import type { Metadata } from "../types/metadata-interface";
import type { AbsoluteTemplateString } from "../types/metadata-types";

function resolveTitleTemplate(
  template: string | null | undefined,
  title: string,
) {
  return template ? template.replace(/%s/g, title) : title;
}

export function resolveTitle(
  title: Metadata["title"],
  stashedTemplate: string | null | undefined,
): AbsoluteTemplateString {
  let resolved;
  const template = typeof title !== "string" && title && "template" in title
    ? title.template
    : null;

  if (typeof title === "string") {
    resolved = resolveTitleTemplate(stashedTemplate, title);
  } else if (title) {
    if ("default" in title) {
      resolved = resolveTitleTemplate(stashedTemplate, title.default);
    }
    if ("absolute" in title && title.absolute) {
      resolved = title.absolute;
    }
  }

  if (title && typeof title !== "string") {
    return {
      template,
      absolute: resolved || "",
    };
  } else {
    return { absolute: resolved || title || "", template };
  }
}