import { cache } from "react";
import { detectLanguage } from "@/app/common/lang-detection/detection";
import { Metadata } from "next";

export type Paste = {
  /**
   * The paste content.
   */
  content: string;

  /**
   * The date the paste was created.
   */
  created: string;

  /**
   * The detected language of the paste.
   */
  language: string;
};

/**
 * Fetches a paste from the API.
 */
export const getPaste = cache(async (id: string) => {
  const response: Response = await fetch(
    `${process.env.NEXT_PUBLIC_API_ENDPOINT}/${id}`,
    {
      next: {
        revalidate: 300, // Keep this response cached for 5 minutes
      },
    },
  );
  const json = await response.json();

  if (json.code && json.message) {
    return undefined;
  }
  return {
    content: json.content,
    created: json.created,
    language: await detectLanguage(json.content),
  };
}) as (id: string) => Promise<Paste | undefined>;

/**
 * Generates metadata for a paste.
 *
 * @param id The ID of the paste.
 */
export async function generatePasteMetadata(id: string): Promise<Metadata> {
  const data: Paste | undefined = await getPaste(id);
  if (data == undefined) {
    return {
      description: "Not found",
    };
  }

  return {
    title: `Paste - ${id}.${data.language}`,
    description: `Click to view the paste.`,
  };
}