export class ApiError extends Error {
  constructor(status, message) {
    super(message);
    this.status = status;
  }
}

const unauthorizedListeners = new Set();

export function onUnauthorized(listener) {
  unauthorizedListeners.add(listener);
}

function parseBody(text) {
  if (!text) return null;
  try {
    return JSON.parse(text);
  } catch {
    return null;
  }
}

async function request(method, path, body) {
  const options = { method, credentials: "same-origin", headers: {} };
  if (body !== undefined) {
    options.headers["Content-Type"] = "application/json";
    options.body = JSON.stringify(body);
  }

  const response = await fetch(path, options);
  const data = parseBody(await response.text());

  if (!response.ok) {
    if (response.status === 401 && path !== "/api/login") {
      unauthorizedListeners.forEach((listener) => listener());
    }
    const message = data && data.error ? data.error : `Request failed (${response.status})`;
    throw new ApiError(response.status, message);
  }
  return data;
}

function jobPath(id, suffix = "") {
  return `/api/jobs/${encodeURIComponent(id)}${suffix}`;
}

export const api = {
  session: () => request("GET", "/api/session"),
  login: (username, password) => request("POST", "/api/login", { username, password }),
  logout: () => request("POST", "/api/logout", {}),
  libraries: () => request("GET", "/api/libraries"),
  disk: () => request("GET", "/api/disk"),
  settings: () => request("GET", "/api/settings"),
  saveSettings: (settings) => request("POST", "/api/settings", settings),
  jobs: () => request("GET", "/api/jobs"),
  createJob: (payload) => request("POST", "/api/jobs", payload),
  files: (id) => request("GET", jobPath(id, "/files")),
  extract: (id, path) => request("POST", jobPath(id, "/extract"), { path }),
  move: (id, payload) => request("POST", jobPath(id, "/move"), payload),
  pause: (id) => request("POST", jobPath(id, "/pause"), {}),
  resume: (id) => request("POST", jobPath(id, "/resume"), {}),
  reorder: (id, direction) => request("POST", jobPath(id, "/queue"), { direction }),
  remove: (id) => request("DELETE", jobPath(id)),
  history: () => request("GET", "/api/history"),
  clearHistory: () => request("DELETE", "/api/history"),
};