#!/usr/bin/env python3
"""
Geocode all school postcodes and update the database.

This script should be run as a weekly cron job to ensure all schools
have up-to-date latitude/longitude coordinates.

Usage:
    python scripts/geocode_schools.py [--force]

Options:
    --force     Re-geocode all postcodes, even if already geocoded

Crontab example (run every Sunday at 2am):
    0 2 * * 0 cd /path/to/school_compare && /path/to/venv/bin/python scripts/geocode_schools.py >> /var/log/geocode_schools.log 2>&1
"""

import argparse
import sys
from datetime import datetime
from pathlib import Path
from typing import Dict, Tuple

import requests

# Add parent directory to path for imports
sys.path.insert(0, str(Path(__file__).parent.parent))

from backend.database import SessionLocal
from backend.models import School


def geocode_postcodes_bulk(postcodes: list) -> Dict[str, Tuple[float, float]]:
    """
    Geocode postcodes in bulk using postcodes.io API.
    Returns dict of postcode -> (latitude, longitude).
    """
    results = {}
    valid_postcodes = [
        p.strip().upper()
        for p in postcodes
        if p and isinstance(p, str) and len(p.strip()) >= 5
    ]
    valid_postcodes = list(set(valid_postcodes))

    if not valid_postcodes:
        return results

    batch_size = 100
    total_batches = (len(valid_postcodes) + batch_size - 1) // batch_size

    for i, batch_start in enumerate(range(0, len(valid_postcodes), batch_size)):
        batch = valid_postcodes[batch_start : batch_start + batch_size]
        print(f"  Geocoding batch {i + 1}/{total_batches} ({len(batch)} postcodes)...")

        try:
            response = requests.post(
                "https://api.postcodes.io/postcodes",
                json={"postcodes": batch},
                timeout=30,
            )
            if response.status_code == 200:
                data = response.json()
                for item in data.get("result", []):
                    if item and item.get("result"):
                        pc = item["query"].upper()
                        lat = item["result"].get("latitude")
                        lon = item["result"].get("longitude")
                        if lat and lon:
                            results[pc] = (lat, lon)
            else:
                print(f"    Warning: API returned status {response.status_code}")
        except Exception as e:
            print(f"    Warning: Geocoding batch failed: {e}")

    return results


def geocode_schools(force: bool = False) -> None:
    """
    Geocode all schools in the database.

    Args:
        force: If True, re-geocode all postcodes even if already geocoded
    """
    print(f"\n{'='*60}")
    print(f"School Geocoding Job - {datetime.now().isoformat()}")
    print(f"{'='*60}\n")

    db = SessionLocal()

    try:
        # Get schools that need geocoding
        if force:
            schools = db.query(School).filter(School.postcode.isnot(None)).all()
            print(f"Force mode: Processing all {len(schools)} schools with postcodes")
        else:
            schools = db.query(School).filter(
                School.postcode.isnot(None),
                (School.latitude.is_(None)) | (School.longitude.is_(None))
            ).all()
            print(f"Found {len(schools)} schools without coordinates")

        if not schools:
            print("No schools to geocode. Exiting.")
            return

        # Extract unique postcodes
        postcodes = list(set(
            s.postcode.strip().upper()
            for s in schools
            if s.postcode
        ))
        print(f"Unique postcodes to geocode: {len(postcodes)}")

        # Geocode in bulk
        print("\nGeocoding postcodes...")
        geocoded = geocode_postcodes_bulk(postcodes)
        print(f"Successfully geocoded: {len(geocoded)} postcodes")

        # Update database
        print("\nUpdating database...")
        updated_count = 0
        failed_count = 0

        for school in schools:
            if not school.postcode:
                continue

            pc_upper = school.postcode.strip().upper()
            coords = geocoded.get(pc_upper)

            if coords:
                school.latitude = coords[0]
                school.longitude = coords[1]
                updated_count += 1
            else:
                failed_count += 1

        db.commit()

        print(f"\nResults:")
        print(f"  - Updated: {updated_count} schools")
        print(f"  - Failed (invalid/not found): {failed_count} postcodes")

        # Summary stats
        total_with_coords = db.query(School).filter(
            School.latitude.isnot(None),
            School.longitude.isnot(None)
        ).count()
        total_schools = db.query(School).count()

        print(f"\nDatabase summary:")
        print(f"  - Total schools: {total_schools}")
        print(f"  - Schools with coordinates: {total_with_coords}")
        print(f"  - Coverage: {100*total_with_coords/total_schools:.1f}%")

    except Exception as e:
        print(f"Error during geocoding: {e}")
        db.rollback()
        raise
    finally:
        db.close()
        print(f"\n{'='*60}")
        print(f"Geocoding job completed - {datetime.now().isoformat()}")
        print(f"{'='*60}\n")


def main():
    parser = argparse.ArgumentParser(
        description="Geocode school postcodes and update database"
    )
    parser.add_argument(
        "--force",
        action="store_true",
        help="Re-geocode all postcodes, even if already geocoded"
    )
    args = parser.parse_args()

    geocode_schools(force=args.force)


if __name__ == "__main__":
    main()