"""
router.py — Event router
Only processes app_mention events — when someone tags @intern-eod.
All other channel messages are ignored by Slack before they reach us.
Cron-based miss warnings run independently and are unaffected.
"""

import os
import time
import sheets
import handlers

HR_SLACK_IDS = set(os.environ.get("HR_SLACK_IDS", "").split(","))

# ─────────────────────────────────────────────
# CHANNEL CACHE
# ─────────────────────────────────────────────

_managed_channels_cache: set = set()
_cache_last_updated: float = 0
_CACHE_TTL: int = 300


def _get_managed_channels() -> set:
    global _managed_channels_cache, _cache_last_updated
    if time.time() - _cache_last_updated > _CACHE_TTL:
        try:
            candidates = sheets.get_active_candidates()
            managed = {
                c.get("channel_id", "").strip()
                for c in candidates
                if c.get("channel_id", "").strip()
            }
        except Exception as e:
            print(f"[router] cache refresh failed: {e}")
            managed = set()
        env_channel = os.environ.get("SLACK_CHANNEL_ID", "").strip()
        if env_channel:
            managed.add(env_channel)
        _managed_channels_cache = managed
        _cache_last_updated = time.time()
        print(f"[router] managed channels: {_managed_channels_cache}")
    return _managed_channels_cache


def invalidate_channel_cache() -> None:
    global _cache_last_updated
    _cache_last_updated = 0


# ─────────────────────────────────────────────
# ROLE DETECTION
# ─────────────────────────────────────────────

def _get_ft_slack_ids() -> set:
    try:
        return {c["ft_slack_id"] for c in sheets.get_active_candidates() if c.get("ft_slack_id")}
    except Exception:
        return set()


def _get_sender_role(user_id: str) -> str:
    """Candidate check first — person can be both HR and candidate."""
    try:
        if sheets.get_candidate_by_slack_id(user_id):
            return "candidate"
    except Exception:
        pass
    if user_id in HR_SLACK_IDS:
        return "hr"
    if user_id in _get_ft_slack_ids():
        return "ft"
    return "unknown"


def _get_candidate_with_pending_recommendation() -> dict | None:
    try:
        for candidate in sheets.get_active_candidates():
            if sheets.get_pending_recommendation(candidate["candidate_id"]):
                return candidate
    except Exception:
        pass
    return None


# ─────────────────────────────────────────────
# MAIN ROUTER
# ─────────────────────────────────────────────

def route_event(event: dict) -> None:
    """
    Processes two event types:
    1. app_mention — someone tagged @intern-eod (primary EOD submission path)
    2. message — for HR approve/reject confirmations only
    """
    event_type = event.get("type", "")
    user_id = event.get("user", "")
    channel_id = event.get("channel", "")
    text = event.get("text", "").strip()

    # Ignore bot messages and empty messages
    if event.get("bot_id") or event.get("subtype") or not text or not user_id:
        return

    # Ignore thread replies
    if event.get("thread_ts") and event.get("thread_ts") != event.get("ts"):
        return

    # Only handle managed channels
    if channel_id not in _get_managed_channels():
        return

    role = _get_sender_role(user_id)
    if role == "unknown":
        return

    print(f"[router] type={event_type} role={role} user={user_id} channel={channel_id}")

    print(f"[router] text_preview={text[:80]!r}")

    # ── Candidate: Claude will verify if it is a real EOD report ──
    if role == "candidate":
        candidate = sheets.get_candidate_by_slack_id(user_id)
        if candidate:
            handlers.handle_candidate_message(event, candidate)
        return

    # ── FT: short signal answers ──
    if role == "ft":
        lower = text.strip().lower()
        ft_answers = {"yes","no","partial","specific","vague","on_time",
                      "late_flagged","late_no_flag","not_delivered","engaged",
                      "defensive","collapsed","pushing","avoiding","unclear"}
        if len(lower) < 80 and any(a in lower for a in ft_answers):
            candidate = _get_ft_candidate(user_id, channel_id)
            if candidate:
                handlers.handle_ft_signal_answer(event, candidate)
        return

    # ── HR approve/reject ──
    if role == "hr":
        lower = text.strip().lower()
        if lower in ("approve", "reject"):
            candidate = _get_candidate_with_pending_recommendation()
            if candidate:
                handlers.handle_hr_confirmation(event, candidate)


def _get_ft_candidate(ft_slack_id: str, channel_id: str) -> dict | None:
    try:
        candidates = sheets.get_active_candidates()
        matches = [
            c for c in candidates
            if c.get("ft_slack_id") == ft_slack_id
            and c.get("channel_id", "").strip() == channel_id
        ]
        return matches[0] if matches else None
    except Exception:
        return None