export function readStringValue(value: unknown): string | undefined {
  return typeof value === "string" ? value : undefined;
}

export function normalizeNullableString(value: unknown): string | null {
  if (typeof value !== "string") {
    return null;
  }
  const trimmed = value.trim();
  return trimmed ? trimmed : null;
}

export function normalizeOptionalString(value: unknown): string | undefined {
  return normalizeNullableString(value) ?? undefined;
}

export function normalizeStringifiedOptionalString(value: unknown): string | undefined {
  if (typeof value === "string") {
    return normalizeOptionalString(value);
  }
  if (typeof value === "number" || typeof value === "boolean" || typeof value === "bigint") {
    return normalizeOptionalString(String(value));
  }
  return undefined;
}

export function normalizeOptionalLowercaseString(value: unknown): string | undefined {
  return normalizeOptionalString(value)?.toLowerCase();
}

export function normalizeLowercaseStringOrEmpty(value: unknown): string {
  return normalizeOptionalLowercaseString(value) ?? "";
}

export function lowercasePreservingWhitespace(value: string): string {
  return value.toLowerCase();
}

export function localeLowercasePreservingWhitespace(value: string): string {
  return value.toLocaleLowerCase();
}

export function resolvePrimaryStringValue(value: unknown): string | undefined {
  if (typeof value === "string") {
    return normalizeOptionalString(value);
  }
  if (!value || typeof value !== "object") {
    return undefined;
  }
  return normalizeOptionalString((value as { primary?: unknown }).primary);
}

export function normalizeOptionalThreadValue(value: unknown): string | number | undefined {
  if (typeof value === "number") {
    return Number.isFinite(value) ? Math.trunc(value) : undefined;
  }
  return normalizeOptionalString(value);
}

export function normalizeOptionalStringifiedId(value: unknown): string | undefined {
  const normalized = normalizeOptionalThreadValue(value);
  return normalized == null ? undefined : String(normalized);
}

export function hasNonEmptyString(value: unknown): value is string {
  return normalizeOptionalString(value) !== undefined;
}