"""
OpenStreetMap Data Extractor
============================
Downloads and processes real road network data from OpenStreetMap
for use in accident reconstruction simulation.
"""

import os
import json
from pathlib import Path
from typing import Dict, List, Tuple, Optional

try:
    import osmnx as ox
    OSMNX_AVAILABLE = True
except ImportError:
    OSMNX_AVAILABLE = False
    print("Warning: osmnx not installed. Install with: pip install osmnx")

try:
    import folium
    FOLIUM_AVAILABLE = True
except ImportError:
    FOLIUM_AVAILABLE = False

import sys
sys.path.insert(0, str(Path(__file__).parent.parent))

from config import CASE_STUDY_LOCATION, ALTERNATIVE_LOCATIONS, OSM_DATA_DIR


def download_road_network(
    latitude: float,
    longitude: float,
    radius: int = 200,
    network_type: str = "drive",
    save_path: Optional[str] = None
) -> Dict:
    """
    Download road network from OpenStreetMap.
    
    Args:
        latitude: Center latitude
        longitude: Center longitude
        radius: Radius in meters
        network_type: Type of network ('drive', 'walk', 'bike', 'all')
        save_path: Optional path to save the network
    
    Returns:
        Dictionary containing network data
    """
    if not OSMNX_AVAILABLE:
        print("osmnx not available. Using fallback data.")
        return create_fallback_network(latitude, longitude, radius)
    
    try:
        # Configure osmnx
        ox.settings.use_cache = True
        ox.settings.log_console = True
        
        # Download the road network
        print(f"Downloading road network for ({latitude}, {longitude})...")
        G = ox.graph_from_point(
            (latitude, longitude),
            dist=radius,
            network_type=network_type,
            simplify=True
        )
        
        # Get nodes and edges
        nodes, edges = ox.graph_to_gdfs(G)
        
        # Convert to dictionary format
        network_data = {
            "center": {"lat": latitude, "lng": longitude},
            "radius": radius,
            "nodes": [],
            "edges": [],
            "bounds": {
                "north": nodes.geometry.y.max(),
                "south": nodes.geometry.y.min(),
                "east": nodes.geometry.x.max(),
                "west": nodes.geometry.x.min()
            }
        }
        
        # Process nodes
        for idx, row in nodes.iterrows():
            network_data["nodes"].append({
                "id": str(idx),
                "lat": row.geometry.y,
                "lng": row.geometry.x
            })
        
        # Process edges
        for idx, row in edges.iterrows():
            edge_data = {
                "from": str(idx[0]),
                "to": str(idx[1]),
                "length": row.get("length", 0),
                "name": row.get("name", "Unknown"),
                "highway": row.get("highway", "unclassified"),
                "lanes": row.get("lanes", 1),
                "maxspeed": row.get("maxspeed", "50")
            }
            
            # Get geometry if available
            if hasattr(row.geometry, 'coords'):
                edge_data["geometry"] = list(row.geometry.coords)
            
            network_data["edges"].append(edge_data)
        
        # Save if path provided
        if save_path:
            save_path = Path(save_path)
            save_path.parent.mkdir(parents=True, exist_ok=True)
            
            with open(save_path, 'w') as f:
                json.dump(network_data, f, indent=2)
            
            # Also save as GraphML for SUMO conversion
            graphml_path = save_path.with_suffix('.graphml')
            ox.save_graphml(G, graphml_path)
            
            print(f"Network saved to {save_path}")
            print(f"GraphML saved to {graphml_path}")
        
        return network_data
        
    except Exception as e:
        print(f"Error downloading network: {e}")
        return create_fallback_network(latitude, longitude, radius)


def create_fallback_network(
    latitude: float,
    longitude: float,
    radius: int = 200
) -> Dict:
    """
    Create a fallback network when OSM download fails.
    Creates a simple roundabout structure.
    """
    import math
    
    # Create a simple roundabout with 4 approaches
    network_data = {
        "center": {"lat": latitude, "lng": longitude},
        "radius": radius,
        "nodes": [],
        "edges": [],
        "bounds": {
            "north": latitude + 0.002,
            "south": latitude - 0.002,
            "east": longitude + 0.002,
            "west": longitude - 0.002
        }
    }
    
    # Create roundabout nodes (8 points in a circle)
    roundabout_radius = 0.0003  # Approximately 30 meters
    num_points = 8
    
    for i in range(num_points):
        angle = (2 * math.pi * i) / num_points
        lat = latitude + roundabout_radius * math.cos(angle)
        lng = longitude + roundabout_radius * math.sin(angle)
        
        network_data["nodes"].append({
            "id": f"r{i}",
            "lat": lat,
            "lng": lng,
            "type": "roundabout"
        })
    
    # Create approach nodes (4 directions)
    approach_distance = 0.001  # Approximately 100 meters
    approaches = [
        ("north", latitude + approach_distance, longitude),
        ("south", latitude - approach_distance, longitude),
        ("east", latitude, longitude + approach_distance),
        ("west", latitude, longitude - approach_distance)
    ]
    
    for name, lat, lng in approaches:
        network_data["nodes"].append({
            "id": f"a_{name}",
            "lat": lat,
            "lng": lng,
            "type": "approach"
        })
    
    # Create roundabout edges (circular)
    for i in range(num_points):
        next_i = (i + 1) % num_points
        network_data["edges"].append({
            "from": f"r{i}",
            "to": f"r{next_i}",
            "length": 20,
            "name": "Roundabout",
            "highway": "primary",
            "lanes": 2
        })
    
    # Connect approaches to roundabout
    approach_connections = [
        ("a_north", "r0", "r6"),
        ("a_east", "r2", "r0"),
        ("a_south", "r4", "r2"),
        ("a_west", "r6", "r4")
    ]
    
    for approach, entry, exit in approach_connections:
        # Entry edge
        network_data["edges"].append({
            "from": approach,
            "to": entry,
            "length": 80,
            "name": "Approach Road",
            "highway": "primary",
            "lanes": 2
        })
        # Exit edge
        network_data["edges"].append({
            "from": exit,
            "to": approach,
            "length": 80,
            "name": "Exit Road",
            "highway": "primary",
            "lanes": 2
        })
    
    return network_data


def extract_intersection_data(
    latitude: float,
    longitude: float,
    radius: int = 100
) -> Dict:
    """
    Extract intersection-specific data from OSM.
    """
    if not OSMNX_AVAILABLE:
        return create_fallback_intersection(latitude, longitude)
    
    try:
        # Get features around the point
        tags = {"highway": True}
        gdf = ox.features_from_point((latitude, longitude), tags, dist=radius)
        
        intersection_data = {
            "center": {"lat": latitude, "lng": longitude},
            "features": []
        }
        
        for idx, row in gdf.iterrows():
            feature = {
                "type": row.get("highway", "unknown"),
                "name": row.get("name", "Unknown")
            }
            if hasattr(row.geometry, 'centroid'):
                feature["lat"] = row.geometry.centroid.y
                feature["lng"] = row.geometry.centroid.x
            
            intersection_data["features"].append(feature)
        
        return intersection_data
        
    except Exception as e:
        print(f"Error extracting intersection: {e}")
        return create_fallback_intersection(latitude, longitude)


def create_fallback_intersection(latitude: float, longitude: float) -> Dict:
    """Create fallback intersection data."""
    return {
        "center": {"lat": latitude, "lng": longitude},
        "type": "roundabout",
        "approaches": 4,
        "lanes": 2,
        "features": [
            {"type": "primary", "name": "Main Road North-South"},
            {"type": "primary", "name": "Main Road East-West"}
        ]
    }


def create_location_map(
    location: Dict,
    network_data: Optional[Dict] = None,
    save_path: Optional[str] = None
) -> 'folium.Map':
    """
    Create an interactive Folium map for the location.
    """
    if not FOLIUM_AVAILABLE:
        print("Folium not available")
        return None
    
    # Create base map
    m = folium.Map(
        location=[location["latitude"], location["longitude"]],
        zoom_start=17,
        tiles="OpenStreetMap"
    )
    
    # Add center marker
    folium.Marker(
        location=[location["latitude"], location["longitude"]],
        popup=location.get("name", "Location"),
        icon=folium.Icon(color="red", icon="info-sign")
    ).add_to(m)
    
    # Add radius circle
    folium.Circle(
        location=[location["latitude"], location["longitude"]],
        radius=location.get("radius_meters", 200),
        color="blue",
        fill=True,
        fill_opacity=0.1
    ).add_to(m)
    
    # Add network data if available
    if network_data:
        # Add nodes
        for node in network_data.get("nodes", []):
            folium.CircleMarker(
                location=[node["lat"], node["lng"]],
                radius=3,
                color="green",
                fill=True
            ).add_to(m)
        
        # Add edges
        for edge in network_data.get("edges", []):
            if "geometry" in edge:
                # Use actual geometry
                coords = [(c[1], c[0]) for c in edge["geometry"]]
                folium.PolyLine(
                    locations=coords,
                    color="gray",
                    weight=2
                ).add_to(m)
    
    # Save if path provided
    if save_path:
        m.save(save_path)
        print(f"Map saved to {save_path}")
    
    return m


def download_all_locations():
    """Download network data for all configured locations."""
    
    # Create output directory
    OSM_DATA_DIR.mkdir(parents=True, exist_ok=True)
    
    # Download primary location
    print("\n" + "="*50)
    print("Downloading primary location...")
    print("="*50)
    
    primary_data = download_road_network(
        latitude=CASE_STUDY_LOCATION["latitude"],
        longitude=CASE_STUDY_LOCATION["longitude"],
        radius=CASE_STUDY_LOCATION["radius_meters"],
        save_path=OSM_DATA_DIR / "primary_location.json"
    )
    
    # Create map for primary location
    create_location_map(
        CASE_STUDY_LOCATION,
        primary_data,
        save_path=str(OSM_DATA_DIR / "primary_location_map.html")
    )
    
    # Download alternative locations
    for loc_key, loc_data in ALTERNATIVE_LOCATIONS.items():
        print(f"\n" + "="*50)
        print(f"Downloading {loc_data['name']}...")
        print("="*50)
        
        network_data = download_road_network(
            latitude=loc_data["latitude"],
            longitude=loc_data["longitude"],
            radius=loc_data["radius_meters"],
            save_path=OSM_DATA_DIR / f"{loc_key}.json"
        )
        
        create_location_map(
            {
                "latitude": loc_data["latitude"],
                "longitude": loc_data["longitude"],
                "radius_meters": loc_data["radius_meters"],
                "name": loc_data["name"]
            },
            network_data,
            save_path=str(OSM_DATA_DIR / f"{loc_key}_map.html")
        )
    
    print("\n" + "="*50)
    print("All locations downloaded successfully!")
    print("="*50)


if __name__ == "__main__":
    download_all_locations()