"""Point the app at a dedicated test database before any test module imports it."""
import os

import psycopg2
from psycopg2 import sql

ADMIN_URL = os.environ.get("TEST_ADMIN_DATABASE_URL", "postgresql://postgres:postgres@127.0.0.1:5432/postgres")
TEST_DATABASE = "books_test"


def _ensure_test_database() -> None:
    conn = psycopg2.connect(ADMIN_URL)
    conn.autocommit = True  # CREATE DATABASE cannot run inside a transaction
    try:
        with conn.cursor() as cur:
            cur.execute("SELECT 1 FROM pg_database WHERE datname = %s", (TEST_DATABASE,))
            if cur.fetchone() is None:
                cur.execute(sql.SQL("CREATE DATABASE {}").format(sql.Identifier(TEST_DATABASE)))
    finally:
        conn.close()


_ensure_test_database()
# Assigned, never defaulted: tests TRUNCATE tables, so they must not inherit a real DATABASE_URL.
os.environ["DATABASE_URL"] = ADMIN_URL.rsplit("/", 1)[0] + "/" + TEST_DATABASE
os.environ["PASSWORD_PEPPER"] = "test-pepper-0123456789abcdef0123456789abcdef"