function rand() {
  let str = "";
  const lookups =
    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".split("");
  while (str.length < 16) {
    const n = Math.random() * lookups.length;
    str += lookups[Math.floor(n)];
  }
  return str;
}

async function auth() {
  let session = rand();
  const sig = await openpgp.sign({
    message: new openpgp.CleartextMessage("vybe_auth " + session, ""),
    signingKeys: window.keys.priv,
  });
  window.session = session;
  window.socket.emit("authenticate", { name: window.name, message: sig });
}

async function register(e) {
  e.preventDefault();
  const name = document.getElementById("name").value;
  if (!name) return;
  const keys = await openpgp.generateKey({
    userIDs: [{ name }],
  });
  const priv = await openpgp.readKey({ armoredKey: keys.privateKey });
  const pub = await openpgp.readKey({ armoredKey: keys.publicKey });
  window.keys = { priv, pub };
  localStorage.setItem("keys", JSON.stringify(keys));
  localStorage.setItem("name", name);
  window.name = name;
  window.socket.emit("create_user", { name, pubkey: keys.publicKey });
}

async function message(e) {
  e.preventDefault();
  const msg = document.getElementById("msg").value;
  if (!msg) return;
  window.socket.emit("send_message", {
    message: msg,
    thread: window.currentThreadId,
  });
  document.getElementById("msg").value = "";
  const el = document.createElement("div");
  el.classList.add("message");
  el.innerHTML = `<strong>${window.name}: </strong>${msg}`;
  document.getElementById("messages").appendChild(el);
}

function startThreadPicker() {
  document.getElementById("chat").classList.add("hidden");
  document.getElementById("threads").classList.remove("hidden");
  window.socket.emit("list_threads");
}

function chooseThread(thread) {
  window.currentThreadId = thread.id;
  window.earliestMessage = null;
  document.getElementById("loadmore").classList.remove("hidden");
  document.getElementById("chat").classList.remove("hidden");
  document.getElementById("messages").innerHTML = "";
  document.getElementById("threadname").innerHTML = thread.name;
  document.getElementById("threads").classList.add("hidden");
}

function createThread(e) {
  e.preventDefault();
  window.socket.emit("create_thread", {
    name: document.getElementById("newthreadname").value,
  });
}

async function loadKeys(keys) {
  const priv = await openpgp.readKey({ armoredKey: keys.privateKey });
  const pub = await openpgp.readKey({ armoredKey: keys.publicKey });
  window.keys = { priv, pub };
  await auth();
}

async function loadMessages() {
  window.socket.emit(
    "get_history",
    window.earliestMessage
      ? { before: window.earliestMessage, thread: window.currentThreadId }
      : { thread: window.currentThreadId }
  );
}

window.onload = () => {
  window.currentThreadId = 1;
  window.socket = io();
  window.socket.on("create_user", auth);
  window.socket.on("new_message", (msg) => {
    if (msg.thread !== window.currentThreadId) return;
    const el = document.createElement("div");
    el.classList.add("message");
    const strong = document.createElement('strong');
    strong.textContent = msg.name + ': ';
    el.append(strong, msg.message);
    document.getElementById("messages").appendChild(el);
    if (!window.earliestMessage) window.earliestMessage = msg.id;
  });
  window.socket.on("send_message", (msg) => {
    if (!window.earliestMessage) window.earliestMessage = msg.id;
  });
  window.socket.on("get_history", (msg) => {
    if (msg.messages.length > 0) {
      window.earliestMessage = msg.messages[msg.messages.length - 1].id;
      for (let message of msg.messages) {
        const el = document.createElement("div");
        el.classList.add("message");
        const strong = document.createElement('strong');
        strong.textContent = message.name + ': ';
        el.append(strong, message.message);
        document.getElementById("messages").prepend(el);
      }
    }
    if (!msg.more) document.getElementById("loadmore").classList.add("hidden");
  });
  window.socket.on("authenticate", (msg) => {
    if (msg.success) {
      document.getElementById("register").classList.add("hidden");
      document.getElementById("chat").classList.remove("hidden");
    }
    let emitter = window.socket.emit;
    window.socket.emit = (type, data) => {
      if (data)
        return emitter.call(window.socket, type, {
          ...data,
          __session: window.session,
        });
      else return emitter.call(window.socket, type);
    };
  });
  window.socket.on("list_threads", (msg) => {
    document.getElementById("threadlist").innerHTML = "";
    for (let thread of msg.threads) {
      const el = document.createElement("div");
      el.classList.add("thread");
      el.innerHTML = thread.name;
      const btn = document.createElement("button");
      btn.innerHTML = "choose";
      btn.onclick = () => chooseThread(thread);
      el.appendChild(btn);
      document.getElementById("threadlist").appendChild(el);
    }
  });
  window.socket.on("create_thread", (msg) => {
    chooseThread({
      name: document.getElementById("newthreadname").value,
      id: msg.id,
    });
    document.getElementById("newthreadname").value = "";
  });
  const keys = localStorage.getItem("keys");
  if (keys) {
    window.name = localStorage.getItem("name");
    loadKeys(JSON.parse(keys)).then(() => {});
  }
  else
    document.getElementById("register").classList.remove("hidden");
  document.getElementById("registerform").onsubmit = register;
  document.getElementById("msginput").onsubmit = message;
  document.getElementById("loadmore").onclick = loadMessages;
  document.getElementById("change").onclick = startThreadPicker;
  document.getElementById("createthread").onsubmit = createThread;
};