import { createRequire } from "node:module";
import * as path from "node:path";

/**
 * `pg` is not a dependency of this directory and pnpm's strict layout means a
 * bare `import "pg"` does not resolve here. Borrow it from the app that already
 * owns a Postgres client rather than adding a duplicate declaration of the same
 * driver to the workspace root.
 */
const requireFrom = createRequire(
  path.join(__dirname, "..", "..", "apps", "edr-hr-api", "package.json"),
);
const { Client } = requireFrom("pg") as typeof import("pg");

/**
 * Direct database reads for assertions.
 *
 * The suite's doctrine (docs/hr-finance-ui-e2e-matrix.md) is that every scenario
 * checks the DOM, the network response AND the database row, and fails if the
 * three disagree. A UI that renders the right number from a stale cache, or an
 * API that answers 200 without writing, both pass a DOM-only test.
 *
 * READ-ONLY by intent. Fixtures are created through the product's own endpoints
 * or the seed scripts, never here — a test that sets up state with raw SQL stops
 * proving the code path that normally creates it.
 */
const config = {
  host: process.env.DB_HOST ?? "localhost",
  port: Number(process.env.DB_PORT ?? 5432),
  user: process.env.DB_USER ?? "postgres",
  password: process.env.DB_PASSWORD,
  database: process.env.DB_NAME ?? "smart_office_e2e",
};

export async function query<T = Record<string, unknown>>(
  sql: string,
  params: unknown[] = [],
): Promise<T[]> {
  if (config.database === "smart_office_prod") {
    // The suite must never read prod as if it were the fixture database: an
    // assertion that passes there is meaningless and the mistake is silent.
    throw new Error("Refusing to run e2e assertions against smart_office_prod");
  }
  const client = new Client(config);
  await client.connect();
  try {
    const { rows } = await client.query(sql, params);
    return rows as T[];
  } finally {
    await client.end();
  }
}

/** Convenience for the common "one row, one column" assertion. */
export async function scalar<T = string>(sql: string, params: unknown[] = []): Promise<T | null> {
  const rows = await query<Record<string, T>>(sql, params);
  if (!rows.length) return null;
  return Object.values(rows[0])[0] ?? null;
}