"""Live map overlays: parsers, TTL cache, and upstream fetchers.

Moving objects (aircraft, vessels, trains) and alerts are vectors. Radar /
GIBS fire tiles are rasters served directly to the browser — this module
only returns tile *templates* and GeoJSON/JSON for vectors.

Third-party APIs that leak keys, lack CORS, or rate-limit by IP are fetched
here (FastAPI), never from Leaflet. Viewport bbox only; never a global ADS-B
or AIS poll.
"""

from __future__ import annotations

import asyncio
import math
import time
from datetime import datetime, timezone
from typing import Any, Awaitable, Callable

import httpx

from config import OSINT_USER_AGENT

MARKER_FIELDS = ("id", "lat", "lon", "heading", "speed", "label", "extra")

ADSB_LOL_BASE = "https://api.adsb.lol"
AMTRAKER_TRAINS = "https://api.amtraker.com/v3/trains"
RAINVIEWER_MAPS = "https://api.rainviewer.com/public/weather-maps.json"
NWS_ALERTS = "https://api.weather.gov/alerts/active"
IEM_SBW = "https://mesonet.agron.iastate.edu/geojson/sbw.geojson"
WFIGS_INCIDENTS = (
    "https://services3.arcgis.com/T4QMspbfLg3qTGWY/arcgis/rest/services/"
    "WFIGS_Incident_Locations_Current/FeatureServer/0/query"
)
WFIGS_PERIMETERS = (
    "https://services3.arcgis.com/T4QMspbfLg3qTGWY/arcgis/rest/services/"
    "WFIGS_Interagency_Perimeters_Current/FeatureServer/0/query"
)
NHC_STORMS = "https://www.nhc.noaa.gov/CurrentStorms.json"

IEM_NEXRAD = "https://mesonet.agron.iastate.edu/cache/tile.py/1.0.0/nexrad-n0q/{z}/{x}/{y}.png"
GIBS_THERMAL = (
    "https://gibs.earthdata.nasa.gov/wmts/epsg3857/best/"
    "VIIRS_SNPP_Thermal_Anomalies_375m_All/default/{time}/"
    "GoogleMapsCompatible_Level9/{z}/{y}/{x}.png"
)

CONUS = (-125.0, 24.0, -66.0, 50.0)
MAX_RADIUS_NM = 150
DEFAULT_LIMIT = 2000

_HTTP_TIMEOUT = 25.0
_COMPASS = {
    "N": 0, "NE": 45, "E": 90, "SE": 135,
    "S": 180, "SW": 225, "W": 270, "NW": 315,
    "NNE": 22, "ENE": 67, "ESE": 112, "SSE": 157,
    "SSW": 202, "WSW": 247, "WNW": 292, "NNW": 337,
}

_cache: dict[str, tuple[float, Any]] = {}
_cache_lock = asyncio.Lock()

# Last-known AIS positions (MMSI -> marker). Filled by ais_stream worker.
vessel_last_known: dict[str, dict] = {}
vessel_lock = asyncio.Lock()


def overlay_catalog() -> dict:
    """Tile templates + vector endpoint map for the layer panel. No secrets."""
    today = datetime.now(timezone.utc).date().isoformat()
    return {
        "radar_iem": {
            "id": "radar_iem",
            "title": "IEM NEXRAD (CONUS)",
            "kind": "raster",
            "tileUrl": IEM_NEXRAD,
            "maxZoom": 18,
            "attribution": "Iowa Environmental Mesonet",
        },
        "radar_rainviewer": {
            "id": "radar_rainviewer",
            "title": "RainViewer (global)",
            "kind": "raster",
            "tileUrl": None,  # filled from /api/map/radar frames
            "maxZoom": 7,
            "attribution": '<a href="https://www.rainviewer.com/">Weather data by RainViewer</a>',
        },
        "gibs_thermal": {
            "id": "gibs_thermal",
            "title": "GIBS VIIRS thermal anomalies",
            "kind": "raster",
            "tileUrl": GIBS_THERMAL.replace("{time}", today),
            "timeTemplate": GIBS_THERMAL,
            "maxZoom": 9,
            "attribution": "NASA GIBS / EOSDIS",
        },
        "nws_alerts": {"id": "nws_alerts", "kind": "geojson", "endpoint": "/api/weather-alerts"},
        "wfigs_incidents": {"id": "wfigs_incidents", "kind": "points", "endpoint": "/api/fire-incidents"},
        "wfigs_perimeters": {"id": "wfigs_perimeters", "kind": "geojson", "endpoint": "/api/fire-perimeters"},
        "aircraft": {"id": "aircraft", "kind": "points", "endpoint": "/api/aircraft"},
        "vessels": {"id": "vessels", "kind": "points", "endpoint": "/api/vessels"},
        "trains": {"id": "trains", "kind": "points", "endpoint": "/api/trains"},
        "storms": {"id": "storms", "kind": "points", "endpoint": "/api/storms"},
    }


def parse_bbox(bbox: str) -> tuple[float, float, float, float]:
    """Parse 'minlon,minlat,maxlon,maxlat' into four floats."""
    parts = [p.strip() for p in (bbox or "").split(",")]
    if len(parts) != 4:
        raise ValueError("bbox must be 'minlon,minlat,maxlon,maxlat'")
    try:
        minlon, minlat, maxlon, maxlat = (float(p) for p in parts)
    except ValueError as exc:
        raise ValueError("bbox values must be floats") from exc
    return minlon, minlat, maxlon, maxlat


def bbox_center_radius_nm(
    minlon: float, minlat: float, maxlon: float, maxlat: float,
) -> tuple[float, float, int]:
    """Viewport center + half-diagonal radius in nautical miles, clamped ≤ 150."""
    lat = (minlat + maxlat) / 2.0
    lon = (minlon + maxlon) / 2.0
    # Half the diagonal of the box, in nm (1 deg lat ≈ 60 nm).
    dlat = abs(maxlat - minlat) / 2.0
    dlon = abs(maxlon - minlon) / 2.0
    km = _haversine_km(lat, lon, lat + dlat, lon + dlon)
    nm = km / 1.852
    radius = max(1, min(MAX_RADIUS_NM, int(math.ceil(nm))))
    return lat, lon, radius


def _haversine_km(lat1: float, lon1: float, lat2: float, lon2: float) -> float:
    r = 6371.0
    p1, p2 = math.radians(lat1), math.radians(lat2)
    dphi = math.radians(lat2 - lat1)
    dlmb = math.radians(lon2 - lon1)
    a = math.sin(dphi / 2) ** 2 + math.cos(p1) * math.cos(p2) * math.sin(dlmb / 2) ** 2
    return 2 * r * math.asin(min(1.0, math.sqrt(a)))


def to_marker(
    id_: str,
    lat: float | None,
    lon: float | None,
    heading: float | None = None,
    speed: float | None = None,
    label: str | None = None,
    extra: dict | None = None,
) -> dict:
    return {
        "id": str(id_),
        "lat": lat,
        "lon": lon,
        "heading": heading,
        "speed": speed,
        "label": label or str(id_),
        "extra": extra or {},
    }


def filter_points_bbox(
    points: list[dict],
    minlon: float, minlat: float, maxlon: float, maxlat: float,
    limit: int = DEFAULT_LIMIT,
) -> list[dict]:
    out = []
    for p in points:
        lat, lon = p.get("lat"), p.get("lon")
        if lat is None or lon is None:
            continue
        if minlat <= lat <= maxlat and minlon <= lon <= maxlon:
            out.append(p)
            if len(out) >= limit:
                break
    return out


def _f(value: object) -> float | None:
    if value is None or value == "":
        return None
    try:
        return float(value)
    except (TypeError, ValueError):
        return None


def _heading(value: object) -> float | None:
    if value is None or value == "":
        return None
    if isinstance(value, str):
        key = value.strip().upper()
        if key in _COMPASS:
            return float(_COMPASS[key])
    num = _f(value)
    if num is None:
        return None
    if num < 0 or num > 360:
        return None
    return num


def transform_adsb_lol(payload: dict | list | None) -> list[dict]:
    """Map ADSB.lol v2 aircraft list to shared markers. Dedup on hex."""
    if payload is None:
        return []
    if isinstance(payload, list):
        aircraft = payload
    else:
        aircraft = payload.get("ac") or payload.get("aircraft") or []
    seen: set[str] = set()
    out: list[dict] = []
    for ac in aircraft:
        hex_id = str(ac.get("hex") or "").strip().lower()
        lat, lon = _f(ac.get("lat")), _f(ac.get("lon"))
        if not hex_id or lat is None or lon is None:
            continue
        if hex_id in seen:
            continue
        seen.add(hex_id)
        flight = str(ac.get("flight") or "").strip() or hex_id
        out.append(to_marker(
            hex_id, lat, lon,
            heading=_heading(ac.get("track")),
            speed=_f(ac.get("gs")),
            label=flight,
            extra={
                "hex": hex_id,
                "reg": ac.get("r"),
                "type": ac.get("t"),
                "alt_baro": ac.get("alt_baro"),
                "squawk": ac.get("squawk"),
                "emergency": ac.get("emergency"),
                "category": ac.get("category"),
                "seen_pos": ac.get("seen_pos"),
                "src": "adsb.lol",
            },
        ))
    return out


def transform_amtraker(payload: dict | None) -> list[dict]:
    """Flatten Amtraker `{trainNum: [Train, ...]}` to one marker per trainID."""
    if not payload or not isinstance(payload, dict):
        return []
    out: list[dict] = []
    for _num, trains in payload.items():
        if not isinstance(trains, list):
            continue
        for tr in trains:
            if not isinstance(tr, dict):
                continue
            lat, lon = _f(tr.get("lat")), _f(tr.get("lon"))
            if lat is None or lon is None:
                continue
            tid = str(tr.get("trainID") or tr.get("trainId") or "").strip()
            tnum = str(tr.get("trainNum") or _num)
            route = str(tr.get("routeName") or "").strip()
            label = f"{route} #{tnum}".strip() if route else f"Train {tnum}"
            late = tr.get("late")
            if late is None:
                late = tr.get("lateMin")
            out.append(to_marker(
                tid or tnum, lat, lon,
                heading=_heading(tr.get("heading")),
                speed=_f(tr.get("velocity") or tr.get("speed")),
                label=label,
                extra={
                    "route": route,
                    "trainNum": tnum,
                    "late_min": late,
                    "iconColor": tr.get("iconColor"),
                    "stations": tr.get("stations") or [],
                    "src": "amtraker",
                },
            ))
    return out


def transform_ais_frame(frame: dict | None) -> dict | None:
    """Decode one AISStream JSON envelope to a marker (or None if unusable)."""
    if not frame or not isinstance(frame, dict):
        return None
    meta = frame.get("MetaData") or {}
    mmsi = meta.get("MMSI") or meta.get("mmsi")
    if mmsi is None:
        return None
    name = str(meta.get("ShipName") or meta.get("shipName") or "").strip()
    lat = _f(meta.get("Latitude") if "Latitude" in meta else meta.get("latitude"))
    lon = _f(meta.get("Longitude") if "Longitude" in meta else meta.get("longitude"))
    msg = frame.get("Message") or {}
    pos = (
        msg.get("PositionReport")
        or msg.get("StandardClassBPositionReport")
        or msg.get("ExtendedClassBPositionReport")
        or {}
    )
    extra: dict[str, Any] = {"src": "aisstream", "mmsi": mmsi}
    if frame.get("MessageType") == "ShipStaticData":
        static = msg.get("ShipStaticData") or {}
        dest = str(static.get("Destination") or static.get("destination") or "").strip()
        extra["dest"] = dest
        extra["static"] = True
        if not name:
            name = str(static.get("Name") or static.get("name") or "").strip()
        if lat is None or lon is None:
            # Static-only update: caller merges onto last-known by MMSI.
            return to_marker(str(mmsi), None, None, label=name or str(mmsi), extra=extra)
    heading = pos.get("TrueHeading")
    if heading in (511, 511.0, None):
        heading = pos.get("Cog")
    sog = pos.get("Sog")
    navstat = pos.get("NavigationalStatus")
    extra["navstat"] = navstat
    extra["cog"] = pos.get("Cog")
    extra["dest"] = extra.get("dest")
    if lat is None or lon is None:
        return None
    return to_marker(
        str(mmsi), lat, lon,
        heading=_heading(heading),
        speed=_f(sog),
        label=name or str(mmsi),
        extra=extra,
    )


def transform_wfigs_incidents(fc: dict | None) -> list[dict]:
    if not fc:
        return []
    out: list[dict] = []
    for feat in fc.get("features") or []:
        geom = feat.get("geometry") or {}
        coords = geom.get("coordinates") or []
        if len(coords) < 2:
            continue
        lon, lat = _f(coords[0]), _f(coords[1])
        if lat is None or lon is None:
            continue
        props = feat.get("properties") or {}
        name = str(props.get("IncidentName") or "Incident").strip()
        out.append(to_marker(
            name, lat, lon,
            label=name,
            extra={
                "acres": props.get("IncidentSize"),
                "contained": props.get("PercentContained"),
                "state": props.get("POOState"),
                "category": props.get("IncidentTypeCategory"),
                "cause": props.get("FireCause"),
                "discovered": props.get("FireDiscoveryDateTime"),
                "src": "wfigs",
            },
        ))
    return out


def transform_nhc_storms(payload: dict | None) -> list[dict]:
    if not payload:
        return []
    storms = payload.get("activeStorms") or []
    class_label = {
        "TD": "Tropical Depression",
        "TS": "Tropical Storm",
        "HU": "Hurricane",
        "STD": "Subtropical Depression",
        "STS": "Subtropical Storm",
        "PTC": "Potential Tropical Cyclone",
        "PC": "Post-Tropical Cyclone",
    }
    out: list[dict] = []
    for s in storms:
        lat = _f(s.get("latitudeNumeric") or s.get("lat"))
        lon = _f(s.get("longitudeNumeric") or s.get("lon"))
        if lat is None or lon is None:
            continue
        sid = str(s.get("id") or s.get("binNumber") or "").strip()
        name = str(s.get("name") or "Storm").strip()
        klass = str(s.get("classification") or "").upper()
        kind = class_label.get(klass, klass or "Storm")
        out.append(to_marker(
            sid or name, lat, lon,
            heading=_heading(s.get("movementDir")),
            speed=_f(s.get("movementSpeed")),
            label=f"{kind} {name}".strip(),
            extra={
                "classification": klass,
                "intensity_kt": s.get("intensity"),
                "src": "nhc",
            },
        ))
    return out


def rainviewer_tile_url(host: str, path: str, size: int = 256, color: int = 2,
                        smooth: int = 1, snow: int = 1) -> str:
    host = host.rstrip("/")
    path = path if path.startswith("/") else f"/{path}"
    return f"{host}{path}/{size}/{{z}}/{{x}}/{{y}}/{color}/{smooth}_{snow}.png"


def _headers() -> dict[str, str]:
    return {"User-Agent": OSINT_USER_AGENT, "Accept": "application/json"}


async def _ttl_get(key: str, ttl: float, factory: Callable[[], Awaitable[Any]]) -> Any:
    now = time.monotonic()
    hit = _cache.get(key)
    if hit and now - hit[0] < ttl:
        return hit[1]
    async with _cache_lock:
        hit = _cache.get(key)
        if hit and time.monotonic() - hit[0] < ttl:
            return hit[1]
        value = await factory()
        _cache[key] = (time.monotonic(), value)
        return value


async def _get_json(url: str, params: dict | None = None) -> Any:
    async with httpx.AsyncClient(timeout=_HTTP_TIMEOUT, follow_redirects=True,
                                 headers=_headers()) as client:
        resp = await client.get(url, params=params)
        resp.raise_for_status()
        return resp.json()


async def fetch_aircraft(bbox: str, limit: int = DEFAULT_LIMIT) -> list[dict]:
    minlon, minlat, maxlon, maxlat = parse_bbox(bbox)
    lat, lon, radius = bbox_center_radius_nm(minlon, minlat, maxlon, maxlat)
    cache_key = f"adsb:{lat:.2f}:{lon:.2f}:{radius}"

    async def _load():
        url = f"{ADSB_LOL_BASE}/v2/lat/{lat:.4f}/lon/{lon:.4f}/dist/{radius}"
        return transform_adsb_lol(await _get_json(url))

    rows = await _ttl_get(cache_key, 8.0, _load)
    return filter_points_bbox(rows, minlon, minlat, maxlon, maxlat, limit)


async def fetch_trains(bbox: str | None, limit: int = DEFAULT_LIMIT) -> list[dict]:
    async def _load():
        return transform_amtraker(await _get_json(AMTRAKER_TRAINS))

    rows = await _ttl_get("amtraker:trains", 20.0, _load)
    if bbox:
        minlon, minlat, maxlon, maxlat = parse_bbox(bbox)
        return filter_points_bbox(rows, minlon, minlat, maxlon, maxlat, limit)
    return rows[:limit]


async def fetch_vessels(bbox: str | None, limit: int = DEFAULT_LIMIT) -> list[dict]:
    async with vessel_lock:
        rows = [dict(v) for v in vessel_last_known.values()
                if v.get("lat") is not None and v.get("lon") is not None]
    if bbox:
        minlon, minlat, maxlon, maxlat = parse_bbox(bbox)
        return filter_points_bbox(rows, minlon, minlat, maxlon, maxlat, limit)
    return rows[:limit]


async def upsert_vessel(marker: dict) -> None:
    """Merge an AIS marker into last-known by MMSI. Static-only updates names."""
    vid = str(marker.get("id") or "")
    if not vid:
        return
    async with vessel_lock:
        prev = vessel_last_known.get(vid, {})
        extra = {**(prev.get("extra") or {}), **(marker.get("extra") or {})}
        lat = marker.get("lat") if marker.get("lat") is not None else prev.get("lat")
        lon = marker.get("lon") if marker.get("lon") is not None else prev.get("lon")
        label = marker.get("label")
        if not label or label == vid:
            label = prev.get("label") or vid
        vessel_last_known[vid] = {
            **to_marker(
                vid, lat, lon,
                heading=marker.get("heading") if marker.get("heading") is not None else prev.get("heading"),
                speed=marker.get("speed") if marker.get("speed") is not None else prev.get("speed"),
                label=label,
                extra=extra,
            ),
            "seen_at": datetime.now(timezone.utc).isoformat(),
        }


def _wfigs_params(bbox: str | None) -> dict:
    params = {
        "where": "1=1",
        "outSR": "4326",
        "f": "geojson",
        "resultRecordCount": 2000,
    }
    if bbox:
        minlon, minlat, maxlon, maxlat = parse_bbox(bbox)
        params["geometry"] = f"{minlon},{minlat},{maxlon},{maxlat}"
        params["geometryType"] = "esriGeometryEnvelope"
        params["inSR"] = "4326"
        params["spatialRel"] = "esriSpatialRelIntersects"
    return params


async def fetch_fire_incidents(bbox: str | None, limit: int = DEFAULT_LIMIT) -> list[dict]:
    params = _wfigs_params(bbox)
    params["outFields"] = (
        "IncidentName,IncidentSize,FireDiscoveryDateTime,POOState,"
        "PercentContained,IncidentTypeCategory,FireCause"
    )

    async def _load():
        return transform_wfigs_incidents(await _get_json(WFIGS_INCIDENTS, params))

    rows = await _ttl_get(f"wfigs:inc:{bbox or 'all'}", 600.0, _load)
    return rows[:limit]


async def fetch_fire_perimeters(bbox: str | None) -> dict:
    params = _wfigs_params(bbox)
    params["outFields"] = (
        "poly_IncidentName,poly_GISAcres,attr_IncidentSize,"
        "attr_PercentContained,attr_FireDiscoveryDateTime"
    )

    async def _load():
        return await _get_json(WFIGS_PERIMETERS, params)

    fc = await _ttl_get(f"wfigs:per:{bbox or 'all'}", 600.0, _load)
    if not isinstance(fc, dict):
        return {"type": "FeatureCollection", "features": []}
    return fc


async def fetch_weather_alerts(area: str | None, bbox: str | None) -> dict:
    """Cached NWS active alerts + IEM storm-based warning polygons."""

    async def _load():
        nws_params: dict[str, str] = {"status": "actual"}
        if area:
            nws_params["area"] = area.upper()
        elif bbox:
            minlon, minlat, maxlon, maxlat = parse_bbox(bbox)
            nws_params["bbox"] = f"{minlon},{minlat},{maxlon},{maxlat}"
        nws_fc: dict = {"features": []}
        sbw_fc: dict = {"features": []}
        try:
            nws_fc = await _get_json(NWS_ALERTS, nws_params)
        except Exception:
            nws_fc = {"features": []}
        try:
            sbw_fc = await _get_json(IEM_SBW)
        except Exception:
            sbw_fc = {"features": []}
        features = []
        for feat in nws_fc.get("features") or []:
            props = feat.get("properties") or {}
            props["source"] = "nws"
            feat["properties"] = props
            features.append(feat)
        for feat in sbw_fc.get("features") or []:
            props = feat.get("properties") or {}
            props["source"] = "iem-sbw"
            # IEM uses `ps` (phenomenon) / `wfo`; map a display event.
            if "event" not in props:
                props["event"] = props.get("ps") or "Storm-based warning"
            feat["properties"] = props
            if bbox:
                # Cheap reject: skip if no geometry; keep otherwise (polygons).
                if not feat.get("geometry"):
                    continue
            features.append(feat)
        return {"type": "FeatureCollection", "features": features}

    key = f"alerts:{area or ''}:{bbox or ''}"
    return await _ttl_get(key, 30.0, _load)


async def fetch_radar_meta() -> dict:
    async def _load():
        data = await _get_json(RAINVIEWER_MAPS)
        host = data.get("host") or "https://tilecache.rainviewer.com"
        radar = (data.get("radar") or {})
        past = radar.get("past") or []
        nowcast = radar.get("nowcast") or []
        frames = []
        for fr in past + nowcast:
            path = fr.get("path")
            if not path:
                continue
            frames.append({
                "time": fr.get("time"),
                "path": path,
                "tileUrl": rainviewer_tile_url(host, path),
            })
        latest = frames[-1]["tileUrl"] if frames else None
        return {
            "provider": "rainviewer",
            "host": host,
            "tileUrl": latest,
            "frames": frames,
            "attribution": "Weather data by RainViewer",
            "iemTileUrl": IEM_NEXRAD,
        }

    return await _ttl_get("radar:rv", 300.0, _load)


async def fetch_storms() -> list[dict]:
    async def _load():
        return transform_nhc_storms(await _get_json(NHC_STORMS))

    return await _ttl_get("nhc:storms", 300.0, _load)