services/wikidata_service.py

"""
Wikidata service for finding historical events.

Queries Wikidata for events at specific coordinates and times.
"""

from __future__ import annotations

import hashlib
import json
import math
import os
import ssl
import time
from dataclasses import dataclass, field
from datetime import datetime
from pathlib import Path
from typing import Any, Dict, List, Optional, Tuple
import urllib.request
import urllib.parse
import urllib.error

# Note: We use urllib with SSL fallback to avoid permission issues with requests/certifi
USE_REQUESTS = False

# Cache configuration
ROOT_DIR = Path(__file__).resolve().parent.parent
CACHE_DIR = ROOT_DIR / "data" / "wikidata_cache"
CACHE_DIR.mkdir(parents=True, exist_ok=True)
CACHE_TTL_SECONDS = 86400 * 7  # 7 days

WIKIDATA_SPARQL_ENDPOINT = "https://query.wikidata.org/sparql"

# Rate limiting
_last_request_time: float = 0.0
MIN_REQUEST_INTERVAL = 1.5  # seconds between requests


@dataclass
class WikidataEvent:
    """Represents a historical event from Wikidata."""
    qid: str
    name: str
    description: str = ""
    year: Optional[int] = None
    month: Optional[int] = None
    day: Optional[int] = None
    lat: Optional[float] = None
    lon: Optional[float] = None
    participants: List[str] = field(default_factory=list)
    location_name: str = ""
    event_type: str = ""
    wikipedia_url: str = ""
    image_url: str = ""
    distance_km: float = 0.0
    year_delta: int = 0
    confidence: float = 0.0
    source: str = "wikidata"

    def to_dict(self) -> Dict[str, Any]:
        return {
            "qid": self.qid,
            "name": self.name,
            "description": self.description,
            "year": self.year,
            "month": self.month,
            "day": self.day,
            "lat": self.lat,
            "lon": self.lon,
            "participants": self.participants,
            "location_name": self.location_name,
            "event_type": self.event_type,
            "wikipedia_url": self.wikipedia_url,
            "image_url": self.image_url,
            "distance_km": self.distance_km,
            "year_delta": self.year_delta,
            "confidence": self.confidence,
            "source": self.source,
            # Compatibility fields for existing code
            "summary": self.description,
            "narrative": self.description,
            "actors": self.participants,
            "themes": [self.event_type] if self.event_type else [],
            "artifacts": [],
            "visual_motifs": [],
            "facets": {"type": self.event_type},
            "sources": [{"label": "Wikidata", "url": f"https://www.wikidata.org/wiki/{self.qid}"}],
            "match_confidence": self.confidence,
        }


def _cache_key(lat: float, lon: float, year: int, radius_km: float) -> str:
    """Generate a cache key for the query parameters."""
    raw = f"{lat:.2f}_{lon:.2f}_{year}_{radius_km:.0f}"
    return hashlib.md5(raw.encode()).hexdigest()


def _get_cached(cache_key: str) -> Optional[List[Dict]]:
    """Retrieve cached results if they exist and aren't expired."""
    cache_file = CACHE_DIR / f"{cache_key}.json"
    if not cache_file.exists():
        return None
    
    try:
        with open(cache_file, "r", encoding="utf-8") as f:
            data = json.load(f)
        
        cached_time = data.get("timestamp", 0)
        if time.time() - cached_time > CACHE_TTL_SECONDS:
            cache_file.unlink(missing_ok=True)
            return None
        
        return data.get("events", [])
    except (json.JSONDecodeError, OSError):
        return None


def _save_cache(cache_key: str, events: List[Dict]) -> None:
    """Save results to cache."""
    cache_file = CACHE_DIR / f"{cache_key}.json"
    try:
        with open(cache_file, "w", encoding="utf-8") as f:
            json.dump({"timestamp": time.time(), "events": events}, f, ensure_ascii=False)
    except OSError:
        pass


def _rate_limit() -> None:
    """Ensure we don't exceed Wikidata rate limits."""
    global _last_request_time
    elapsed = time.time() - _last_request_time
    if elapsed < MIN_REQUEST_INTERVAL:
        time.sleep(MIN_REQUEST_INTERVAL - elapsed)
    _last_request_time = time.time()


def _haversine(lat1: float, lon1: float, lat2: float, lon2: float) -> float:
    """Calculate distance in km between two points."""
    R = 6371.0
    phi1, phi2 = math.radians(lat1), math.radians(lat2)
    dphi = math.radians(lat2 - lat1)
    dlam = math.radians(lon2 - lon1)
    a = math.sin(dphi / 2) ** 2 + math.cos(phi1) * math.cos(phi2) * math.sin(dlam / 2) ** 2
    return R * 2 * math.atan2(math.sqrt(a), math.sqrt(max(0, 1 - a)))


def _build_sparql_query(lat: float, lon: float, year: int, radius_km: float, limit: int = 20) -> str:
    """
    Build SPARQL query for historical events near coordinates and year.
    
    This query searches for:
    - Events (Q1656682) that occurred at a location
    - Battles, treaties, revolutions, etc.
    - Events with point in time or start time within the year range
    """
    # Wikidata uses negative years for BCE
    year_start = year - 15
    year_end = year + 15
    
    # Convert radius to degrees (rough approximation)
    degree_radius = radius_km / 111.0
    
    query = f"""
    SELECT DISTINCT ?event ?eventLabel ?eventDescription ?date ?coord ?locationLabel ?participantLabel ?typeLabel ?article ?image
    WHERE {{
      # Find events with coordinates
      ?event wdt:P31/wdt:P279* wd:Q1656682 .  # instance of event or subclass
      
      # Get coordinates - either direct or via location
      OPTIONAL {{
        ?event wdt:P625 ?directCoord .
      }}
      OPTIONAL {{
        ?event wdt:P276 ?location .
        ?location wdt:P625 ?locationCoord .
      }}
      BIND(COALESCE(?directCoord, ?locationCoord) AS ?coord)
      
      # Filter by coordinate bounding box
      FILTER(BOUND(?coord))
      BIND(geof:latitude(?coord) AS ?lat)
      BIND(geof:longitude(?coord) AS ?lon)
      FILTER(?lat >= {lat - degree_radius} && ?lat <= {lat + degree_radius})
      FILTER(?lon >= {lon - degree_radius} && ?lon <= {lon + degree_radius})
      
      # Get date
      OPTIONAL {{ ?event wdt:P585 ?pointInTime . }}
      OPTIONAL {{ ?event wdt:P580 ?startTime . }}
      BIND(COALESCE(?pointInTime, ?startTime) AS ?date)
      
      # Filter by year range
      FILTER(BOUND(?date))
      FILTER(YEAR(?date) >= {year_start} && YEAR(?date) <= {year_end})
      
      # Optional: participants
      OPTIONAL {{ ?event wdt:P710 ?participant . }}
      
      # Optional: event type
      OPTIONAL {{ ?event wdt:P31 ?type . }}
      
      # Optional: Wikipedia article
      OPTIONAL {{
        ?article schema:about ?event ;
                 schema:isPartOf <https://en.wikipedia.org/> .
      }}
      
      # Optional: image
      OPTIONAL {{ ?event wdt:P18 ?image . }}
      
      # Location label
      OPTIONAL {{ ?event wdt:P276 ?loc . }}
      
      SERVICE wikibase:label {{ bd:serviceParam wikibase:language "en,de,fr,es,it" . }}
    }}
    ORDER BY ABS(YEAR(?date) - {year})
    LIMIT {limit}
    """
    return query


def _build_fallback_query(lat: float, lon: float, year: int, limit: int = 15) -> str:
    """
    Simpler fallback query that searches for any notable events in the year range.
    Uses text search and broader event types.
    """
    year_start = year - 20
    year_end = year + 20
    
    query = f"""
    SELECT DISTINCT ?event ?eventLabel ?eventDescription ?date ?coord ?locationLabel ?article
    WHERE {{
      # Broader event types
      VALUES ?eventType {{
        wd:Q178561    # battle
        wd:Q131569    # treaty
        wd:Q7278      # political revolution
        wd:Q8076      # assassination
        wd:Q3882219   # coronation
        wd:Q1318295   # military offensive
        wd:Q2001676   # massacre
        wd:Q18669875  # historical event
        wd:Q13418847  # historical period
        wd:Q3024240   # historical event
      }}
      ?event wdt:P31 ?eventType .
      
      # Date filter
      OPTIONAL {{ ?event wdt:P585 ?pointInTime . }}
      OPTIONAL {{ ?event wdt:P580 ?startTime . }}
      BIND(COALESCE(?pointInTime, ?startTime) AS ?date)
      FILTER(BOUND(?date))
      FILTER(YEAR(?date) >= {year_start} && YEAR(?date) <= {year_end})
      
      # Get coordinates via location
      OPTIONAL {{
        ?event wdt:P276 ?location .
        ?location wdt:P625 ?coord .
      }}
      OPTIONAL {{
        ?event wdt:P625 ?directCoord .
      }}
      BIND(COALESCE(?coord, ?directCoord) AS ?finalCoord)
      
      # Wikipedia article
      OPTIONAL {{
        ?article schema:about ?event ;
                 schema:isPartOf <https://en.wikipedia.org/> .
      }}
      
      SERVICE wikibase:label {{ bd:serviceParam wikibase:language "en" . }}
    }}
    ORDER BY ABS(YEAR(?date) - {year})
    LIMIT {limit}
    """
    return query


def _execute_sparql(query: str) -> Optional[Dict]:
    """Execute SPARQL query against Wikidata endpoint."""
    _rate_limit()
    
    headers = {
        "Accept": "application/sparql-results+json",
        "User-Agent": "Meridian-Historical-App/1.0 (https://github.com/meridian; contact@example.com)"
    }
    
    # Try using requests library first (better SSL handling)
    if USE_REQUESTS:
        try:
            response = requests.get(
                WIKIDATA_SPARQL_ENDPOINT,
                params={"query": query},
                headers=headers,
                timeout=30,
                verify=certifi.where(),
            )
            response.raise_for_status()
            return response.json()
        except Exception as e:
            print(f"[Wikidata] SPARQL query failed (requests): {e}")
            # Fall through to urllib fallback
    
    # Fallback to urllib with SSL context
    params = urllib.parse.urlencode({"query": query})
    url = f"{WIKIDATA_SPARQL_ENDPOINT}?{params}"
    
    try:
        # Create SSL context that doesn't verify certificates (fallback)
        ssl_context = ssl.create_default_context()
        ssl_context.check_hostname = False
        ssl_context.verify_mode = ssl.CERT_NONE
        
        req = urllib.request.Request(url, headers=headers)
        with urllib.request.urlopen(req, timeout=30, context=ssl_context) as response:
            return json.loads(response.read().decode("utf-8"))
    except (urllib.error.URLError, urllib.error.HTTPError, json.JSONDecodeError, TimeoutError) as e:
        print(f"[Wikidata] SPARQL query failed (urllib): {e}")
        return None


def _parse_wikidata_date(date_str: str) -> Tuple[Optional[int], Optional[int], Optional[int]]:
    """Parse Wikidata date string to year, month, day."""
    if not date_str:
        return None, None, None
    
    # Handle BCE dates (negative years)
    # Wikidata format: -0044-03-15T00:00:00Z for 44 BCE
    try:
        if date_str.startswith("-"):
            # BCE date
            parts = date_str[1:].split("T")[0].split("-")
            year = -int(parts[0])
            month = int(parts[1]) if len(parts) > 1 else None
            day = int(parts[2]) if len(parts) > 2 else None
            return year, month, day
        else:
            # CE date
            parts = date_str.split("T")[0].split("-")
            year = int(parts[0])
            month = int(parts[1]) if len(parts) > 1 else None
            day = int(parts[2]) if len(parts) > 2 else None
            return year, month, day
    except (ValueError, IndexError):
        return None, None, None


def _parse_coordinates(coord_str: str) -> Tuple[Optional[float], Optional[float]]:
    """Parse Wikidata coordinate string to lat, lon."""
    if not coord_str:
        return None, None
    
    # Format: Point(lon lat)
    try:
        if coord_str.startswith("Point("):
            inner = coord_str[6:-1]
            lon_str, lat_str = inner.split()
            return float(lat_str), float(lon_str)
    except (ValueError, IndexError):
        pass
    
    return None, None


def _results_to_events(
    results: Dict,
    query_lat: float,
    query_lon: float,
    query_year: int,
) -> List[WikidataEvent]:
    """Convert SPARQL results to WikidataEvent objects."""
    events_map: Dict[str, WikidataEvent] = {}
    
    bindings = results.get("results", {}).get("bindings", [])
    
    for binding in bindings:
        # Extract QID
        event_uri = binding.get("event", {}).get("value", "")
        if not event_uri:
            continue
        qid = event_uri.split("/")[-1]
        
        # Get or create event
        if qid not in events_map:
            name = binding.get("eventLabel", {}).get("value", "Unknown Event")
            description = binding.get("eventDescription", {}).get("value", "")
            
            # Parse date
            date_str = binding.get("date", {}).get("value", "")
            year, month, day = _parse_wikidata_date(date_str)
            
            # Parse coordinates
            coord_str = binding.get("coord", {}).get("value", "")
            lat, lon = _parse_coordinates(coord_str)
            
            # Location name
            location_name = binding.get("locationLabel", {}).get("value", "")
            
            # Event type
            event_type = binding.get("typeLabel", {}).get("value", "")
            
            # Wikipedia URL
            wikipedia_url = binding.get("article", {}).get("value", "")
            
            # Image URL
            image_url = binding.get("image", {}).get("value", "")
            
            # Calculate distance and confidence
            distance_km = 0.0
            if lat is not None and lon is not None:
                distance_km = _haversine(query_lat, query_lon, lat, lon)
            
            year_delta = abs((year or query_year) - query_year)
            
            # Confidence scoring
            confidence = 0.7
            if distance_km < 50:
                confidence += 0.15
            elif distance_km < 150:
                confidence += 0.1
            
            if year_delta == 0:
                confidence += 0.15
            elif year_delta <= 5:
                confidence += 0.1
            
            if wikipedia_url:
                confidence += 0.05
            
            confidence = min(confidence, 0.98)
            
            events_map[qid] = WikidataEvent(
                qid=qid,
                name=name,
                description=description,
                year=year,
                month=month,
                day=day,
                lat=lat,
                lon=lon,
                location_name=location_name,
                event_type=event_type,
                wikipedia_url=wikipedia_url,
                image_url=image_url,
                distance_km=round(distance_km, 2),
                year_delta=year_delta,
                confidence=round(confidence, 3),
            )
        
        # Add participant if present
        participant = binding.get("participantLabel", {}).get("value", "")
        if participant and participant not in events_map[qid].participants:
            events_map[qid].participants.append(participant)
    
    # Sort by relevance (lower distance + year_delta = better)
    events = list(events_map.values())
    events.sort(key=lambda e: e.distance_km + e.year_delta * 5 - e.confidence * 20)
    
    return events


def search_events_by_geo_time(
    lat: float,
    lon: float,
    year: int,
    radius_km: float = 300.0,
    limit: int = 10,
    use_cache: bool = True,
) -> List[Dict]:
    """
    Search Wikidata for historical events near coordinates and year.
    
    Args:
        lat: Latitude
        lon: Longitude
        year: Target year (negative for BCE)
        radius_km: Search radius in kilometers
        limit: Maximum number of results
        use_cache: Whether to use cached results
    
    Returns:
        List of event dictionaries compatible with existing code
    """
    # Check cache first
    cache_key = _cache_key(lat, lon, year, radius_km)
    if use_cache:
        cached = _get_cached(cache_key)
        if cached is not None:
            print(f"[Wikidata] Cache hit for {lat:.2f}, {lon:.2f}, {year}")
            return cached[:limit]
    
    print(f"[Wikidata] Querying for events near {lat:.2f}, {lon:.2f}, year {year}")
    
    # Try primary query first
    query = _build_sparql_query(lat, lon, year, radius_km, limit * 2)
    results = _execute_sparql(query)
    
    events: List[WikidataEvent] = []
    if results:
        events = _results_to_events(results, lat, lon, year)
    
    # If no results, try fallback query
    if not events:
        print("[Wikidata] Primary query returned no results, trying fallback...")
        fallback_query = _build_fallback_query(lat, lon, year, limit * 2)
        fallback_results = _execute_sparql(fallback_query)
        if fallback_results:
            events = _results_to_events(fallback_results, lat, lon, year)
    
    # Convert to dicts and cache
    event_dicts = [e.to_dict() for e in events[:limit]]
    
    if use_cache and event_dicts:
        _save_cache(cache_key, event_dicts)
    
    print(f"[Wikidata] Found {len(event_dicts)} events")
    return event_dicts


def get_event_detail(qid: str) -> Optional[Dict]:
    """
    Fetch detailed information about a specific Wikidata event.
    
    Args:
        qid: Wikidata QID (e.g., "Q784")
    
    Returns:
        Event dictionary with full details, or None if not found
    """
    query = f"""
    SELECT ?event ?eventLabel ?eventDescription ?date ?coord ?locationLabel 
           ?participantLabel ?typeLabel ?article ?image ?causeLabel ?effectLabel
    WHERE {{
      BIND(wd:{qid} AS ?event)
      
      OPTIONAL {{ ?event wdt:P585 ?pointInTime . }}
      OPTIONAL {{ ?event wdt:P580 ?startTime . }}
      BIND(COALESCE(?pointInTime, ?startTime) AS ?date)
      
      OPTIONAL {{ ?event wdt:P625 ?coord . }}
      OPTIONAL {{
        ?event wdt:P276 ?location .
        ?location wdt:P625 ?locCoord .
      }}
      
      OPTIONAL {{ ?event wdt:P710 ?participant . }}
      OPTIONAL {{ ?event wdt:P31 ?type . }}
      OPTIONAL {{ ?event wdt:P828 ?cause . }}
      OPTIONAL {{ ?event wdt:P1542 ?effect . }}
      OPTIONAL {{ ?event wdt:P18 ?image . }}
      
      OPTIONAL {{
        ?article schema:about ?event ;
                 schema:isPartOf <https://en.wikipedia.org/> .
      }}
      
      SERVICE wikibase:label {{ bd:serviceParam wikibase:language "en" . }}
    }}
    LIMIT 50
    """
    
    results = _execute_sparql(query)
    if not results:
        return None
    
    events = _results_to_events(results, 0, 0, 0)
    if events:
        event = events[0]
        event_dict = event.to_dict()
        
        # Extract causes and effects from results
        bindings = results.get("results", {}).get("bindings", [])
        causes = set()
        effects = set()
        for binding in bindings:
            cause = binding.get("causeLabel", {}).get("value", "")
            effect = binding.get("effectLabel", {}).get("value", "")
            if cause:
                causes.add(cause)
            if effect:
                effects.add(effect)
        
        event_dict["causes"] = list(causes)
        event_dict["effects"] = list(effects)
        event_dict["relationships"] = {
            "causes": list(causes),
            "consequences": list(effects),
        }
        
        return event_dict
    
    return None


def search_events_by_name(name: str, limit: int = 5) -> List[Dict]:
    """
    Search Wikidata for events by name.
    
    Args:
        name: Event name to search for
        limit: Maximum results
    
    Returns:
        List of matching events
    """
    # Escape special characters
    escaped_name = name.replace('"', '\\"')
    
    query = f"""
    SELECT DISTINCT ?event ?eventLabel ?eventDescription ?date ?coord ?locationLabel ?article
    WHERE {{
      ?event wdt:P31/wdt:P279* wd:Q1656682 .
      ?event rdfs:label ?label .
      FILTER(LANG(?label) = "en")
      FILTER(CONTAINS(LCASE(?label), LCASE("{escaped_name}")))
      
      OPTIONAL {{ ?event wdt:P585 ?pointInTime . }}
      OPTIONAL {{ ?event wdt:P580 ?startTime . }}
      BIND(COALESCE(?pointInTime, ?startTime) AS ?date)
      
      OPTIONAL {{ ?event wdt:P625 ?coord . }}
      OPTIONAL {{
        ?event wdt:P276 ?location .
        ?location wdt:P625 ?locCoord .
      }}
      
      OPTIONAL {{
        ?article schema:about ?event ;
                 schema:isPartOf <https://en.wikipedia.org/> .
      }}
      
      SERVICE wikibase:label {{ bd:serviceParam wikibase:language "en" . }}
    }}
    LIMIT {limit}
    """
    
    results = _execute_sparql(query)
    if not results:
        return []
    
    events = _results_to_events(results, 0, 0, 0)
    return [e.to_dict() for e in events]


# MCP-compatible function exports
def mcp_search_historical_events(
    latitude: float,
    longitude: float,
    year: int,
    radius_km: float = 300.0,
    limit: int = 10,
) -> Dict:
    """
    MCP tool: Search for historical events by coordinates and year.
    
    This queries Wikidata for events that occurred near the specified
    location and time, returning structured event data suitable for
    prompt generation.
    """
    try:
        events = search_events_by_geo_time(
            lat=latitude,
            lon=longitude,
            year=year,
            radius_km=radius_km,
            limit=limit,
        )
        return {
            "success": True,
            "query": {
                "latitude": latitude,
                "longitude": longitude,
                "year": year,
                "radius_km": radius_km,
            },
            "count": len(events),
            "events": events,
            "source": "wikidata",
        }
    except Exception as e:
        return {
            "success": False,
            "error": str(e),
        }


def mcp_get_event_by_qid(qid: str) -> Dict:
    """
    MCP tool: Get detailed information about a Wikidata event.
    """
    try:
        event = get_event_detail(qid)
        if event:
            return {
                "success": True,
                "event": event,
            }
        return {
            "success": False,
            "error": f"Event {qid} not found",
        }
    except Exception as e:
        return {
            "success": False,
            "error": str(e),
        }