#!/usr/bin/env python3
"""
Reverse geocode Mexican institutions with missing city fields.

Uses Nominatim API to extract city names from latitude/longitude coordinates
for institutions that have coordinates but missing city field.

Respects Nominatim rate limit: 1 request per second
"""

import sys
import time
from pathlib import Path
from datetime import datetime, timezone
from typing import Optional, Dict, Any
import requests
import yaml

# Add project root to path
project_root = Path(__file__).parent.parent
sys.path.insert(0, str(project_root))


def reverse_geocode(lat: float, lon: float) -> Optional[Dict[str, Any]]:
    """
    Reverse geocode coordinates using Nominatim API.
    
    Returns:
        Dictionary with address components or None if request fails
    """
    url = "https://nominatim.openstreetmap.org/reverse"
    params = {
        'format': 'json',
        'lat': lat,
        'lon': lon,
        'zoom': 18,  # High zoom for city-level detail
        'addressdetails': 1,
        'accept-language': 'es,en'  # Spanish first, then English
    }
    headers = {
        'User-Agent': 'GLAM-Heritage-Custodian-Project/1.0 (heritage data enrichment)'
    }
    
    try:
        response = requests.get(url, params=params, headers=headers, timeout=10)
        response.raise_for_status()
        data = response.json()
        
        if 'error' in data:
            print(f"  ❌ Geocoding error: {data['error']}")
            return None
            
        return data
    except requests.exceptions.RequestException as e:
        print(f"  ❌ Request failed: {e}")
        return None


def extract_city_from_geocode(geocode_data: Dict[str, Any]) -> Optional[str]:
    """
    Extract city name from Nominatim response.
    
    Tries multiple address components in priority order:
    1. city
    2. town
    3. municipality
    4. village
    5. hamlet
    6. suburb (if no better option)
    """
    address = geocode_data.get('address', {})
    
    # Priority order for city-level components
    city_keys = ['city', 'town', 'municipality', 'village', 'hamlet']
    
    for key in city_keys:
        if key in address:
            return address[key]
    
    # Fallback to suburb if nothing else found
    if 'suburb' in address:
        return address['suburb']
    
    return None


def process_mexican_institutions(input_path: Path, dry_run: bool = False):
    """
    Process Mexican institutions and reverse geocode missing cities.
    """
    print("🗺️  Reverse geocoding Mexican institutions...\n")
    
    # Load dataset
    with open(input_path, 'r', encoding='utf-8') as f:
        data = yaml.safe_load(f)
    
    institutions = data if isinstance(data, list) else [data]
    
    # Find Mexican institutions with coordinates but no city
    candidates = []
    for inst in institutions:
        locations = inst.get('locations', [])
        if not locations:
            continue
        
        loc = locations[0]  # Primary location
        country = loc.get('country', '')
        city = loc.get('city')
        lat = loc.get('latitude')
        lon = loc.get('longitude')
        
        if country == 'MX' and not city and lat and lon:
            candidates.append(inst)
    
    print(f"Found {len(candidates)} Mexican institutions needing reverse geocoding\n")
    
    if dry_run:
        print("🔍 DRY RUN MODE - No files will be modified\n")
    
    # Process each candidate
    geocoded_count = 0
    failed_count = 0
    
    for inst in candidates:
        name = inst.get('name', 'Unknown')
        loc = inst['locations'][0]
        region = loc.get('region', 'Unknown')
        lat = loc['latitude']
        lon = loc['longitude']
        
        print(f"📍 {name}")
        print(f"   Region: {region}")
        print(f"   Coords: {lat}, {lon}")
        
        # Reverse geocode
        geocode_data = reverse_geocode(lat, lon)
        
        if geocode_data:
            city = extract_city_from_geocode(geocode_data)
            
            if city:
                print(f"   ✅ Found city: {city}")
                
                if not dry_run:
                    # Update location
                    loc['city'] = city
                    
                    # Add enrichment history
                    if 'provenance' not in inst:
                        inst['provenance'] = {}
                    
                    if 'enrichment_history' not in inst['provenance']:
                        inst['provenance']['enrichment_history'] = []
                    
                    inst['provenance']['enrichment_history'].append({
                        'enrichment_date': datetime.now(timezone.utc).isoformat(),
                        'enrichment_method': 'Nominatim reverse geocoding',
                        'fields_updated': ['locations.city'],
                        'source': f'Nominatim API reverse geocode ({lat}, {lon})',
                        'notes': f'Extracted city name from coordinates using OpenStreetMap Nominatim'
                    })
                
                geocoded_count += 1
            else:
                print(f"   ⚠️  No city found in geocode response")
                failed_count += 1
        else:
            print(f"   ❌ Geocoding failed")
            failed_count += 1
        
        print()
        
        # Rate limit: 1 request per second
        time.sleep(1.1)
    
    # Save results
    if not dry_run and geocoded_count > 0:
        # Create backup
        backup_path = input_path.parent / f"{input_path.stem}_backup_before_reverse_geocoding.yaml"
        with open(input_path, 'r', encoding='utf-8') as f:
            backup_data = f.read()
        with open(backup_path, 'w', encoding='utf-8') as f:
            f.write(backup_data)
        print(f"✅ Backup created: {backup_path}")
        
        # Write updated data
        with open(input_path, 'w', encoding='utf-8') as f:
            yaml.dump(institutions, f, allow_unicode=True, sort_keys=False)
        print(f"✅ Updated data written to: {input_path}")
    
    # Print summary
    print("\n" + "="*80)
    print("REVERSE GEOCODING SUMMARY")
    print("="*80)
    print(f"Institutions processed: {len(candidates)}")
    print(f"Successfully geocoded: {geocoded_count}")
    print(f"Failed/No city found: {failed_count}")
    print("="*80)
    
    if dry_run:
        print("\n💡 Run without --dry-run flag to apply changes")


def main():
    import argparse
    
    parser = argparse.ArgumentParser(description='Reverse geocode Mexican institutions')
    parser.add_argument('--dry-run', action='store_true',
                       help='Test mode - do not modify files')
    parser.add_argument('--input', type=Path,
                       default=Path('data/instances/all/globalglam-20251113-mexico-deduplicated.yaml'),
                       help='Input YAML file path')
    
    args = parser.parse_args()
    
    if not args.input.exists():
        print(f"❌ Error: Input file not found: {args.input}")
        sys.exit(1)
    
    process_mexican_institutions(args.input, dry_run=args.dry_run)


if __name__ == '__main__':
    main()