"""
Cron job storage and management.

Jobs are stored in ~/.hermes/cron/jobs.json
Output is saved to ~/.hermes/cron/output/{job_id}/{timestamp}.md
"""

import contextlib
import copy
import json
import logging
import shutil
import tempfile
import threading
import time
import os
import re
import uuid

# Cross-process advisory file locking for jobs.json critical sections.
# fcntl is Unix-only; on Windows fall back to msvcrt. Either may be absent,
# in which case _jobs_lock() degrades to in-process locking only (the old
# behaviour) rather than failing.
try:
    import fcntl
except ImportError:  # pragma: no cover - non-Unix
    fcntl = None
try:
    import msvcrt
except ImportError:  # pragma: no cover - non-Windows
    msvcrt = None
from datetime import datetime, timedelta
from pathlib import Path
from hermes_constants import get_hermes_home
from typing import Optional, Dict, List, Any, Union

logger = logging.getLogger(__name__)

from hermes_time import now as _hermes_now
from utils import atomic_replace

try:
    from croniter import croniter
    HAS_CRONITER = True
except ImportError:
    HAS_CRONITER = False

# =============================================================================
# Configuration
# =============================================================================

HERMES_DIR = get_hermes_home().resolve()
CRON_DIR = HERMES_DIR / "cron"
JOBS_FILE = CRON_DIR / "jobs.json"
# Heartbeat file the in-process ticker touches on every loop iteration. The
# gateway process and the (separate) ``hermes cron status`` process share it
# so status can tell whether the ticker THREAD is alive, not just whether the
# gateway PROCESS exists — a ticker that dies silently inside a live gateway
# would otherwise report healthy (#32612, #32895).
TICKER_HEARTBEAT_FILE = CRON_DIR / "ticker_heartbeat"
# Last tick that completed WITHOUT raising. Distinguishing this from the plain
# heartbeat lets status detect a ticker that is alive but failing every tick.
TICKER_SUCCESS_FILE = CRON_DIR / "ticker_last_success"
# Default ticker loop interval (seconds). The single source of truth shared by
# the in-process ticker (cron/scheduler_provider.py) and the staleness
# threshold in `hermes cron status` (hermes_cli/cron.py), so the two never
# drift apart.
TICKER_INTERVAL_SECONDS = 60

# In-process lock protecting load_jobs→modify→save_jobs cycles.
# Required when tick() runs jobs in parallel threads — without this,
# concurrent mark_job_run / advance_next_run calls can clobber each other.
_jobs_file_lock = threading.RLock()
_jobs_lock_state = threading.local()
OUTPUT_DIR = CRON_DIR / "output"
ONESHOT_GRACE_SECONDS = 120


def _jobs_lock_file() -> Path:
    """Return the advisory lock path for the current cron directory."""
    return CRON_DIR / ".jobs.lock"


@contextlib.contextmanager
def _jobs_lock():
    """Serialize a load_jobs→modify→save_jobs critical section.

    Combines the in-process threading lock (cheap mutual exclusion between
    the gateway's parallel tick threads) with a cross-process advisory file
    lock on ``<cron dir>/.jobs.lock`` (mutual exclusion between the gateway process
    and standalone ``hermes`` CLI invocations, which previously shared no lock
    at all — a `cron pause` could be silently clobbered by a concurrent
    gateway write, leaving a "paused" job still firing).

    The flock is blocking, but every critical section that uses it is short
    (field updates only — no agent execution), so contention resolves in
    milliseconds. If neither fcntl nor msvcrt is available the manager still
    provides in-process locking, matching the historical behaviour.

    Nested calls in the same thread reuse the held lock so legacy callers that
    invoke save_jobs() inside a broader mutation section don't deadlock or try
    to reacquire the advisory file lock.
    """
    depth = getattr(_jobs_lock_state, "depth", 0)
    if depth:
        _jobs_lock_state.depth = depth + 1
        try:
            yield
        finally:
            _jobs_lock_state.depth -= 1
        return

    with _jobs_file_lock:
        _jobs_lock_state.depth = 1
        lock_fd = None
        try:
            try:
                ensure_dirs()
                lock_fd = open(_jobs_lock_file(), "a+", encoding="utf-8")
                lock_fd.seek(0)
                if fcntl is not None:
                    fcntl.flock(lock_fd, fcntl.LOCK_EX)
                elif msvcrt is not None:
                    getattr(msvcrt, "locking")(lock_fd.fileno(), getattr(msvcrt, "LK_LOCK"), 1)
            except (OSError, IOError) as e:
                # Never let a locking failure take down cron writes — fall back to
                # in-process-only protection (still held via _jobs_file_lock).
                logger.warning("jobs.json cross-process lock unavailable (%s); "
                               "proceeding with in-process lock only", e)
            try:
                yield
            finally:
                if lock_fd is not None:
                    try:
                        if fcntl is not None:
                            fcntl.flock(lock_fd, fcntl.LOCK_UN)
                        elif msvcrt is not None:
                            getattr(msvcrt, "locking")(lock_fd.fileno(), getattr(msvcrt, "LK_UNLCK"), 1)
                    except (OSError, IOError):
                        pass
                    finally:
                        lock_fd.close()
        finally:
            _jobs_lock_state.depth = 0

# Fields on a cron job that must never change after creation. ``id`` is used
# as a filesystem path component under ``OUTPUT_DIR``; allowing it to be
# updated lets an unsafe value (``../escape``, absolute path, nested) leak
# into output writes/deletes.
_IMMUTABLE_JOB_FIELDS = frozenset({"id"})


def _job_output_dir(job_id: str) -> Path:
    """Resolve a job's output directory, rejecting any path-escape attempt.

    Job IDs are filesystem path components under ``OUTPUT_DIR``. A legacy or
    crafted ID containing ``..``, absolute paths, or nested separators would
    allow output writes/deletes to escape the cron output sandbox. Reject
    anything that isn't a single safe path component.
    """
    text = str(job_id or "").strip()
    if not text or text in {".", ".."} or "/" in text or "\\" in text:
        raise ValueError(f"Invalid cron job id for output path: {job_id!r}")
    if Path(text).is_absolute() or Path(text).drive:
        raise ValueError(f"Invalid cron job id for output path: {job_id!r}")
    return OUTPUT_DIR / text


def _normalize_skill_list(skill: Optional[str] = None, skills: Optional[Any] = None) -> List[str]:
    """Normalize legacy/single-skill and multi-skill inputs into a unique ordered list."""
    if skills is None:
        raw_items = [skill] if skill else []
    elif isinstance(skills, str):
        raw_items = [skills]
    else:
        raw_items = list(skills)

    normalized: List[str] = []
    for item in raw_items:
        text = str(item or "").strip()
        if text and text not in normalized:
            normalized.append(text)
    return normalized


def _apply_skill_fields(job: Dict[str, Any]) -> Dict[str, Any]:
    """Return a job dict with canonical `skills` and legacy `skill` fields aligned."""
    normalized = dict(job)
    skills = _normalize_skill_list(normalized.get("skill"), normalized.get("skills"))
    normalized["skills"] = skills
    normalized["skill"] = skills[0] if skills else None
    return normalized


def _coerce_job_text(value: Any, fallback: str = "") -> str:
    """Coerce legacy/hand-edited nullable cron fields to strings for readers."""
    if value is None:
        return fallback
    return str(value)


def _schedule_display_for_job(job: Dict[str, Any]) -> str:
    display = _coerce_job_text(job.get("schedule_display")).strip()
    if display:
        return display

    schedule = job.get("schedule")
    if isinstance(schedule, dict):
        for key in ("display", "value", "expr", "run_at"):
            text = _coerce_job_text(schedule.get(key)).strip()
            if text:
                return text
    elif schedule is not None:
        return str(schedule)

    return "?"


def _normalize_job_record(job: Dict[str, Any]) -> Dict[str, Any]:
    """Return a read-safe cron job shape for UI/API/tool/scheduler consumers.

    Older or hand-edited jobs can have nullable fields like ``prompt``,
    ``name``, or ``schedule_display``.  Keep storage untouched on read, but
    ensure consumers never crash while formatting or running those records.
    """
    normalized = _apply_skill_fields(job)
    job_id = _coerce_job_text(normalized.get("id"), "unknown")
    prompt = _coerce_job_text(normalized.get("prompt"))
    normalized["id"] = job_id
    normalized["prompt"] = prompt

    name = _coerce_job_text(normalized.get("name")).strip()
    if not name:
        script = _coerce_job_text(normalized.get("script")).strip()
        label_source = (
            prompt
            or (normalized["skills"][0] if normalized.get("skills") else "")
            or script
            or job_id
            or "cron job"
        )
        name = label_source[:50].strip() or "cron job"
    normalized["name"] = name
    normalized["schedule_display"] = _schedule_display_for_job(normalized)

    state = _coerce_job_text(normalized.get("state")).strip()
    if not state:
        state = "scheduled" if normalized.get("enabled", True) else "paused"
    normalized["state"] = state

    return normalized


def _secure_dir(path: Path):
    """Set directory to owner-only access (0700). No-op on Windows."""
    try:
        os.chmod(path, 0o700)
    except (OSError, NotImplementedError):
        pass  # Windows or other platforms where chmod is not supported


def _secure_file(path: Path):
    """Set file to owner-only read/write (0600). No-op on Windows."""
    try:
        if path.exists():
            os.chmod(path, 0o600)
    except (OSError, NotImplementedError):
        pass


def ensure_dirs():
    """Ensure cron directories exist with secure permissions."""
    CRON_DIR.mkdir(parents=True, exist_ok=True)
    OUTPUT_DIR.mkdir(parents=True, exist_ok=True)
    _secure_dir(CRON_DIR)
    _secure_dir(OUTPUT_DIR)


# =============================================================================
# Schedule Parsing
# =============================================================================

def parse_duration(s: str) -> int:
    """
    Parse duration string into minutes.
    
    Examples:
        "30m" → 30
        "2h" → 120
        "1d" → 1440
    """
    s = s.strip().lower()
    match = re.match(r'^(\d+)\s*(m|min|mins|minute|minutes|h|hr|hrs|hour|hours|d|day|days)$', s)
    if not match:
        raise ValueError(f"Invalid duration: '{s}'. Use format like '30m', '2h', or '1d'")
    
    value = int(match.group(1))
    unit = match.group(2)[0]  # First char: m, h, or d
    
    multipliers = {'m': 1, 'h': 60, 'd': 1440}
    return value * multipliers[unit]


def parse_schedule(schedule: str) -> Dict[str, Any]:
    """
    Parse schedule string into structured format.
    
    Returns dict with:
        - kind: "once" | "interval" | "cron"
        - For "once": "run_at" (ISO timestamp)
        - For "interval": "minutes" (int)
        - For "cron": "expr" (cron expression)
    
    Examples:
        "30m"              → once in 30 minutes
        "2h"               → once in 2 hours
        "every 30m"        → recurring every 30 minutes
        "every 2h"         → recurring every 2 hours
        "0 9 * * *"        → cron expression
        "2026-02-03T14:00" → once at timestamp
    """
    schedule = schedule.strip()
    original = schedule
    schedule_lower = schedule.lower()
    
    # "every X" pattern → recurring interval
    if schedule_lower.startswith("every "):
        duration_str = schedule[6:].strip()
        minutes = parse_duration(duration_str)
        return {
            "kind": "interval",
            "minutes": minutes,
            "display": f"every {minutes}m"
        }
    
    # Check for cron expression (5 or 6 space-separated fields)
    # Cron fields: minute hour day month weekday [year]
    parts = schedule.split()
    if len(parts) >= 5 and all(
        re.match(r'^[\d\*\-,/]+$', p) for p in parts[:5]
    ):
        if not HAS_CRONITER:
            raise ValueError("Cron expressions require 'croniter' package. Install with: pip install croniter")
        # Validate cron expression
        try:
            croniter(schedule)
        except Exception as e:
            raise ValueError(f"Invalid cron expression '{schedule}': {e}")
        return {
            "kind": "cron",
            "expr": schedule,
            "display": schedule
        }
    
    # ISO timestamp (contains T or looks like date)
    if 'T' in schedule or re.match(r'^\d{4}-\d{2}-\d{2}', schedule):
        try:
            # Parse and validate
            dt = datetime.fromisoformat(schedule.replace('Z', '+00:00'))
            # Make naive timestamps timezone-aware at parse time so the stored
            # value doesn't depend on the system timezone matching at check time.
            #
            # Anchor to the CONFIGURED Hermes timezone, not the server's local
            # timezone. The due-check (`get_due_jobs`) compares `next_run_at`
            # against `hermes_time.now()`, which uses the configured zone. If a
            # naive "20:07" were interpreted as server-local (e.g. UTC) while
            # now() runs in Asia/Kolkata, the stored instant would land hours
            # off from the user's wall-clock intent — far enough that one-shots
            # never become due and recurring jobs fire at the wrong time. Using
            # the configured zone makes "20:07" mean 20:07 on the same clock the
            # scheduler checks against (#51021).
            if dt.tzinfo is None:
                hermes_tz = _hermes_now().tzinfo
                dt = dt.replace(tzinfo=hermes_tz)
            return {
                "kind": "once",
                "run_at": dt.isoformat(),
                "display": f"once at {dt.strftime('%Y-%m-%d %H:%M')}"
            }
        except ValueError as e:
            raise ValueError(f"Invalid timestamp '{schedule}': {e}")
    
    # Duration like "30m", "2h", "1d" → one-shot from now
    try:
        minutes = parse_duration(schedule)
        run_at = _hermes_now() + timedelta(minutes=minutes)
        return {
            "kind": "once",
            "run_at": run_at.isoformat(),
            "display": f"once in {original}"
        }
    except ValueError:
        pass
    
    raise ValueError(
        f"Invalid schedule '{original}'. Use:\n"
        f"  - Duration: '30m', '2h', '1d' (one-shot)\n"
        f"  - Interval: 'every 30m', 'every 2h' (recurring)\n"
        f"  - Cron: '0 9 * * *' (cron expression)\n"
        f"  - Timestamp: '2026-02-03T14:00:00' (one-shot at time)"
    )


def _ensure_aware(dt: datetime) -> datetime:
    """Return a timezone-aware datetime in Hermes configured timezone.

    Backward compatibility:
    - Older stored timestamps may be naive.
    - Naive values are interpreted as *system-local wall time* (the timezone
      `datetime.now()` used when they were created), then converted to the
      configured Hermes timezone.

    This preserves relative ordering for legacy naive timestamps across
    timezone changes and avoids false not-due results.
    """
    target_tz = _hermes_now().tzinfo
    if dt.tzinfo is None:
        local_tz = datetime.now().astimezone().tzinfo
        return dt.replace(tzinfo=local_tz).astimezone(target_tz)
    return dt.astimezone(target_tz)


def _timezone_offset_mismatch(stored: datetime, current: datetime) -> bool:
    """Return True when a stored aware timestamp uses a different UTC offset.

    Naive stored timestamps return False: they carry no offset to compare, and
    are normalized by ``_ensure_aware`` instead — they intentionally never take
    the offset-repair path.
    """
    if stored.tzinfo is None or current.tzinfo is None:
        return False
    return stored.utcoffset() != current.utcoffset()


def _stored_wall_clock_is_future(stored: datetime, current: datetime) -> bool:
    """Return True when the stored local wall-clock time has not arrived yet.

    Cron schedules express local wall-clock intent. If Hermes/system local time
    changes after next_run_at was persisted, an old offset can make a future
    wall-clock run look due at the converted absolute time (for example
    21:00+10 becomes 13:00+02). Comparing naive wall-clock values lets us
    distinguish that migration case from a genuinely missed run whose scheduled
    wall time has already passed.
    """
    return stored.replace(tzinfo=None) > current.replace(tzinfo=None)


def _recoverable_oneshot_run_at(
    schedule: Dict[str, Any],
    now: datetime,
    *,
    last_run_at: Optional[str] = None,
) -> Optional[str]:
    """Return a one-shot run time if it is still eligible to fire.

    One-shot jobs get a small grace window so jobs created a few seconds after
    their requested minute still run on the next tick. Once a one-shot has
    already run, it is never eligible again.
    """
    if schedule.get("kind") != "once":
        return None
    if last_run_at:
        return None

    run_at = schedule.get("run_at")
    if not run_at:
        return None

    run_at_dt = _ensure_aware(datetime.fromisoformat(run_at))
    if run_at_dt >= now - timedelta(seconds=ONESHOT_GRACE_SECONDS):
        return run_at
    return None


def _compute_grace_seconds(schedule: dict) -> int:
    """Compute how late a job can be and still catch up instead of fast-forwarding.

    Uses half the schedule period, clamped between 120 seconds and 2 hours.
    This ensures daily jobs can catch up if missed by up to 2 hours,
    while frequent jobs (every 5-10 min) still fast-forward quickly.
    """
    MIN_GRACE = 120
    MAX_GRACE = 7200  # 2 hours

    kind = schedule.get("kind")

    if kind == "interval":
        period_seconds = schedule.get("minutes", 1) * 60
        grace = period_seconds // 2
        return max(MIN_GRACE, min(grace, MAX_GRACE))

    if kind == "cron" and HAS_CRONITER:
        try:
            now = _hermes_now()
            cron = croniter(schedule["expr"], now)
            first = cron.get_next(datetime)
            second = cron.get_next(datetime)
            period_seconds = int((second - first).total_seconds())
            grace = period_seconds // 2
            return max(MIN_GRACE, min(grace, MAX_GRACE))
        except Exception:
            pass

    return MIN_GRACE


def compute_next_run(schedule: Dict[str, Any], last_run_at: Optional[str] = None) -> Optional[str]:
    """
    Compute the next run time for a schedule.

    Returns ISO timestamp string, or None if no more runs.
    """
    now = _hermes_now()

    if schedule["kind"] == "once":
        return _recoverable_oneshot_run_at(schedule, now, last_run_at=last_run_at)

    elif schedule["kind"] == "interval":
        minutes = schedule["minutes"]
        if last_run_at:
            # Next run is last_run + interval
            last = _ensure_aware(datetime.fromisoformat(last_run_at))
            next_run = last + timedelta(minutes=minutes)
        else:
            # First run is now + interval
            next_run = now + timedelta(minutes=minutes)
        return next_run.isoformat()

    elif schedule["kind"] == "cron":
        if not HAS_CRONITER:
            logger.warning(
                "Cannot compute next run for cron schedule %r: 'croniter' is "
                "not installed. croniter is a core dependency as of v0.9.x; "
                "reinstall hermes-agent or run 'pip install croniter' in your "
                "runtime env.",
                schedule.get("expr"),
            )
            return None
        # Use last_run_at as the croniter base when available, consistent
        # with interval jobs.  This ensures that after a crash/restart,
        # the next run is anchored to the actual last execution time
        # rather than to an arbitrary restart time.
        base_time = now
        if last_run_at:
            base_time = _ensure_aware(datetime.fromisoformat(last_run_at))
        cron = croniter(schedule["expr"], base_time)
        next_run = cron.get_next(datetime)
        return next_run.isoformat()

    return None


# =============================================================================
# Ticker heartbeat (liveness signal for `hermes cron status`)
# =============================================================================

def _atomic_write_epoch(path: Path) -> None:
    """Atomically write the current epoch time to ``path``.

    Uses the same tmpfile + ``atomic_replace`` pattern as ``save_jobs`` so a
    concurrent reader in another process (``hermes cron status``) never sees a
    torn/truncated file. Best-effort: failures are swallowed by callers.
    """
    ensure_dirs()
    fd, tmp_path = tempfile.mkstemp(dir=str(CRON_DIR), suffix=".tmp", prefix=".hb_")
    try:
        with os.fdopen(fd, "w", encoding="utf-8") as f:
            f.write(str(time.time()))
            f.flush()
            os.fsync(f.fileno())
        atomic_replace(tmp_path, path)
    except BaseException:
        try:
            os.unlink(tmp_path)
        except OSError:
            pass
        raise


def record_ticker_heartbeat(success: bool = False) -> None:
    """Record a ticker liveness signal, and optionally a successful-tick signal.

    The ticker calls this once per loop iteration. ``success=True`` additionally
    bumps the *last successful tick* marker. We track two distinct signals so
    `hermes cron status` can tell a thread that is merely *alive and looping*
    (heartbeat fresh, success stale) from one that is actually *firing jobs*
    (both fresh) — a ticker stuck failing every tick would otherwise keep the
    plain heartbeat fresh and falsely report healthy (#32612, #32895).

    Best-effort: a write failure must never disrupt the tick loop.
    """
    try:
        _atomic_write_epoch(TICKER_HEARTBEAT_FILE)
    except Exception:
        pass
    if success:
        try:
            _atomic_write_epoch(TICKER_SUCCESS_FILE)
        except Exception:
            pass


def _epoch_file_age(path: Path) -> Optional[float]:
    try:
        raw = path.read_text(encoding="utf-8").strip()
        return max(0.0, time.time() - float(raw))
    except Exception:
        return None


def get_ticker_heartbeat_age() -> Optional[float]:
    """Seconds since the ticker loop last iterated, or None if unknown.

    None = heartbeat file missing/unreadable (older build, never ran, or a
    torn read). Callers treat None as "cannot determine", not "dead".
    """
    return _epoch_file_age(TICKER_HEARTBEAT_FILE)


def get_ticker_success_age() -> Optional[float]:
    """Seconds since the ticker last completed a tick WITHOUT raising, or None."""
    return _epoch_file_age(TICKER_SUCCESS_FILE)


# =============================================================================
# Job CRUD Operations
# =============================================================================

def load_jobs() -> List[Dict[str, Any]]:
    """Load all jobs from storage."""
    ensure_dirs()
    if not JOBS_FILE.exists():
        return []

    _strict_retry = False  # track whether we used the strict=False fallback

    try:
        with open(JOBS_FILE, 'r', encoding='utf-8') as f:
            data = json.load(f)
    except json.JSONDecodeError:
        # Retry with strict=False to handle bare control chars in string values
        _strict_retry = True
        try:
            with open(JOBS_FILE, 'r', encoding='utf-8') as f:
                data = json.loads(f.read(), strict=False)
        except Exception as e:
            logger.error("Failed to auto-repair jobs.json: %s", e)
            raise RuntimeError(f"Cron database corrupted and unrepairable: {e}") from e
    except IOError as e:
        logger.error("IOError reading jobs.json: %s", e)
        raise RuntimeError(f"Failed to read cron database: {e}") from e

    # Validate the top-level JSON shape: accept a dict (expected) or a bare
    # list (auto-repair). Anything else (str/number/null) is corruption that
    # would otherwise raise an uncaught AttributeError on ``.get()`` and take
    # down the whole cron subsystem.
    if isinstance(data, dict):
        jobs = data.get("jobs", [])
        if _strict_retry and jobs:
            # Hit control-character corruption — rewrite with proper escaping.
            save_jobs(jobs)
            logger.warning("Auto-repaired jobs.json (had invalid control characters)")
        return jobs
    if isinstance(data, list):
        # Bare array — likely saved/edited outside save_jobs(). Wrap it back
        # into the expected {"jobs": [...]} structure.
        if data:
            save_jobs(data)
            logger.warning("Auto-repaired jobs.json (bare list wrapped as dict)")
        return data

    raise RuntimeError(
        f"Cron database corrupted: expected {{'jobs': [...]}}, got {type(data).__name__}"
    )


def _save_jobs_unlocked(jobs: List[Dict[str, Any]]):
    """Save all jobs to storage. Caller must hold _jobs_lock()."""
    ensure_dirs()
    fd, tmp_path = tempfile.mkstemp(dir=str(JOBS_FILE.parent), suffix='.tmp', prefix='.jobs_')
    try:
        with os.fdopen(fd, 'w', encoding='utf-8') as f:
            json.dump({"jobs": jobs, "updated_at": _hermes_now().isoformat()}, f, indent=2)
            f.flush()
            os.fsync(f.fileno())
        atomic_replace(tmp_path, JOBS_FILE)
        _secure_file(JOBS_FILE)
    except BaseException:
        try:
            os.unlink(tmp_path)
        except OSError:
            pass
        raise


def save_jobs(jobs: List[Dict[str, Any]]):
    """Save all jobs to storage."""
    with _jobs_lock():
        _save_jobs_unlocked(jobs)


def _normalize_workdir(workdir: Optional[str]) -> Optional[str]:
    """Normalize and validate a cron job workdir.

    Rules:
      - Empty / None → None (feature off, preserves old behaviour).
      - ``~`` is expanded.  Relative paths are rejected — cron jobs run detached
        from any shell cwd, so relative paths have no stable meaning.
      - The path must exist and be a directory at create/update time.  We do
        NOT re-check at run time (a user might briefly unmount the dir; the
        scheduler will just fall back to old behaviour with a logged warning).

    Returns the absolute path string, or None when disabled.
    Raises ValueError on invalid input.
    """
    if workdir is None:
        return None
    raw = str(workdir).strip()
    if not raw:
        return None
    expanded = Path(raw).expanduser()
    if not expanded.is_absolute():
        raise ValueError(
            f"Cron workdir must be an absolute path (got {raw!r}). "
            f"Cron jobs run detached from any shell cwd, so relative paths are ambiguous."
        )
    resolved = expanded.resolve()
    if not resolved.exists():
        raise ValueError(f"Cron workdir does not exist: {resolved}")
    if not resolved.is_dir():
        raise ValueError(f"Cron workdir is not a directory: {resolved}")
    return str(resolved)


def _resolve_default_model_snapshot() -> Optional[str]:
    """Resolve the global default model the same way the cron ticker does.

    Mirrors the unpinned-model resolution in ``cron/scheduler.py`` ``run_job``:
    read ``config.yaml`` ``model.default`` (or the ``model`` alias / bare string
    form), applying the managed-scope overlay and env expansion. Used by
    ``create_job`` to snapshot the default model for unpinned jobs so a later
    swap of the global default is detected at fire time (#44585).

    Returns the resolved model string, or ``None`` if config is missing/empty
    or resolution fails (fail-open — caller treats ``None`` as "no snapshot").
    """
    try:
        import yaml
        from hermes_cli.config import _expand_env_vars

        cfg_path = get_hermes_home() / "config.yaml"
        if not cfg_path.exists():
            return None
        with cfg_path.open(encoding="utf-8") as f:
            cfg = yaml.safe_load(f) or {}
        try:
            from hermes_cli import managed_scope
            cfg = managed_scope.apply_managed_overlay(cfg)
        except Exception:
            pass
        cfg = _expand_env_vars(cfg)
        model_cfg = cfg.get("model") or {}
        if isinstance(model_cfg, str):
            return model_cfg.strip() or None
        if isinstance(model_cfg, dict):
            default = model_cfg.get("default") or model_cfg.get("model")
            if isinstance(default, str):
                return default.strip() or None
        return None
    except Exception:
        return None


def create_job(
    prompt: Optional[str],
    schedule: str,
    name: Optional[str] = None,
    repeat: Optional[int] = None,
    deliver: Optional[str] = None,
    origin: Optional[Dict[str, Any]] = None,
    skill: Optional[str] = None,
    skills: Optional[List[str]] = None,
    model: Optional[str] = None,
    provider: Optional[str] = None,
    base_url: Optional[str] = None,
    script: Optional[str] = None,
    context_from: Optional[Union[str, List[str]]] = None,
    enabled_toolsets: Optional[List[str]] = None,
    workdir: Optional[str] = None,
    no_agent: bool = False,
    attach_to_session: Optional[bool] = None,
) -> Dict[str, Any]:
    """
    Create a new cron job.

    Args:
        prompt: The prompt to run (must be self-contained, or a task instruction when skill is set).
                Ignored when ``no_agent=True`` except as an optional name hint.
        schedule: Schedule string (see parse_schedule)
        name: Optional friendly name
        repeat: How many times to run (None = forever, 1 = once)
        deliver: Where to deliver output ("origin", "local", "telegram", etc.)
        origin: Source info where job was created (for "origin" delivery)
        skill: Optional legacy single skill name to load before running the prompt
        skills: Optional ordered list of skills to load before running the prompt
        model: Optional per-job model override
        provider: Optional per-job provider override
        base_url: Optional per-job base URL override
        script: Optional path to a script whose stdout feeds the job. With
                ``no_agent=True`` the script IS the job — its stdout is
                delivered verbatim. Without ``no_agent``, its stdout is
                injected into the agent's prompt as context (data-collection /
                change-detection pattern). Paths resolve under
                ~/.hermes/scripts/; ``.sh`` / ``.bash`` files run via bash,
                anything else via Python.
        context_from: Optional job ID (or list of job IDs) whose most recent output
                      is injected into the prompt as context before each run.
                      Useful for chaining cron jobs: job A finds data, job B processes it.
        enabled_toolsets: Optional list of toolset names to restrict the agent to.
                          When set, only tools from these toolsets are loaded, reducing
                          token overhead. When omitted, all default tools are loaded.
                          Ignored when ``no_agent=True``.
        workdir: Optional absolute path.  When set, the job runs as if launched
                from that directory: AGENTS.md / CLAUDE.md / .cursorrules from
                that directory are injected into the system prompt, and the
                terminal/file/code_exec tools use it as their working directory
                (via TERMINAL_CWD).  When unset, the old behaviour is preserved
                (no context files injected, tools use the scheduler's cwd).
                With ``no_agent=True``, ``workdir`` is still applied as the
                script's cwd so relative paths inside the script behave
                predictably.
        no_agent: When True, skip the agent entirely — run ``script`` on schedule
                and deliver its stdout directly. Empty stdout = silent (no
                delivery). Requires ``script`` to be set. Ideal for classic
                watchdogs and periodic alerts that don't need LLM reasoning.

    Returns:
        The created job dict
    """
    parsed_schedule = parse_schedule(schedule)

    # Normalize repeat: treat 0 or negative values as None (infinite)
    if repeat is not None and repeat <= 0:
        repeat = None

    # Auto-set repeat=1 for one-shot schedules if not specified
    if parsed_schedule["kind"] == "once" and repeat is None:
        repeat = 1

    # Default delivery to origin if available, otherwise local
    if deliver is None:
        deliver = "origin" if origin else "local"

    job_id = uuid.uuid4().hex[:12]
    now = _hermes_now().isoformat()

    normalized_skills = _normalize_skill_list(skill, skills)
    normalized_model = str(model).strip() if isinstance(model, str) else None
    normalized_provider = str(provider).strip() if isinstance(provider, str) else None
    normalized_base_url = str(base_url).strip().rstrip("/") if isinstance(base_url, str) else None
    normalized_model = normalized_model or None
    normalized_provider = normalized_provider or None
    normalized_base_url = normalized_base_url or None
    normalized_script = str(script).strip() if isinstance(script, str) else None
    normalized_script = normalized_script or None
    normalized_toolsets = [str(t).strip() for t in enabled_toolsets if str(t).strip()] if enabled_toolsets else None
    normalized_toolsets = normalized_toolsets or None
    normalized_workdir = _normalize_workdir(workdir)
    normalized_no_agent = bool(no_agent)
    normalized_attach = attach_to_session if isinstance(attach_to_session, bool) else None

    # no_agent jobs are meaningless without a script — the script IS the job.
    # Surface this as a clear ValueError at create time so bad configs never
    # reach the scheduler.
    if normalized_no_agent and not normalized_script:
        raise ValueError(
            "no_agent=True requires a script — with no agent and no script "
            "there is nothing for the job to run."
        )

    # Normalize context_from: accept str or list of str, store as list or None
    if isinstance(context_from, str):
        context_from = [context_from.strip()] if context_from.strip() else None
    elif isinstance(context_from, list):
        context_from = [str(j).strip() for j in context_from if str(j).strip()] or None
    else:
        context_from = None

    prompt_text = _coerce_job_text(prompt)
    label_source = (prompt_text or (normalized_skills[0] if normalized_skills else None) or (normalized_script if normalized_no_agent else None)) or "cron job"

    # Provider/model-drift guard (#44585). When the caller does NOT pin a
    # provider and/or model, the job follows the global default — model.default
    # in config.yaml and whatever resolve_runtime_provider() picks at fire time.
    # That global state can change (e.g. a temporary switch to a paid provider
    # OR a paid model like claude-fable-5 on the SAME provider), and an unpinned
    # job would then silently inherit it and spend real money. To detect that,
    # snapshot what resolution WOULD pick *right now*, at creation, for each
    # axis the job leaves unpinned. The fire-time guard (run_job) fails closed
    # when an unpinned job's currently-resolved provider OR model differs from
    # its snapshot.
    #
    # Only captured for agent-backed jobs (no_agent script jobs make no paid
    # inference). Each axis is snapshotted only when that axis is unpinned —
    # a pinned provider/model doesn't drift with global state. Fail-open to None
    # on any resolution error so job creation never breaks; a missing snapshot
    # preserves the legacy no-guard behaviour for that axis.
    provider_snapshot: Optional[str] = None
    model_snapshot: Optional[str] = None
    if not normalized_no_agent:
        if normalized_provider is None:
            try:
                from hermes_cli.runtime_provider import resolve_runtime_provider
                _runtime_kwargs = {"requested": None}
                if normalized_base_url:
                    _runtime_kwargs["explicit_base_url"] = normalized_base_url
                _snap = resolve_runtime_provider(**_runtime_kwargs)
                _snap_provider = str(_snap.get("provider") or "").strip().lower()
                provider_snapshot = _snap_provider or None
            except Exception:
                provider_snapshot = None
        if normalized_model is None:
            # Mirror the fire-time unpinned-model resolution (run_job reads
            # config.yaml model.default / model). Capture that value so a later
            # swap of the global default model is detected even when the
            # provider is unchanged (e.g. a premium model on the same endpoint).
            try:
                model_snapshot = _resolve_default_model_snapshot() or None
            except Exception:
                model_snapshot = None

    job = {
        "id": job_id,
        "name": name or label_source[:50].strip(),
        "prompt": prompt_text,
        "skills": normalized_skills,
        "skill": normalized_skills[0] if normalized_skills else None,
        "model": normalized_model,
        "provider": normalized_provider,
        # Provider/model resolution captured at creation for unpinned jobs
        # (#44585). None for pinned axes, no_agent jobs, resolution failures, and
        # any pre-existing job written before these fields existed (back-compat).
        "provider_snapshot": provider_snapshot,
        "model_snapshot": model_snapshot,
        "base_url": normalized_base_url,
        "script": normalized_script,
        "no_agent": normalized_no_agent,
        "context_from": context_from,
        "schedule": parsed_schedule,
        "schedule_display": parsed_schedule.get("display", schedule),
        "repeat": {
            "times": repeat,  # None = forever
            "completed": 0
        },
        "enabled": True,
        "state": "scheduled",
        "paused_at": None,
        "paused_reason": None,
        "created_at": now,
        "next_run_at": compute_next_run(parsed_schedule),
        "last_run_at": None,
        "last_status": None,
        "last_error": None,
        "last_delivery_error": None,
        # Delivery configuration
        "deliver": deliver,
        "origin": origin,  # Tracks where job was created for "origin" delivery
        "enabled_toolsets": normalized_toolsets,
        "workdir": normalized_workdir,
    }
    # Only persist attach_to_session when explicitly set, so existing jobs and
    # the common case stay byte-identical (absent key => fall back to the
    # global cron.mirror_delivery config, default off).
    if normalized_attach is not None:
        job["attach_to_session"] = normalized_attach

    with _jobs_lock():
        jobs = load_jobs()
        jobs.append(job)
        save_jobs(jobs)

    return job


def get_job(job_id: str) -> Optional[Dict[str, Any]]:
    """Get a job by ID."""
    jobs = load_jobs()
    for job in jobs:
        if job["id"] == job_id:
            return _normalize_job_record(job)
    return None


class AmbiguousJobReference(LookupError):
    """Raised when a job name matches more than one job."""

    def __init__(self, ref: str, matches: List[Dict[str, Any]]):
        self.ref = ref
        self.matches = matches
        ids = ", ".join(m["id"] for m in matches)
        super().__init__(
            f"Job name '{ref}' is ambiguous — matches {len(matches)} jobs: {ids}. "
            f"Use the job ID instead."
        )


def resolve_job_ref(ref: str) -> Optional[Dict[str, Any]]:
    """Resolve a job reference (ID or name) to a job record.

    - Exact ID match wins (works even if a different job's name equals this ID).
    - Otherwise, case-insensitive name match.
    - If a name matches more than one job, raises AmbiguousJobReference so the
      caller can surface the matching IDs rather than silently picking one.
    """
    if not ref:
        return None
    jobs = load_jobs()
    for job in jobs:
        if job["id"] == ref:
            return _normalize_job_record(job)
    ref_lower = ref.lower()
    name_matches = [j for j in jobs if (j.get("name") or "").lower() == ref_lower]
    if not name_matches:
        return None
    if len(name_matches) > 1:
        raise AmbiguousJobReference(
            ref, [_normalize_job_record(j) for j in name_matches]
        )
    return _normalize_job_record(name_matches[0])


def list_jobs(include_disabled: bool = False) -> List[Dict[str, Any]]:
    """List all jobs, optionally including disabled ones."""
    jobs = [_normalize_job_record(j) for j in load_jobs()]
    if not include_disabled:
        jobs = [j for j in jobs if j.get("enabled", True)]
    return jobs


def update_job(job_id: str, updates: Dict[str, Any]) -> Optional[Dict[str, Any]]:
    """Update a job by ID, refreshing derived schedule fields when needed."""
    # Block mutation of immutable fields. ``id`` in particular is a filesystem
    # path component under OUTPUT_DIR — letting an update change it leaks
    # path-escape values into output writes/deletes.
    bad_fields = _IMMUTABLE_JOB_FIELDS.intersection(updates or {})
    if bad_fields:
        raise ValueError(
            f"Cron job field(s) cannot be updated: {', '.join(sorted(bad_fields))}"
        )

    with _jobs_lock():
        jobs = load_jobs()
        for i, job in enumerate(jobs):
            if job["id"] != job_id:
                continue

            # Validate / normalize workdir if present in updates.  Empty string
            # or None both mean "clear the field" (restore old behaviour).
            if "workdir" in updates:
                _wd = updates["workdir"]
                if _wd in {None, "", False}:
                    updates["workdir"] = None
                else:
                    updates["workdir"] = _normalize_workdir(_wd)

            updated = _apply_skill_fields({**job, **updates})
            schedule_changed = "schedule" in updates

            if "skills" in updates or "skill" in updates:
                normalized_skills = _normalize_skill_list(updated.get("skill"), updated.get("skills"))
                updated["skills"] = normalized_skills
                updated["skill"] = normalized_skills[0] if normalized_skills else None

            if schedule_changed:
                updated_schedule = updated["schedule"]
                # The API may pass schedule as a raw string (e.g. "every 10m")
                # instead of a pre-parsed dict.  Normalize it the same way
                # create_job() does so downstream code can call .get() safely.
                if isinstance(updated_schedule, str):
                    updated_schedule = parse_schedule(updated_schedule)
                    updated["schedule"] = updated_schedule
                updated["schedule_display"] = updates.get(
                    "schedule_display",
                    updated_schedule.get("display", updated.get("schedule_display")),
                )
                if updated.get("state") != "paused":
                    updated["next_run_at"] = compute_next_run(updated_schedule)

            if updated.get("enabled", True) and updated.get("state") != "paused" and not updated.get("next_run_at"):
                updated["next_run_at"] = compute_next_run(updated["schedule"])

            jobs[i] = updated
            save_jobs(jobs)
            return _normalize_job_record(jobs[i])
    return None


def pause_job(job_id: str, reason: Optional[str] = None) -> Optional[Dict[str, Any]]:
    """Pause a job without deleting it. Accepts a job ID or name."""
    job = resolve_job_ref(job_id)
    if not job:
        return None
    return update_job(
        job["id"],
        {
            "enabled": False,
            "state": "paused",
            "paused_at": _hermes_now().isoformat(),
            "paused_reason": reason,
        },
    )


def resume_job(job_id: str) -> Optional[Dict[str, Any]]:
    """Resume a paused job and compute the next future run from now. Accepts a job ID or name."""
    job = resolve_job_ref(job_id)
    if not job:
        return None

    next_run_at = compute_next_run(job["schedule"])
    return update_job(
        job["id"],
        {
            "enabled": True,
            "state": "scheduled",
            "paused_at": None,
            "paused_reason": None,
            "next_run_at": next_run_at,
        },
    )


def trigger_job(job_id: str) -> Optional[Dict[str, Any]]:
    """Schedule a job to run on the next scheduler tick. Accepts a job ID or name."""
    job = resolve_job_ref(job_id)
    if not job:
        return None
    return update_job(
        job["id"],
        {
            "enabled": True,
            "state": "scheduled",
            "paused_at": None,
            "paused_reason": None,
            "next_run_at": _hermes_now().isoformat(),
        },
    )


def remove_job(job_id: str) -> bool:
    """Remove a job by ID or name."""
    job = resolve_job_ref(job_id)
    if not job:
        return False
    canonical_id = job["id"]
    with _jobs_lock():
        jobs = load_jobs()
        original_len = len(jobs)
        jobs = [j for j in jobs if j["id"] != canonical_id]
        if len(jobs) < original_len:
            # Resolve the output dir BEFORE saving so a legacy unsafe ID (e.g.
            # left over from before the create-time guard) fails closed without
            # half-applying the removal.
            job_output_dir = _job_output_dir(canonical_id)
            save_jobs(jobs)
            # Clean up output directory to prevent orphaned dirs accumulating
            if job_output_dir.exists():
                shutil.rmtree(job_output_dir)
            return True
    return False


def mark_job_run(job_id: str, success: bool, error: Optional[str] = None,
                 delivery_error: Optional[str] = None):
    """
    Mark a job as having been run.
    
    Updates last_run_at, last_status, increments completed count,
    computes next_run_at, and auto-deletes if repeat limit reached.

    ``delivery_error`` is tracked separately from the agent error — a job
    can succeed (agent produced output) but fail delivery (platform down).
    """
    with _jobs_lock():
        jobs = load_jobs()
        for i, job in enumerate(jobs):
            if job["id"] == job_id:
                now = _hermes_now().isoformat()
                job["last_run_at"] = now
                job["last_status"] = "ok" if success else "error"
                job["last_error"] = error if not success else None
                # Track delivery failures separately — cleared on successful delivery
                job["last_delivery_error"] = delivery_error
                # Clear any external-fire claim so a re-armed recurring job can
                # be claimed again on its next fire (Phase 4C CAS).
                job["fire_claim"] = None
                
                # Increment completed count
                if job.get("repeat"):
                    job["repeat"]["completed"] = job["repeat"].get("completed", 0) + 1
                    
                    # Check if we've hit the repeat limit
                    times = job["repeat"].get("times")
                    completed = job["repeat"]["completed"]
                    if times is not None and times > 0 and completed >= times:
                        # Remove the job (limit reached)
                        jobs.pop(i)
                        save_jobs(jobs)
                        return
                
                # Compute next run
                job["next_run_at"] = compute_next_run(job["schedule"], now)

                # If no next run, decide whether this is terminal completion
                # (one-shot) or a transient failure (recurring schedule couldn't
                # compute — e.g. 'croniter' missing from the runtime env).
                # Recurring jobs must NEVER be silently disabled: that turns a
                # missing runtime dep into "job completed" and the user's
                # schedule quietly goes off. See issue #16265.
                if job["next_run_at"] is None:
                    kind = job.get("schedule", {}).get("kind")
                    if kind in {"cron", "interval"}:
                        job["state"] = "error"
                        if not job.get("last_error"):
                            job["last_error"] = (
                                "Failed to compute next run for recurring "
                                "schedule (is the 'croniter' package "
                                "installed in the gateway's Python env?)"
                            )
                        logger.error(
                            "Job '%s' (%s) could not compute next_run_at; "
                            "leaving enabled and marking state=error so the "
                            "job is not silently disabled.",
                            job.get("name", job["id"]),
                            kind,
                        )
                    else:
                        job["enabled"] = False
                        job["state"] = "completed"
                elif job.get("state") != "paused":
                    job["state"] = "scheduled"

                save_jobs(jobs)
                return

        logger.warning("mark_job_run: job_id %s not found, skipping save", job_id)


def advance_next_run(job_id: str) -> bool:
    """Preemptively advance next_run_at for a recurring job before execution.

    Call this BEFORE run_job() so that if the process crashes mid-execution,
    the job won't re-fire on the next gateway restart.  This converts the
    scheduler from at-least-once to at-most-once for recurring jobs — missing
    one run is far better than firing dozens of times in a crash loop.

    One-shot jobs are left unchanged so they can still retry on restart.

    Returns True if next_run_at was advanced, False otherwise.
    """
    with _jobs_lock():
        jobs = load_jobs()
        for job in jobs:
            if job["id"] == job_id:
                kind = job.get("schedule", {}).get("kind")
                if kind not in {"cron", "interval"}:
                    return False
                now = _hermes_now().isoformat()
                new_next = compute_next_run(job["schedule"], now)
                if new_next and new_next != job.get("next_run_at"):
                    job["next_run_at"] = new_next
                    save_jobs(jobs)
                    return True
                return False
        return False


def _machine_id() -> str:
    """Stable-ish identifier for claim attribution/debugging (NOT correctness).

    Uses ``HERMES_MACHINE_ID`` if set, else hostname + pid. The CAS correctness
    comes from the file lock + the fresh-claim check, not from this value.
    """
    explicit = os.getenv("HERMES_MACHINE_ID", "").strip()
    if explicit:
        return explicit
    try:
        import socket
        host = socket.gethostname()
    except Exception:
        host = "unknown"
    return f"{host}:{os.getpid()}"


def claim_job_for_fire(job_id: str, *, claim_ttl_seconds: int = 300) -> bool:
    """Atomically claim a job for a single external 'fire' (multi-machine
    at-most-once). Returns True iff THIS caller won the claim.

    Used by the external-provider fire path (``CronScheduler.fire_due``) when an
    external scheduler (Chronos) signals a job is due across N gateway replicas:
    exactly one wins. Single-machine deployments always win.

    Under the file lock: reject if the job is missing/disabled/paused. If a
    fresh claim (younger than ``claim_ttl_seconds``) already exists, lose.
    Otherwise stamp a ``fire_claim`` and, for recurring jobs, advance
    ``next_run_at`` (mirrors ``advance_next_run``'s at-most-once bump so a stale
    re-delivery for the old time can't re-fire). One-shots keep ``next_run_at``
    but the fresh ``fire_claim`` blocks a duplicate retry for the same fire.
    ``mark_job_run`` clears the claim on completion so a re-armed recurring job
    is claimable again next fire.

    The stale-claim TTL means a machine that crashed after claiming but before
    completing doesn't wedge the job forever — after the TTL another fire can
    reclaim it.
    """
    with _jobs_lock():
        jobs = load_jobs()
        for job in jobs:
            if job["id"] != job_id:
                continue
            if not job.get("enabled", True) or job.get("state") == "paused":
                return False
            now = _hermes_now()
            existing = job.get("fire_claim")
            if existing:
                try:
                    claimed_at = _ensure_aware(datetime.fromisoformat(existing["at"]))
                    if (now - claimed_at).total_seconds() < claim_ttl_seconds:
                        return False  # someone holds a fresh claim
                except Exception:
                    pass  # malformed claim → overwrite
            job["fire_claim"] = {"at": now.isoformat(), "by": _machine_id()}
            kind = job.get("schedule", {}).get("kind")
            if kind in {"cron", "interval"}:
                nxt = compute_next_run(job["schedule"], now.isoformat())
                if nxt:
                    job["next_run_at"] = nxt
            save_jobs(jobs)
            return True
        return False


def get_due_jobs() -> List[Dict[str, Any]]:
    """Get all jobs that are due to run now.

    For recurring jobs (cron/interval), if the scheduled time is stale (more
    than one period in the past, e.g. because the gateway was down OR because a
    long-running previous execution overran the interval), the accumulated
    missed runs are collapsed — ``next_run_at`` is fast-forwarded to the next
    future occurrence so a backlog does NOT burst-fire on restart — but the job
    still fires ONCE now. This prevents the perpetual-defer loop (#33315) where
    a job whose runtime exceeds ``interval + grace`` would be skipped forever.

    Note: firing once on catch-up flows through ``mark_job_run``, so a job with
    a ``repeat.times`` limit consumes one of its runs on that catch-up fire.
    """
    with _jobs_lock():
        return _get_due_jobs_locked()


def _get_due_jobs_locked() -> List[Dict[str, Any]]:
    """Inner implementation of get_due_jobs(); must be called with _jobs_lock held."""
    now = _hermes_now()
    raw_jobs = load_jobs()
    jobs = [_apply_skill_fields(j) for j in copy.deepcopy(raw_jobs)]
    due = []
    needs_save = False

    for job in jobs:
        if not job.get("enabled", True):
            continue

        next_run = job.get("next_run_at")
        if not next_run:
            schedule = job.get("schedule", {})
            kind = schedule.get("kind")

            # One-shot jobs use a small grace window via the dedicated helper.
            recovered_next = _recoverable_oneshot_run_at(
                schedule,
                now,
                last_run_at=job.get("last_run_at"),
            )
            recovery_kind = "one-shot" if recovered_next else None

            # Recurring jobs reach here only when something — typically a
            # direct jobs.json edit that bypassed add_job() — left
            # next_run_at unset.  Without this branch, such jobs are
            # silently skipped forever; recompute next_run_at from the
            # schedule so they pick up at their next scheduled tick.
            if not recovered_next and kind in {"cron", "interval"}:
                recovered_next = compute_next_run(schedule, now.isoformat())
                if recovered_next:
                    recovery_kind = kind

            if not recovered_next:
                continue

            job["next_run_at"] = recovered_next
            next_run = recovered_next
            logger.info(
                "Job '%s' had no next_run_at; recovering %s run at %s",
                job.get("name", job["id"]),
                recovery_kind,
                recovered_next,
            )
            for rj in raw_jobs:
                if rj["id"] == job["id"]:
                    rj["next_run_at"] = recovered_next
                    needs_save = True
                    break

        raw_next_run_dt = datetime.fromisoformat(next_run)
        schedule = job.get("schedule", {})
        kind = schedule.get("kind")

        next_run_dt = _ensure_aware(raw_next_run_dt)
        # Migration repair: a cron job persists next_run_at as an absolute
        # instant, but the cron expr describes local wall-clock intent. If the
        # configured/system timezone changed after persistence, the stored
        # instant's offset no longer matches now's, and its converted time can
        # look due hours early (21:00+10 -> 13:00+02). When the stored *wall
        # clock* is still in the future, recompute from the schedule so we fire
        # at the intended local time instead of early-then-again.
        #
        # TRADE-OFF: this cannot distinguish a config/host TZ migration from a
        # legitimate DST offset change. A DST boundary that satisfies all four
        # conditions will recompute (and thus SKIP the pending occurrence, no
        # catch-up) rather than fire it. Accepted: in the pure-migration case
        # the recompute lands on the same wall-clock time later the same period,
        # and DST-boundary collisions with a still-future stored wall clock are
        # rare relative to the double-fire bug this prevents (#28934).
        if (
            kind == "cron"
            and next_run_dt <= now
            and _timezone_offset_mismatch(raw_next_run_dt, now)
            and _stored_wall_clock_is_future(raw_next_run_dt, now)
        ):
            new_next = compute_next_run(schedule, now.isoformat())
            if new_next:
                logger.info(
                    "Job '%s' next_run_at offset changed (%s -> %s). "
                    "Recomputing cron run to preserve local wall-clock intent: %s",
                    job.get("name", job["id"]),
                    raw_next_run_dt.utcoffset(),
                    now.utcoffset(),
                    new_next,
                )
                for rj in raw_jobs:
                    if rj["id"] == job["id"]:
                        rj["next_run_at"] = new_next
                        needs_save = True
                        break
                continue

        if next_run_dt <= now:

            # For recurring jobs, check if the scheduled time is stale
            # (gateway was down and missed the window). Fast-forward to
            # the next future occurrence instead of firing a stale run.
            grace = _compute_grace_seconds(schedule)
            if kind in {"cron", "interval"} and (now - next_run_dt).total_seconds() > grace:
                # Job is past its catch-up grace window — skip accumulated
                # missed runs but still execute once now to avoid deferring
                # indefinitely (e.g. a long-running job just finished).
                new_next = compute_next_run(schedule, now.isoformat())
                if new_next:
                    logger.info(
                        "Job '%s' missed its scheduled time (%s, grace=%ds). "
                        "Running now; next run provisionally set to: %s "
                        "(re-anchored on completion)",
                        job.get("name", job["id"]),
                        next_run,
                        grace,
                        new_next,
                    )
                    # Persist the fast-forward to storage now (skip accumulated
                    # slots). In the built-in ticker path this is shortly
                    # overwritten by advance_next_run + mark_job_run, but it is
                    # NOT redundant: it (a) protects the crash window between
                    # here and mark_job_run, and (b) covers the external
                    # fire_due provider path, which does not call
                    # advance_next_run. mark_job_run re-anchors next_run_at off
                    # the actual completion time, so this value is provisional.
                    for rj in raw_jobs:
                        if rj["id"] == job["id"]:
                            rj["next_run_at"] = new_next
                            needs_save = True
                            break
                    # Fall through to due.append(job) — execute once now

            due.append(job)

    if needs_save:
        save_jobs(raw_jobs)

    return due


def save_job_output(job_id: str, output: str):
    """Save job output to file."""
    ensure_dirs()
    job_output_dir = _job_output_dir(job_id)
    job_output_dir.mkdir(parents=True, exist_ok=True)
    _secure_dir(job_output_dir)
    
    timestamp = _hermes_now().strftime("%Y-%m-%d_%H-%M-%S")
    output_file = job_output_dir / f"{timestamp}.md"
    
    fd, tmp_path = tempfile.mkstemp(dir=str(job_output_dir), suffix='.tmp', prefix='.output_')
    try:
        with os.fdopen(fd, 'w', encoding='utf-8') as f:
            f.write(output)
            f.flush()
            os.fsync(f.fileno())
        atomic_replace(tmp_path, output_file)
        _secure_file(output_file)
    except BaseException:
        try:
            os.unlink(tmp_path)
        except OSError:
            pass
        raise
    
    return output_file


# =============================================================================
# Skill reference rewriting (curator integration)
# =============================================================================

def rewrite_skill_refs(
    consolidated: Optional[Dict[str, str]] = None,
    pruned: Optional[List[str]] = None,
) -> Dict[str, Any]:
    """Rewrite cron job skill references after a curator consolidation pass.

    When the curator consolidates a skill X into umbrella Y (or archives X
    as pruned), any cron job that lists ``X`` in its ``skills`` field will
    fail to load ``X`` at run time — the scheduler logs a warning and
    skips the skill, so the job runs without the instructions it was
    scheduled to follow. See cron/scheduler.py where ``skill_view`` is
    called per skill name.

    This function repairs cron jobs in-place:

    - A skill listed in ``consolidated`` is replaced with its umbrella
      target (the ``into`` value). If the umbrella is already in the
      job's skill list, the stale name is dropped without duplication.
    - A skill listed in ``pruned`` is dropped outright — there is no
      forwarding target.
    - Ordering and other skills in the list are preserved.
    - The legacy ``skill`` field is realigned via ``_apply_skill_fields``.

    Args:
        consolidated: mapping of ``old_skill_name -> umbrella_skill_name``.
        pruned: list of skill names that were archived with no forwarding
            target.

    Returns a report dict::

        {
            "rewrites": [
                {
                    "job_id": ...,
                    "job_name": ...,
                    "before": [...],
                    "after": [...],
                    "mapped": {"old": "new", ...},
                    "dropped": ["old", ...],
                },
                ...
            ],
            "jobs_updated": N,
            "jobs_scanned": M,
        }

    Best-effort: exceptions from loading/saving propagate to the caller so
    tests can assert behaviour; the curator invocation site wraps this
    call in a try/except so a failure here never breaks the curator.
    """
    consolidated = dict(consolidated or {})
    pruned_set = set(pruned or [])
    # A skill listed in both wins as "consolidated" — it has a target,
    # which is the more useful of the two outcomes.
    pruned_set -= set(consolidated.keys())

    if not consolidated and not pruned_set:
        return {"rewrites": [], "jobs_updated": 0, "jobs_scanned": 0}

    with _jobs_lock():
        jobs = load_jobs()
        rewrites: List[Dict[str, Any]] = []
        changed = False

        for job in jobs:
            skills_before = _normalize_skill_list(job.get("skill"), job.get("skills"))
            if not skills_before:
                continue

            mapped: Dict[str, str] = {}
            dropped: List[str] = []
            new_skills: List[str] = []

            for name in skills_before:
                if name in consolidated:
                    target = consolidated[name]
                    mapped[name] = target
                    if target and target not in new_skills:
                        new_skills.append(target)
                elif name in pruned_set:
                    dropped.append(name)
                elif name not in new_skills:
                    new_skills.append(name)

            if not mapped and not dropped:
                continue

            job["skills"] = new_skills
            job["skill"] = new_skills[0] if new_skills else None
            changed = True

            rewrites.append({
                "job_id": job.get("id"),
                "job_name": job.get("name") or job.get("id"),
                "before": list(skills_before),
                "after": list(new_skills),
                "mapped": mapped,
                "dropped": dropped,
            })

        if changed:
            save_jobs(jobs)
            logger.info(
                "Curator rewrote skill references in %d cron job(s)", len(rewrites)
            )

        return {
            "rewrites": rewrites,
            "jobs_updated": len(rewrites),
            "jobs_scanned": len(jobs),
        }
