import os
from dotenv import load_dotenv

BASE_DIR = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
load_dotenv(os.path.join(BASE_DIR, ".env"))

GOOGLE_API_KEY = os.getenv("GOOGLE_MAPS_API_KEY")


def get_gmaps():
    """Lazy load Google Maps client."""
    if not GOOGLE_API_KEY:
        return None
    try:
        import googlemaps
        return googlemaps.Client(key=GOOGLE_API_KEY)
    except Exception:
        return None


# Keep all existing TWIN_CITY_MAP, FERRY_CITIES, HILL_CITIES etc.
TWIN_CITY_MAP = {
    "hubli":   ["hubli", "hubballi", "dharwad", "hubli-dharwad"],
    "dharwad": ["hubli", "hubballi", "dharwad", "hubli-dharwad"],
}

FERRY_CITIES = ["mumbai", "kochi", "guwahati", "port blair", "panaji", "kavaratti"]
HILL_CITIES  = ["gangtok", "shillong", "shimla", "darjeeling", "mussoorie", "nainital", "manali", "ooty"]

WATER_KEYWORDS = {
    "ferry":   ["jetty", "ghat", "wharf", "pier", "dock", "ferry", "harbour", "harbor", "port", "gateway", "island", "creek"],
    "shikara": ["lake", "dal", "nagin", "ghat", "houseboat", "boulevard", "water", "floating", "char chinar"],
}


def get_location_info(place: str, city: str) -> dict:
    gmaps = get_gmaps()
    if not gmaps:
        return {"city": city.lower(), "district": city.lower(), "state": "unknown", "sublocality": "", "lat": 0, "lng": 0}

    try:
        results = gmaps.geocode(f"{place}, {city}, India")
        if not results:
            results = gmaps.geocode(f"{place}, India")
        if not results:
            return {"city": city.lower(), "district": city.lower(), "state": "unknown", "sublocality": "", "lat": 0, "lng": 0}

        components = results[0]["address_components"]
        location   = results[0]["geometry"]["location"]
        data = {"lat": location["lat"], "lng": location["lng"], "city": "", "district": "", "state": "", "sublocality": "", "locality": ""}

        for comp in components:
            types = comp["types"]
            if "locality"                    in types: data["city"]        = comp["long_name"].lower()
            elif "administrative_area_level_2" in types: data["district"]    = comp["long_name"].lower()
            elif "administrative_area_level_1" in types: data["state"]       = comp["long_name"].lower()
            elif "sublocality" in types or "sublocality_level_1" in types:   data["sublocality"] = comp["long_name"].lower()

        return data
    except Exception as e:
        print(f"⚠️  Geocoding failed: {e}")
        return {"city": city.lower(), "district": city.lower(), "state": "unknown", "sublocality": "", "lat": 0, "lng": 0}


def is_within_city(place: str, expected_city: str) -> bool:
    gmaps = get_gmaps()
    if not gmaps:
        return True
    loc      = get_location_info(place, expected_city)
    expected = expected_city.lower()
    return (
        expected in loc.get("city", "") or
        expected in loc.get("district", "") or
        loc.get("city", "").replace(" ", "") in expected.replace(" ", "") or
        loc.get("district", "").replace(" ", "") in expected.replace(" ", "")
    )


def _is_in_twin_city(loc_data: dict, valid_cities: list) -> bool:
    city_str = (loc_data.get("city", "") + " " + loc_data.get("district", "") + " " + loc_data.get("sublocality", "")).lower()
    return any(vc in city_str for vc in valid_cities)


def validate_corridor(transport_type: str, source: str, destination: str, city: str) -> dict:
    t          = transport_type.lower()
    city_lower = city.lower()

    if t in ["bus", "metro", "train"]:
        return {"valid": True, "reason": None}

    if t == "chigari":
        valid_twin = TWIN_CITY_MAP.get(city_lower)
        if not valid_twin:
            return {"valid": False, "reason": f"Chigari only operates in Hubli-Dharwad, not {city}."}
        src_loc    = get_location_info(source, city)
        dest_loc   = get_location_info(destination, city)
        src_valid  = _is_in_twin_city(src_loc,  valid_twin)
        dest_valid = _is_in_twin_city(dest_loc, valid_twin)
        if src_valid and dest_valid:
            return {"valid": True, "reason": None}
        elif not src_valid:
            return {"valid": False, "reason": f"'{source}' is outside Hubli-Dharwad corridor."}
        else:
            return {"valid": False, "reason": f"'{destination}' is outside Hubli-Dharwad corridor."}

    elif t == "tram":
        if city_lower != "kolkata":
            return {"valid": False, "reason": f"Tram only in Kolkata, not {city}."}
        return {"valid": True, "reason": None}

    elif t == "ferry":
        if city_lower not in FERRY_CITIES:
            return {"valid": False, "reason": f"Ferry not available in {city}."}
        if city_lower == "kavaratti":
            return {"valid": True, "reason": None}
        water_kw   = WATER_KEYWORDS["ferry"]
        near_water = any(kw in source.lower() or kw in destination.lower() for kw in water_kw)
        if near_water:
            return {"valid": True, "reason": None}
        return {"valid": True, "reason": None}

    elif t == "toy_train":
        if city_lower != "shimla":
            return {"valid": False, "reason": f"Toy Train only on Kalka-Shimla route, not {city}."}
        return {"valid": True, "reason": None}

    elif t == "shikara":
        if city_lower != "srinagar":
            return {"valid": False, "reason": f"Shikara only in Srinagar, not {city}."}
        water_kw   = WATER_KEYWORDS["shikara"]
        near_water = any(kw in source.lower() or kw in destination.lower() for kw in water_kw)
        if near_water:
            return {"valid": True, "reason": None}
        return {"valid": True, "reason": None}

    elif t == "shared_cab":
        if city_lower not in HILL_CITIES:
            return {"valid": False, "reason": f"Shared cab not standard in {city}."}
        return {"valid": True, "reason": None}

    return {"valid": True, "reason": None}