import { sign } from "jsonwebtoken";
import { file } from "bun";

const getAdminApiKey = async () => {
  const keyPath = process.env.GHOST_ADMIN_API_KEY_PATH;
  if (!keyPath) {
    throw new Error(
      "Environment variable GHOST_ADMIN_API_KEY_PATH is not set.",
    );
  }

  const keyFile = file(keyPath);
  if (!(await keyFile.exists())) {
    throw new Error(`Key file not found at path: ${keyPath}`);
  }

  return await keyFile.text();
};

const getEndpoint = () => {
  const endpoint = process.env.GHOST_URL;
  if (!endpoint) {
    throw new Error("Environment variable GHOST_URL is not set.");
  }

  return endpoint;
};

const createJwt = (key: string) => {
  const [id, secret] = key.split(":");
  if (!id || !secret) {
    throw new Error("Invalid API key format. Expected format: {id}:{secret}");
  }

  return sign({}, Buffer.from(secret, "hex"), {
    keyid: id,
    algorithm: "HS256",
    expiresIn: "5m",
    audience: `/admin/`,
  });
};

const upload = async (
  slug: string,
  path: string,
  type: string | undefined,
): Promise<any> => {
  const endpoint = getEndpoint();
  const fullEndpoint = `${endpoint}${slug}`;

  const key = await getAdminApiKey();
  const token = createJwt(key);

  const f = Bun.file(path, { type });
  const formData = new FormData();
  formData.append("file", f);

  const response = await fetch(fullEndpoint, {
    method: "POST",
    headers: {
      Authorization: `Ghost ${token}`,
    },
    body: formData,
  });

  if (!response.ok) {
    throw new Error(
      `Failed to upload to ${fullEndpoint}: ${response.status} ${response.statusText}`,
    );
  }

  return await response.json();
};

export const uploadImage = async (imagePath: string): Promise<string> => {
  const slug = `/ghost/api/admin/images/upload`;
  return (await upload(slug, imagePath, "image/jpeg")).images[0].url;
};

export const uploadFile = async (filePath: string): Promise<string> => {
  const slug = `/ghost/api/admin/files/upload`;
  return (await upload(slug, filePath, undefined)).files[0].url;
};

export const uploadPost = async (post: any): Promise<string> => {
  const endpoint = getEndpoint();
  const fullEndpoint = `${endpoint}/ghost/api/admin/posts`;

  const key = await getAdminApiKey();
  const token = createJwt(key);

  const response = await fetch(fullEndpoint, {
    method: "POST",
    headers: {
      Authorization: `Ghost ${token}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      posts: [post],
    }),
  });

  if (!response.ok) {
    throw new Error(
      `Failed to upload to ${fullEndpoint}: ${response.status} ${response.statusText}`,
    );
  }

  return (await response.json()).posts[0].url;
};