// Create: describe a WAI app, watch it build itself from WAI widgets as a model writes it,
// try its room, and take its program (app.oui) away: `wai create <dir> --from app.oui` makes
// it a starter project on the person's machine (catalogue `app.export`).
//
// The page calls no model of its own and holds no key on any server. A program comes from
// the visitor's own model (an endpoint and a key they type, called from this page alone),
// from their coding agent (`wai mcp --toolset app`, through its bridge on 127.0.0.1), or from a
// recorded stream; the page says which. Each chunk is parsed by wai-app's WebAssembly build
// (joule-ui's line language), and the snapshot, every widget of it accepted by the WAI
// registry, is rendered at once.
import { openSession, guide } from "./session.js";
import { Renderer } from "./renderer.js";
import { components, context } from "./components.js";
import { ownModel, bridge, replay } from "./model.js";

const root = document.getElementById("create");
const $ = (id) => document.getElementById(id);

const session = await openSession();
// The room service each kind of room is tried on (`data-service-live`, `-watch`, `-show`),
// else `data-service`; every one on this page's own origin.
const services = { live: root.dataset.serviceLive, watch: root.dataset.serviceWatch, show: root.dataset.serviceShow };
const ctx = context({ session, service: root.dataset.service, services, frame: root.dataset.frame });
const renderer = new Renderer($("app"), components, ctx);
const test = (window.createTest = { session, ctx, renderer, snapshots: [], last: null, source: null, done: 0, errors: [] });

const SAYS = {
  none: "No model is called until you choose one. This page has no model of its own and holds no key.",
  own: (u) => `Model: your own, at ${u}, called from this page with the key you typed. The key stays in this tab's memory and goes to that address alone; it is never stored.`,
  agent: (u) => `Model: your coding agent, which streams the app to this page through the bridge on your machine (${u}).`,
  replay: (n) => `Model: none. This replays a recorded stream (${n}).`,
};
const says = (t) => { $("model-says").textContent = t; };

function sourceNow() {
  const r = document.querySelector('input[name="source"]:checked');
  return r ? r.value : "replay";
}
function showSource() {
  const s = sourceNow();
  for (const id of ["own", "agent", "replay"]) $(id).hidden = id !== s;
  says(SAYS.none);
}
for (const r of document.querySelectorAll('input[name="source"]')) r.addEventListener("change", showSource);
showSource();

// ---------------------------------------------------------------------------- the stream

let running = 0;
async function build(chunks, label) {
  const run = ++running;
  session.reset();
  test.snapshots = [];
  test.source = label;
  test.errors = [];
  $("export").disabled = true;
  $("download").hidden = true;
  $("export-status").textContent = "";
  $("export-command").textContent = "";
  root.dataset.state = "streaming";
  try {
    for await (const c of chunks) {
      if (run !== running) return;
      show(session.push(c));
    }
    if (run !== running) return;
    show(session.finish());
    root.dataset.state = "done";
    test.done++;
  } catch (e) {
    root.dataset.state = "failed";
    test.errors.push(String(e.message || e));
    says(`The stream stopped: ${e.message || e}`);
  }
}

function show(s) {
  renderer.render(s);
  test.last = s;
  test.snapshots.push({ widgets: s.nodes.length, keys: s.nodes.map((n) => n.key), errors: s.errors.map((e) => `${e.line}:${e.code}`), chars: session.program().length, finished: s.finished });
  drawProgram(s);
  drawProblems(s);
  const ok = s.finished && s.room && !s.errors.some((e) => !e.warning);
  $("export").disabled = !ok;
}

function drawProgram(s) {
  const lines = session.program().split("\n");
  const bad = new Map();
  for (const e of s.errors) if (e.line) bad.set(e.line, `${e.code}: ${e.message}`);
  const pending = s.statements.filter((x) => !x.complete).map((x) => x.line);
  const ol = $("program");
  ol.replaceChildren(...lines.map((l, i) => {
    const li = document.createElement("li");
    li.textContent = l || " ";
    li.value = i + 1;
    if (bad.has(i + 1)) { li.className = "bad"; li.title = bad.get(i + 1); }
    else if (pending.includes(i + 1)) li.className = "pending";
    return li;
  }));
  ol.scrollTop = ol.scrollHeight;
}

function drawProblems(s) {
  const ul = $("problems");
  const shown = s.errors.length ? s.errors : [];
  ul.replaceChildren(...shown.map((e) => {
    const li = document.createElement("li");
    li.dataset.code = e.code;
    li.className = e.warning ? "warn" : "bad";
    li.textContent = `${e.line ? `line ${e.line}` : "the app"}: ${e.message} (${e.code})`;
    return li;
  }));
  if (!shown.length) {
    const li = document.createElement("li");
    li.className = "ok";
    li.textContent = s.finished ? "None: every line was accepted." : s.tree ? "None so far." : "Waiting for the first line.";
    ul.append(li);
  }
}

// ---------------------------------------------------------------------------- the sources

let disconnect = null;
$("describe").addEventListener("submit", async (e) => {
  e.preventDefault();
  const prompt = $("prompt").value.trim();
  const s = sourceNow();
  if (s === "own") {
    const endpoint = $("own-endpoint").value.trim();
    const model = $("own-model").value.trim();
    let u;
    try { u = new URL(endpoint); } catch { return says("Give your model's address: the full URL of its chat/completions route."); }
    says(SAYS.own(u.host));
    // The key is read here, at the call, and handed to the call alone.
    await build(ownModel({ endpoint, model, key: $("own-key").value, system: guide(), prompt }), "own");
  } else if (s === "agent") {
    connectAgent();
  } else {
    const name = $("recording").value;
    says(SAYS.replay(name));
    const rec = await (await fetch(`${root.dataset.recorded}wai-app-${name}.json`, { cache: "no-store" })).json();
    $("prompt").value = rec.prompt;
    await build(replay(rec, { speed: Number(root.dataset.speed || 1) }), "replay");
  }
});

function connectAgent() {
  if (disconnect) disconnect();
  const url = $("agent-bridge").value.trim();
  const code = $("agent-code").value.trim();
  try {
    says(SAYS.agent(new URL(url).host));
    disconnect = bridge({
      url, code,
      onProgram: (iter) => build(iter, "agent"),
      onState: (st) => { $("agent-state").textContent = st === "connected" ? "Connected: ask your agent to build the app." : st === "retrying" ? "Not connected: is `wai mcp --toolset app` running, and the code right?" : "Closed."; },
    });
  } catch (e) {
    says(String(e.message || e));
  }
}

// ---------------------------------------------------------------------------- the export

// The program in its canonical form, as a file: `wai create <dir> --from app.oui` makes the
// project of it, on the person's machine, with the one writer every WAI project has.
$("export").addEventListener("click", () => {
  const status = $("export-status");
  try {
    const text = session.canonical();
    const title = (test.last && test.last.tree && test.last.tree.props && test.last.tree.props.title && test.last.tree.props.title.value) || "wai-app";
    const dir = title.toLowerCase().replace(/[^a-z0-9]+/g, "-").replace(/^-|-$/g, "") || "wai-app";
    const a = $("download");
    if (a.href) URL.revokeObjectURL(a.href);
    a.href = URL.createObjectURL(new Blob([text], { type: "text/plain" }));
    a.download = "app.oui";
    a.textContent = `app.oui (${text.split("\n").filter(Boolean).length} lines)`;
    a.hidden = false;
    const command = `wai create ${dir} --from app.oui`;
    $("export-command").textContent = command;
    test.exported = { file: "app.oui", text, command };
    status.textContent = "Then, where you saved it: run the command below, and `wai dev` in the project it makes. The project is Apache-2.0, and no key is in it.";
    a.click();
  } catch (e) {
    status.textContent = `Not exported: ${e.message || e}`;
  }
});