// Measuring on test-filius: projects through the service, people through
// tickets, the shared document through /sync, rooms through /sim. The
// secrets come from ~/.filius-test.env and are never printed.
import { readFileSync } from 'node:fs';
import { randomUUID } from 'node:crypto';
import { homedir } from 'node:os';
import * as Y from 'yjs';
import { openProjectArchive } from '@mdg-filius/fls';
import { writeProject } from '@mdg-filius/doc';
import { signTicket } from '../../packages/server/test/tickets.js';
import { HocuspocusProvider, HocuspocusProviderWebsocket } from '@hocuspocus/provider';
import WebSocket from 'ws';

const env = Object.fromEntries(
  readFileSync(`${homedir()}/.filius-test.env`, 'utf8')
    .split('\n')
    .filter((l) => l.includes('='))
    .map((l) => [l.slice(0, l.indexOf('=')).trim(), l.slice(l.indexOf('=') + 1).trim()]),
);
export const HOST = process.env.FILIUS_HOST ?? 'test-filius.hub.mdg-hamburg.de';
export const BASE = `https://${HOST}`;
const SECRET = env.FILIUS_TICKET_SECRET!;
const KEY = env.FILIUS_SERVICE_KEY!;
export const made: string[] = [];
/**
 * How many seconds before now the tickets are signed (0: as the dashboard
 * signs them). F before TICKET_AHEAD_SECONDS refused a ticket from its
 * future, and test-filius' clock was behind this machine's (886 ms, then
 * 8 ms with NTP); against such an F, 2 helps.
 */
const SKEW_SECONDS = Number(process.env.SKEW_SECONDS ?? 0);

export async function svc(method: string, path: string, body?: unknown): Promise<{ status: number; json: any }> {
  const r = await fetch(`${BASE}${path}`, { method, headers: { 'x-filius-service-key': KEY, 'content-type': 'application/json' }, ...(body === undefined ? {} : { body: JSON.stringify(body) }) });
  return { status: r.status, json: await r.json().catch(() => null) };
}

export async function newProject(): Promise<string> {
  const id = randomUUID();
  const r = await svc('POST', '/svc/projects', { project: id });
  if (r.status !== 201) throw new Error(`project not made: ${r.status}`);
  made.push(id);
  return id;
}

export async function cleanUp(): Promise<void> {
  for (const id of made.splice(0)) await svc('DELETE', `/svc/projects/${id}`);
}

/** The address a person's browser opens: a fresh ticket, then the editor on the project. */
export function signInAddress(project: string, { user = randomUUID(), name = 'Messung', level = 'write' }: { user?: string; name?: string; level?: string } = {}): string {
  const ticket = signTicket({ u: user, n: name.toLowerCase().replace(/\W/g, ''), d: name, c: '#3366cc', lang: 'de', p: project, lvl: level }, SECRET, Math.floor(Date.now() / 1000) - SKEW_SECONDS);
  return `${BASE}/__auth?ticket=${encodeURIComponent(ticket)}&next=${encodeURIComponent(`/?project=${project}`)}`;
}

export async function signIn(project: string, { user = randomUUID(), name = 'Messung', level = 'write' }: { user?: string; name?: string; level?: string } = {}): Promise<string> {
  const ticket = signTicket({ u: user, n: name.toLowerCase().replace(/\W/g, ''), d: name, c: '#3366cc', lang: 'de', p: project, lvl: level }, SECRET, Math.floor(Date.now() / 1000) - SKEW_SECONDS);
  const r = await fetch(`${BASE}/__auth?ticket=${encodeURIComponent(ticket)}&next=/`, { redirect: 'manual' });
  if (r.status !== 302) throw new Error(`not signed in: ${r.status}`);
  return r.headers.get('set-cookie')!.split(';')[0]!;
}

export function readExample(file: string) {
  return openProjectArchive(new Uint8Array(readFileSync(new URL(`../../corpus/${file}`, import.meta.url))), () => randomUUID());
}

export interface Shared {
  doc: Y.Doc;
  provider: any;
  close(): void;
}

export function joinDoc(project: string, cookie: string): Promise<Shared> {
  const doc = new Y.Doc();
  class Browser extends WebSocket {
    constructor(url: string, protocols?: string | string[]) {
      super(url, protocols, { headers: { cookie, origin: BASE } });
      this.on('error', () => {});
    }
  }
  const socket = new HocuspocusProviderWebsocket({ url: `wss://${HOST}/sync`, WebSocketPolyfill: Browser });
  return new Promise((resolve, reject) => {
    const timer = setTimeout(() => reject(new Error('not synced in 15 s')), 15_000);
    const provider = new HocuspocusProvider({
      websocketProvider: socket,
      name: project,
      document: doc,
      token: 'cookie',
      onSynced: () => {
        clearTimeout(timer);
        resolve({
          doc,
          provider,
          close: () => {
            provider.destroy();
            socket.destroy();
          },
        });
      },
      onAuthenticationFailed: ({ reason }: any) => reject(new Error(`refused ${reason}`)),
    });
    provider.attach();
  });
}

export async function whenStored(shared: Shared, ms = 15_000): Promise<void> {
  for (let waited = 0; shared.provider.unsyncedChanges > 0; waited += 20) {
    if (waited > ms) throw new Error('not stored');
    await new Promise((r) => setTimeout(r, 20));
  }
}

/** A project of F with an example written into it, as one person's editor would. */
export async function seededProject(file: string) {
  const project = await newProject();
  const example = readExample(file);
  const shared = await joinDoc(project, await signIn(project));
  writeProject(shared.doc, example);
  await whenStored(shared);
  shared.close();
  return { project, example };
}

export interface Room {
  send(m: object): void;
  messages: any[];
  waitFor(test: (m: any) => boolean, ms?: number): Promise<any>;
  onMessage: ((m: any) => void) | undefined;
  close(): void;
  closed: Promise<string>;
}

export function openRoom(project: string, cookie: string): Promise<Room> {
  return new Promise((resolve, reject) => {
    const socket = new WebSocket(`wss://${HOST}/sim?project=${project}`, { headers: { cookie, origin: BASE } });
    const messages: any[] = [];
    const waiters: { test: (m: any) => boolean; resolve: (m: any) => void }[] = [];
    let closedWith: (r: string) => void = () => {};
    const room: Room = {
      send: (m) => socket.send(JSON.stringify({ v: 1, ...m })),
      messages,
      onMessage: undefined,
      waitFor: (test, ms = 10_000) =>
        new Promise((resolve, reject) => {
          const found = messages.find(test);
          if (found) return resolve(found);
          const timer = setTimeout(() => reject(new Error('waited in vain')), ms);
          waiters.push({
            test,
            resolve: (m) => {
              clearTimeout(timer);
              resolve(m);
            },
          });
        }),
      close: () => socket.close(),
      closed: new Promise((r) => (closedWith = r)),
    };
    socket.on('message', (data: Buffer) => {
      const m = JSON.parse(data.toString());
      room.onMessage?.(m);
      if (m.kind !== 'activity') messages.push(m);
      for (const w of [...waiters])
        if (w.test(m)) {
          waiters.splice(waiters.indexOf(w), 1);
          w.resolve(m);
        }
    });
    socket.on('open', () => resolve(room));
    socket.on('error', (e: Error) => reject(e));
    socket.on('close', (code: number, reason: Buffer) => closedWith(`${code} ${reason}`));
  });
}