import requests # type: ignore
import zipfile
import io
import os
import shutil
from pathlib import Path

class GTFSSyncManager:
    def __init__(self):
        self.CKAN_BASE_URL = "https://ckan0.cf.opendata.inter.prod-toronto.ca/api/3/action/package_show"
        self.PACKAGE_ID = "merged-gtfs-ttc-routes-and-schedules"
        self.STATIC_DIR = Path(__file__).parent.parent / "static"
        self.DB_PATH = Path(__file__).parent.parent / "src" / "ttc_gtfs.duckdb"

    def get_remote_metadata(self):
        """Queries CKAN API for the latest ZIP URL and its modification date."""
        try:
            params = {"id": self.PACKAGE_ID}
            response = requests.get(self.CKAN_BASE_URL, params=params, timeout=10)
            data = response.json()
            
            # Extract the metadata_modified date and the resource URL
            last_modified = data["result"]["metadata_modified"]
            resources = data["result"]["resources"]
            download_url = next((r["url"] for r in resources if r["format"].lower() == "zip"), None)
            
            return {"url": download_url, "updated_at": last_modified}
        except Exception as e:
            print(f"Metadata fetch failed: {e}")
            return None

    def perform_full_sync(self, download_url):
        """Downloads, extracts, and clears the old DB to force a rebuild."""
        print(f"--- Downloading New GTFS Bundle from {download_url} ---")
        
        if self.STATIC_DIR.exists():
            shutil.rmtree(self.STATIC_DIR)
        self.STATIC_DIR.mkdir(parents=True, exist_ok=True)

        r = requests.get(download_url)
        with zipfile.ZipFile(io.BytesIO(r.content)) as z:
            z.extractall(self.STATIC_DIR)
            print(f"✓ Extracted {len(z.namelist())} files to {self.STATIC_DIR}.")
        
        # Nuke the old DB so init_db triggers a fresh import
        if self.DB_PATH.exists():
            os.remove(self.DB_PATH)
            print("✓ Old database deleted for rebuild.")