ng-eventually/examples/notebook/app.ts

/**
 * Notebook — a minimal application written against `@ng-eventually/polyfill`.
 *
 * It exists for two reasons, and the second is the one that matters:
 *
 * 1. **It shows how to use the library.** Every call here is what a real consumer
 *    writes; there is no test scaffolding, no privileged import, no reaching into the
 *    library's internals. If something is awkward here, it is awkward for everyone.
 *
 * 2. **It is what the applicative e2e suite drives** (`packages/polyfill/e2e/notebook.ts`).
 *    The other suite talks to a bag of methods on `window.__sdk`, which proves the
 *    functions run but never that an application could be written with them — and that
 *    gap shipped a real defect: a document's inbox was green in tests and unusable in
 *    practice, because the harness handed the address across an identity boundary
 *    through a variable. No application can do that. This app can only do what an
 *    application can do, so a test that passes here means the surface is usable, not
 *    merely callable.
 *
 * ── The domain is deliberately thin ───────────────────────────────────────
 * Notes. Each user writes their own, may publish one, may hand a reader the key to a
 * private one, and may leave a message on someone else's note. That is enough to
 * exercise placement by scope, capability possession, directed sharing, per-document
 * inboxes and reactive reads — without inventing a product.
 *
 * ── Plain DOM, on purpose ─────────────────────────────────────────────────
 * The library imposes no framework, so its example must not adopt one: a consumer
 * reading this should see the SDK calls, not a component tree. The UI here is the
 * shortest thing that makes each act reachable.
 */

import {
  // SDK-shaped — these survive migration, the real SDK replaces them in place.
  docs,
  ensureIdentity,
  inbox,
  init,
  readUnion,
  storeRegistry,
  subscribeDoc,
  type Nuri,
  type Scope,
  // Polyfill-era — ONE call, and it is the whole of what goes away.
  configure,
} from "@ng-eventually/polyfill";
import { ng as realNg, init as realInit } from "@ng-org/web";

// --- the domain, such as it is ---------------------------------------------

const TITLE = "urn:notebook:title";
const BODY = "urn:notebook:body";

interface Note {
  doc: Nuri;
  title: string;
  body: string;
}

// --- bootstrap: ONE polyfill-era call --------------------------------------
//
// Everything else an application calls is SDK surface, preserved at migration. This one
// is the scaffolding, and at migration it goes: the app imports the real SDK, and the
// identity comes from the wallet instead of a barrier.

configure({
  ng: realNg,
  useShape: (() => {}) as never, // this example reads through `readUnion`, not the ORM
  init: realInit,
  sharedWallet: {
    fileUrl: "/shared-wallet.ngw",
    password: (globalThis as { __NOTEBOOK_WALLET_PASSWORD__?: string }).__NOTEBOOK_WALLET_PASSWORD__ ?? "",
  },
  getSession: async () => {
    const s = session ?? (await sessionReady);
    return {
      sessionId: s.session_id,
      privateStoreId: (s as Record<string, string>).private_store_id!,
      protectedStoreId: (s as Record<string, string>).protected_store_id,
      publicStoreId: (s as Record<string, string>).public_store_id,
    };
  },
  normalizeId: (id) => id.trim().replace(/^@/, "").toLowerCase(),
});

// The library's `init`, not the injected one — and this line is SDK-shaped, kept at
// migration. It settles the identity before handing the page to the broker, so the
// round-trip leaves with the identifier in the URL it carries. `realInit` called here
// would navigate away first, and the barrier would never show.
let session: { session_id: string } | null = null;
const sessionReady = new Promise<{ session_id: string }>((resolve) => {
  init((event: { status: string; session?: { session_id: string } }) => {
    if (event.status === "loggedin" && event.session) {
      session = event.session;
      resolve(event.session);
    }
  }, true, []);
});

// --- the acts ---------------------------------------------------------------

/** Write a new note in `scope`. The document is created, then filled. */
async function writeNote(scope: Scope, title: string, body: string): Promise<Nuri> {
  const doc = await storeRegistry.createEntityDoc(scope);
  const s = await sessionReady;
  await docs.sparqlUpdate(
    s.session_id,
    `INSERT DATA { <${doc}> <${TITLE}> "${escape(title)}" ; <${BODY}> "${escape(body)}" }`,
    doc,
  );
  return doc;
}

/** My notes in `scope`, read the way the library intends: list, then read. */
async function myNotes(scope: Scope): Promise<Note[]> {
  const docsOfScope = await storeRegistry.listMyEntityDocs(scope);
  const subjects = await readUnion(docsOfScope);
  return subjects.map((s) => ({
    doc: s.graph,
    title: s.props[TITLE]?.[0] ?? "(sans titre)",
    body: s.props[BODY]?.[0] ?? "",
  }));
}

/**
 * Read someone else's note from its REFERENCE.
 *
 * A reference is what circulates — you do not discover a note, someone gives you its
 * reference (a message, a URL, a QR code). It carries no key, and that is the point:
 * if the note is in a PUBLIC store the store hands its key to whoever asks, so the
 * reference is enough; if it is protected, the reference names the note and opens
 * nothing, until its owner shares it (see `shareNote`).
 *
 * It arrives as a plain string, from a field or a URL, and goes straight in: the
 * library validates it. Nothing to narrow, nothing to cast, and nothing that will have
 * to change when the real SDK takes that same string.
 */
async function readSharedNote(reference: string): Promise<Note | null> {
  const [note] = await readUnion([reference]);
  if (!note) return null;
  return {
    doc: note.graph,
    title: note.props[TITLE]?.[0] ?? "(sans titre)",
    body: note.props[BODY]?.[0] ?? "",
  };
}

/**
 * Hand a reader access to one of my notes.
 *
 * Names the NOTE and the PERSON — the two things this app has. Neither the key nor the
 * recipient's inbox appears: an application will handle neither once this is native
 * (upstream the verifier fills `ContactDetails.read_cap` itself), so it handles neither
 * now. Refuses if the note is not mine to share.
 */
async function shareNote(doc: Nuri, withUser: string): Promise<void> {
  await inbox.share(doc, withUser);
}

/** Open a note for messages — only its owner can, and only they will read them. */
async function openNoteForMessages(doc: Nuri): Promise<void> {
  await storeRegistry.openDocumentInbox(doc);
}

/** Leave a message on someone else's note. One call, naming the NOTE. */
async function leaveMessage(doc: Nuri, text: string): Promise<void> {
  await inbox.postToDocument(doc, { payload: { text } });
}

/** The messages left on one of my notes — named by the note, like leaving one. */
async function messagesOn(doc: Nuri): Promise<string[]> {
  const deposits = await inbox.readForDocument(doc);
  return deposits.map((d) => String((d.payload as { text?: string })?.text ?? ""));
}

/** Re-render whenever a note changes — locally or from a peer. */
function watchNote(doc: Nuri, onChange: () => void): () => void {
  return subscribeDoc(doc, onChange);
}

// --- identity ---------------------------------------------------------------

let identity = "";

/**
 * Sign in, and learn who you are.
 *
 * One await, and it covers everything: the library settles the identity, waits for the
 * connection work it fires (restoring what others shared with you, draining your
 * inboxes), and **returns the identity**. The application keeps it only to display it —
 * no call takes it, because a session belongs to one user and the target's own
 * `doc_create` carries no user at all.
 *
 * This used to read the library's private storage key to find out who it was, which is a
 * boundary no consumer should be able to see. Writing this application is what made that
 * visible.
 */
async function signIn(): Promise<void> {
  identity = await ensureIdentity();
  await sessionReady;
}

function escape(s: string): string {
  return s.replace(/\\/g, "\\\\").replace(/"/g, '\\"').replace(/\n/g, "\\n");
}

// --- the thinnest UI that makes each act reachable --------------------------

const el = (id: string): HTMLElement => document.getElementById(id)!;
const val = (id: string): string => (el(id) as HTMLInputElement).value.trim();

async function refresh(): Promise<void> {
  const scope = (el("scope") as HTMLSelectElement).value as Scope;
  const notes = await myNotes(scope);
  el("notes").innerHTML = notes
    .map(
      (n) => `<li data-doc="${n.doc}">
        <b class="t">${n.title}</b> — <span class="b">${n.body}</span>
        <button class="share" data-doc="${n.doc}">partager</button>
        <button class="open" data-doc="${n.doc}">ouvrir aux messages</button>
        <button class="msgs" data-doc="${n.doc}">messages</button>
        <div><code class="ref" data-testid="ref">${n.doc}</code></div>
      </li>`,
    )
    .join("");
  // What `ensureIdentity()` returns is an OPAQUE identifier, not a display name: the SDK
  // publishes none. So it is shown verbatim and marked as an identifier — never parsed,
  // never split, never dressed up as a person's name.
  const idTag = document.createElement("code");
  idTag.textContent = identity;
  el("who").replaceChildren("id ", idTag);
}

function wire(): void {
  // Changing the scope changes which notes are listed — without this the list keeps
  // showing the previous scope's notes, which reads as "my note disappeared".
  el("scope").addEventListener("change", () => void refresh());
  el("write").addEventListener("click", async () => {
    await writeNote((el("scope") as HTMLSelectElement).value as Scope, val("title"), val("body"));
    await refresh();
  });
  el("openRef").addEventListener("click", async () => {
    el("shared").textContent = ""; // never show a previous answer beside a new question
    const note = await readSharedNote(val("reference"));
    el("shared").textContent = note ? `${note.title} — ${note.body}` : "(illisible)";
  });
  el("leave").addEventListener("click", async () => {
    el("left").textContent = "";
    await leaveMessage(val("onNote") as Nuri, val("message"));
    el("left").textContent = "déposé";
  });
  el("notes").addEventListener("click", async (e) => {
    const target = e.target as HTMLElement;
    const doc = target.dataset.doc as Nuri | undefined;
    if (!doc) return;
    el("shareResult").textContent = "";
    el("messages").textContent = "";
    if (target.classList.contains("share")) {
      await shareNote(doc, val("shareWith"));
      el("shareResult").textContent = "partagé";
    } else if (target.classList.contains("open")) {
      await openNoteForMessages(doc);
      el("shareResult").textContent = "ouverte aux messages";
    } else if (target.classList.contains("msgs")) {
      el("messages").textContent = (await messagesOn(doc)).join(" | ") || "(aucun)";
    }
  });
}

async function main(): Promise<void> {
  wire();
  await signIn();
  await refresh();
}

void main();

// The e2e suite drives this app through the DOM. It exposes nothing else: a test that
// needed a back door would be testing something an application cannot do. `watchNote`
// is here because reactivity has no visible surface in this UI yet — not as an escape
// hatch, and it takes no identity: switching user means reloading with another `?ng-id=`,
// exactly as switching upstream means opening another wallet.
(globalThis as { __notebook?: unknown }).__notebook = { watchNote };