"""Bot Mode roster probe — canonical Bot Chat system prompt section.

When the desktop's Bot Mode manages this install (any profile carries a
``ui_meta['hermes-bots']`` block in its profile.yaml), a bot's canonical
"Bot Chat" session — and ONLY that session — gets a short "Messaging other
agents" section so the bot can receive teammate DMs, reply with attribution,
and hand off @mentions.  Regular sessions never carry the section; the
desktop's composer middleware owns the @mention send path there.

The caller (agent/system_prompt.py) enforces the session-title gate against
``BOT_CHAT_TITLE``; this module answers "is this install Bot-Mode-managed,
and what should the section say for this profile".

This replaces the plugin-side SOUL.md backfill: the protocol is injected by
the core at prompt-build time instead of appended to user-authored SOUL
files.  If the profile's SOUL.md already carries the section (created by an
older plugin version), the probe stays silent so the text never doubles up.

Silent (returns ``""``) when:
- no profile on this install is Bot-Mode-managed (the dominant case),
- the current profile's SOUL.md already contains the protocol heading,
- anything at all goes wrong (never crash a prompt build).

Deterministic within a process: the result is computed once and cached, so
compression-triggered prompt rebuilds produce identical bytes.

Toggle via ``agent.bot_mode_protocol`` in config.yaml (default True).
"""

from __future__ import annotations

import os
import threading
from pathlib import Path

_PROTOCOL_HEADING = "## Messaging other agents"

# The canonical per-bot conversation title — the only session shape that
# receives the protocol section. Must match the desktop plugin's
# createCanonicalChat title and the `-c "Bot Chat"` resume target.
BOT_CHAT_TITLE = "Bot Chat"

_lock = threading.Lock()
_cached: dict[str, str] = {}


def _hermes_root(home: Path) -> Path:
    """Root ~/.hermes for both the default profile and named profiles."""
    if home.parent.name == "profiles":
        return home.parent.parent
    return home


def _profile_name(home: Path) -> str:
    if home.parent.name == "profiles":
        return home.name
    return "default"


def _is_bot_managed(profile_dir: Path) -> bool:
    """True when profile.yaml carries a ui_meta['hermes-bots'] block.

    Cheap substring check before the YAML parse keeps the silent path fast.
    """
    meta = profile_dir / "profile.yaml"
    try:
        if not meta.is_file():
            return False
        raw = meta.read_text(encoding="utf-8", errors="replace")
        if "hermes-bots" not in raw:
            return False
        import yaml

        data = yaml.safe_load(raw)
        ui_meta = data.get("ui_meta") if isinstance(data, dict) else None
        return isinstance(ui_meta, dict) and isinstance(ui_meta.get("hermes-bots"), dict)
    except Exception:
        return False


def _roster(root: Path) -> list[tuple[str, Path]]:
    """(name, dir) for the default profile + every named profile."""
    entries: list[tuple[str, Path]] = [("default", root)]
    try:
        profiles = root / "profiles"
        if profiles.is_dir():
            for child in sorted(profiles.iterdir()):
                if child.is_dir():
                    entries.append((child.name, child))
    except Exception:
        pass
    return entries


def _soul_has_protocol(profile_dir: Path) -> bool:
    try:
        soul = profile_dir / "SOUL.md"
        return soul.is_file() and _PROTOCOL_HEADING in soul.read_text(encoding="utf-8", errors="replace")
    except Exception:
        return False


def _handle(name: str) -> str:
    # The mention middleware aliases the default profile as @hermes.
    return "hermes" if name == "default" else name


def _peers(root: Path) -> list[str]:
    """Registered peer gateway names (``hermes peer``), for the protocol text.

    Reads config.yaml directly (cheap, no config-loader import) — the section
    is optional and absent on most installs. Never raises.
    """
    try:
        cfg_path = root / "config.yaml"
        if not cfg_path.is_file():
            return []
        raw = cfg_path.read_text(encoding="utf-8", errors="replace")
        if "bot_peers" not in raw:
            return []
        import yaml

        data = yaml.safe_load(raw)
        peers = data.get("bot_peers") if isinstance(data, dict) else None
        if not isinstance(peers, dict):
            return []
        return sorted(str(name) for name in peers if str(name).strip())
    except Exception:
        return []


def _peer_paragraph(root: Path) -> str:
    """Protocol addendum for cross-machine DMs — only when peers exist."""
    peers = _peers(root)
    if not peers:
        return ""
    listed = ", ".join(f"`{p}`" for p in peers)
    return (
        "\n\nTeammates on OTHER machines: this install also has peer gateways "
        f"registered ({listed}). Message an agent on a peer the same way — write "
        "the message to a temp file first, then pipe it on stdin (same terminal-"
        "tool pattern: background=true, notify_on_complete=true; the reply prints "
        "on stdout when it completes):\n"
        "```\n"
        "hermes peer dm <peer>/<agent-name> < /tmp/dm.txt\n"
        "```\n"
        "Use `<peer>` alone for the peer's main agent. Run `hermes peer list` "
        "for the live peer list."
    )


def _build_section(home: Path) -> str:
    root = _hermes_root(home)
    me = _profile_name(home)

    roster = _roster(root)
    if not any(_is_bot_managed(d) for _n, d in roster):
        return ""

    # An older plugin build may have appended the protocol to SOUL.md
    # already — never double it up.
    my_dir = home if me == "default" else root / "profiles" / me
    if _soul_has_protocol(my_dir):
        return ""

    handle = _handle(me)
    teammates = ", ".join(f"`{n}`" for n, _d in roster if n != me) or "(none yet)"

    return (
        f"{_PROTOCOL_HEADING}\n"
        "This install runs Bot Mode: each Hermes profile is an agent teammate with "
        'one canonical "Bot Chat" conversation. To message a teammate: write the '
        "message to a temp file with the file tool FIRST (never inline it into the "
        "command — quotes truncate it and $( ) would execute), then run on the "
        "terminal tool (background=true, notify_on_complete=true) and finish your "
        "turn — the reply arrives later as a new message:\n"
        "```\n"
        f'hermes -p <agent-name> chat --in ~ -c "Bot Chat" --create-if-missing -Q --query-file /tmp/dm.txt\n'
        "```\n"
        f'The file must open with the "Message from 🤖 {handle} (@{handle}):" prefix so they '
        "know who is talking. When YOU receive a message with that prefix, you are "
        "being messaged by a teammate agent — address them (not the user) and reply "
        "concisely. When the user says \"ask <name>\" or \"tell <name> ...\", that is a "
        "handoff: message that agent, wait for the reply, and report back, saying "
        "which agent it came from. Run `hermes profile list` for the LIVE teammate "
        f"list before a handoff. Teammates at session start: {teammates}."
        + _peer_paragraph(root)
    )


def get_bot_mode_protocol_section(home: str | os.PathLike | None = None, *, force_refresh: bool = False) -> str:
    """Cached probe entry point — one filesystem pass per (process, home).

    ``home`` should be the AGENT'S OWN resolved home (session-db derived),
    not the ambient HERMES_HOME — build threads can lose the ContextVar
    override and the env var would then name the wrong profile.
    """
    resolved = str(home) if home else (os.getenv("HERMES_HOME") or os.path.expanduser("~/.hermes"))
    with _lock:
        if force_refresh or resolved not in _cached:
            try:
                _cached[resolved] = _build_section(Path(resolved))
            except Exception:
                _cached[resolved] = ""
        return _cached[resolved]


# ── capability epoch ─────────────────────────────────────────────────────────
#
# Bot Chat sessions are effectively eternal — the "new sessions come along
# often" assumption behind build-once system prompts does not hold. When the
# user changes a bot's capabilities (skills, toolsets, MCP servers, SOUL) or
# the teammate roster changes, they expect the change to work on the NEXT
# message. The fingerprint below hashes exactly that capability surface; the
# built Bot Chat prompt embeds it, and the restore path in
# agent/conversation_loop.py rebuilds the prompt when the stored epoch no
# longer matches the disk state. This is the /model exception applied to
# capabilities: a LOUD, USER-INITIATED, once-per-change cache break — never
# a per-turn drift (unchanged state hashes identically and the stored bytes
# are reused verbatim).

_EPOCH_PREFIX = "Capability epoch: "
_EPOCH_RE_TEXT = r"Capability epoch: ([0-9a-f]{12})"


def capability_fingerprint(home: str | os.PathLike | None = None) -> str:
    """12-hex digest of the capability surface for ``home``'s profile.

    Sources: the profile's disabled skills + enabled toolsets + MCP server
    config (config.yaml), SOUL.md bytes, installed skill names, and the
    Bot-Mode roster (managed profile names). Deliberately NOT cached — the
    whole point is detecting on-disk drift; callers compare it against the
    epoch embedded in a stored prompt. Never raises.
    """
    import hashlib
    import json

    resolved = Path(str(home) if home else (os.getenv("HERMES_HOME") or os.path.expanduser("~/.hermes")))
    surface: dict = {}
    try:
        # Canonical loader (managed overlay + env expansion + normalization),
        # scoped to the bot's home via the override the loaders already honor.
        from hermes_cli.config import load_config_readonly
        from hermes_constants import reset_hermes_home_override, set_hermes_home_override

        token = set_hermes_home_override(str(resolved))
        try:
            cfg = load_config_readonly() or {}
        finally:
            reset_hermes_home_override(token)
        skills_cfg = cfg.get("skills") if isinstance(cfg.get("skills"), dict) else {}
        tools_cfg = cfg.get("tools") if isinstance(cfg.get("tools"), dict) else {}
        skills_cfg = skills_cfg or {}
        tools_cfg = tools_cfg or {}
        surface["disabled_skills"] = sorted(str(s).lower() for s in (skills_cfg.get("disabled") or []))
        surface["enabled_toolsets"] = sorted(str(t) for t in (tools_cfg.get("enabled_toolsets") or []))
        mcp = cfg.get("mcp_servers")
        surface["mcp"] = json.dumps(mcp, sort_keys=True, default=str) if isinstance(mcp, dict) else ""
    except Exception:
        pass
    try:
        soul = resolved / "SOUL.md"
        surface["soul"] = hashlib.sha256(soul.read_bytes()).hexdigest() if soul.is_file() else ""
    except Exception:
        surface["soul"] = ""
    try:
        names = []
        skills_root = resolved / "skills"
        if skills_root.is_dir():
            for skill_md in skills_root.glob("**/SKILL.md"):
                names.append(str(skill_md.parent.relative_to(skills_root)))
        surface["skills"] = sorted(names)
    except Exception:
        surface["skills"] = []
    try:
        root = _hermes_root(resolved)
        surface["roster"] = sorted(n for n, d in _roster(root) if _is_bot_managed(d))
    except Exception:
        surface["roster"] = []
    try:
        # Peer gateways are part of the messaging surface: registering one
        # must refresh eternal Bot Chat prompts so the cross-machine DM
        # paragraph appears on the next message.
        surface["peers"] = _peers(_hermes_root(resolved))
    except Exception:
        surface["peers"] = []
    try:
        blob = json.dumps(surface, sort_keys=True).encode("utf-8")
        return hashlib.sha256(blob).hexdigest()[:12]
    except Exception:
        return "unavailable"


def epoch_line(home: str | os.PathLike | None = None) -> str:
    """The epoch stamp appended to a Bot Chat prompt."""
    return f"{_EPOCH_PREFIX}{capability_fingerprint(home)}"


def stored_prompt_capability_stale(stored_prompt: str, home: str | os.PathLike | None = None) -> bool:
    """True when ``stored_prompt`` is a Bot Chat prompt whose embedded
    capability epoch no longer matches the current disk state.

    Non-Bot-Chat prompts (no epoch stamp) are never stale by this check.
    Fails closed to "not stale" — a broken probe must never turn into a
    rebuild-every-turn cache burner.
    """
    import re

    try:
        m = re.search(_EPOCH_RE_TEXT, stored_prompt or "")
        if not m:
            return False
        current = capability_fingerprint(home)
        if current == "unavailable":
            return False
        return m.group(1) != current
    except Exception:
        return False


def stored_bot_chat_prompt_needs_upgrade(stored_prompt: str, home: str | os.PathLike | None = None) -> bool:
    """True when a Bot Chat session's stored prompt PREDATES this feature.

    Legacy Bot Chats (created before bundling / this epoch mechanism)
    persisted prompts with no protocol section and no epoch stamp; without
    an explicit upgrade they would be stranded forever — the staleness check
    above only fires on stamped prompts. This is a one-time migration per
    legacy session: the caller must only invoke it for sessions titled
    "Bot Chat", and only rebuilds when the probe would actually emit a
    section (a profile whose SOUL.md already carries the legacy plugin-side
    append keeps its protocol-free prompt — rebuilding those would loop,
    since the probe stays silent and the rebuilt prompt would be unstamped
    again). Fails closed to "no upgrade".
    """
    try:
        if _EPOCH_PREFIX in (stored_prompt or ""):
            return False
        if _PROTOCOL_HEADING in (stored_prompt or ""):
            return False
        # Only upgrade when the rebuild would actually add the section —
        # this is what guarantees the rebuilt prompt carries a stamp and
        # the upgrade can never re-fire.
        return bool(get_bot_mode_protocol_section(home))
    except Exception:
        return False


def _reset_cache_for_tests() -> None:
    with _lock:
        _cached.clear()