export type UnknownRecord = Record<string, unknown>;

export function isRecord(v: unknown): v is UnknownRecord {
  return typeof v === "object" && v !== null && !Array.isArray(v);
}

function read(o: unknown, key: string): unknown {
  if (!isRecord(o)) return undefined;
  return o[key];
}

export function getString(o: unknown, key: string): string | undefined {
  const v = read(o, key);
  return typeof v === "string" && v.length > 0 ? v : undefined;
}

export function getNumber(o: unknown, key: string): number | undefined {
  const v = read(o, key);
  return typeof v === "number" ? v : undefined;
}

export function getBool(o: unknown, key: string): boolean | undefined {
  const v = read(o, key);
  return typeof v === "boolean" ? v : undefined;
}

export function getObject(o: unknown, key: string): UnknownRecord | undefined {
  const v = read(o, key);
  return isRecord(v) ? v : undefined;
}

export function getArray(o: unknown, key: string): unknown[] | undefined {
  const v = read(o, key);
  return Array.isArray(v) ? v : undefined;
}