#!/usr/bin/env python3
"""Download Wikimedia Commons contributions for a user."""

import json
import time

import requests

from flickr_mail.database import init_db, get_session
from flickr_mail.models import Contribution


API_URL = "https://commons.wikimedia.org/w/api.php"
USERNAME = "Edward"

# Identify ourselves properly to Wikimedia
USER_AGENT = "CommonsContributionsDownloader/0.1 (edward@4angle.com)"

SESSION = requests.Session()
SESSION.headers.update({"User-Agent": USER_AGENT})


def fetch_contributions(
    continue_token: str | None = None,
) -> tuple[list[dict], str | None]:
    """Fetch a batch of contributions from the API."""
    params = {
        "action": "query",
        "list": "usercontribs",
        "ucuser": USERNAME,
        "uclimit": "500",
        "ucprop": "ids|title|timestamp|comment|size|sizediff|flags|tags",
        "format": "json",
    }

    if continue_token:
        params["uccontinue"] = continue_token

    response = SESSION.get(API_URL, params=params)
    response.raise_for_status()
    data = response.json()

    contributions = data.get("query", {}).get("usercontribs", [])

    # Get continuation token if more results available
    new_continue = data.get("continue", {}).get("uccontinue")

    return contributions, new_continue


def insert_contribution(session, c: dict) -> None:
    """Insert a contribution row (caller must ensure revid is new)."""
    session.add(Contribution(
        userid=c.get("userid"),
        user=c.get("user"),
        pageid=c.get("pageid"),
        revid=c.get("revid"),
        parentid=c.get("parentid"),
        ns=c.get("ns"),
        title=c.get("title"),
        timestamp=c.get("timestamp"),
        minor=c.get("minor"),
        top=c.get("top"),
        comment=c.get("comment"),
        size=c.get("size"),
        sizediff=c.get("sizediff"),
        tags=json.dumps(c.get("tags", [])),
    ))


def main() -> None:
    """Main entry point."""
    init_db()
    session = get_session()

    try:
        existing_count = session.query(Contribution).count()

        # Get the latest timestamp to know where to resume from
        latest = (
            session.query(Contribution)
            .order_by(Contribution.timestamp.desc())
            .first()
        )

        if existing_count > 0 and latest:
            print(f"Database has {existing_count} contributions")
            print(f"Latest: {latest.timestamp}")
            print("Fetching new contributions...")
        else:
            print(f"Downloading contributions for user: {USERNAME}")

        batch_num = 0
        new_count = 0
        continue_token = None

        while True:
            batch_num += 1
            print(f"  Fetching batch {batch_num}...", end=" ", flush=True)

            contributions, continue_token = fetch_contributions(continue_token)

            if not contributions:
                print("no results")
                break

            # One DB query per batch to identify already-known revisions.
            revids = [c["revid"] for c in contributions if "revid" in c]
            existing_revids = {
                row[0]
                for row in (
                    session.query(Contribution.revid)
                    .filter(Contribution.revid.in_(revids))
                    .all()
                )
            }

            batch_new = 0
            for c in contributions:
                revid = c.get("revid")
                if revid in existing_revids:
                    continue

                insert_contribution(session, c)
                batch_new += 1

            new_count += batch_new
            print(f"got {len(contributions)}, {batch_new} new")

            session.commit()

            if batch_new == 0:
                # All contributions in this batch already exist, we're caught up
                print("  Caught up with existing data")
                break

            if not continue_token:
                break

            # Be polite to the API
            time.sleep(0.5)

        total = session.query(Contribution).count()
        print(f"\nDone! {new_count} new contributions, {total} total in database")

    except Exception:
        session.rollback()
        raise
    finally:
        session.close()


if __name__ == "__main__":
    main()