from typing import Any
from psycopg import sql

from data import RawExpr, Expression


def LOWER(expression: Expression) -> RawExpr:
    """
    Wrap an Expression in the SQL function LOWER().
    """
    expr, values = expression.as_tuple()
    final_expr = sql.SQL("LOWER({})").format(expr)
    final_values = values

    return RawExpr(final_expr, final_values)

def asexpr(value: Any) -> RawExpr:
    """
    Turn a value into an expression.
    """
    return RawExpr(sql.Placeholder(), (value,))