from pathlib import Path
import sys

from sqlalchemy import text

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))

from app.database import engine  # noqa: E402


def _column_exists(conn, table_name: str, column_name: str) -> bool:
    return bool(conn.execute(
        text("""
            SELECT COUNT(1)
            FROM information_schema.columns
            WHERE table_schema = DATABASE()
              AND table_name = :table_name
              AND column_name = :column_name
        """),
        {"table_name": table_name, "column_name": column_name},
    ).scalar())


def main() -> None:
    with engine.begin() as conn:
        if not _column_exists(conn, "products", "process_unit_price_yuan"):
            conn.execute(text("""
                ALTER TABLE products
                ADD COLUMN process_unit_price_yuan DECIMAL(12,4) NOT NULL DEFAULT 0 AFTER operator_count
            """))
        if not _column_exists(conn, "production_report_items", "process_unit_price_yuan"):
            conn.execute(text("""
                ALTER TABLE production_report_items
                ADD COLUMN process_unit_price_yuan DECIMAL(12,4) NOT NULL DEFAULT 0 AFTER operator_count
            """))
        conn.execute(text("""
            UPDATE production_report_items item
            JOIN products product
              ON product.attendance_point_name = item.attendance_point_name
             AND product.project_no = item.project_no
             AND product.product_name = item.product_name
             AND product.process_name = IFNULL(item.process_name, '')
             AND product.device_no = ''
            SET item.process_unit_price_yuan = product.process_unit_price_yuan
            WHERE item.process_unit_price_yuan IS NULL OR item.process_unit_price_yuan = 0
        """))
    print("process unit price columns migrated")


if __name__ == "__main__":
    main()