"""Tour engine — the NEW subsystem in P4 (Custom AI Guide Tour).

Composes primitives that already ship in SanadV3 into a configurable guided tour:
ordered narrated stops with BLOCKING arrival sequencing and entitlement-aware
degradation. Everything else (nav goals, arrival feedback, arbitration, narration
channel) is reused verbatim from the vendored engine.

Two pieces:
  * TourStore   — file-IO CRUD for tour definitions (data/tours/<id>.json).
  * TourRuntime — a background-thread state machine that runs one tour, stop by
                  stop: acquire nav → goto+arm → BLOCK on arrival (the nav arbiter
                  is released by navigation.goal_monitor on any terminal status) →
                  narrate via live_sub.send_state → optional gesture/expression →
                  dwell → advance → release.

Degradation (driven by license flags, never crashes):
  * no navigation entitlement / web_nav3 unreachable → "preset" stops (narrate in
    place, no drive).
  * no P2 (mask/multilingual) → single-language narration, no gesture/expression.
  * no P3 (recognition) → generic greeting (the orchestrator skips the recognition
    primer; handled at construct time).

Kept Python-3.8 compatible. Pure threads + time.sleep (no asyncio in the runtime).
"""
from __future__ import annotations

import json
import os
import re
import threading
import time
from pathlib import Path
from typing import Any, Callable, Dict, List, Optional


def _now() -> str:
    return time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())


def _slug(name: str) -> str:
    s = re.sub(r"[^a-zA-Z0-9_-]+", "-", (name or "").strip().lower()).strip("-")
    return s or "tour"


# ─────────────────────────── store ───────────────────────────
class TourStore(object):
    """CRUD for tour definitions. A tour = {id, name, stops:[Stop], created}.
    Stop = {place, narration, expression, gesture, dwell_sec, greet}."""

    def __init__(self, root: Optional[str] = None):
        if not root:
            root = os.environ.get("SANAD_TOURS_DIR", "")
        if not root:
            try:
                from Project.Sanad.config import BASE_DIR
                root = str(Path(BASE_DIR) / "data" / "tours")
            except Exception:
                root = str(Path.cwd() / "data" / "tours")
        self.root = Path(root)
        self._lock = threading.RLock()
        try:
            self.root.mkdir(parents=True, exist_ok=True)
        except Exception:
            pass

    def _path(self, tid: str) -> Path:
        return self.root / ("%s.json" % tid)

    def _write(self, tid: str, data: Dict[str, Any]) -> None:
        tmp = self.root / ("%s.json.tmp" % tid)
        tmp.write_text(json.dumps(data, ensure_ascii=False, indent=2), encoding="utf-8")
        tmp.replace(self._path(tid))

    def list(self) -> List[Dict[str, Any]]:
        out = []
        with self._lock:
            for p in sorted(self.root.glob("*.json")):
                try:
                    out.append(json.loads(p.read_text(encoding="utf-8")))
                except Exception:
                    continue
        return out

    def get(self, tid: str) -> Optional[Dict[str, Any]]:
        with self._lock:
            p = self._path(tid)
            if not p.exists():
                return None
            try:
                return json.loads(p.read_text(encoding="utf-8"))
            except Exception:
                return None

    def _norm_stops(self, stops: Any) -> List[Dict[str, Any]]:
        out = []
        for s in (stops or []):
            if not isinstance(s, dict):
                continue
            out.append({
                "place": str(s.get("place", "") or ""),
                "narration": str(s.get("narration", "") or ""),
                "expression": str(s.get("expression", "") or ""),
                "gesture": str(s.get("gesture", "") or ""),
                "greet": bool(s.get("greet", False)),
                "dwell_sec": float(s.get("dwell_sec", 8) or 8),
            })
        return out

    def save(self, name: str, stops: Any, tid: Optional[str] = None) -> Dict[str, Any]:
        with self._lock:
            if not tid:
                base = _slug(name)
                tid = base
                n = 1
                while self._path(tid).exists():
                    n += 1
                    tid = "%s-%d" % (base, n)
            existing = self.get(tid) or {}
            data = {
                "id": tid, "name": name or tid,
                "stops": self._norm_stops(stops),
                "created": existing.get("created", _now()),
                "updated": _now(),
            }
            self._write(tid, data)
            return data

    def delete(self, tid: str) -> bool:
        with self._lock:
            p = self._path(tid)
            if not p.exists():
                return False
            try:
                p.unlink()
                return True
            except Exception:
                return False


# ─────────────────────────── runtime ───────────────────────────
class TourRuntime(object):
    """Runs ONE tour at a time in a daemon thread. All nav primitives are injected
    (loosely coupled) so a missing subsystem simply degrades."""

    def __init__(self, store, nav_client=None, goal_monitor=None, arbiter=None,
                 live_sub=None, mask_face=None, log=None,
                 has_nav: bool = False, has_mask: bool = False):
        self.store = store
        self.nav = nav_client
        self.gm = goal_monitor          # navigation.goal_monitor module (arm_goal/request_cancel)
        self.arb = arbiter              # dashboard.routes._arbiter module (acquire/nav_active/release)
        self.live_sub = live_sub
        self.mask_face = mask_face
        self.log = log
        self.has_nav = bool(has_nav and nav_client is not None)
        self.has_mask = bool(has_mask and mask_face is not None)
        self.timeout = float(os.environ.get("SANAD_NAV_GOAL_TIMEOUT_S", "240"))
        self._lock = threading.Lock()
        self._thread = None            # type: Optional[threading.Thread]
        self._state = "idle"           # idle|running|paused|stopping|done|error
        self._tour_id = ""
        self._tour_name = ""
        self._idx = -1
        self._place = ""
        self._total = 0
        self._started = ""
        self._msg = ""
        self._skip = threading.Event()

    # -- helpers --
    def _li(self, msg, *a):
        if self.log:
            try:
                self.log.info(msg, *a)
            except Exception:
                pass

    def _narrate(self, event, text):
        if self.live_sub is not None and hasattr(self.live_sub, "send_state") and text:
            try:
                self.live_sub.send_state(event, text)
            except Exception:
                self._li("tour: send_state failed")

    def _ensure_live(self):
        ls = self.live_sub
        if ls is None:
            return
        try:
            if hasattr(ls, "is_running") and not ls.is_running() and hasattr(ls, "start"):
                ls.start()
        except Exception:
            self._li("tour: could not start live session")

    # -- public control --
    def status(self) -> Dict[str, Any]:
        with self._lock:
            return {
                "state": self._state, "tour_id": self._tour_id, "tour_name": self._tour_name,
                "stop_index": self._idx, "stop_place": self._place, "total_stops": self._total,
                "started_at": self._started, "message": self._msg,
                "capabilities": {"navigation": self.has_nav, "mask": self.has_mask},
            }

    def start(self, tour_id: str) -> Dict[str, Any]:
        with self._lock:
            if self._state in ("running", "paused", "stopping"):
                return {"ok": False, "error": "a tour is %s (%s) — stop it and wait first"
                        % (self._state, self._tour_id)}
            # A stop() that just set state=idle may still have a worker draining
            # its nav cancel — never spawn a 2nd concurrent tour thread.
            if self._thread is not None and self._thread.is_alive():
                return {"ok": False, "error": "previous tour is still finishing — retry shortly"}
            tour = self.store.get(tour_id)
            if tour is None:
                return {"ok": False, "error": "no tour '%s'" % tour_id}
            self._state = "running"
            self._tour_id = tour_id
            self._tour_name = tour.get("name", tour_id)
            self._total = len(tour.get("stops") or [])
            self._idx = -1
            self._place = ""
            self._started = _now()
            self._msg = ""
            self._skip.clear()
            self._thread = threading.Thread(target=self._run, args=(tour,), daemon=True, name="tour")
            self._thread.start()
            return {"ok": True, "started": tour_id, "stops": self._total,
                    "degraded": (not self.has_nav)}

    def pause(self) -> Dict[str, Any]:
        with self._lock:
            if self._state == "running":
                self._state = "paused"
            return self.status()

    def resume(self) -> Dict[str, Any]:
        with self._lock:
            if self._state == "paused":
                self._state = "running"
            return self.status()

    def skip(self) -> Dict[str, Any]:
        self._skip.set()
        return {"ok": True, "skipping": self._idx}

    def stop(self) -> Dict[str, Any]:
        with self._lock:
            if self._state in ("idle", "done", "error"):
                return {"ok": True, "state": self._state}
            self._state = "stopping"
        # cancel any in-flight nav goal + disarm the monitor + free the arbiter
        try:
            if self.gm is not None and hasattr(self.gm, "request_cancel"):
                self.gm.request_cancel()
        except Exception:
            pass
        self._disarm_gm()
        self._release_nav()
        return {"ok": True, "state": "stopping"}

    # -- nav helpers --
    def _release_nav(self):
        try:
            if self.arb is not None and self.arb.nav_active():
                self.arb.release_nav()
        except Exception:
            pass

    def _disarm_gm(self):
        """Stop goal_monitor watching. MUST fire on any armed-but-no-goal exit,
        else its 240s watchdog later pushes a bogus 'couldn't get there' to the child."""
        try:
            if self.gm is not None and hasattr(self.gm, "disarm"):
                self.gm.disarm()
        except Exception:
            pass

    def _drive_to(self, place: str) -> str:
        """Drive to `place` and BLOCK until arrival/terminal. Returns a short
        outcome string. Reuses goal_monitor's arbiter-release as the arrival signal."""
        if not (self.has_nav and place):
            return "preset"
        try:
            if not self.arb.acquire_nav():
                return "nav_busy"       # manual loco holds the legs
        except Exception:
            return "nav_unavailable"
        try:
            if self.gm is not None and hasattr(self.gm, "arm_goal"):
                self.gm.arm_goal(place)          # watch for arrival; releases arbiter on terminal
            res = self.nav.goto(place)           # fire-and-forget Nav2 goal
            if not (isinstance(res, dict) and res.get("ok")):
                self._disarm_gm(); self._release_nav()
                return "goto_failed"
        except Exception:
            self._disarm_gm(); self._release_nav()
            return "goto_error"
        # BLOCK: goal_monitor releases the arbiter on the terminal status.
        waited = 0.0
        while waited < self.timeout:
            if self._state == "stopping":
                self._disarm_gm()               # goal_monitor still armed on our behalf
                return "stopped"
            try:
                if not self.arb.nav_active():
                    return "arrived"             # terminal reached (goal_monitor freed nav + disarmed)
            except Exception:
                return "arrived"
            time.sleep(1.0)
            waited += 1.0
        # watchdog — never hang a tour
        try:
            if self.gm is not None and hasattr(self.gm, "request_cancel"):
                self.gm.request_cancel()
        except Exception:
            pass
        self._disarm_gm(); self._release_nav()
        return "timeout"

    # -- the run loop --
    def _run(self, tour: Dict[str, Any]):
        self._ensure_live()
        stops = tour.get("stops") or []
        try:
            for i, stop in enumerate(stops):
                # pause / stop gates
                while True:
                    with self._lock:
                        st = self._state
                    if st == "stopping":
                        raise _Stopped()
                    if st != "paused":
                        break
                    time.sleep(0.5)
                self._skip.clear()
                with self._lock:
                    self._idx = i
                    self._place = stop.get("place", "")
                self._li("tour '%s' stop %d/%d → %s", self._tour_id, i + 1, len(stops), self._place or "(in place)")

                outcome = self._drive_to(stop.get("place", ""))
                if outcome not in ("arrived", "preset"):
                    self._li("tour stop %d (%s): NOT reached (%s) — narrating in place",
                             i + 1, self._place or "?", outcome)
                if self._state == "stopping":
                    raise _Stopped()

                # narrate this stop (the child speaks it in the configured language;
                # multilingual only if P2 entitled — handled by the persona).
                narration = stop.get("narration") or ""
                if narration:
                    self._narrate("tour_stop", narration)

                # gesture / expression on the mask (P2 only).
                if self.has_mask and self.mask_face is not None:
                    expr = stop.get("expression")
                    if expr:
                        try:
                            self.mask_face.react(str(expr))
                        except Exception:
                            self._li("tour: mask react failed")

                # dwell (interruptible by skip/stop)
                dwell = float(stop.get("dwell_sec", 8) or 8)
                t = 0.0
                while t < dwell:
                    if self._state == "stopping":
                        raise _Stopped()
                    if self._skip.is_set():
                        break
                    time.sleep(0.5)
                    t += 0.5
            with self._lock:
                self._state = "done"
                self._msg = "tour complete"
            self._narrate("tour_done", "The tour is complete. Thank the guest warmly.")
        except _Stopped:
            with self._lock:
                self._state = "idle"
                self._msg = "stopped"
            self._release_nav()
        except Exception as exc:
            with self._lock:
                self._state = "error"
                self._msg = str(exc)
            self._release_nav()
            self._li("tour run crashed: %s", exc)


class _Stopped(Exception):
    pass