// The terdut-server client. The page is served by the server itself, so every
// call is same-origin and carries the session cookie.

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

// Called whenever the server says the session is gone, so the app can put the
// login form back up wherever the user happened to be.
let onUnauthorized = () => {};
export function setUnauthorizedHandler(fn) {
  onUnauthorized = fn;
}

async function call(method, path, { query, body, signal } = {}) {
  const url = new URL('/api' + path, location.origin);
  for (const [k, v] of Object.entries(query || {})) {
    if (v === '' || v == null) continue;
    url.searchParams.set(k, v);
  }

  const headers = { Accept: 'application/json' };
  if (body !== undefined) headers['Content-Type'] = 'application/json';

  let resp;
  try {
    resp = await fetch(url, {
      method,
      headers,
      body: body === undefined ? undefined : JSON.stringify(body),
      credentials: 'same-origin',
      signal,
    });
  } catch (err) {
    if (err.name === 'AbortError') throw err;
    throw new ApiError(0, 'Cannot reach the server.');
  }

  if (resp.status === 204) return null;

  let data = null;
  try {
    data = await resp.json();
  } catch {
    /* non-JSON body: keep null */
  }

  if (!resp.ok) {
    if (resp.status === 401 && path !== '/login') onUnauthorized();
    const message = (data && data.error) || `Server answered ${resp.status}.`;
    throw new ApiError(resp.status, message);
  }
  return data;
}

// session
export const me = () => call('GET', '/me');
export const login = (username, password) => call('POST', '/login', { body: { username, password } });
export const logout = () => call('POST', '/logout');
export const setPassword = (userID, password, currentPassword) =>
  call('PUT', `/users/${userID}/password`, { body: { password, current_password: currentPassword } });

// users
export const users = () => call('GET', '/users');

// What one person is in. /teams answers "what am I in" and cannot be asked
// about anybody else, which is what the admin page's per-user view needs.
export const userTeams = (id) => call('GET', `/users/${id}/teams`);

// Where this user's pages go. An empty topic clears it, which the server
// treats as "no topic of their own" rather than an error.
export const setNotifyTarget = (id, ntfyTopic) =>
  call('PUT', `/users/${id}/notify`, { body: { ntfy_topic: ntfyTopic } });

// incidents
export const incidents = (query, opts) => call('GET', '/incidents', { query, ...opts });
export const incident = (id) => call('GET', `/incidents/${id}`);
export const timeline = (id) => call('GET', `/incidents/${id}/timeline`);

export const acknowledge = (id) => call('POST', `/incidents/${id}/acknowledge`);
export const unacknowledge = (id) => call('DELETE', `/incidents/${id}/acknowledge`);
export const resolve = (id, resolution) => call('POST', `/incidents/${id}/resolve`, resolution ? { body: { resolution } } : {});
export const assign = (id, userID) => call('POST', `/incidents/${id}/assign`, { body: { user_id: userID } });
export const snooze = (id, spec) => call('POST', `/incidents/${id}/snooze`, { body: spec });
export const unsnooze = (id) => call('DELETE', `/incidents/${id}/snooze`);
export const archive = (id) => call('POST', `/incidents/${id}/archive`);
export const unarchive = (id) => call('DELETE', `/incidents/${id}/archive`);
export const addNote = (id, content, pinned = false) => call('POST', `/incidents/${id}/notes`, { body: { content, pinned } });
export const similar = (id) => call('GET', `/incidents/${id}/similar`);
export const deleteNote = (id, eventID) => call('DELETE', `/incidents/${id}/notes/${eventID}`);

// stats
export const statsIncidents = (query) => call('GET', '/stats/incidents', { query });
export const statsTop = (query) => call('GET', '/stats/alerts/top', { query });
export const statsByHour = (query) => call('GET', '/stats/alerts/by-hour', { query });
export const statsByDay = (query) => call('GET', '/stats/alerts/by-day', { query });

// alerts
export const alerts = (query, opts) => call('GET', '/alerts', { query, ...opts });

// schedule
// Sign-up, both halves unauthenticated: the caller has no account yet.
export const signupInfo = (invite) =>
  call('GET', '/signup', { query: invite ? { invite } : {} });
export const signup = (body) => call('POST', '/signup', { body });

export const invites = (id) => call('GET', `/teams/${id}/invites`);
export const createInvite = (id, role, maxUses) =>
  call('POST', `/teams/${id}/invites`, { body: { role, max_uses: maxUses } });
export const revokeInvite = (id, inviteID) => call('DELETE', `/teams/${id}/invites/${inviteID}`);

export const testNotification = () => call('POST', '/me/notify/test');
export const dismissOnboarding = (dismissed) =>
  call('PUT', '/me/onboarding', { body: { dismissed } });

export const teams = () => call('GET', '/teams');
export const createTeam = (name) => call('POST', '/teams', { body: { name } });
export const renameTeam = (id, name) => call('PUT', `/teams/${id}`, { body: { name } });
export const deleteTeam = (id) => call('DELETE', `/teams/${id}`);

// A team's own settings. Every write is owner-only and every read is
// member-only; the server answers 403 and 404 respectively, so the UI shows
// what the role allows rather than guarding it.
export const teamMembers = (id) => call('GET', `/teams/${id}/members`);
export const addTeamMember = (id, userID, role) =>
  call('POST', `/teams/${id}/members`, { body: { user_id: userID, role } });
export const removeTeamMember = (id, userID) => call('DELETE', `/teams/${id}/members/${userID}`);

export const integrations = (id) => call('GET', `/teams/${id}/integrations`);
export const createIntegration = (id, name) =>
  call('POST', `/teams/${id}/integrations`, { body: { name } });
export const deleteIntegration = (id, integrationID) =>
  call('DELETE', `/teams/${id}/integrations/${integrationID}`);

export const deadman = (id) => call('GET', `/teams/${id}/deadman`);
export const setDeadman = (id, body) => call('PUT', `/teams/${id}/deadman`, { body });

export const escalation = (id) => call('GET', `/teams/${id}/escalation`);
export const setEscalation = (id, body) => call('PUT', `/teams/${id}/escalation`, { body });

export const assignSchedule = (id, userID, dates, replace = false) =>
  call('POST', `/teams/${id}/schedule`, { body: { user_id: userID, dates, replace } });
export const unassignSchedule = (id, entryID) => call('DELETE', `/teams/${id}/schedule/${entryID}`);

// Administration. Every one of these is refused with 403 for anybody without
// the flag, so the UI hides the section rather than guarding it.
export const adminTeams = () => call('GET', '/admin/teams');
// One team and who is in it: { team, members }. /teams/{id}/members is
// member-only and answers 404 to an administrator from outside the team, which
// is the rule rather than an oversight -- this asks the other question.
export const adminTeam = (id) => call('GET', `/admin/teams/${id}`);
export const adminSettings = () => call('GET', '/admin/settings');
export const setAdminSettings = (body) => call('PUT', '/admin/settings', { body });
export const setUserAdmin = (id, isAdmin) =>
  call('PUT', `/users/${id}/admin`, { body: { is_admin: isAdmin } });
export const setUserDisabled = (id, disabled) =>
  call('PUT', `/users/${id}/disabled`, { body: { disabled } });
export const deleteUser = (id) => call('DELETE', `/users/${id}`);
export const schedule = (teamID, from, to) =>
  call('GET', `/teams/${teamID}/schedule`, { query: { from, to } });

// One entry per team the viewer belongs to, for the teams that have somebody
// scheduled today. An empty array means nobody anywhere, which is a real answer
// rather than an error — unlike the pre-teams endpoint, which 404ed.
export const onCallNow = () => call('GET', '/schedule/current');