"""
One-time migration: SQLite → PostgreSQL
=========================================
Copies all articles from data/news.db into the PostgreSQL factcheck database,
then deletes the old SQLite file.

Usage:
    python migrate_to_postgres.py
"""

import sqlite3
import os
from db.database import get_connection, init_db

SQLITE_PATH = os.path.join(
    os.path.dirname(os.path.abspath(__file__)), "data", "news.db"
)


def migrate():
    # 1. Ensure PostgreSQL table exists
    init_db()

    # 2. Check if SQLite DB exists
    if not os.path.exists(SQLITE_PATH):
        print(f"No SQLite database found at {SQLITE_PATH}. Nothing to migrate.")
        return

    # 3. Read all articles from SQLite
    sqlite_conn = sqlite3.connect(SQLITE_PATH)
    sqlite_conn.row_factory = sqlite3.Row
    rows = sqlite_conn.execute("SELECT * FROM articles").fetchall()
    articles = [dict(row) for row in rows]
    sqlite_conn.close()

    print(f"Found {len(articles)} articles in SQLite database.")

    if not articles:
        print("No articles to migrate.")
        return

    # 4. Insert into PostgreSQL
    pg_conn = get_connection()
    cursor = pg_conn.cursor()
    inserted = 0

    for article in articles:
        cursor.execute(
            "INSERT INTO articles (title, url, source, published, scraped_at) "
            "VALUES (%s, %s, %s, %s, %s) "
            "ON CONFLICT (url) DO NOTHING",
            (
                article["title"],
                article["url"],
                article["source"],
                article.get("published", "N/A"),
                article.get("scraped_at", ""),
            ),
        )
        if cursor.rowcount > 0:
            inserted += 1

    pg_conn.commit()
    pg_conn.close()

    print(f"Migrated {inserted} articles to PostgreSQL.")
    if inserted < len(articles):
        print(f"  ({len(articles) - inserted} duplicates skipped)")

    # 5. Delete old SQLite database
    os.remove(SQLITE_PATH)
    print(f"Deleted old SQLite database: {SQLITE_PATH}")
    print("\nMigration complete!")


if __name__ == "__main__":
    migrate()