"""
Geocoding service for FleetMind
Handles address validation with Google Maps API and smart mock fallback
"""

import os
import googlemaps
import logging
import asyncio
from concurrent.futures import ThreadPoolExecutor
from typing import Dict, Optional

logger = logging.getLogger(__name__)

# Thread pool for running blocking geocoding calls
_geocoding_executor = ThreadPoolExecutor(max_workers=3, thread_name_prefix="geocoding")

# Timeout for geocoding operations (seconds)
GEOCODING_TIMEOUT = 10

# Common city coordinates for mock geocoding
CITY_COORDINATES = {
    "san francisco": (37.7749, -122.4194),
    "sf": (37.7749, -122.4194),
    "new york": (40.7128, -74.0060),
    "nyc": (40.7128, -74.0060),
    "los angeles": (34.0522, -118.2437),
    "la": (34.0522, -118.2437),
    "chicago": (41.8781, -87.6298),
    "houston": (29.7604, -95.3698),
    "phoenix": (33.4484, -112.0740),
    "philadelphia": (39.9526, -75.1652),
    "san antonio": (29.4241, -98.4936),
    "san diego": (32.7157, -117.1611),
    "dallas": (32.7767, -96.7970),
    "austin": (30.2672, -97.7431),
    "seattle": (47.6062, -122.3321),
    "boston": (42.3601, -71.0589),
    "denver": (39.7392, -104.9903),
    "miami": (25.7617, -80.1918),
    "atlanta": (33.7490, -84.3880),
    "portland": (45.5152, -122.6784),
}


class GeocodingService:
    """Handle address geocoding with Google Maps API and smart mock fallback"""

    def __init__(self):
        self.google_maps_key = os.getenv("GOOGLE_MAPS_API_KEY", "")
        self.use_mock = not self.google_maps_key or self.google_maps_key.startswith("your_")

        if self.use_mock:
            logger.info("Geocoding: Using mock (GOOGLE_MAPS_API_KEY not configured)")
            self.gmaps_client = None
        else:
            try:
                # Configure with timeout to prevent hanging
                self.gmaps_client = googlemaps.Client(
                    key=self.google_maps_key,
                    timeout=GEOCODING_TIMEOUT,  # 10 second timeout
                    retry_timeout=GEOCODING_TIMEOUT  # Total retry timeout
                )
                logger.info("Geocoding: Using Google Maps API (timeout: 10s)")
            except Exception as e:
                logger.error(f"Failed to initialize Google Maps client: {e}")
                self.use_mock = True
                self.gmaps_client = None

    def geocode(self, address: str) -> Dict:
        """
        Geocode address, using mock if API unavailable.
        This is a synchronous method with built-in timeout.

        Args:
            address: Street address to geocode

        Returns:
            Dict with keys: lat, lng, formatted_address, confidence
        """
        if self.use_mock:
            return self._geocode_mock(address)
        else:
            try:
                return self._geocode_google(address)
            except Exception as e:
                logger.error(f"Google Maps API failed: {e}, falling back to mock")
                return self._geocode_mock(address)

    async def geocode_async(self, address: str) -> Dict:
        """
        Async-safe geocoding that runs blocking calls in a thread pool.
        Use this in async contexts to prevent blocking the event loop.

        Args:
            address: Street address to geocode

        Returns:
            Dict with keys: lat, lng, formatted_address, confidence
        """
        if self.use_mock:
            return self._geocode_mock(address)

        loop = asyncio.get_event_loop()
        try:
            # Run blocking geocode in thread pool with timeout
            result = await asyncio.wait_for(
                loop.run_in_executor(_geocoding_executor, self._geocode_google, address),
                timeout=GEOCODING_TIMEOUT + 2  # Extra buffer beyond client timeout
            )
            return result
        except asyncio.TimeoutError:
            logger.error(f"Geocoding timed out for address: {address}, falling back to mock")
            return self._geocode_mock(address)
        except Exception as e:
            logger.error(f"Async geocoding failed: {e}, falling back to mock")
            return self._geocode_mock(address)

    def _geocode_google(self, address: str) -> Dict:
        """Real Google Maps API geocoding"""
        try:
            # Call Google Maps Geocoding API
            result = self.gmaps_client.geocode(address)

            if not result:
                # No results found, fall back to mock
                logger.warning(f"Google Maps API found no results for: {address}")
                return self._geocode_mock(address)

            # Get first result
            first_result = result[0]
            location = first_result['geometry']['location']

            return {
                "lat": location['lat'],
                "lng": location['lng'],
                "formatted_address": first_result.get('formatted_address', address),
                "confidence": "high (Google Maps API)"
            }

        except Exception as e:
            logger.error(f"Google Maps geocoding error: {e}")
            raise

    def _geocode_mock(self, address: str) -> Dict:
        """
        Smart mock geocoding for testing
        Tries to detect city name and use approximate coordinates
        """
        address_lower = address.lower()

        # Try to find a city match
        for city, coords in CITY_COORDINATES.items():
            if city in address_lower:
                logger.info(f"Mock geocoding detected city: {city}")
                return {
                    "lat": coords[0],
                    "lng": coords[1],
                    "formatted_address": address,
                    "confidence": f"medium (mock - {city})"
                }

        # Default to San Francisco if no city detected
        logger.info("Mock geocoding: Using default SF coordinates")
        return {
            "lat": 37.7749,
            "lng": -122.4194,
            "formatted_address": address,
            "confidence": "low (mock - default)"
        }

    def reverse_geocode(self, lat: float, lng: float) -> Dict:
        """
        Reverse geocode coordinates to address.
        This is a synchronous method with built-in timeout.

        Args:
            lat: Latitude
            lng: Longitude

        Returns:
            Dict with keys: address, city, state, country, formatted_address
        """
        if self.use_mock:
            return self._reverse_geocode_mock(lat, lng)
        else:
            try:
                return self._reverse_geocode_google(lat, lng)
            except Exception as e:
                logger.error(f"Google Maps reverse geocoding failed: {e}, falling back to mock")
                return self._reverse_geocode_mock(lat, lng)

    async def reverse_geocode_async(self, lat: float, lng: float) -> Dict:
        """
        Async-safe reverse geocoding that runs blocking calls in a thread pool.
        Use this in async contexts to prevent blocking the event loop.

        Args:
            lat: Latitude
            lng: Longitude

        Returns:
            Dict with keys: address, city, state, country, formatted_address
        """
        if self.use_mock:
            return self._reverse_geocode_mock(lat, lng)

        loop = asyncio.get_event_loop()
        try:
            # Run blocking reverse_geocode in thread pool with timeout
            result = await asyncio.wait_for(
                loop.run_in_executor(
                    _geocoding_executor,
                    self._reverse_geocode_google,
                    lat,
                    lng
                ),
                timeout=GEOCODING_TIMEOUT + 2
            )
            return result
        except asyncio.TimeoutError:
            logger.error(f"Reverse geocoding timed out for ({lat}, {lng}), falling back to mock")
            return self._reverse_geocode_mock(lat, lng)
        except Exception as e:
            logger.error(f"Async reverse geocoding failed: {e}, falling back to mock")
            return self._reverse_geocode_mock(lat, lng)

    def _reverse_geocode_google(self, lat: float, lng: float) -> Dict:
        """Real Google Maps API reverse geocoding"""
        try:
            # Call Google Maps Reverse Geocoding API
            result = self.gmaps_client.reverse_geocode((lat, lng))

            if not result:
                logger.warning(f"Google Maps API found no results for: ({lat}, {lng})")
                return self._reverse_geocode_mock(lat, lng)

            # Get first result
            first_result = result[0]

            # Extract address components
            address_components = first_result.get('address_components', [])
            city = ""
            state = ""
            country = ""

            for component in address_components:
                types = component.get('types', [])
                if 'locality' in types:
                    city = component.get('long_name', '')
                elif 'administrative_area_level_1' in types:
                    state = component.get('short_name', '')
                elif 'country' in types:
                    country = component.get('long_name', '')

            return {
                "address": first_result.get('formatted_address', f"{lat}, {lng}"),
                "city": city,
                "state": state,
                "country": country,
                "formatted_address": first_result.get('formatted_address', f"{lat}, {lng}"),
                "confidence": "high (Google Maps API)"
            }

        except Exception as e:
            logger.error(f"Google Maps reverse geocoding error: {e}")
            raise

    def _reverse_geocode_mock(self, lat: float, lng: float) -> Dict:
        """
        Mock reverse geocoding
        Tries to match coordinates to known cities
        """
        # Find closest city
        min_distance = float('inf')
        closest_city = "Unknown Location"

        for city, coords in CITY_COORDINATES.items():
            # Simple distance calculation
            distance = ((lat - coords[0]) ** 2 + (lng - coords[1]) ** 2) ** 0.5
            if distance < min_distance:
                min_distance = distance
                closest_city = city

        # If very close to a known city (within ~0.1 degrees, roughly 11km)
        if min_distance < 0.1:
            logger.info(f"Mock reverse geocoding: Matched to {closest_city}")
            return {
                "address": f"Near {closest_city.title()}",
                "city": closest_city.title(),
                "state": "CA" if "san francisco" in closest_city or "la" in closest_city else "",
                "country": "USA",
                "formatted_address": f"Near {closest_city.title()}, USA",
                "confidence": f"medium (mock - near {closest_city})"
            }
        else:
            logger.info(f"Mock reverse geocoding: Unknown location at ({lat}, {lng})")
            return {
                "address": f"{lat}, {lng}",
                "city": "",
                "state": "",
                "country": "",
                "formatted_address": f"Coordinates: {lat}, {lng}",
                "confidence": "low (mock - no match)"
            }

    def get_status(self) -> str:
        """Get geocoding service status"""
        if self.use_mock:
            return "⚠️ Using mock geocoding (add GOOGLE_MAPS_API_KEY for real)"
        else:
            return "✅ Google Maps API connected"