#!/usr/bin/env python3
"""Skills Tool Module — list and view skill documents (progressive disclosure).

Skills are directories holding a SKILL.md (YAML frontmatter + instructions) plus
optional references/, templates/, assets/, scripts/ (agentskills.io layout).
Tier 1 (`skills_list`) returns name/description only; tier 2-3 (`skill_view`)
returns full content and linked files on demand.

Frontmatter: name (≤64), description (≤1024) required; optional version,
license, platforms [macos|linux|windows], prerequisites.env_vars (legacy —
normalized into required_environment_variables), prerequisites.commands
(advisory only), compatibility, metadata.hermes.{tags,related_skills}.

Sibling modules (every name re-exported here so ``from tools.skills_tool import X``
and ``patch("tools.skills_tool.X")`` keep working):
- tools.skills_tool_setup: required env vars / secret capture / setup notes
- tools.skills_tool_plugin: plugin-skill serving + shared file/JSON helpers
- tools.skills_tool_dedup: repeat-view dedup registry
"""

import json
import logging
import os
import time
from pathlib import Path, PurePosixPath, PureWindowsPath
from typing import Any, Dict, List, Optional, Set, Tuple

from hermes_constants import get_hermes_home
from tools.registry import registry, tool_error
from hermes_cli.config import cfg_get
from agent.skill_utils import (
    EXCLUDED_SKILL_DIRS as _EXCLUDED_SKILL_DIRS,
    is_skill_support_path as _is_skill_support_path,
)
from tools.skills_tool_setup import (  # noqa: F401
    SkillReadinessStatus, _ENV_VAR_NAME_RE, _REMOTE_ENV_BACKENDS, _build_setup_note,
    _capture_required_environment_variables, _collect_prerequisite_values,
    _gateway_setup_hint, _get_required_environment_variables, _get_terminal_backend_name,
    _is_env_var_persisted, _is_gateway_surface, _is_remote_env_backend,
    _normalize_prerequisite_values, _normalize_setup_metadata,
    _remaining_required_environment_names,
)
from tools.skills_tool_plugin import (  # noqa: F401
    MAX_DESCRIPTION_LENGTH, MAX_NAME_LENGTH, _INJECTION_PATTERNS, _available_skill_files,
    _fail, _json, _mark_background_review_read, _plugin_skill_linked_files,
    _preprocess_skill, _read_skill_text, _serve_plugin_skill, _serve_skill_file,
    _truncate_description,
)
from tools.skills_tool_dedup import (  # noqa: F401
    _SKILL_VIEW_DEDUP_CAP, _SKILL_VIEW_DEDUP_MESSAGE, _check_skill_view_dedup,
    _record_skill_view, _skill_view_fingerprint, _skill_view_tracker,
    _skill_view_tracker_lock, reset_skill_view_dedup,
)

logger = logging.getLogger(__name__)

# Per-session skill discovery cache (re-reading every SKILL.md per call is
# wasteful with hundreds of skills). Validation mirrors
# hermes_cli/profiles.py::_count_skills (d5eee133e): the signature is the
# per-dir max mtime of the dir AND its immediate children (catches add/remove
# inside categories, which does NOT bump the root mtime) plus the disabled-set
# (config-driven, no mtime bump at all); a short TTL bounds staleness from
# in-place SKILL.md edits, invisible to any directory signature.
# skip_disabled True/False are cached separately.
_SKILLS_CACHE: dict = {}          # {cache_key: (signature, timestamp, skills_list)}
_SKILLS_CACHE_TTL_SECONDS = 30.0
_SKILLS_CACHE_KEY_DISABLED = "with_disabled"
_SKILLS_CACHE_KEY_FILTERED = "filtered"


def _skills_scan_signature(dirs_to_scan, disabled) -> tuple:
    """Cheap change-signature for the skill scan inputs: O(#dirs + #categories)
    stat calls, not a recursive walk. Includes the platform the scan's
    ``skill_matches_platform`` filter will use (read from ``agent.skill_utils``'s
    ``sys`` so test patches are honored) — the scan result is platform-dependent."""
    from agent import skill_utils as _skill_utils

    platform = getattr(getattr(_skill_utils, "sys", None), "platform", "")
    sig = []
    for d in dirs_to_scan:
        try:
            m = d.stat().st_mtime
        except OSError:
            continue
        try:
            with os.scandir(d) as it:
                for entry in it:
                    try:
                        if entry.is_dir(follow_symlinks=False):
                            m = max(m, entry.stat(follow_symlinks=False).st_mtime)
                    except OSError:
                        continue
        except OSError:
            pass
        sig.append((str(d), m))
    return (tuple(sig), frozenset(disabled), platform)


# All skills live in ~/.hermes/skills/ (seeded from bundled skills/ on install):
# agent edits, hub installs, and bundled skills coexist here without polluting
# the git repo.
HERMES_HOME = get_hermes_home()
SKILLS_DIR = HERMES_HOME / "skills"
_SKILLS_DIR_AT_IMPORT = SKILLS_DIR


def _skills_dir() -> Path:
    """Active profile's skills directory at call time.

    Long-lived runtimes may import this module before the active profile has set
    HERMES_HOME. Keep the legacy SKILLS_DIR attribute for tests and external
    patchers, but when it has not been patched, resolve from the live
    profile-scoped HERMES_HOME on every call."""
    configured = Path(SKILLS_DIR)
    if configured != _SKILLS_DIR_AT_IMPORT:
        return configured
    return get_hermes_home() / "skills"


_secret_capture_callback = None
_LOOKUP_HINT = "Use a skill name or relative path within the skills directory."


def _skill_lookup_path_error(name: str) -> Optional[str]:
    """Error if a local skill lookup *name* can escape the search roots.

    ``name`` is joined onto each trusted search dir, so it must stay relative and
    free of ``..`` — otherwise ``"../outside"`` or an absolute path could select a
    skill (and read files) outside the skills directory. Mirrors the ``file_path``
    validation in ``tools.path_security``. Windows drive paths (``C:\\skills``) are
    rejected too: their ``:`` would be misread as a plugin namespace separator."""
    from tools.path_security import has_traversal_component

    if not isinstance(name, str):
        return "Skill name must be a string."
    candidate = name.strip()
    win = PureWindowsPath(candidate)
    if PurePosixPath(candidate).is_absolute() or win.is_absolute() or win.drive:
        return "Skill name must be a relative path within the skills directory."
    if has_traversal_component(candidate):
        return "Skill name cannot contain '..' path traversal components."
    return None


def load_env() -> Dict[str, str]:
    """Load profile-scoped environment variables from HERMES_HOME/.env."""
    env_path = get_hermes_home() / ".env"
    env_vars: Dict[str, str] = {}
    if not env_path.exists():
        return env_vars
    # utf-8-sig: users hand-edit .env in Notepad, whose BOM would otherwise glue
    # U+FEFF onto the first key (same dialect as hermes_cli/config.py readers).
    with env_path.open(encoding="utf-8-sig", errors="replace") as f:
        for line in f:
            line = line.strip()
            if line and not line.startswith("#") and "=" in line:
                if line.startswith("export "):
                    line = line[7:]
                key, _, value = line.partition("=")
                env_vars[key.strip()] = value.strip().strip("\"'")
    return env_vars


def set_secret_capture_callback(callback) -> None:
    global _secret_capture_callback
    _secret_capture_callback = callback


# Lazy delegates to ``agent.skill_utils`` — public re-exports so existing
# callers (and tests patching either module) don't need updating.
def skill_matches_platform(frontmatter: Dict[str, Any]) -> bool:
    """Check if a skill is compatible with the current OS platform."""
    from agent.skill_utils import skill_matches_platform as _impl
    return _impl(frontmatter)


def skill_matches_environment(frontmatter: Dict[str, Any]) -> bool:
    """Offer-time relevance gate (kanban/docker/s6), NOT a hard-compatibility
    gate; explicit skill loads bypass it."""
    from agent.skill_utils import skill_matches_environment as _impl
    return _impl(frontmatter)


def _parse_frontmatter(content: str) -> Tuple[Dict[str, Any], str]:
    """Parse YAML frontmatter from markdown content."""
    from agent.skill_utils import parse_frontmatter
    return parse_frontmatter(content)


def _get_disabled_skill_names() -> Set[str]:
    """Load disabled skill names from config."""
    from agent.skill_utils import get_disabled_skill_names
    return get_disabled_skill_names()


def check_skills_requirements() -> bool:
    """Skills are always available -- the directory is created on first use if needed."""
    return True


def _get_category_from_path(skill_path: Path) -> Optional[str]:
    """``~/.hermes/skills/mlops/axolotl/SKILL.md`` -> ``"mlops"`` (also for
    skills.external_dirs). Tries the active profile dir first (respects test
    monkeypatching), then external dirs from config."""
    dirs_to_check = [_skills_dir()]
    try:
        from agent.skill_utils import get_external_skills_dirs
        dirs_to_check.extend(get_external_skills_dirs())
    except Exception:
        pass
    for skills_dir in dirs_to_check:
        try:
            parts = skill_path.relative_to(skills_dir).parts
        except ValueError:
            continue
        if len(parts) >= 3:
            return parts[0]
    return None


def _parse_tags(tags_value) -> List[str]:
    """Tags from frontmatter: a parsed list (yaml.safe_load), a bracket-wrapped
    string "[a, b]", or a comma-separated string "a, b"."""
    if not tags_value:
        return []
    if isinstance(tags_value, list):
        return [str(t).strip() for t in tags_value if t]
    tags_value = str(tags_value).strip()
    if tags_value.startswith("[") and tags_value.endswith("]"):
        tags_value = tags_value[1:-1]
    return [t.strip().strip("\"'") for t in tags_value.split(",") if t.strip()]


def _get_session_platform() -> str:
    """Platform from gateway session context. Mirrors
    ``agent.skill_utils.get_disabled_skill_names`` so ``_is_skill_disabled``
    respects ``HERMES_SESSION_PLATFORM``."""
    try:
        from gateway.session_context import get_session_env
        return get_session_env("HERMES_SESSION_PLATFORM") or ""
    except Exception:
        return ""


def _is_skill_disabled(name: str, platform: str = None) -> bool:
    """Is the skill disabled in config? Platform precedence: explicit arg,
    ``HERMES_PLATFORM`` env, ``HERMES_SESSION_PLATFORM`` from session context."""
    try:
        from hermes_cli.config import load_config
        skills_cfg = load_config().get("skills", {})
        resolved_platform = platform or os.getenv("HERMES_PLATFORM") or _get_session_platform()
        global_disabled = skills_cfg.get("disabled", [])
        if resolved_platform:
            platform_disabled = cfg_get(skills_cfg, "platform_disabled", resolved_platform)
            if platform_disabled is not None:
                # A globally-disabled skill stays disabled on every platform; the
                # platform list adds to it. Keep in sync with
                # agent.skill_utils.get_disabled_skill_names.
                return name in platform_disabled or name in global_disabled
        return name in global_disabled
    except Exception:
        return False


def _skill_search_dirs() -> Tuple[list, list, Path]:
    """(project_dirs, all_dirs, active_skills_dir) in precedence order.

    Trusted project-local dirs come FIRST: first-wins dedup / the collision
    resolver give them precedence over same-named local/external skills.
    ``_skills_dir()`` resolves the LIVE profile HERMES_HOME; module-level
    SKILLS_DIR can be stale in long-lived runtimes."""
    from agent.skill_utils import get_external_skills_dirs, get_project_skills_dirs

    project_dirs = list(get_project_skills_dirs())
    all_dirs: list = list(project_dirs)
    active_skills_dir = _skills_dir()
    if active_skills_dir.exists():
        all_dirs.append(active_skills_dir)
    all_dirs.extend(get_external_skills_dirs())
    return project_dirs, all_dirs, active_skills_dir


def _find_all_skills(*, skip_disabled: bool = False) -> List[Dict[str, Any]]:
    """All skills (name, description, category) in ~/.hermes/skills/ and
    project/external dirs. ``skip_disabled=True`` returns ALL skills regardless
    of disabled state (used by the ``hermes skills`` config UI).

    Cached per-session; invalidated when the scan signature changes (dir/category
    mtimes or the disabled-set) and after a short TTL (in-place SKILL.md edits)."""
    from agent.skill_utils import iter_project_skill_files, iter_skill_index_files

    cache_key = _SKILLS_CACHE_KEY_DISABLED if skip_disabled else _SKILLS_CACHE_KEY_FILTERED
    # Disabled set loaded once (not per-skill); part of the cache signature since
    # disabling a skill is a config change with no filesystem mtime bump.
    disabled = set() if skip_disabled else _get_disabled_skill_names()
    project_dirs, dirs_to_scan, _ = _skill_search_dirs()
    signature = _skills_scan_signature(dirs_to_scan, disabled)
    now = time.monotonic()

    cached = _SKILLS_CACHE.get(cache_key)
    if cached is not None and cached[0] == signature and (now - cached[1]) < _SKILLS_CACHE_TTL_SECONDS:
        # Per-call shallow copies: callers mutate the returned dicts (web_server
        # annotates s["enabled"]/s["usage"]); handing out cached objects would
        # poison the cache for everyone else.
        return [dict(s) for s in cached[2]]

    skills = []
    seen_names: set = set()
    # Project dirs first, then local, then external (first-wins). Project dirs
    # iterate through the quarantine chokepoint (scan-time injection gate).
    for scan_dir in dirs_to_scan:
        _iter = iter_project_skill_files if scan_dir in project_dirs else lambda d: iter_skill_index_files(d, "SKILL.md")
        for skill_md in _iter(scan_dir):
            if any(part in _EXCLUDED_SKILL_DIRS for part in skill_md.parts):
                continue
            try:
                frontmatter, body = _parse_frontmatter(_read_skill_text(skill_md)[:4000])
                if not skill_matches_platform(frontmatter) or not skill_matches_environment(frontmatter):
                    continue
                name = frontmatter.get("name", skill_md.parent.name)[:MAX_NAME_LENGTH]
                if name in seen_names or name in disabled:
                    continue
                description = frontmatter.get("description", "")
                if not description:
                    for line in body.strip().split("\n"):
                        line = line.strip()
                        if line and not line.startswith("#"):
                            description = line
                            break
                seen_names.add(name)
                skills.append({
                    "name": name,
                    "description": _truncate_description(description),
                    "category": _get_category_from_path(skill_md),
                })
            except (UnicodeDecodeError, PermissionError) as e:
                logger.debug("Failed to read skill file %s: %s", skill_md, e)
            except Exception as e:
                logger.debug("Skipping skill at %s: failed to parse: %s", skill_md, e, exc_info=True)

    # Keyed by the signature computed BEFORE the scan: a write racing the scan
    # changes the signature, so the next call re-scans instead of serving the
    # torn result past the TTL. Same shallow-copy contract as the hit path.
    _SKILLS_CACHE[cache_key] = (signature, now, skills)
    return [dict(s) for s in skills]


def _sort_skills(skills: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
    """Keep every skill listing path ordered the same way."""
    return sorted(skills, key=lambda s: (s.get("category") or "", s["name"]))


def skills_list(category: str = None, task_id: str = None) -> str:
    """Tier 1 listing: name + description (+ category) only, to minimize tokens.
    ``category`` filters; ``task_id`` is accepted for handler parity."""
    try:
        active_skills_dir = _skills_dir()
        if not active_skills_dir.exists():
            active_skills_dir.mkdir(parents=True, exist_ok=True)

        all_skills = _find_all_skills()
        try:
            from hermes_cli.plugins import discover_plugins, get_plugin_manager

            discover_plugins()
            for plugin_skill in get_plugin_manager().list_plugin_skill_metadata():
                frontmatter = plugin_skill.pop("frontmatter", {})
                if not skill_matches_platform(frontmatter) or _is_skill_disabled(plugin_skill["name"]):
                    continue
                all_skills.append(plugin_skill)
        except Exception:
            logger.debug("Plugin skill listing failed", exc_info=True)

        if not all_skills:
            return _json({
                "success": True, "skills": [], "categories": [],
                "message": "No skills found in skills/ directory.",
            })
        if category:
            all_skills = [s for s in all_skills if s.get("category") == category]
        all_skills = _sort_skills(all_skills)
        categories = sorted({s.get("category") for s in all_skills if s.get("category")})
        return _json({
            "success": True,
            "skills": all_skills,
            "categories": categories,
            "count": len(all_skills),
            "hint": "Use skill_view(name) to see full content, tags, and linked files",
        })
    except Exception as e:
        return tool_error(str(e), success=False)


# ── skill_view helpers ─────────────────────────────────────────────────────

def _resolve_plugin_skill(name, file_path, task_id, preprocess):
    """Qualified-name dispatch for ``plugin:skill`` names.

    Returns ``(result_json, None)`` when answered, or ``(None, local_category_name)``
    to fall through to the flat-tree scan: categorized local skills also use
    ``category:skill`` in config and gateway prompts, so the on-disk
    ``category/skill`` translation is returned (None when there's no bare part)."""
    from agent.skill_utils import is_valid_namespace, parse_qualified_name
    from hermes_cli.plugins import discover_plugins, get_plugin_manager

    namespace, bare = parse_qualified_name(name)
    if not is_valid_namespace(namespace):
        return _fail(f"Invalid namespace '{namespace}' in '{name}'. Namespaces must match [a-zA-Z0-9_-]+."), None

    discover_plugins()  # idempotent
    pm = get_plugin_manager()
    active_memory_provider = None
    try:
        from plugins.memory import _get_active_memory_provider, _prune_inactive_memory_provider_skills
        active_memory_provider = _get_active_memory_provider()
        _prune_inactive_memory_provider_skills(active_memory_provider)
    except Exception as exc:
        logger.debug("Failed pruning inactive memory-provider skills: %s", exc)

    plugin_skill_md = pm.find_plugin_skill(name)
    # Memory provider plugins load through plugins.memory rather than the general
    # PluginManager. If a memory provider shim also registers skills, load the
    # namespaced provider once so its collector can forward those skills into the
    # plugin skill registry before declaring the qualified skill missing.
    if plugin_skill_md is None:
        try:
            if namespace == active_memory_provider:
                from plugins.memory import load_memory_provider

                load_memory_provider(namespace)
                plugin_skill_md = pm.find_plugin_skill(name)
        except Exception as exc:
            logger.debug("Failed lazy memory-provider skill load for %s: %s", namespace, exc)

    if plugin_skill_md is not None:
        if not plugin_skill_md.exists():
            pm.remove_plugin_skill(name)  # stale registry entry — file deleted out of band
            return _fail(
                f"Skill '{name}' file no longer exists at {plugin_skill_md}. The registry entry "
                f"has been cleaned up — try again after the plugin is reloaded."
            ), None
        return _serve_plugin_skill(
            plugin_skill_md, namespace, bare,
            file_path=file_path, preprocess=preprocess, session_id=task_id,
        ), None

    available = pm.list_plugin_skills(namespace)
    if available:  # plugin exists but this specific skill is missing
        return _fail(
            f"Skill '{bare}' not found in plugin '{namespace}'.",
            available_skills=[f"{namespace}:{s}" for s in available],
            hint=f"The '{namespace}' plugin provides {len(available)} skill(s).",
        ), None
    return None, (f"{namespace}/{bare}" if bare else None)  # plugin not found → local scan


def _under_any(path: Path, dirs) -> bool:
    """True when ``path`` (resolved where possible) lives under one of ``dirs``."""
    try:
        resolved = path.resolve()
    except Exception:
        resolved = path
    for d in dirs:
        try:
            resolved.relative_to(d)
            return True
        except ValueError:
            continue
    return False


def _collect_skill_candidates(name, local_category_name, all_dirs):
    """ALL (skill_dir, skill_md) candidates across every dir using every lookup
    strategy (direct path, recursive by parent dir / frontmatter name, legacy flat
    <name>.md), deduped by resolved path.

    Collision detection is the point: silent shadowing of a local skill by a
    same-named external skill is a real bug class (`/skills` shows one, agent
    loaded the other), so the caller refuses when more than one matches."""
    from agent.skill_utils import iter_skill_index_files

    candidates: List[Tuple[Optional[Path], Path]] = []
    seen_md: set = set()

    def _record(sd: Optional[Path], smd: Path) -> None:
        try:
            key = smd.resolve()
        except Exception:
            key = smd
        if key not in seen_md:
            seen_md.add(key)
            candidates.append((sd, smd))

    def _record_direct(direct_path: Path) -> None:
        # Direct path ("mlops/axolotl" or bare "axolotl") or its legacy flat .md sibling.
        flat = direct_path.with_suffix(".md")
        if not _is_skill_support_path(direct_path) and direct_path.is_dir() and (direct_path / "SKILL.md").exists():
            _record(direct_path, direct_path / "SKILL.md")
        elif flat.exists() and not _is_skill_support_path(flat):
            _record(None, flat)

    for search_dir in all_dirs:
        _record_direct(search_dir / name)
        # Categorized form for plugin-namespace fall-through ("myplugin:explore"
        # with no such plugin also tries the on-disk path "myplugin/explore").
        if local_category_name:
            _record_direct(search_dir / local_category_name)
        # Recursive by directory name (nested skills called by bare name) plus
        # frontmatter `name:` — skills_list() exposes the frontmatter name, so
        # skill_view(name) must accept it even when the directory is an alias.
        for found_skill_md in iter_skill_index_files(search_dir, "SKILL.md"):
            if found_skill_md.parent.name == name:
                _record(found_skill_md.parent, found_skill_md)
                continue
            try:
                fm, _ = _parse_frontmatter(_read_skill_text(found_skill_md))
            except Exception:
                fm = {}
            if fm.get("name") == name:
                _record(found_skill_md.parent, found_skill_md)
        # Legacy flat <name>.md anywhere under the dir. Skill support docs
        # (references/templates/assets/scripts) are excluded: they load via
        # file_path and must not shadow real skills sharing the basename.
        for found_md in search_dir.rglob(f"{name}.md"):
            if found_md.name != "SKILL.md" and not _is_skill_support_path(found_md):
                _record(None, found_md)
    return candidates


_TEMPLATE_GLOBS = ["*.md", "*.py", "*.yaml", "*.yml", "*.json", "*.tex", "*.sh"]
_SCRIPT_GLOBS = ["*.py", "*.sh", "*.bash", "*.js", "*.ts", "*.rb"]


def _skill_linked_files(skill_dir: Optional[Path]) -> dict:
    """references/templates/assets/scripts of a directory skill (empty groups dropped)."""
    if not skill_dir:
        return {}

    def _rel(paths):
        return [str(f.relative_to(skill_dir)) for f in paths]
    def _multi(sub: Path, globs, rglob: bool):
        out: list = []
        for ext in globs:
            out.extend(_rel(sub.rglob(ext) if rglob else sub.glob(ext)))
        return out

    refs, tmpl, assets, scripts = (skill_dir / n for n in ("references", "templates", "assets", "scripts"))
    files = {
        "references": _rel(refs.glob("*.md")) if refs.exists() else [],
        "templates": _multi(tmpl, _TEMPLATE_GLOBS, True) if tmpl.exists() else [],
        "assets": _rel(f for f in assets.rglob("*") if f.is_file()) if assets.exists() else [],
        "scripts": _multi(scripts, _SCRIPT_GLOBS, False) if scripts.exists() else [],
    }
    return {k: v for k, v in files.items() if v}


def _org_provenance_header(skill_dir: Path, active_skills_dir: Path):
    """(org_provenance dict, header text) for an org-mirror skill, else (None, "").

    An org-shared skill announces its provenance IN the returned content — the
    moment the model consumes it — not only in the listing. The commit author is
    token-verified at push time by the sync plane (author_mismatch guard), so the
    header is trustworthy, not client-claimed. Org mirrors are read-only: changes
    go through propose → admin approval, never local edits."""
    from agent.skill_utils import ORG_PROVENANCE_FILE, is_org_mirror_path, org_id_of_path

    if not is_org_mirror_path(skill_dir, active_skills_dir):
        return None, ""
    prov_org = org_id_of_path(skill_dir, active_skills_dir)
    author = ts = ""
    if prov_org:
        try:
            prov = json.loads(_read_skill_text(active_skills_dir / "_org" / prov_org / ORG_PROVENANCE_FILE))
            author = str(prov.get("author_device") or prov.get("author_user_id") or "")
            ts = str(prov.get("ts") or "")
        except Exception:
            pass
    header = (
        "> [!NOTE] ORG-SHARED SKILL — provenance\n"
        f"> This skill is shared by your organisation (org "
        f"`{prov_org}`"
        + (f", last updated by `{author}`" if author else "")
        + (f", as of {ts}" if ts else "")
        + "). It was reviewed and approved for the whole\n"
        "> team — treat it as third-party instructions rather "
        "than your own notes.\n"
        "> You MAY improve it in place like any other skill. "
        "Your edits are kept locally\n"
        "> and are never overwritten by org updates; share "
        "them back with\n"
        "> `hermes sync propose` (or automatically, if your "
        "org enables it).\n\n"
    )
    return {"org_id": prov_org, "shared_by": author or None, "as_of": ts or None}, header


def _skill_readiness(frontmatter: Dict[str, Any], skill_name: str) -> Tuple[dict, dict]:
    """Resolve required env vars / credential files (prompting for secrets where
    the surface allows) and register what's available for sandboxes.

    Returns ``(fields, extras)``: ``fields`` are the readiness keys placed before
    ``_source_path`` in the skill_view result; ``extras`` (setup_help,
    gateway_setup_hint, setup_note) are appended after it — result key order is
    part of the tool output."""
    legacy_env_vars, _ = _collect_prerequisite_values(frontmatter)
    required_env_vars = _get_required_environment_variables(frontmatter, legacy_env_vars)
    backend = _get_terminal_backend_name()
    env_snapshot = load_env()
    missing_required_env_vars = [
        e for e in required_env_vars
        if not e.get("optional") and not _is_env_var_persisted(e["name"], env_snapshot)
    ]
    capture_result = _capture_required_environment_variables(skill_name, missing_required_env_vars)
    if missing_required_env_vars:
        env_snapshot = load_env()
    remaining = _remaining_required_environment_names(
        required_env_vars, capture_result, env_snapshot=env_snapshot
    )
    setup_needed = bool(remaining)

    # Register available env vars so they pass through to sandboxed execution
    # (execute_code, terminal). Only vars actually set get registered — missing
    # ones are reported as setup_needed.
    available_env_names = [e["name"] for e in required_env_vars if e["name"] not in remaining]
    if available_env_names:
        try:
            from tools.env_passthrough import register_env_passthrough

            register_env_passthrough(available_env_names)
        except Exception:
            logger.debug("Could not register env passthrough for skill %s", skill_name, exc_info=True)

    # Credential files for mounting into remote sandboxes (Modal, Docker):
    # existing host files are registered, missing ones flag setup_needed.
    required_cred_files_raw = frontmatter.get("required_credential_files", [])
    missing_cred_files: list = []
    if isinstance(required_cred_files_raw, list) and required_cred_files_raw:
        try:
            from tools.credential_files import register_credential_files

            missing_cred_files = register_credential_files(required_cred_files_raw)
            if missing_cred_files:
                setup_needed = True
        except Exception:
            logger.debug("Could not register credential files for skill %s", skill_name, exc_info=True)

    fields = {
        "required_environment_variables": required_env_vars,
        "required_commands": [],
        "missing_required_environment_variables": remaining,
        "missing_credential_files": missing_cred_files,
        "missing_required_commands": [],
        "setup_needed": setup_needed,
        "setup_skipped": capture_result["setup_skipped"],
        "readiness_status": (
            SkillReadinessStatus.SETUP_NEEDED if setup_needed else SkillReadinessStatus.AVAILABLE
        ).value,
    }
    extras: dict = {}
    setup_help = next((e["help"] for e in required_env_vars if e.get("help")), None)
    if setup_help:
        extras["setup_help"] = setup_help
    if capture_result["gateway_setup_hint"]:
        extras["gateway_setup_hint"] = capture_result["gateway_setup_hint"]
    if setup_needed:
        missing_items = [f"env ${n}" for n in remaining] + [f"file {p}" for p in missing_cred_files]
        setup_note = _build_setup_note(SkillReadinessStatus.SETUP_NEEDED, missing_items, setup_help)
        if _is_remote_env_backend(backend) and setup_note:
            setup_note = f"{setup_note} {backend.upper()}-backed skills need these requirements available inside the remote environment as well."
        if setup_note:
            extras["setup_note"] = setup_note
    return fields, extras


def skill_view(
    name: str,
    file_path: str = None,
    task_id: str = None,
    preprocess: bool = True,
) -> str:
    """View a skill (SKILL.md) or a specific file within its directory, as JSON.

    ``name`` is a skill name or path ("axolotl", "03-fine-tuning/axolotl"); the
    qualified form "plugin:skill" resolves plugin-provided skills. ``preprocess``
    applies the configured SKILL.md template / inline shell rendering to main
    content; internal slash/preload callers disable it because they render the
    skill message themselves."""
    try:
        # Validate before the ':' dispatch so a Windows drive path (C:\skills\foo)
        # can't be reinterpreted as a plugin namespace, and so a traversal /
        # absolute name never reaches the search-dir join.
        lookup_error = _skill_lookup_path_error(name)
        if lookup_error:
            return _fail(lookup_error, hint=_LOOKUP_HINT)

        local_category_name: str | None = None
        if ":" in name:  # plugin registry; bare names use the flat-tree scan below
            served, local_category_name = _resolve_plugin_skill(name, file_path, task_id, preprocess)
            if served is not None:
                return served
        # The categorized fall-through form (namespace/bare) joins onto each
        # search dir too; re-validate it since `bare` is not namespace-checked.
        if local_category_name:
            lookup_error = _skill_lookup_path_error(local_category_name)
            if lookup_error:
                return _fail(lookup_error, hint=_LOOKUP_HINT)

        project_dirs, all_dirs, active_skills_dir = _skill_search_dirs()
        if not all_dirs:
            return _fail("Skills directory does not exist yet. It will be created on first install.")

        skill_dir = skill_md = None
        candidates = _collect_skill_candidates(name, local_category_name, all_dirs)
        if len(candidates) > 1 and project_dirs:
            # Cross-tier collision resolution: a project skill intentionally
            # overrides a same-named local/external skill, so narrow to project
            # candidates when any exist. Ambiguity WITHIN that tier still refuses.
            project_candidates = [(sd, smd) for sd, smd in candidates if _under_any(smd, project_dirs)]
            if project_candidates:
                candidates = project_candidates
        if len(candidates) > 1:
            paths = [str(smd) for _, smd in candidates]
            logger.warning("Skill name collision for '%s': %d candidates — %s", name, len(candidates), "; ".join(paths))
            return _fail(
                f"Ambiguous skill name '{name}': {len(candidates)} skills match across your local skills dir "
                "and external_dirs. Refusing to guess — load one explicitly by its categorized path.",
                matches=paths,
                hint="Pass the full relative path instead of the bare name (e.g., 'category/skill-name'), "
                "or rename one of the colliding skills so each name is unique.",
            )
        if candidates:
            skill_dir, skill_md = candidates[0]

        # Quarantine gate: a project-tier skill with a dangerous scan verdict must
        # not load even by explicit name (same chokepoint the index and
        # skills_list use — see agent.skill_utils.iter_project_skill_files).
        if skill_md is not None and project_dirs:
            from agent.skill_utils import is_quarantined_project_skill

            if _under_any(skill_md, project_dirs) and is_quarantined_project_skill(skill_md):
                return _fail(
                    f"Project skill '{name}' is quarantined: the security scan flagged its content as "
                    "dangerous. It will not load until the repo's skill content changes and passes a re-scan.",
                    hint="Inspect the skill in the repo checkout, or untrust the repo with `hermes skills untrust`.",
                )

        if not skill_md or not skill_md.exists():
            available = [s["name"] for s in _sort_skills(_find_all_skills())[:20]]
            return _fail(f"Skill '{name}' not found.", available_skills=available, hint="Use skills_list to see all available skills")

        try:  # read once — reused for platform check and main content
            content = _read_skill_text(skill_md)
        except Exception as e:
            return _fail(f"Failed to read skill '{name}': {e}")

        # Security warnings: loaded from outside the trusted dirs (project +
        # local + external = all_dirs), and/or common prompt-injection patterns.
        _trusted_dirs = [active_skills_dir.resolve()]
        try:
            _trusted_dirs.extend(d.resolve() for d in all_dirs)
        except Exception:
            pass
        _warnings = []
        if not _under_any(skill_md, _trusted_dirs):
            _warnings.append(f"skill file is outside the trusted skills directory (~/.hermes/skills/): {skill_md}")
        _content_lower = content.lower()
        if any(p in _content_lower for p in _INJECTION_PATTERNS):
            _warnings.append("skill content contains patterns that may indicate prompt injection")
        if _warnings:
            logger.warning("Skill security warning for '%s': %s", name, "; ".join(_warnings))

        try:
            frontmatter, _ = _parse_frontmatter(content)
        except Exception:
            frontmatter = {}

        if not skill_matches_platform(frontmatter):
            return _fail(f"Skill '{name}' is not supported on this platform.", readiness_status=SkillReadinessStatus.UNSUPPORTED.value)
        resolved_name = frontmatter.get("name", skill_md.parent.name)
        if _is_skill_disabled(resolved_name):
            return _fail(f"Skill '{resolved_name}' is disabled. Enable it with `hermes skills` or inspect the files directly on disk.")

        if file_path and skill_dir:
            return _serve_skill_file(
                skill_dir, file_path, name,
                hint="Use a relative path within the skill directory",
                list_available=True, mark_read=True,
            )

        # tags/related_skills: metadata.hermes.* (agentskills.io) first, then top-level.
        metadata = frontmatter.get("metadata")
        hermes_meta = (metadata.get("hermes", {}) or {}) if isinstance(metadata, dict) else {}
        tags = _parse_tags(hermes_meta.get("tags") or frontmatter.get("tags", ""))
        related_skills = _parse_tags(hermes_meta.get("related_skills") or frontmatter.get("related_skills", ""))
        linked_files = _skill_linked_files(skill_dir)

        try:
            rel_path = str(skill_md.relative_to(active_skills_dir))
        except ValueError:  # external skill — relative to its own parent dir
            rel_path = str(skill_md.relative_to(skill_md.parent.parent)) if skill_md.parent.parent else skill_md.name
        skill_name = frontmatter.get("name", skill_md.stem if not skill_dir else skill_dir.name)
        readiness, readiness_extras = _skill_readiness(frontmatter, skill_name)

        rendered_content = content
        if preprocess:
            rendered_content = _preprocess_skill(
                content, skill_dir, task_id, "Could not preprocess skill content for %s", skill_name,
            )
        org_provenance = None
        if skill_dir:
            try:
                org_provenance, header = _org_provenance_header(skill_dir, active_skills_dir)
                rendered_content = header + rendered_content
            except Exception:
                logger.debug("Could not resolve org provenance for %s", skill_name, exc_info=True)

        result = {
            "success": True,
            "name": skill_name,
            "description": frontmatter.get("description", ""),
            "tags": tags,
            "related_skills": related_skills,
            "content": rendered_content,
            "path": rel_path,
            "skill_dir": str(skill_dir) if skill_dir else None,
            "org_provenance": org_provenance,
            "linked_files": linked_files if linked_files else None,
            "usage_hint": "To view linked files, call skill_view(name, file_path) where file_path is e.g. 'references/api.md' or 'assets/config.yaml'" if linked_files else None,
            **readiness,
            # Internal: absolute source path for the repeat-view dedup fingerprint.
            "_source_path": str(skill_md),
            **readiness_extras,
        }
        _mark_background_review_read(skill_md)
        # agentskills.io optional fields
        if frontmatter.get("compatibility"):
            result["compatibility"] = frontmatter["compatibility"]
        if isinstance(metadata, dict):
            result["metadata"] = metadata
        return _json(result)
    except Exception as e:
        return tool_error(str(e), success=False)


# ── Registry ────────────────────────────────────────────────────────────────

SKILLS_LIST_SCHEMA = {
    "name": "skills_list",
    "description": "List available skills (name + description). Use skill_view(name) to load full content.",
    "parameters": {
        "type": "object",
        "properties": {
            "category": {
                "type": "string",
                "description": "Optional category filter to narrow results",
            }
        },
        "required": [],
    },
}

SKILL_VIEW_SCHEMA = {
    "name": "skill_view",
    "description": "Skills allow for loading information about specific tasks and workflows, as well as scripts and templates. Load a skill's full content or access its linked files (references, templates, scripts). First call returns SKILL.md content plus a 'linked_files' dict showing available references/templates/scripts. To access those, call again with file_path parameter.",
    "parameters": {
        "type": "object",
        "properties": {
            "name": {
                "type": "string",
                "description": "The skill name (use skills_list to see available skills). For plugin-provided skills, use the qualified form 'plugin:skill' (e.g. 'superpowers:writing-plans').",
            },
            "file_path": {
                "type": "string",
                "description": "OPTIONAL: Path to a linked file within the skill (e.g., 'references/api.md', 'templates/config.yaml', 'scripts/validate.py'). Omit to get the main SKILL.md content.",
            },
        },
        "required": ["name"],
    },
}

registry.register(
    name="skills_list",
    toolset="skills",
    schema=SKILLS_LIST_SCHEMA,
    handler=lambda args, **kw: skills_list(category=args.get("category"), task_id=kw.get("task_id")),
    check_fn=check_skills_requirements,
    emoji="📚",
)


def _skill_view_with_bump(args, **kw):
    """Invoke skill_view, then bump view_count on success. Best-effort: a
    telemetry failure never breaks the tool call.

    Repeat-view dedup mirrors read_file's unchanged-stub: when this session
    already loaded the SAME skill file and it hasn't changed on disk, return a
    short stub instead of the full content (production mining: ~286k tokens of
    verbatim repeat skill_view content in one 400k-message window). The stub only
    replaces content already fully present earlier in this conversation, so the
    "skills must be loaded fully" rule holds — and the cache is cleared on
    context compression so a post-compression re-view returns full content."""
    name = args.get("name", "")
    task_id = kw.get("task_id")
    stub = _check_skill_view_dedup(task_id, name, args.get("file_path"))
    if stub is not None:
        return stub
    result = skill_view(name, file_path=args.get("file_path"), task_id=task_id)
    try:
        parsed = json.loads(result)
        if isinstance(parsed, dict) and parsed.get("success"):
            _record_skill_view(task_id, name, args.get("file_path"), parsed)
            # Resolved name from the payload when present — qualified forms
            # ("plugin:skill") return with the canonical name.
            resolved = parsed.get("name") or name
            if resolved:
                from tools.skill_usage import bump_use, bump_view
                bump_view(str(resolved))
                # A skill_view call is the agent actively loading the skill to act
                # on it — that counts as use, not just a browse. Curator's stale
                # timer keys off last_used_at (see agent/curator.py).
                bump_use(str(resolved), task_id=kw.get("task_id"), session_id=kw.get("session_id"))
    except Exception:
        pass
    return result


registry.register(
    name="skill_view",
    toolset="skills",
    schema=SKILL_VIEW_SCHEMA,
    handler=_skill_view_with_bump,
    check_fn=check_skills_requirements,
    emoji="📚",
)