# ================================================================
# services/data/app/external/madrid_opendata.py - FIXED XML PARSER
# ================================================================
"""Madrid Open Data API client with fixed XML parser for actual structure"""

import math
import xml.etree.ElementTree as ET
from typing import List, Dict, Any, Optional
from datetime import datetime, timedelta
import structlog
import re

from app.external.base_client import BaseAPIClient
from app.core.config import settings

import pyproj

logger = structlog.get_logger()

class MadridOpenDataClient(BaseAPIClient):
    
    def __init__(self):
        super().__init__(
            base_url="https://datos.madrid.es",
            api_key=None
        )
        
        # WORKING Madrid traffic endpoints (verified)
        self.traffic_endpoints = [
            # Primary working endpoint
            "https://datos.madrid.es/egob/catalogo/202087-0-trafico-intensidad.xml",
        ]
    
    async def get_current_traffic(self, latitude: float, longitude: float) -> Optional[Dict[str, Any]]:
        """Get current traffic data for location using working Madrid endpoints"""
        try:
            logger.debug("Fetching Madrid traffic data", lat=latitude, lon=longitude)
            
            # Try the working endpoint
            for endpoint in self.traffic_endpoints:
                try:
                    logger.debug("Trying traffic endpoint", endpoint=endpoint)
                    traffic_data = await self._fetch_traffic_xml_data(endpoint)
                    
                    if traffic_data:
                        logger.info("Successfully fetched Madrid traffic data", 
                                  endpoint=endpoint, 
                                  points=len(traffic_data))
                        
                        # Find nearest traffic measurement point
                        nearest_point = self._find_nearest_traffic_point(latitude, longitude, traffic_data)
                        
                        if nearest_point:
                            parsed_data = self._parse_traffic_measurement(nearest_point)
                            logger.debug("Successfully parsed real Madrid traffic data", 
                                       point_name=nearest_point.get('descripcion'),
                                       point_id=nearest_point.get('idelem'))
                            return parsed_data
                        else:
                            logger.debug("No nearby traffic points found", 
                                       lat=latitude, lon=longitude,
                                       closest_distance=self._get_closest_distance(latitude, longitude, traffic_data))
                    
                except Exception as e:
                    logger.debug("Failed to fetch from endpoint", endpoint=endpoint, error=str(e))
                    continue
            
            # If no real data available, use synthetic data
            logger.info("No nearby Madrid traffic points found, using synthetic data")
            return await self._generate_synthetic_traffic(latitude, longitude)
            
        except Exception as e:
            logger.error("Failed to get current traffic", error=str(e))
            return await self._generate_synthetic_traffic(latitude, longitude)
    
    async def _fetch_traffic_xml_data(self, endpoint: str) -> Optional[List[Dict[str, Any]]]:
        """Fetch and parse Madrid traffic XML data"""
        try:
            xml_content = await self._fetch_xml_content_robust(endpoint)
            
            if not xml_content:
                logger.debug("No XML content received", endpoint=endpoint)
                return None
            
            # Log XML structure for debugging
            logger.debug("Madrid XML content preview", 
                        length=len(xml_content),
                        first_500=xml_content[:500] if len(xml_content) > 500 else xml_content)
            
            # Parse Madrid traffic XML with the correct structure
            traffic_points = self._parse_madrid_traffic_xml(xml_content)
            
            if traffic_points:
                logger.debug("Successfully parsed Madrid traffic XML", points=len(traffic_points))
                return traffic_points
            else:
                logger.warning("No traffic points found in XML", endpoint=endpoint)
                return None
                
        except Exception as e:
            logger.error("Error fetching traffic XML data", endpoint=endpoint, error=str(e))
            return None
    
    def _parse_madrid_traffic_xml(self, xml_content: str) -> List[Dict[str, Any]]:
        """Parse Madrid traffic XML with correct structure (<pms><pm>...</pm></pms>)"""
        traffic_points = []
        
        try:
            # Clean the XML to handle undefined entities and encoding issues
            cleaned_xml = self._clean_madrid_xml(xml_content)
            
            # Parse XML
            root = ET.fromstring(cleaned_xml)
            
            # Log XML structure
            logger.debug("Madrid XML structure", 
                        root_tag=root.tag, 
                        children_count=len(list(root)))
            
            # Madrid uses <pms> root with <pm> children
            if root.tag == 'pms':
                pm_elements = root.findall('pm')
                logger.debug("Found PM elements", count=len(pm_elements))
                
                for pm in pm_elements:
                    try:
                        traffic_point = self._extract_madrid_pm_element(pm)
                        
                        # Validate essential data (coordinates and ID)
                        if (traffic_point.get('latitude') and 
                            traffic_point.get('longitude') and
                            traffic_point.get('idelem')):
                            traffic_points.append(traffic_point)
                            
                            # Log first few points for debugging
                            if len(traffic_points) <= 3:
                                logger.debug("Sample traffic point", 
                                           id=traffic_point['idelem'],
                                           lat=traffic_point['latitude'],
                                           lon=traffic_point['longitude'],
                                           intensity=traffic_point.get('intensidad'))
                        
                    except Exception as e:
                        logger.debug("Error parsing PM element", error=str(e))
                        continue
            else:
                logger.warning("Unexpected XML root tag", root_tag=root.tag)
            
            logger.debug("Madrid traffic XML parsing completed", valid_points=len(traffic_points))
            return traffic_points
            
        except ET.ParseError as e:
            logger.warning("Failed to parse Madrid XML", error=str(e))
            # Try regex extraction as fallback
            return self._extract_traffic_data_regex(xml_content)
        except Exception as e:
            logger.error("Error in Madrid traffic XML parsing", error=str(e))
            return []
    
    def _clean_madrid_xml(self, xml_content: str) -> str:
        """Clean Madrid XML to handle undefined entities and encoding issues"""
        try:
            # Remove BOM if present
            xml_content = xml_content.lstrip('\ufeff')
            
            # Remove or replace undefined entities that cause parsing errors
            # Common undefined entities in Madrid data
            xml_content = xml_content.replace('&nbsp;', ' ')
            xml_content = xml_content.replace('&copy;', '©')
            xml_content = xml_content.replace('&reg;', '®')
            xml_content = xml_content.replace('&trade;', '™')
            
            # Fix unescaped ampersands (but not already escaped ones)
            xml_content = re.sub(r'&(?![a-zA-Z0-9#]{1,10};)', '&amp;', xml_content)
            
            # Remove invalid control characters
            xml_content = re.sub(r'[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]', '', xml_content)
            
            # Handle Spanish characters that might be causing issues
            spanish_chars = {
                'ñ': 'n', 'Ñ': 'N',
                'á': 'a', 'é': 'e', 'í': 'i', 'ó': 'o', 'ú': 'u',
                'Á': 'A', 'É': 'E', 'Í': 'I', 'Ó': 'O', 'Ú': 'U',
                'ü': 'u', 'Ü': 'U'
            }
            
            for spanish_char, replacement in spanish_chars.items():
                xml_content = xml_content.replace(spanish_char, replacement)
            
            return xml_content
            
        except Exception as e:
            logger.warning("Error cleaning Madrid XML", error=str(e))
            return xml_content
    
    def _extract_madrid_pm_element(self, pm_element) -> Dict[str, Any]:
        """Extract traffic data from Madrid <pm> element with proper coordinate conversion"""
        try:
            # Based on the actual Madrid XML structure shown in logs
            point_data = {}
            utm_x = None
            utm_y = None
            
            # Extract all child elements
            for child in pm_element:
                tag = child.tag
                text = child.text.strip() if child.text else ''
                
                if tag == 'idelem':
                    point_data['idelem'] = text
                elif tag == 'descripcion':
                    point_data['descripcion'] = text
                elif tag == 'intensidad':
                    point_data['intensidad'] = self._safe_int(text)
                elif tag == 'ocupacion':
                    point_data['ocupacion'] = self._safe_float(text)
                elif tag == 'carga':
                    point_data['carga'] = self._safe_int(text)
                elif tag == 'nivelServicio':
                    point_data['nivelServicio'] = self._safe_int(text)
                elif tag == 'st_x':
                    # Store UTM X coordinate for later conversion
                    utm_x = text
                    point_data['utm_x'] = text  # Keep original for debugging
                elif tag == 'st_y':
                    # Store UTM Y coordinate for later conversion
                    utm_y = text
                    point_data['utm_y'] = text  # Keep original for debugging
                elif tag == 'error':
                    point_data['error'] = text
                elif tag == 'subarea':
                    point_data['subarea'] = text
                elif tag == 'accesoAsociado':
                    point_data['accesoAsociado'] = text
                elif tag == 'intensidadSat':
                    point_data['intensidadSat'] = self._safe_int(text)
            
            # Convert UTM coordinates to lat/lon if both are available
            if utm_x and utm_y:
                latitude, longitude = self._convert_utm_coordinates_accurate(utm_x, utm_y)
                
                if latitude is not None and longitude is not None:
                    # Validate that coordinates are actually in Madrid area
                    if self._validate_madrid_coordinates(latitude, longitude):
                        point_data['latitude'] = latitude
                        point_data['longitude'] = longitude
                        
                        # Log first few successful conversions for verification
                        if len(getattr(self, '_conversion_log_count', [])) < 3:
                            if not hasattr(self, '_conversion_log_count'):
                                self._conversion_log_count = []
                            self._conversion_log_count.append(1)
                            
                            logger.debug("Successful UTM conversion", 
                                    idelem=point_data.get('idelem'),
                                    utm_x=utm_x, 
                                    utm_y=utm_y,
                                    latitude=latitude, 
                                    longitude=longitude,
                                    descripcion=point_data.get('descripcion'))
                    else:
                        # Log invalid coordinates for debugging
                        logger.debug("Invalid Madrid coordinates after conversion", 
                                idelem=point_data.get('idelem'),
                                utm_x=utm_x, 
                                utm_y=utm_y,
                                converted_lat=latitude, 
                                converted_lon=longitude,
                                descripcion=point_data.get('descripcion'))
                        # Don't include this point - return empty dict
                        return {}
                else:
                    # Conversion failed
                    logger.debug("UTM conversion failed", 
                            idelem=point_data.get('idelem'),
                            utm_x=utm_x, 
                            utm_y=utm_y)
                    return {}
            else:
                # Missing coordinates
                logger.debug("Missing UTM coordinates", 
                        idelem=point_data.get('idelem'),
                        has_utm_x=utm_x is not None,
                        has_utm_y=utm_y is not None)
                return {}
            
            return point_data
            
        except Exception as e:
            logger.debug("Error extracting Madrid PM element", error=str(e))
            return {}

    
    def _convert_utm_coordinates_accurate(self, utm_x_str: str, utm_y_str: str) -> tuple[Optional[float], Optional[float]]:
        """Convert UTM coordinates to lat/lon using accurate pyproj library"""
        try:
            utm_x = float(utm_x_str.replace(',', '.'))
            utm_y = float(utm_y_str.replace(',', '.'))
            
            # Define UTM Zone 30N projection (EPSG:25830)
            utm_proj = pyproj.Proj(proj='utm', zone=30, ellps='WGS84', preserve_units=False)
            
            # Convert to latitude/longitude
            longitude, latitude = utm_proj(utm_x, utm_y, inverse=True)
            
            return round(latitude, 6), round(longitude, 6)
        except (ValueError, TypeError, Exception):
            return None, None

    def _validate_madrid_coordinates(self, latitude: float, longitude: float) -> bool:
        """Validate that converted coordinates are actually in Madrid area"""
        # Madrid bounds (expanded slightly to include metro area)
        madrid_lat_min, madrid_lat_max = 40.31, 40.56
        madrid_lon_min, madrid_lon_max = -3.89, -3.51
        
        return (madrid_lat_min <= latitude <= madrid_lat_max and 
                madrid_lon_min <= longitude <= madrid_lon_max)
    
    def _safe_int(self, value_str: str) -> int:
        """Safely convert string to int"""
        try:
            return int(float(value_str.replace(',', '.')))
        except (ValueError, TypeError):
            return 0
    
    def _safe_float(self, value_str: str) -> float:
        """Safely convert string to float"""
        try:
            return float(value_str.replace(',', '.'))
        except (ValueError, TypeError):
            return 0.0
    
    async def _fetch_xml_content_robust(self, url: str) -> Optional[str]:
        """Fetch XML content with robust headers for Madrid endpoints"""
        try:
            import httpx
            
            # Headers optimized for Madrid Open Data
            headers = {
                'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
                'Accept': 'application/xml,text/xml,*/*',
                'Accept-Language': 'es-ES,es;q=0.9,en;q=0.8',
                'Accept-Encoding': 'gzip, deflate, br',
                'Cache-Control': 'no-cache',
                'Referer': 'https://datos.madrid.es/'
            }
            
            async with httpx.AsyncClient(
                timeout=30.0,
                follow_redirects=True,
                headers=headers
            ) as client:
                
                logger.debug("Fetching XML from Madrid endpoint", url=url)
                response = await client.get(url)
                
                logger.debug("Madrid API response", 
                           status=response.status_code,
                           content_type=response.headers.get('content-type'),
                           content_length=len(response.content))
                
                if response.status_code == 200:
                    try:
                        content = response.text
                        if content and len(content) > 100:
                            return content
                    except UnicodeDecodeError:
                        # Try manual encoding for Spanish content
                        for encoding in ['utf-8', 'latin-1', 'windows-1252', 'iso-8859-1']:
                            try:
                                content = response.content.decode(encoding)
                                if content and len(content) > 100:
                                    logger.debug("Successfully decoded with encoding", encoding=encoding)
                                    return content
                            except UnicodeDecodeError:
                                continue
                
                return None
                    
        except Exception as e:
            logger.warning("Failed to fetch Madrid XML content", url=url, error=str(e))
            return None
    
    def _extract_traffic_data_regex(self, xml_content: str) -> List[Dict[str, Any]]:
        """Extract traffic data using regex when XML parsing fails"""
        traffic_points = []
        
        try:
            # Pattern to match Madrid PM elements
            pm_pattern = r'<pm>(.*?)</pm>'
            pm_matches = re.findall(pm_pattern, xml_content, re.DOTALL)
            
            for pm_content in pm_matches:
                try:
                    # Extract individual fields
                    idelem_match = re.search(r'<idelem>(.*?)</idelem>', pm_content)
                    intensidad_match = re.search(r'<intensidad>(.*?)</intensidad>', pm_content)
                    st_x_match = re.search(r'<st_x>(.*?)</st_x>', pm_content)
                    st_y_match = re.search(r'<st_y>(.*?)</st_y>', pm_content)
                    descripcion_match = re.search(r'<descripcion>(.*?)</descripcion>', pm_content)
                    
                    if idelem_match and st_x_match and st_y_match:
                        idelem = idelem_match.group(1)
                        st_x = st_x_match.group(1)
                        st_y = st_y_match.group(1)
                        intensidad = intensidad_match.group(1) if intensidad_match else '0'
                        descripcion = descripcion_match.group(1) if descripcion_match else f'Point {idelem}'
                        
                        # Convert coordinates
                        longitude = self._convert_utm_to_lon(st_x)
                        latitude = self._convert_utm_to_lat(st_y)
                        
                        if latitude and longitude:
                            traffic_point = {
                                'idelem': idelem,
                                'descripcion': descripcion,
                                'intensidad': self._safe_int(intensidad),
                                'latitude': latitude,
                                'longitude': longitude,
                                'ocupacion': 0,
                                'carga': 0,
                                'nivelServicio': 0,
                                'error': 'N'
                            }
                            
                            traffic_points.append(traffic_point)
                            
                except Exception as e:
                    logger.debug("Error parsing regex PM match", error=str(e))
                    continue
            
            logger.debug("Regex extraction results", count=len(traffic_points))
            return traffic_points
            
        except Exception as e:
            logger.error("Error in regex extraction", error=str(e))
            return []
    
    def _get_closest_distance(self, latitude: float, longitude: float, traffic_data: List[Dict]) -> float:
        """Get distance to closest traffic point for debugging"""
        if not traffic_data:
            return float('inf')
        
        min_distance = float('inf')
        for point in traffic_data:
            if point.get('latitude') and point.get('longitude'):
                distance = self._calculate_distance(
                    latitude, longitude,
                    point['latitude'], point['longitude']
                )
                min_distance = min(min_distance, distance)
        
        return min_distance
    
    def _find_nearest_traffic_point(self, latitude: float, longitude: float, traffic_data: List[Dict]) -> Optional[Dict]:
        """Find the nearest traffic measurement point to given coordinates"""
        if not traffic_data:
            return None
        
        min_distance = float('inf')
        nearest_point = None
        
        for point in traffic_data:
            if point.get('latitude') and point.get('longitude'):
                distance = self._calculate_distance(
                    latitude, longitude,
                    point['latitude'], point['longitude']
                )
                
                if distance < min_distance:
                    min_distance = distance
                    nearest_point = point
        
        # Madrid area search radius (15km)
        if nearest_point and min_distance <= 15.0:
            logger.debug("Found nearest Madrid traffic point", 
                        distance_km=min_distance, 
                        point_name=nearest_point.get('descripcion'),
                        point_id=nearest_point.get('idelem'))
            return nearest_point
        
        logger.debug("No nearby Madrid traffic points found", 
                    min_distance=min_distance,
                    total_points=len(traffic_data))
        return None
    
    def _calculate_distance(self, lat1: float, lon1: float, lat2: float, lon2: float) -> float:
        """Calculate distance between two coordinates in km using Haversine formula"""
        R = 6371  # Earth's radius in km
        
        dlat = math.radians(lat2 - lat1)
        dlon = math.radians(lon2 - lon1)
        
        a = (math.sin(dlat/2) * math.sin(dlat/2) +
             math.cos(math.radians(lat1)) * math.cos(math.radians(lat2)) *
             math.sin(dlon/2) * math.sin(dlon/2))
        
        c = 2 * math.atan2(math.sqrt(a), math.sqrt(1-a))
        distance = R * c
        
        return distance
    
    def _parse_traffic_measurement(self, traffic_point: Dict) -> Dict[str, Any]:
        """Parse Madrid traffic measurement into standardized format"""
        try:
            # Madrid traffic service levels: 0=fluid, 1=dense, 2=congested, 3=cut
            service_level_map = {
                0: "low",
                1: "medium", 
                2: "high",
                3: "blocked"
            }
            
            service_level = traffic_point.get('nivelServicio', 0)
            
            # Estimate speed based on service level and road type
            if service_level == 0:  # Fluid
                average_speed = 45
            elif service_level == 1:  # Dense
                average_speed = 25
            elif service_level == 2:  # Congested
                average_speed = 15
            else:  # Cut/Blocked
                average_speed = 5
            
            congestion_level = service_level_map.get(service_level, "medium")
            
            # Calculate pedestrian estimate based on location
            hour = datetime.now().hour
            if 13 <= hour <= 15:  # Lunch time
                pedestrian_multiplier = 2.5
            elif 8 <= hour <= 9 or 18 <= hour <= 20:  # Rush hours
                pedestrian_multiplier = 2.0
            else:
                pedestrian_multiplier = 1.0
            
            pedestrian_count = int(100 * pedestrian_multiplier)
            
            return {
                "date": datetime.now(),
                "traffic_volume": traffic_point.get('intensidad', 0),
                "pedestrian_count": pedestrian_count,
                "congestion_level": congestion_level,
                "average_speed": average_speed,
                "occupation_percentage": traffic_point.get('ocupacion', 0),
                "load_percentage": traffic_point.get('carga', 0),
                "measurement_point_id": traffic_point.get('idelem'),
                "measurement_point_name": traffic_point.get('descripcion'),
                "road_type": "URB",
                "source": "madrid_opendata"
            }
            
        except Exception as e:
            logger.error("Error parsing traffic measurement", error=str(e))
            return self._get_default_traffic_data()
    
    def _get_default_traffic_data(self) -> Dict[str, Any]:
        """Get default traffic data when parsing fails"""
        return {
            "date": datetime.now(),
            "traffic_volume": 100,
            "pedestrian_count": 150,
            "congestion_level": "medium",
            "average_speed": 25,
            "occupation_percentage": 30,
            "load_percentage": 40,
            "measurement_point_id": "unknown",
            "measurement_point_name": "Unknown location",
            "road_type": "URB",
            "source": "synthetic"
        }
    
    async def _generate_synthetic_traffic(self, latitude: float, longitude: float) -> Dict[str, Any]:
        """Generate realistic Madrid traffic data as fallback"""
        now = datetime.now()
        hour = now.hour
        is_weekend = now.weekday() >= 5
        
        base_traffic = 100
        
        if not is_weekend:
            if 7 <= hour <= 9:
                traffic_multiplier = 2.2
                congestion = "high"
                avg_speed = 15
            elif 18 <= hour <= 20:
                traffic_multiplier = 2.5
                congestion = "high"
                avg_speed = 12
            elif 12 <= hour <= 14:
                traffic_multiplier = 1.6
                congestion = "medium"
                avg_speed = 25
            else:
                traffic_multiplier = 1.0
                congestion = "low"
                avg_speed = 40
        else:
            if 11 <= hour <= 14:
                traffic_multiplier = 1.4
                congestion = "medium"
                avg_speed = 30
            else:
                traffic_multiplier = 0.8
                congestion = "low"
                avg_speed = 45
        
        traffic_volume = int(base_traffic * traffic_multiplier)
        
        # Pedestrian calculation
        pedestrian_base = 150
        if 13 <= hour <= 15:
            pedestrian_count = int(pedestrian_base * 2.5)
        elif 8 <= hour <= 9 or 18 <= hour <= 20:
            pedestrian_count = int(pedestrian_base * 2.0)
        else:
            pedestrian_count = int(pedestrian_base * 1.0)
        
        return {
            "date": now,
            "traffic_volume": traffic_volume,
            "pedestrian_count": pedestrian_count,
            "congestion_level": congestion,
            "average_speed": max(10, avg_speed),
            "occupation_percentage": min(100, traffic_volume // 2),
            "load_percentage": min(100, traffic_volume // 3),
            "measurement_point_id": "madrid_synthetic",
            "measurement_point_name": "Madrid Centro (Synthetic)",
            "road_type": "URB",
            "source": "synthetic"
        }
    
    # Placeholder methods for completeness
    async def get_historical_traffic(self, latitude: float, longitude: float, start_date: datetime, end_date: datetime) -> List[Dict[str, Any]]:
        """Get historical traffic data"""
        return []
    
    async def get_events(self, latitude: float, longitude: float, radius_km: float = 5.0) -> List[Dict[str, Any]]:
        """Get traffic incidents and events"""
        return []