import { DataSource } from "typeorm";

/**
 * `iam.users.name` is a localized object ({ en, am, … }), not a string — a
 * plain `String(name)` there yields "[object Object]" in an audit trail.
 */
export interface IamUserRow {
  name?: Record<string, string> | string | null;
  username?: string | null;
  email?: string | null;
}

/** Best display name for a user row: English label → any locale → login → email. */
export function pickUserName(user: IamUserRow): string | null {
  const { name } = user;
  if (typeof name === "string" && name.trim()) return name.trim();
  if (name && typeof name === "object") {
    const localized =
      name.en ??
      Object.values(name).find((v) => typeof v === "string" && v.trim());
    if (localized?.trim()) return localized.trim();
  }
  return user.username?.trim() || user.email?.trim() || null;
}

/**
 * Display names for a set of IAM user ids — one query for the whole set.
 * `iam.users` is owned by the auth system and has no entity here, so it is read
 * directly. A miss is not an error: the caller still holds the id and can fall
 * back to it.
 */
export async function resolveIamUserNames(
  dataSource: DataSource,
  userIds: (string | null | undefined)[],
): Promise<Map<string, string>> {
  const resolved = new Map<string, string>();
  const ids = [...new Set(userIds.filter((id): id is string => Boolean(id)))];
  if (ids.length === 0) return resolved;

  const rows = (await dataSource.query(
    `SELECT id, name, username, email FROM iam.users WHERE id = ANY($1::uuid[])`,
    [ids],
  )) as Array<IamUserRow & { id: string }>;
  for (const row of rows) {
    const name = pickUserName(row);
    if (name) resolved.set(row.id, name);
  }
  return resolved;
}