bounded_probe_run (not run()):
            # run()'s post-timeout cleanup joins pipe readers unbounded and a
            # conhost descendant holding duplicated handles wedges it forever.
            # It also passes CREATE_NO_WINDOW for the pythonw.exe backend.
            from hermes_cli._subprocess_compat import bounded_probe_run

            result = bounded_probe_run(
                ["wmic", "process", "get", "ProcessId,CommandLine", "/FORMAT:LIST"],
                timeout=10,
                errors="ignore",
            )
            if result is None or result.returncode != 0 or result.stdout is None:
                return []
            current_cmd = ""
            for line in result.stdout.split("\n"):
                line = line.strip()
                if line.startswith("CommandLine="):
                    current_cmd = line[len("CommandLine=") :]
                elif line.startswith("ProcessId="):
                    try:
                        _consider(int(line[len("ProcessId=") :]), current_cmd)
                    except ValueError:
                        pass
        else:
            # ps (not `pgrep -f "hermes.*dashboard"`) keeps us consistent with
            # gateway._scan_gateway_pids and avoids a greedy regex matching
            # unrelated cmdlines that merely contain both words.
            result = subprocess.run(
                ["ps", "-A", "-o", "pid=,command="],
                capture_output=True, text=True, encoding="utf-8", errors="replace", timeout=10,
            )
            if result.returncode == 0:
                for line in getattr(result, "stdout", "").split("\n"):
                    parts = line.strip().split(None, 1)
                    if len(parts) != 2 or "grep" in line:
                        continue
                    try:
                        _consider(int(parts[0]), parts[1])
                    except ValueError:
                        continue
    except (FileNotFoundError, subprocess.TimeoutExpired, OSError):
        return []

    if exclude_pids:
        found = [proc for proc in found if proc[0] not in exclude_pids]

    # Spawn-ledger augmentation: substring patterns miss profiled launches
    # (`hermes --profile p serve ...`). Every serve/dashboard registers itself
    # in the spawn ledger with live-verified (pid, create_time) — positive
    # identity. Add entries the scan missed, preferring the ledger's full argv.
    try:
        from hermes_cli.process_identity import ledger_entries

        seen = {pid for pid, _ in found}
        for entry in ledger_entries():
            pid = entry.get("pid")
            if (
                entry.get("purpose") not in ("serve", "dashboard")
                or not isinstance(pid, int)
                or pid == self_pid
                or pid in seen
                or (exclude_pids and pid in exclude_pids)
            ):
                continue
            found.append((pid, str(entry.get("argv") or "")))
    except Exception:
        pass  # ledger unavailable → scan-only behavior

    return found


def _hermes_home_for_pid(pid: int) -> str | None:
    """Best-effort ``HERMES_HOME`` from *pid*'s environment (psutil, then /proc)."""
    try:
        import psutil

        home = psutil.Process(pid).environ().get("HERMES_HOME")
        if home:
            return home
    except Exception:
        pass
    try:
        raw = Path(f"/proc/{pid}/environ").read_bytes()
    except OSError:
        return None
    for part in raw.split(b"\x00"):
        if part.startswith(b"HERMES_HOME="):
            return part.split(b"=", 1)[1].decode("utf-8", errors="replace") or None
    return None


def _dashboard_subcommand_index(argv: list[str]) -> int | None:
    for i, tok in enumerate(argv):
        if tok in ("serve", "dashboard"):
            return i
    return None


def _profile_flag_value(argv: list[str]) -> str | None:
    """Value of the first ``--profile X`` / ``-p X`` / ``--profile=X`` in *argv*."""
    for i, tok in enumerate(argv):
        if tok in ("--profile", "-p") and i + 1 < len(argv):
            return str(argv[i + 1])
        if tok.startswith("--profile="):
            return tok.split("=", 1)[1]
    return None


def _is_ephemeral_port_zero_backend(argv: list[str]) -> bool:
    """True for Desktop-style ``serve|dashboard --port 0`` backends.

    Ephemeral-port backends are owned by Hermes Desktop (or are PPID-1 orphans
    of a prior update respawn). Replaying them after ``hermes update``
    multiplies listening backends because ``--port 0`` always binds a fresh
    port. Covers both ``serve`` and the legacy ``dashboard --no-open``
    fallback older Desktop runtimes use.
    """
    if _dashboard_subcommand_index(argv) is None:
        return False
    for i, tok in enumerate(argv):
        if tok == "--port" and i + 1 < len(argv) and str(argv[i + 1]) == "0":
            return True
        if tok.startswith("--port=") and tok.split("=", 1)[1].strip() == "0":
            return True
    return False


def _normalize_dashboard_cmdline(argv: list[str]) -> tuple[str, ...]:
    """Collapse argv to profile flags + serve/dashboard tail for dedupe."""
    idx = _dashboard_subcommand_index(argv)
    if idx is None:
        return tuple(argv)
    prefix: list[str] = []
    i = 0
    while i < idx:
        tok = argv[i]
        if tok in ("--profile", "-p") and i + 1 < idx:
            prefix.extend([tok, argv[i + 1]])
            i += 2
            continue
        if tok.startswith("--profile="):
            prefix.append(tok)
        i += 1
    return tuple(prefix + list(argv[idx:]))


def _resolved_home(home: str) -> Path:
    try:
        return Path(home).resolve()
    except (OSError, RuntimeError, ValueError):
        return Path(home)


def _normalized_home_for_compare(home: str) -> str:
    """Install-identity key for *home*: symlinked / differently-spelled roots
    compare equal (same normalization as ``home:`` respawn keys)."""
    return os.path.normcase(str(_resolved_home(home)))


def _profile_key_for_respawn(argv: list[str], hermes_home: str | None = None) -> str:
    """Stable owner key: ``HERMES_HOME`` when known, else ``--profile`` / ``-p``.

    ``HERMES_HOME`` ending in ``profiles/<name>`` → ``profile:<name>`` so it
    shares a cap with an explicit ``--profile``; other homes keep a resolved
    ``home:`` key so unrelated installs never collapse together.
    """
    if hermes_home:
        parts = _resolved_home(hermes_home).parts
        if len(parts) >= 2 and parts[-2] == "profiles" and parts[-1]:
            return f"profile:{parts[-1]}"
        return f"home:{_normalized_home_for_compare(hermes_home)}"
    return f"profile:{_profile_flag_value(argv) or 'default'}"


def _filter_dashboard_respawn_candidates(
    candidates: list[tuple[int, list[str], str | None]],
    *,
    own_home: str | None = None,
) -> list[list[str]]:
    """Select which killed manual backends to respawn after ``hermes update``.

    Candidates are ``(pid, argv, hermes_home)``; *own_home* (default
    ``get_hermes_home()``) is a parameter so tests can pin it. Rules:
    1. Never resurrect Desktop ephemeral ``--port 0`` backends — Desktop owns
       their lifecycle; they are the PPID-1 orphans that multiplied across updates.
    2. Never replay a backend from a **foreign** ``HERMES_HOME``: the respawn
       is argv-only (no ``env=``), so it would come back on the *updating*
       install's home and steal the foreign install's fixed port, leaving its
       supervisor to crash-loop on ``EADDRINUSE``. Unreadable (``None``) stays eligible.
    3. Dedupe by normalized cmdline. 4. At most one backend per profile / home.

    Does **not** blanket-skip PPID-1: a prior update respawn detaches with
    ``start_new_session=True``, so fixed-port manual backends sit under init
    and must stay eligible next update.
    """
    if own_home is None:
        try:
            from hermes_constants import get_hermes_home

            own_home = str(get_hermes_home())
        except Exception:
            own_home = ""
    own_key = _normalized_home_for_compare(own_home) if own_home else ""

    selected: list[list[str]] = []
    seen_cmdlines: set[tuple[str, ...]] = set()
    seen_profiles: set[str] = set()

    for _pid, argv, hermes_home in candidates:
        if not argv or _is_ephemeral_port_zero_backend(argv):
            continue
        if own_key and hermes_home and _normalized_home_for_compare(hermes_home) != own_key:
            continue
        norm = _normalize_dashboard_cmdline(argv)
        profile_key = _profile_key_for_respawn(argv, hermes_home)
        if norm in seen_cmdlines or profile_key in seen_profiles:
            continue
        seen_cmdlines.add(norm)
        seen_profiles.add(profile_key)
        selected.append(list(argv))

    return selected


def _exclude_pids_from_env() -> set[int]:
    """PIDs Desktop marks as live backends (``HERMES_DESKTOP_CHILD_PID``).

    Desktop may manage several backends (one per active profile) and passes
    them comma-separated; a lone int still parses for back-compat.
    """
    out: set[int] = set()
    for part in os.environ.get("HERMES_DESKTOP_CHILD_PID", "").split(","):
        part = part.strip()
        if not part:
            continue
        try:
            out.add(int(part))
        except ValueError:
            continue
    return out


def _kill_pids_windows(pids: list[int], killed: list[int], failed: list[tuple[int, str]]) -> None:
    """``taskkill /F`` each PID after re-verifying its identity."""
    from gateway.status import get_process_start_time
    from hermes_cli._subprocess_compat import pid_is_hermes, windows_hide_flags

    # Capture identity immediately after discovery: a PID reused before the
    # destructive action fails the start-time check.
    pid_start_times = {pid: get_process_start_time(pid) for pid in pids}
    for pid in pids:
        try:
            expected_start_time = pid_start_times.get(pid)
            if expected_start_time is None:
                failed.append((pid, "could not verify process identity"))
                continue
            if not pid_is_hermes(pid, expected_start_time=expected_start_time):
                failed.append((pid, "not hermes-owned or process identity changed"))
                continue
            result = subprocess.run(
                ["taskkill", "/PID", str(pid), "/F"],
                stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.DEVNULL,
                text=True, encoding="utf-8", errors="replace", timeout=10,
                creationflags=windows_hide_flags(),
            )
            if result.returncode == 0:
                killed.append(pid)
            else:
                failed.append((pid, (result.stderr or result.stdout or "").strip()))
        except (FileNotFoundError, subprocess.TimeoutExpired, OSError) as e:
            failed.append((pid, str(e)))


def _kill_pids_posix(pids: list[int], killed: list[int], failed: list[tuple[int, str]]) -> None:
    """SIGTERM, wait up to ~3s for graceful exit, SIGKILL survivors."""
    import signal as _signal
    import time as _time

    def _send(pid: int, sig) -> None:
        try:
            os.kill(pid, sig)
            if sig == _signal.SIGKILL:
                killed.append(pid)
        except ProcessLookupError:
            killed.append(pid)  # already gone — count as killed
        except (PermissionError, OSError) as e:
            failed.append((pid, str(e)))

    for pid in pids:
        _send(pid, _signal.SIGTERM)

    deadline = _time.monotonic() + 3.0
    pending = [p for p in pids if p not in killed and p not in {f[0] for f in failed}]
    while pending and _time.monotonic() < deadline:
        _time.sleep(0.1)
        # os.kill(pid, 0) is NOT a no-op on Windows; use the portable check.
        from gateway.status import _pid_exists
        alive = [p for p in pending if _pid_exists(p)]
        killed.extend(p for p in pending if p not in alive)
        pending = alive

    for pid in pending:
        _send(pid, _signal.SIGKILL)


def _kill_stale_dashboard_processes(
    reason: str = "the running backend no longer matches the updated frontend",
    *,
    restart_managed: bool = False,
    already_restarted_units: "set[str] | None" = None,
) -> dict[str, list]:
    """Kill running ``hermes dashboard`` / ``hermes serve`` processes.

    Called at the end of ``hermes update`` (default ``reason``) and from
    ``hermes dashboard --stop``; after an update the running process serves
    stale Python against a fresh JS bundle. POSIX: SIGTERM, ~3s grace, SIGKILL
    survivors. Windows: ``taskkill /F``.

    With ``restart_managed`` (update path only — ``--stop`` never restarts) a
    detected ``hermes-dashboard.service`` is restarted through systemd, any
    other killed PID owned by a systemd unit has that unit restarted after the
    kill (systemd treats our SIGTERM as a clean stop, so ``Restart=on-failure``
    never fires), and manual PIDs are respawned from their captured argv.
    *already_restarted_units* (no ``.service`` suffix) were restarted by the
    caller already; PIDs they own are left untouched, not killed twice.
    """
    if restart_managed and _m()._restart_managed_dashboard_service(reason):
        # The dashboard unit is handled but every OTHER backend is not (a host
        # may also run hermes-serve.service hosting tui_gateway): record the
        # unit as handled (the filter below drops PIDs it owns) and keep going.
        _dash_unit = getattr(_m(), "_DASHBOARD_SYSTEMD_UNIT", "hermes-dashboard.service")
        already_restarted_units = set(already_restarted_units or ()) | {
            str(_dash_unit).removesuffix(".service")
        }

    exclude = _exclude_pids_from_env()
    if restart_managed:
        # An SSH-owned backend belongs to an attached Desktop client even when
        # the updater runs from an unrelated shell; killing it strands that
        # client's fixed SSH port-forward. Same ownership records as the reaper.
        exclude |= _lock_owned_serve_pids()

    pids = _m()._find_stale_dashboard_pids(exclude_pids=exclude or None)
    if not pids:
        return _empty_result()

    # Snapshot systemd cgroup/unit and argv BEFORE killing (the cgroup
    # disappears with the process). Linux + update path only.
    pid_cgroup: dict[int, str | None] = {}
    pid_service: dict[int, str | None] = {}
    pid_cmdline: dict[int, list[str]] = {}
    pid_home: dict[int, str | None] = {}
    if restart_managed and sys.platform != "win32":
        for pid in pids:
            pid_cgroup[pid] = _m()._get_pid_cgroup_path(pid)
            pid_service[pid] = _m()._get_systemd_service_for_pid(pid)
            if not pid_service[pid]:
                # Manual process: keep exact argv + HERMES_HOME for the
                # post-update respawn and its per-profile cap.
                cmdline = _m()._dashboard_cmdline_for_pid(pid)
                if cmdline:
                    pid_cmdline[pid] = cmdline
                    pid_home[pid] = _hermes_home_for_pid(pid)

        if already_restarted_units:
            pids = [
                pid for pid in pids
                if (pid_service.get(pid) or "").removesuffix(".service") not in already_restarted_units
            ]
            if not pids:
                return _empty_result()

    print(f"\n⟲ Stopping {len(pids)} dashboard process(es) ({reason})")

    killed: list[int] = []
    failed: list[tuple[int, str]] = []
    if sys.platform == "win32":
        _kill_pids_windows(pids, killed, failed)
    else:
        _kill_pids_posix(pids, killed, failed)

    for pid in killed:
        print(f"    ✓ stopped PID {pid}")
    for pid, err_msg in failed:
        print(f"    ✗ failed to stop PID {pid}: {err_msg}")

    if killed and restart_managed:
        unrecovered = _restart_killed_backends(killed, pid_service, pid_cgroup, pid_cmdline, pid_home)
    else:
        unrecovered = list(killed)
        if killed:
            print("  Restart the dashboard when you're ready:\n    hermes dashboard --port <port>")

    return {"matched": list(pids), "killed": list(killed), "failed": list(failed), "unrecovered": list(unrecovered)}


def _restart_killed_backends(
    killed: list[int], pid_service: dict[int, str | None], pid_cgroup: dict[int, str | None],
    pid_cmdline: dict[int, list[str]], pid_home: dict[int, str | None],
) -> list[int]:
    """Update path: restart systemd-owned units, respawn manual argv.

    Respawns are detached, headless, logged to logs/dashboard-restart.log;
    Desktop ``--port 0`` backends are filtered out and duplicates collapse to
    one per profile. Returns the PIDs that were not brought back.
    """
    unrecovered: list[int] = []
    failed_restarts: list[tuple[str, str]] = []
    seen_services: set[str] = set()
    respawn_candidates: list[tuple[int, list[str], str | None]] = []
    for pid in killed:
        svc_name = pid_service.get(pid)
        if svc_name:
            if svc_name in seen_services:
                continue
            seen_services.add(svc_name)
            if _m()._try_restart_systemd_service(svc_name, pid_cgroup.get(pid)):
                print(f"    ✓ restarted systemd service {svc_name}")
            else:
                failed_restarts.append((svc_name, "systemctl restart returned non-zero"))
                unrecovered.append(pid)
        elif pid in pid_cmdline:
            respawn_candidates.append((pid, pid_cmdline[pid], pid_home.get(pid)))
        else:
            unrecovered.append(pid)

    for svc, err in failed_restarts:
        print(f"    ⚠ {svc}: {err}")

    respawn_cmds = _filter_dashboard_respawn_candidates(respawn_candidates)
    if respawn_cmds:
        failed_cmds = _m()._respawn_dashboard_processes(respawn_cmds)
        if failed_cmds:
            unrecovered.extend(p for p in killed if pid_cmdline.get(p) in failed_cmds)

    if failed_restarts or unrecovered:
        print("  Restart anything not auto-restarted when you're ready:\n    hermes dashboard --port <port>")
    return unrecovered


def _norm_exe(path) -> str:
    """Canonical lower-cased executable path for comparison."""
    try:
        return str(Path(path).resolve()).lower()
    except (OSError, ValueError):
        return str(path).lower()


def _detect_concurrent_hermes_instances(
    scripts_dir: Path, *, exclude_pid: int | None = None
) -> list[tuple[int, str]]:
    """Find other live processes whose .exe is one of our entry-point shims.

    Windows blocks DELETE/REPLACE on a running .exe (and RENAME when opened
    without ``FILE_SHARE_DELETE``); Desktop spawns ``hermes.EXE`` as a backend
    child, so the update's quarantine rename fails with ``[WinError 32]``.

    Returns ``(pid, process_name)`` for processes whose ``exe`` matches a venv
    shim (``hermes.exe`` / ``hermes-gateway.exe``). Excludes our own PID and
    every *shim* ancestor: the setuptools launcher is a separate native process
    from the ``python.exe`` it loads, so otherwise every update reports its own
    launcher. ``proc.parents()`` (whole chain at once) because a per-hop loop
    bailed on the first AccessDenied. Only shim ancestors are excluded so a
    second hermes.exe under a non-Hermes parent (Desktop child) is still flagged.

    Empty off-Windows, without psutil, or with no other instances. Never raises.
    """
    if not _m()._is_windows():
        return []

    try:
        import psutil
    except Exception:
        return []

    shim_paths = {_norm_exe(shim) for shim in _m()._hermes_exe_shims(scripts_dir)}
    if not shim_paths:
        return []

    seed = int(exclude_pid) if exclude_pid is not None else os.getpid()
    exclude_pids: set[int] = {seed}
    # Broad ``except Exception``: psutil may be partially stubbed in tests.
    try:
        for ancestor in psutil.Process(seed).parents():
            try:
                anc_exe = ancestor.exe()
                if anc_exe and _norm_exe(anc_exe) in shim_paths:
                    exclude_pids.add(int(ancestor.pid))
            except Exception:
                continue
    except Exception:
        pass

    matches: list[tuple[int, str]] = []
    try:
        proc_iter = psutil.process_iter(["pid", "exe", "name"])
    except Exception:
        return []

    for proc in proc_iter:
        try:
            info = proc.info
        except Exception:
            continue
        pid = info.get("pid")
        exe = info.get("exe")
        if not exe or pid is None or pid in exclude_pids:
            continue
        if _norm_exe(exe) in shim_paths:
            name = info.get("name") or Path(exe).name
            matches.append((int(pid), str(name)))

    return matches


def _is_desktop_local_serve_cmdline(command: str) -> bool:
    """True for the Desktop-local serve shape ``hermes serve [--isolated]
    --host 127.0.0.1 --port 0``. Long-lived headless serves (``--host
    <tailscale-ip> --port 9119``) must never match — those are operator-managed
    remote backends that legitimately run with ppid 1 under launchd/nohup."""
    cmd = command.lower()
    if "serve" not in cmd or ("hermes" not in cmd and "hermes_cli" not in cmd):
        return False
    has_loopback = any(
        tok in cmd
        for tok in ("--host 127.0.0.1", "--host=127.0.0.1", "--host localhost", "--host=localhost")
    )
    has_ephemeral = "--port 0" in cmd or "--port=0" in cmd
    return has_loopback and has_ephemeral


def _process_ppid(pid: int) -> int | None:
    """Best-effort parent pid lookup. None on failure (and always on Windows,
    where orphan reap is handled by the desktop tree-kill)."""
    try:
        if sys.platform == "win32":
            return None
        result = subprocess.run(
            ["ps", "-o", "ppid=", "-p", str(pid)],
            capture_output=True, text=True, encoding="utf-8", errors="replace", timeout=5,
        )
        if result.returncode != 0 or not result.stdout:
            return None
        return int(result.stdout.strip().split()[0])
    except (ValueError, FileNotFoundError, subprocess.TimeoutExpired, OSError):
        return None


# --- SSH remote-backend lock ownership -------------------------------------
# ``backend.lock.json`` is written by the Desktop SSH runtime on the *remote*
# host for every ``hermes serve`` it spawns (apps/desktop/electron/
# remote-lifecycle.ts). A backend another client/machine started is legitimate
# and lock-owned even with no parent here (sshd exited → ppid 1). The reap must
# NEVER kill a PID a valid lock claims — that once killed a production backend.
# Schema constants mirror the writer; a mismatched record is simply ignored
# (the reap only ever *spares*).
_LOCKFILE_SCHEMA_VERSION = 2
_PROTOCOL_VERSION = 1
_REMOTE_LOCK_SUBDIR = "desktop-ssh"
_HEX32 = set("0123456789abcdef")


def _hermes_home_dir() -> Path:
    """Resolved Hermes home (HERMES_HOME override or ~/.hermes)."""
    override = os.environ.get("HERMES_HOME", "").strip()
    return Path(override).expanduser() if override else Path.home() / ".hermes"


def _is_hex(value: object, length: int) -> bool:
    return isinstance(value, str) and len(value) == length and not (set(value) - _HEX32)


def _valid_lockfile_payload(parsed: object, ownership_id: str) -> bool:
    """Validate a parsed ``backend.lock.json`` body, mirroring readLockfile().

    An invalid lock is "no ownership claim", which never causes a kill — the
    reap only ever *adds* lock-owned PIDs to its spare-set.
    """
    if (
        not isinstance(parsed, dict)
        or parsed.get("schemaVersion") != _LOCKFILE_SCHEMA_VERSION
        or parsed.get("protocolVersion") != _PROTOCOL_VERSION
        or parsed.get("ownershipId") != ownership_id
        or not _is_hex(parsed.get("spawnNonce"), 16)
        or not _is_hex(parsed.get("tokenFingerprint"), 32)
    ):
        return False
    pid = parsed.get("pid")
    port = parsed.get("port")
    if not isinstance(pid, int) or not 0 < pid <= 4194304:
        return False
    if not isinstance(port, int) or not 0 <= port <= 65535:
        return False
    # String fields must be present and bounded (the writer enforces <=1024).
    for field in ("profile", "hermesPath", "hermesHome", "logPath", "startedAt"):
        value = parsed.get(field)
        if not isinstance(value, str) or len(value) > 1024:
            return False
    # logPath is ``{lock_root}/{ownershipId}/{spawnNonce}.log``. Only the
    # suffix is checked so a relocated HERMES_HOME doesn't falsely reject a
    # legitimate remote-owned backend (a false reject re-introduces the kill).
    return parsed["logPath"].endswith(f"/{ownership_id}/{parsed['spawnNonce']}.log")


def _lock_owned_serve_pids(base_dir: Path | None = None) -> set[int]:
    """PIDs claimed by valid ``{hermes_home}/desktop-ssh/<ownershipId>/backend.lock.json``
    records — legitimately owned (incl. SSH backends other clients started) and
    spared by the reap. Best-effort: a bad record contributes no PID; never raises."""
    import json

    root = base_dir if base_dir is not None else _hermes_home_dir() / _REMOTE_LOCK_SUBDIR
    owned: set[int] = set()
    if not root.is_dir():
        return owned
    try:
        entries = list(root.iterdir())
    except OSError:
        return owned
    for entry in entries:
        ownership_id = entry.name
        lock_path = entry / "backend.lock.json"
        try:
            # Mirror validateOwnershipId(): exactly 32 lowercase hex chars.
            if not entry.is_dir() or not _is_hex(ownership_id, 32) or not lock_path.is_file():
                continue
            with open(lock_path, "rb") as handle:
                data = handle.read()
        except OSError:
            continue
        if len(data) > 65536:
            continue
        try:
            parsed = json.loads(data)
        except (UnicodeDecodeError, ValueError):
            continue
        if _valid_lockfile_payload(parsed, ownership_id):
            try:
                owned.add(int(parsed["pid"]))
            except (TypeError, ValueError):
                continue
    return owned


# Grace window before an orphaned-looking backend may be reaped. Covers the
# gap between process start and the Desktop client writing backend.lock.json.
_REAP_MIN_AGE_SECONDS = 180.0


def _process_age_seconds(pid: int) -> float:
    """Process age from psutil's cross-platform start timestamp."""
    import time as _time

    import psutil as _psutil

    return max(0.0, _time.time() - _psutil.Process(pid).create_time())


def _reap_orphaned_desktop_local_serves(
    *, reason: str = "orphaned desktop-local hermes serve", signal_term=None, signal_kill=None,
    sleep_fn=None, lock_owned_pids_fn=None, process_age_seconds_fn=None,
) -> dict[str, list]:
    """Kill leftover Desktop-local ``hermes serve`` backends with no parent.

    When Electron dies uncleanly, ``serve --host 127.0.0.1 --port 0`` children
    get reparented to pid 1 with their MCP trees alive; each Desktop boot then
    stacks a fresh backend on the corpses until EMFILE. The parent-death
    watchdog (HERMES_PARENT_PID) prevents *future* orphans; this clears
    *already* orphaned ones when a new Desktop backend starts.

    A candidate is reaped only if ALL hold: Desktop-local shape (never a
    fixed-port remote serve); ppid 1 (or 0 on some supervisors); not self /
    parent / a HERMES_DESKTOP_CHILD_PID; not claimed by a valid
    ``backend.lock.json`` (SSH backends other clients started legitimately sit
    at ppid 1 — killing them is an incident, not cleanup); older than
    ``_REAP_MIN_AGE_SECONDS`` with a determinable age — Desktop writes the lock
    only after HERMES_BACKEND_READY, so during concurrent multi-profile startup
    a live sibling is briefly unowned and indistinguishable from a corpse
    (mutual-reap storm); a real corpse just waits for a later scan.
    Best-effort; failures never raise to the caller.
    """
    import signal as _signal
    import time as _time

    signal_term = _signal.SIGTERM if signal_term is None else signal_term
    signal_kill = getattr(_signal, "SIGKILL", _signal.SIGTERM) if signal_kill is None else signal_kill
    sleep_fn = _time.sleep if sleep_fn is None else sleep_fn
    lock_owned_pids_fn = _lock_owned_serve_pids if lock_owned_pids_fn is None else lock_owned_pids_fn
    process_age_seconds_fn = _process_age_seconds if process_age_seconds_fn is None else process_age_seconds_fn

    if sys.platform == "win32":
        # Windows desktop uses taskkill tree teardown; orphan scan is POSIX.
        return _empty_result()

    def _owned_pids() -> set[int]:
        try:
            return set(lock_owned_pids_fn())
        except Exception:
            return set()  # never let lock scanning block or widen the reap

    exclude = _exclude_pids_from_env()
    exclude.add(os.getpid())
    try:
        exclude.add(os.getppid())  # the desktop / sshd wrapper
    except Exception:
        pass
    exclude |= _owned_pids()

    try:
        scanned = _scan_dashboard_processes(exclude_pids=exclude)
    except Exception:
        return _empty_result()

    # Re-read ownership: a lock may have been written between scan and now.
    owned_now = _owned_pids()

    targets: list[tuple[int, str]] = []
    for pid, cmd in scanned:
        if not _is_desktop_local_serve_cmdline(cmd) or pid in owned_now:
            continue
        if _process_ppid(pid) not in (0, 1):
            continue
        try:
            if process_age_seconds_fn(pid) < _REAP_MIN_AGE_SECONDS:
                continue
        except Exception:
            continue  # never let a liveness probe failure widen the reap
        targets.append((pid, cmd))

    if not targets:
        return _empty_result()

    matched = [pid for pid, _ in targets]
    killed: list[int] = []
    failed: list[int] = []

    for pid, _cmd in targets:
        try:
            os.kill(pid, signal_term)
        except ProcessLookupError:
            continue
        except OSError:
            failed.append(pid)

    # Brief grace, then SIGKILL survivors. psutil.pid_exists rather than
    # os.kill(pid, 0), which is a Windows footgun the linter blocks everywhere.
    sleep_fn(1.5)
    import psutil

    for pid, _cmd in targets:
        if pid in failed:
            continue
        if not psutil.pid_exists(pid):
            killed.append(pid)
            continue
        try:
            os.kill(pid, signal_kill)
            killed.append(pid)
        except ProcessLookupError:
            killed.append(pid)
        except OSError:
            failed.append(pid)

    try:
        print(f"⟲ Reaped {len(killed)} orphaned desktop-local serve backend(s) ({reason}): {killed or matched}")
    except Exception:
        pass

    return {"matched": matched, "killed": killed, "failed": failed}