// Cipher client orchestration: auth, contacts, chat, media. Ties crypto + api + UI.

import { api, setToken, MailboxSocket } from "./api.js";
import * as C from "./crypto.js";
import { useAccount, contacts, messages as msgStore } from "./store.js";
import * as accounts from "./accounts.js";
import qrcode from "./vendor/qrcode.js";

const $ = (sel) => document.querySelector(sel);
const el = (tag, props = {}, ...children) => {
  const n = Object.assign(document.createElement(tag), props);
  for (const c of children) n.append(c);
  return n;
};

const state = {
  me: null, // { userId, deviceId, username, displayName }
  token: null,
  socket: null,
  activeContact: null, // contact object
};

// ---------- boot ----------
async function boot() {
  const saved = accounts.getActive();
  if (saved?.token) {
    await activateAccount(saved);
  } else {
    renderAuth();
  }
}

// Switch the whole app to a given account: point the encrypted store at that
// account's namespace, set auth, and (re)enter the app.
async function activateAccount(acct) {
  if (state.socket) { state.socket.close(); state.socket = null; }
  state.me = acct;
  state.token = acct.token;
  state.activeContact = null;
  useAccount(acct.username); // per-account IndexedDB namespace
  setToken(acct.token);
  accounts.setActive(acct.username);
  await enterApp();
}

// ---------- auth ----------
function renderAuth() {
  const root = $("#app");
  root.innerHTML = "";
  const form = el("form", { className: "auth-card" });
  const title = el("h1", { textContent: "Cipher" });
  const tag = el("p", { className: "tagline", textContent: "end-to-end encrypted messaging" });
  const err = el("div", { className: "auth-err" });

  const username = el("input", { placeholder: "username", autocomplete: "username", required: true });
  const displayName = el("input", { placeholder: "display name (register only)", autocomplete: "name" });
  const password = el("input", { type: "password", placeholder: "password", autocomplete: "current-password", required: true });

  const loginBtn = el("button", { type: "submit", className: "primary", textContent: "Log in" });
  const registerBtn = el("button", { type: "button", className: "ghost", textContent: "Create account" });

  const divider = el("div", { className: "auth-divider", textContent: "new device?" });
  const restoreBtn = el("button", { type: "button", className: "link-btn", textContent: "Restore with recovery code", onclick: (e) => { e.preventDefault(); startRecoveryRestore(); } });
  const qrLinkBtn = el("button", { type: "button", className: "link-btn", textContent: "Link from another device", onclick: (e) => { e.preventDefault(); startQrLink(); } });

  form.append(title, tag, err, username, displayName, password, loginBtn, registerBtn, divider, restoreBtn, qrLinkBtn);
  root.append(form);

  form.onsubmit = async (e) => {
    e.preventDefault();
    err.textContent = "";
    const uname = username.value.trim().toLowerCase();
    try {
      loginBtn.disabled = true;
      // Point the store at this account BEFORE anything touches it, so the keys
      // this browser generated at registration are found under the right namespace.
      useAccount(uname);
      const res = await api.login({ username: uname, password: password.value });
      const identity = await C.store.getIdentityKeyPair();
      if (!identity) {
        err.textContent =
          "No keys for @" + uname + " on this device. Log in on the device where you created the account (multi-device linking is coming).";
        loginBtn.disabled = false;
        return;
      }
      await onAuthenticated(res);
    } catch (ex) {
      err.textContent = ex.message;
    } finally {
      loginBtn.disabled = false;
    }
  };

  registerBtn.onclick = async () => {
    err.textContent = "";
    const uname = username.value.trim().toLowerCase();
    if (!uname || password.value.length < 8) {
      err.textContent = "username + 8-char password required";
      return;
    }
    if (accounts.list().some((a) => a.username === uname)) {
      err.textContent = "@" + uname + " already signed in on this browser — use Log in / Switch";
      return;
    }
    try {
      registerBtn.disabled = true;
      registerBtn.textContent = "Generating keys…";
      useAccount(uname); // namespace the store before generating/persisting keys
      const device = await C.generateRegistration();
      const res = await api.register({
        username: uname,
        displayName: displayName.value || uname,
        password: password.value,
        device,
      });
      await onAuthenticated(res);
    } catch (ex) {
      err.textContent = ex.message;
    } finally {
      registerBtn.disabled = false;
      registerBtn.textContent = "Create account";
    }
  };
}

async function onAuthenticated(res) {
  const acct = {
    userId: res.userId,
    deviceId: res.deviceId,
    username: res.username,
    displayName: res.displayName || res.username,
    token: res.token,
  };
  accounts.save(acct);
  accounts.setActive(acct.username);
  await activateAccount(acct);
}

// ---------- main app ----------
async function enterApp() {
  renderShell();
  await refreshContacts();
  connectSocket();
  maybeReplenishPreKeys();
  registerServiceWorker();
}

function renderShell() {
  const root = $("#app");
  root.innerHTML = "";
  const shell = el("div", { className: "shell" });

  // Sidebar
  const sidebar = el("aside", { className: "sidebar" });
  const header = el("div", { className: "side-header", title: "Accounts", onclick: openAccountMenu });
  header.append(
    el("div", { className: "me" },
      document.createTextNode(state.me.displayName || state.me.username),
      el("span", { className: "caret", textContent: " ▾" })
    ),
    el("div", { className: "handle", textContent: "@" + state.me.username })
  );
  const newChat = el("button", { className: "new-chat", textContent: "+ New chat", onclick: startNewChat });
  const list = el("div", { className: "chat-list", id: "chatList" });
  sidebar.append(header, newChat, list);

  // Main pane
  const main = el("section", { className: "main", id: "main" });
  main.append(el("div", { className: "empty", textContent: "Select a chat or start a new one" }));

  shell.append(sidebar, main);
  root.append(shell);
}

async function refreshContacts() {
  const list = $("#chatList");
  if (!list) return;
  list.innerHTML = "";
  const all = await contacts.all();
  for (const c of all) {
    const item = el("div", { className: "chat-item", onclick: () => openChat(c) });
    item.append(
      el("div", { className: "avatar", textContent: (c.displayName || c.username)[0].toUpperCase() }),
      el("div", { className: "chat-meta" },
        el("div", { className: "chat-name", textContent: c.displayName || c.username }),
        el("div", { className: "chat-sub", textContent: "@" + c.username })
      )
    );
    list.append(item);
  }
}

function startNewChat() {
  openModal({
    title: "New chat",
    placeholder: "Enter a username",
    action: "Start chat",
    onSubmit: async (value, setError, close) => {
      const uname = value.trim().toLowerCase();
      if (!uname) return setError("Enter a username");
      if (uname === state.me.username) return setError("That's you 🙂");
      try {
        const user = await api.lookup(uname);
        const contact = {
          userId: user.userId,
          username: user.username,
          displayName: user.displayName,
          deviceIds: [],
        };
        await contacts.put(contact);
        await refreshContacts();
        close();
        await openChat(contact);
      } catch (ex) {
        setError(ex.message === "not found" ? "No user found: @" + uname : ex.message);
      }
    },
  });
}

// Lightweight in-app modal (replaces window.prompt, which Brave/PWAs suppress).
function openModal({ title, placeholder, action, onSubmit }) {
  const input = el("input", { className: "modal-input", placeholder, autocomplete: "off" });
  const err = el("div", { className: "modal-err" });
  const cancel = el("button", { type: "button", className: "ghost", textContent: "Cancel" });
  const submit = el("button", { type: "button", className: "primary", textContent: action });
  const card = el("div", { className: "modal-card" },
    el("h2", { className: "modal-title", textContent: title }),
    input,
    err,
    el("div", { className: "modal-actions" }, cancel, submit)
  );
  const overlay = el("div", { className: "modal-overlay" }, card);
  document.body.append(overlay);
  setTimeout(() => input.focus(), 0);

  const close = () => overlay.remove();
  const setError = (m) => { err.textContent = m; };
  const go = async () => {
    submit.disabled = true;
    setError("");
    try {
      await onSubmit(input.value, setError, close);
    } finally {
      submit.disabled = false;
    }
  };
  cancel.onclick = close;
  submit.onclick = go;
  overlay.onclick = (e) => { if (e.target === overlay) close(); };
  input.onkeydown = (e) => {
    if (e.key === "Enter") { e.preventDefault(); go(); }
    if (e.key === "Escape") close();
  };
}

// ---------- overlay + toast helpers ----------
function makeOverlay(...children) {
  const card = el("div", { className: "modal-card" }, ...children);
  const overlay = el("div", { className: "modal-overlay" }, card);
  overlay.onclick = (e) => { if (e.target === overlay) overlay.remove(); };
  document.body.append(overlay);
  return { overlay, card, close: () => overlay.remove() };
}

function encodeLink(obj) {
  return btoa(JSON.stringify(obj)).replace(/\+/g, "-").replace(/\//g, "_").replace(/=+$/, "");
}
function decodeLink(s) {
  const b = s.trim().replace(/-/g, "+").replace(/_/g, "/");
  return JSON.parse(atob(b));
}
function qrImg(text) {
  const qr = qrcode(0, "M");
  qr.addData(text);
  qr.make();
  const img = el("img", { className: "qr", alt: "linking QR code" });
  img.src = qr.createDataURL(6, 12);
  return img;
}

// ---------- recovery code: set up backup ----------
async function setupRecovery() {
  let code;
  try {
    const blob = await C.exportIdentityBlob(state.me);
    code = C.generateRecoveryCode();
    const payload = await C.encryptWithCode(blob, code);
    await api.putBackup(payload);
  } catch (ex) {
    toast("Couldn't set up recovery: " + ex.message);
    return;
  }
  const codeBox = el("div", { className: "code-box", textContent: code });
  const copy = el("button", {
    type: "button", className: "primary", textContent: "Copy code",
    onclick: () => { navigator.clipboard?.writeText(code); copy.textContent = "Copied ✓"; },
  });
  const done = el("button", { type: "button", className: "ghost", textContent: "I've saved it" });
  const { close } = makeOverlay(
    el("h2", { className: "modal-title", textContent: "Your recovery code" }),
    el("p", { className: "modal-note", textContent: "Save this somewhere safe. It's the ONLY way to restore your account on a new device if you lose this one. We can't recover it for you." }),
    codeBox,
    el("div", { className: "modal-actions" }, copy, done)
  );
  done.onclick = close;
}

// ---------- recovery code: restore on a new device ----------
function startRecoveryRestore() {
  const uname = el("input", { className: "modal-input", placeholder: "username", autocomplete: "username" });
  const pass = el("input", { type: "password", className: "modal-input", placeholder: "password", autocomplete: "current-password" });
  const code = el("input", { className: "modal-input", placeholder: "recovery code (XXXX-XXXX-…)" });
  const err = el("div", { className: "modal-err" });
  const cancel = el("button", { type: "button", className: "ghost", textContent: "Cancel" });
  const go = el("button", { type: "button", className: "primary", textContent: "Restore" });
  const { close } = makeOverlay(
    el("h2", { className: "modal-title", textContent: "Restore with recovery code" }),
    el("p", { className: "modal-note", textContent: "Enter your login and the recovery code you saved when you set up this account." }),
    uname, pass, code, err,
    el("div", { className: "modal-actions" }, cancel, go)
  );
  cancel.onclick = close;
  go.onclick = async () => {
    err.textContent = "";
    const u = uname.value.trim().toLowerCase();
    if (!u || !pass.value || !code.value) { err.textContent = "All fields required"; return; }
    go.disabled = true; go.textContent = "Restoring…";
    try {
      useAccount(u);
      const res = await api.login({ username: u, password: pass.value });
      setToken(res.token);
      const { payload } = await api.getBackup();
      let blob;
      try {
        blob = await C.decryptWithCode(payload, code.value);
      } catch {
        throw new Error("Wrong recovery code");
      }
      const fresh = await C.importIdentityBlob(blob);
      await api.resetKeys(fresh.signedPreKey, fresh.oneTimePreKeys);
      close();
      await onAuthenticated(res);
      toast("Account restored on this device", "info");
    } catch (ex) {
      err.textContent = ex.message === "no backup" ? "No recovery backup found for that account" : ex.message;
      go.disabled = false; go.textContent = "Restore";
    }
  };
}

// ---------- QR linking: authorize a new device (from the signed-in device) ----------
function linkDeviceAuthorizer() {
  const paste = el("textarea", { className: "modal-input", placeholder: "Paste the linking code from your new device", rows: 3 });
  const err = el("div", { className: "modal-err" });
  const status = el("div", { className: "modal-note" });
  const cancel = el("button", { type: "button", className: "ghost", textContent: "Cancel" });
  const approve = el("button", { type: "button", className: "primary", textContent: "Approve link" });
  const scanBtn = el("button", { type: "button", className: "ghost", textContent: "📷 Scan QR" });
  const scanArea = el("div", {});
  const { close } = makeOverlay(
    el("h2", { className: "modal-title", textContent: "Link a device" }),
    el("p", { className: "modal-note", textContent: "On your new device choose “Link from another device”, then scan its QR here or paste its code." }),
    scanBtn, scanArea, paste, status, err,
    el("div", { className: "modal-actions" }, cancel, approve)
  );
  cancel.onclick = close;

  const doApprove = async (linkText) => {
    err.textContent = "";
    let link;
    try { link = decodeLink(linkText); } catch { err.textContent = "Invalid linking code"; return; }
    if (!link.p || !link.k) { err.textContent = "Invalid linking code"; return; }
    approve.disabled = true; status.textContent = "Approving…";
    try {
      const blob = { ...(await C.exportIdentityBlob(state.me)), token: state.me.token };
      const payload = await C.encryptToEphemeral(blob, link.k);
      await api.provisionComplete(link.p, payload);
      close();
      toast("Device linked ✓", "info");
    } catch (ex) {
      err.textContent = ex.message;
      approve.disabled = false; status.textContent = "";
    }
  };
  approve.onclick = () => doApprove(paste.value);

  scanBtn.onclick = async () => {
    if (!("BarcodeDetector" in window)) { err.textContent = "Camera scanning not supported here — paste the code instead"; return; }
    try {
      const stream = await navigator.mediaDevices.getUserMedia({ video: { facingMode: "environment" } });
      const video = el("video", { className: "qr-video", autoplay: true, playsInline: true, muted: true });
      video.srcObject = stream;
      scanArea.innerHTML = ""; scanArea.append(video);
      const detector = new BarcodeDetector({ formats: ["qr_code"] });
      const tick = async () => {
        if (!video.isConnected) { stream.getTracks().forEach((t) => t.stop()); return; }
        try {
          const codes = await detector.detect(video);
          if (codes.length) {
            stream.getTracks().forEach((t) => t.stop());
            scanArea.innerHTML = "";
            await doApprove(codes[0].rawValue);
            return;
          }
        } catch {}
        requestAnimationFrame(tick);
      };
      requestAnimationFrame(tick);
    } catch {
      err.textContent = "Couldn't open camera — paste the code instead";
    }
  };
}

// ---------- QR linking: get linked (on the new device) ----------
async function startQrLink() {
  let eph, provisionId;
  const status = el("div", { className: "modal-note", textContent: "Generating link…" });
  const codeText = el("div", { className: "code-box small" });
  const copy = el("button", { type: "button", className: "ghost", textContent: "Copy code" });
  const cancel = el("button", { type: "button", className: "ghost", textContent: "Cancel" });
  const qrHolder = el("div", {});
  const { overlay, close } = makeOverlay(
    el("h2", { className: "modal-title", textContent: "Link from another device" }),
    el("p", { className: "modal-note", textContent: "On a device already signed in, choose “Link a device” and scan this QR (or paste the code)." }),
    qrHolder, status, codeText, el("div", { className: "modal-actions" }, copy, cancel)
  );
  let cancelled = false;
  cancel.onclick = () => { cancelled = true; close(); };

  try {
    eph = await C.generateEphemeralKeyPair();
    const res = await api.provisionNew(eph.pubB64);
    provisionId = res.provisionId;
  } catch (ex) {
    status.textContent = "Couldn't start linking: " + ex.message;
    return;
  }
  const linkCode = encodeLink({ p: provisionId, k: eph.pubB64 });
  qrHolder.append(qrImg(linkCode));
  codeText.textContent = linkCode;
  status.textContent = "Waiting for approval…";
  copy.onclick = () => { navigator.clipboard?.writeText(linkCode); copy.textContent = "Copied ✓"; };

  // poll for the encrypted blob
  for (let i = 0; i < 150 && !cancelled; i++) {
    await new Promise((r) => setTimeout(r, 1200));
    let got;
    try { got = await api.provisionGet(provisionId); } catch { continue; }
    if (got?.payload) {
      status.textContent = "Approved — restoring…";
      try {
        const blob = await C.decryptFromEphemeral(got.payload, eph.keyPair);
        useAccount(blob.username);
        setToken(blob.token);
        const fresh = await C.importIdentityBlob(blob);
        await api.resetKeys(fresh.signedPreKey, fresh.oneTimePreKeys);
        close();
        await onAuthenticated({
          userId: blob.userId, deviceId: blob.deviceId, username: blob.username,
          displayName: blob.displayName, token: blob.token,
        });
        toast("Device linked ✓", "info");
      } catch (ex) {
        status.textContent = "Link failed: " + ex.message;
      }
      return;
    }
  }
  if (!cancelled) status.textContent = "Link timed out — try again";
}

// ---------- account menu (switch / add / log out) ----------
function openAccountMenu() {
  const all = accounts.list();
  const rows = [];
  for (const a of all) {
    const active = a.username === state.me.username;
    rows.push(
      el("button", {
        type: "button",
        className: "acct-row" + (active ? " active" : ""),
        textContent: (active ? "● " : "○ ") + "@" + a.username,
        onclick: async () => {
          overlay.remove();
          if (!active) await activateAccount(a);
        },
      })
    );
  }
  const recoveryBtn = el("button", {
    type: "button",
    className: "acct-action",
    textContent: "🔑 Set up recovery code",
    onclick: () => { overlay.remove(); setupRecovery(); },
  });
  const linkBtn = el("button", {
    type: "button",
    className: "acct-action",
    textContent: "🔗 Link a device",
    onclick: () => { overlay.remove(); linkDeviceAuthorizer(); },
  });
  const addBtn = el("button", {
    type: "button",
    className: "acct-action",
    textContent: "+ Add another account",
    onclick: () => { overlay.remove(); renderAuth(); },
  });
  const logoutBtn = el("button", {
    type: "button",
    className: "acct-action danger",
    textContent: "Log out @" + state.me.username,
    onclick: async () => {
      overlay.remove();
      accounts.remove(state.me.username);
      if (state.socket) { state.socket.close(); state.socket = null; }
      const remaining = accounts.list();
      if (remaining.length) await activateAccount(remaining[0]);
      else renderAuth();
    },
  });
  const card = el("div", { className: "modal-card" },
    el("h2", { className: "modal-title", textContent: "Accounts" }),
    ...rows,
    recoveryBtn,
    linkBtn,
    addBtn,
    logoutBtn
  );
  const overlay = el("div", { className: "modal-overlay" }, card);
  overlay.onclick = (e) => { if (e.target === overlay) overlay.remove(); };
  document.body.append(overlay);
}

// ---------- toast (surface errors instead of failing silently) ----------
function toast(message, kind = "error") {
  const t = el("div", { className: "toast " + kind, textContent: message });
  let host = $("#toasts");
  if (!host) {
    host = el("div", { id: "toasts" });
    document.body.append(host);
  }
  host.append(t);
  setTimeout(() => t.remove(), 4000);
}

// ---------- chat view ----------
async function openChat(contact) {
  state.activeContact = contact;
  $(".shell")?.classList.add("chat-open");
  const main = $("#main");
  main.innerHTML = "";

  const back = el("button", {
    className: "back-btn",
    textContent: "‹",
    title: "Back",
    onclick: () => {
      state.activeContact = null;
      $(".shell")?.classList.remove("chat-open");
    },
  });
  const head = el("div", { className: "chat-head" });
  head.append(
    back,
    el("div", { className: "avatar", textContent: (contact.displayName || contact.username)[0].toUpperCase() }),
    el("div", {},
      el("div", { className: "chat-name", textContent: contact.displayName || contact.username }),
      el("div", { className: "chat-sub", textContent: "🔒 end-to-end encrypted" })
    )
  );

  const thread = el("div", { className: "thread", id: "thread" });

  const composer = el("form", { className: "composer" });
  const input = el("input", { placeholder: "Type a message", autocomplete: "off" });
  const attach = el("label", { className: "attach", textContent: "📎" });
  const fileInput = el("input", { type: "file", style: "display:none" });
  attach.append(fileInput);
  const sendBtn = el("button", { type: "submit", className: "send", textContent: "Send" });
  composer.append(attach, input, sendBtn);

  main.append(head, thread, composer);

  // load history
  const convo = state.me.userId + ":" + contact.userId;
  const history = await msgStore.forConvo(convo);
  for (const m of history) renderMessage(m);
  scrollThread();

  composer.onsubmit = async (e) => {
    e.preventDefault();
    const text = input.value.trim();
    if (!text) return;
    input.value = "";
    try {
      await sendText(contact, text);
    } catch (ex) {
      console.error("send failed", ex);
      toast("Couldn't send: " + ex.message);
      input.value = text; // restore so the message isn't lost
    }
  };

  fileInput.onchange = async () => {
    const file = fileInput.files[0];
    if (file) {
      try {
        await sendMedia(contact, file);
      } catch (ex) {
        console.error("media send failed", ex);
        toast("Couldn't send file: " + ex.message);
      }
    }
    fileInput.value = "";
  };
}

function convoKey(otherUserId) {
  return state.me.userId + ":" + otherUserId;
}

async function ensureRecipientDevices(contact) {
  const bundle = await api.bundle(contact.userId);
  contact.deviceIds = bundle.bundles.map((b) => b.deviceId);
  await contacts.put(contact);
  await C.ensureSessions(bundle);
  return contact.deviceIds;
}

async function sendText(contact, text) {
  // structured payload lets us carry media refs in the same E2E channel
  const payload = JSON.stringify({ k: "text", text });
  await deliver(contact, payload);
  await persistAndRender(contact.userId, { dir: "out", kind: "text", text, ts: Date.now() });
}

async function sendMedia(contact, file) {
  const buf = await file.arrayBuffer();
  const enc = await C.encryptMedia(buf);
  const { key } = await api.uploadMedia(enc.ciphertext);
  const payload = JSON.stringify({
    k: "media",
    key,
    keyB64: enc.keyB64,
    ivB64: enc.ivB64,
    name: file.name,
    type: file.type,
    size: file.size,
  });
  await deliver(contact, payload);
  await persistAndRender(contact.userId, {
    dir: "out",
    kind: "media",
    name: file.name,
    mime: file.type,
    localUrl: URL.createObjectURL(file),
    ts: Date.now(),
  });
}

async function deliver(contact, plaintextPayload) {
  let deviceIds = contact.deviceIds;
  if (!deviceIds || !deviceIds.length) deviceIds = await ensureRecipientDevices(contact);
  const messages = await C.encryptForUser(contact.userId, deviceIds, plaintextPayload);
  await api.send(contact.userId, messages);
}

// ---------- receiving ----------
function connectSocket() {
  if (state.socket) state.socket.close();
  state.socket = new MailboxSocket(state.token, onEnvelope);
  state.socket.connect();
}

async function onEnvelope(envelope) {
  // Look up / create the sender contact.
  let contact = await contactByUserId(envelope.fromUserId);
  let plaintext;
  try {
    plaintext = await C.decryptEnvelope(envelope, envelope.fromUserId);
  } catch (ex) {
    console.error("decrypt failed", ex);
    toast("Couldn't decrypt a message (session mismatch)");
    throw ex; // leave it unacked so it can retry after the session heals
  }
  let data;
  try {
    data = JSON.parse(plaintext);
  } catch {
    data = { k: "text", text: plaintext };
  }

  if (!contact) {
    // Unknown sender — create a stub contact so the message has a home.
    contact = { userId: envelope.fromUserId, username: envelope.fromUserId.slice(0, 8), displayName: "New contact", deviceIds: [] };
    await contacts.put(contact);
    await refreshContacts();
  }

  if (data.k === "media") {
    await persistAndRender(envelope.fromUserId, {
      dir: "in",
      kind: "media",
      name: data.name,
      mime: data.type,
      mediaRef: { key: data.key, keyB64: data.keyB64, ivB64: data.ivB64 },
      ts: envelope.sentAt || Date.now(),
    });
  } else {
    await persistAndRender(envelope.fromUserId, { dir: "in", kind: "text", text: data.text, ts: envelope.sentAt || Date.now() });
  }
}

async function contactByUserId(userId) {
  return contacts.get(userId);
}

// ---------- persistence + render ----------
async function persistAndRender(otherUserId, msg) {
  const record = { ...msg, convo: convoKey(otherUserId), otherUserId };
  await msgStore.add(record);
  if (state.activeContact && state.activeContact.userId === otherUserId) {
    renderMessage(record);
    scrollThread();
  }
}

function renderMessage(m) {
  const thread = $("#thread");
  if (!thread) return;
  const bubble = el("div", { className: "bubble " + (m.dir === "out" ? "out" : "in") });
  if (m.kind === "media") {
    if (m.mime && m.mime.startsWith("image/")) {
      const img = el("img", { className: "media-img", alt: m.name || "image" });
      if (m.localUrl) img.src = m.localUrl;
      else if (m.mediaRef) loadMediaInto(img, m.mediaRef);
      bubble.append(img);
    } else {
      const link = el("a", { className: "media-file", textContent: "📄 " + (m.name || "file") });
      if (m.mediaRef) makeDownloadable(link, m.mediaRef, m.name);
      bubble.append(link);
    }
  } else {
    bubble.append(el("div", { className: "text", textContent: m.text }));
  }
  bubble.append(el("div", { className: "time", textContent: fmtTime(m.ts) }));
  thread.append(bubble);
}

async function loadMediaInto(img, ref) {
  try {
    const ct = await api.fetchMedia(ref.key);
    const plain = await C.decryptMedia(ct, ref.keyB64, ref.ivB64);
    img.src = URL.createObjectURL(new Blob([plain]));
  } catch (e) {
    img.alt = "failed to load media";
  }
}

async function makeDownloadable(link, ref, name) {
  link.onclick = async (e) => {
    e.preventDefault();
    const ct = await api.fetchMedia(ref.key);
    const plain = await C.decryptMedia(ct, ref.keyB64, ref.ivB64);
    const url = URL.createObjectURL(new Blob([plain]));
    const a = el("a", { href: url, download: name || "file" });
    a.click();
  };
}

function scrollThread() {
  const t = $("#thread");
  if (t) t.scrollTop = t.scrollHeight;
}

function fmtTime(ts) {
  const d = new Date(ts);
  return d.toLocaleTimeString([], { hour: "2-digit", minute: "2-digit" });
}

// ---------- prekey replenishment ----------
async function maybeReplenishPreKeys() {
  try {
    const { count } = await api.keyCount();
    if (count < 20) {
      const otks = await C.generateMoreOneTimePreKeys(100);
      await api.addPreKeys(otks);
    }
  } catch {}
}

function registerServiceWorker() {
  if ("serviceWorker" in navigator) {
    navigator.serviceWorker.register("/sw.js").catch(() => {});
  }
}

boot();