// What the server's tests share: the log kept in memory, a server F with
// test secrets, a project as the service makes it, a person signed in with
// a ticket as the dashboard signs one, and that person in a project with
// Hocuspocus' own provider over a real WebSocket (bringing the session's
// cookie, as the browser does).

import { randomUUID } from 'node:crypto';
import { HocuspocusProvider, HocuspocusProviderWebsocket } from '@hocuspocus/provider';
import { expect } from 'vitest';
import WebSocket from 'ws';
import * as Y from 'yjs';
import { emptyProject, writeProject } from '@mdg-filius/doc';
import { startServer, type DocStore, type FiliusServer, type Log, type ServerOptions, type SessionStore } from '../src/index.js';
import { signTicket } from './tickets.js';

export const TICKET_SECRET = 'test-ticket-secret';
export const SERVICE_KEY = 'test-service-key';
export const EDITOR_ORIGIN = 'http://editor.test';

export type MemoryLog = Log & { readonly lines: Record<string, unknown>[] };

/** The log's lines, kept. */
export function memoryLog(): MemoryLog {
  const lines: Record<string, unknown>[] = [];
  const entry =
    (level: string) =>
    (event: string, fields: Record<string, unknown> = {}) => {
      lines.push(JSON.parse(JSON.stringify({ level, event, ...fields })) as Record<string, unknown>);
    };
  return { lines, info: entry('info'), warn: entry('warn'), error: entry('error') };
}

export type TestServer = FiliusServer & { readonly log: MemoryLog; readonly base: string };

export async function startTestServer(store: DocStore, sessions: SessionStore, options: Partial<ServerOptions> = {}): Promise<TestServer> {
  const log = memoryLog();
  const server = await startServer({
    port: 0,
    host: '127.0.0.1',
    store,
    sessions,
    log,
    ticketSecret: TICKET_SECRET,
    serviceKey: SERVICE_KEY,
    origins: [EDITOR_ORIGIN],
    secureCookie: false,
    ...options,
  });
  return Object.assign(server, { log, base: `http://127.0.0.1:${server.port}` });
}

/** A new project as the service makes it: an empty FILIUS project. */
export async function newProject(store: DocStore): Promise<string> {
  const project = randomUUID();
  const doc = new Y.Doc();
  writeProject(doc, emptyProject());
  expect(await store.create(project, Y.encodeStateAsUpdate(doc))).toBe(true);
  return project;
}

export interface Person {
  readonly user?: string;
  readonly login?: string;
  readonly level?: 'read' | 'write';
  /** The cookie the browser brings to /__auth. */
  readonly cookie?: string;
}

/** The answer of /__auth to a fresh ticket. */
export function exchange(server: TestServer, project: string, { user = randomUUID(), login = 'ab12', level = 'write', cookie }: Person = {}, next = '/'): Promise<Response> {
  const ticket = signTicket({ u: user, n: login, d: 'Ada Beispiel', c: '#3366cc', lang: 'de', p: project, lvl: level }, TICKET_SECRET);
  return fetch(`${server.base}/__auth?ticket=${encodeURIComponent(ticket)}&next=${encodeURIComponent(next)}`, {
    redirect: 'manual',
    ...(cookie === undefined ? {} : { headers: { cookie } }),
  });
}

/** Signed in through /__auth: the cookie for the browser's next requests. */
export async function signIn(server: TestServer, project: string, person: Person = {}): Promise<string> {
  const response = await exchange(server, project, person);
  expect(response.status).toBe(302);
  return response.headers.get('set-cookie')!.split(';')[0]!;
}

export interface Client {
  readonly doc: Y.Doc;
  readonly provider: HocuspocusProvider;
  /** Why F closed the connection, in order. */
  readonly closings: string[];
  /** Why F refused it after it had been in, in order. */
  readonly refusals: string[];
  /** Stateless messages from F. */
  readonly messages: unknown[];
  close(): void;
}

export interface JoinOptions {
  readonly cookie?: string;
  /** Comes back at once when let go (no delay, as a client may). */
  readonly eager?: boolean;
  readonly origin?: string;
}

/** A person in a project: synced, or refused. */
export function join(server: FiliusServer, project: string, { cookie, eager = false, origin }: JoinOptions = {}): Promise<Client> {
  const doc = new Y.Doc();
  const headers = { ...(cookie === undefined ? {} : { cookie }), ...(origin === undefined ? {} : { origin }) };
  class Browser extends WebSocket {
    constructor(url: string, protocols?: string | string[]) {
      super(url, protocols, { headers });
      // Let go while it is still connecting (the test ends, the service has gone), ws reports an error no one awaits.
      this.on('error', () => {});
    }
  }
  const socket = new HocuspocusProviderWebsocket({ url: `ws://127.0.0.1:${server.port}/sync`, WebSocketPolyfill: Browser, ...(eager ? { delay: 0, minDelay: 0, jitter: false } : {}) });
  const closings: string[] = [];
  const refusals: string[] = [];
  const messages: unknown[] = [];
  return new Promise((resolve, reject) => {
    let synced = false;
    const timer = setTimeout(() => {
      provider.destroy();
      socket.destroy();
      reject(new Error('not synced within 3 s'));
    }, 3_000);
    const provider = new HocuspocusProvider({
      websocketProvider: socket,
      name: project,
      document: doc,
      token: 'cookie',
      onSynced: () => {
        if (synced) return;
        synced = true;
        clearTimeout(timer);
        resolve({ doc, provider, closings, refusals, messages, close: () => (provider.destroy(), socket.destroy()) });
      },
      onAuthenticationFailed: ({ reason }) => {
        if (synced) {
          refusals.push(reason);
          return;
        }
        clearTimeout(timer);
        provider.destroy();
        socket.destroy();
        reject(new Error(`refused: ${reason}`));
      },
      onStateless: ({ payload }) => messages.push(JSON.parse(payload)),
      onClose: ({ event }) => {
        if (synced) closings.push(event.reason);
        else reject(new Error(`closed: ${event.reason}`));
      },
    });
    provider.attach();
  });
}

/** Signed in with a fresh ticket, then in the project. */
export async function enter(server: TestServer, project: string, person: Person = {}, options: Omit<JoinOptions, 'cookie'> = {}): Promise<Client> {
  return join(server, project, { ...options, cookie: await signIn(server, project, person) });
}

export const until = async (condition: () => boolean | Promise<boolean>, milliseconds = 5_000) => {
  for (let waited = 0; !(await condition()); waited += 25) {
    if (waited > milliseconds) throw new Error('timed out');
    await new Promise((resolve) => setTimeout(resolve, 25));
  }
};