#!/usr/bin/env node
// Lay out the Create runtime from this repository's working tree, as the WAI site serves it
// and as an exported project carries it under vendor/:
//
//   <out>/create/   wai-app's page files, each named wai-app-<name> (the widgets, the
//                   renderer, the session, the room frame, the styles, Create's own page
//                   and its recordings), and create/pkg/ (wai-app's WebAssembly build, which
//                   this script does not make)
//   <out>/room/     joule-moq-web's room client, each file named wai-app-room-<name>.js
//                   (app.js as wai-app-room-client.js), its imports rewritten to those names
//                   and to the WebAssembly packages room/moq/pkg/wai_app_room_moq.js,
//                   room/moq-e2ee/pkg/wai_app_room_moq_e2ee.js and room/live/pkg/wai_app_room_live.js
//                   (also not made here)
//   <out>/create/wai-app-runtime.json   every file an app needs, by its path under <out>,
//                   with its SHA-256: what an export copies under vendor/
//
// Every served name is unique across the WAI site, whose deploy fingerprints assets keyed
// by basename.
//
//   node wai/wai-app/web/runtime.mjs <out>
//
// The room client's files are those app.js reaches by its imports. A relative path string
// in any of them that this script does not map fails the layout, so a new import is never
// served unrenamed. Run it after the WebAssembly packages are in place: runtime.json lists
// what is there.
import fs from "node:fs";
import path from "node:path";
import crypto from "node:crypto";
import { fileURLToPath } from "node:url";

const HERE = path.dirname(fileURLToPath(import.meta.url));
const REPO = path.resolve(HERE, "../../..");
const WEB = path.join(REPO, "joule-code/joule-code-rs/crates/joule-moq-web/web");
const out = process.argv[2];
if (!out) {
  console.error("usage: node runtime.mjs <out>");
  process.exit(2);
}
const OUT = path.resolve(out);

// wai-app's own files by their served names: unique across the site, which fingerprints its
// assets keyed by basename, and the same in an export's vendor/. Which of them an app needs.
const CREATE_FILES = {
  "app.js": "wai-app-app.js",
  "renderer.js": "wai-app-renderer.js",
  "components.js": "wai-app-components.js",
  "session.js": "wai-app-session.js",
  "ui.css": "wai-app.css",
  "room-frame.html": "wai-app-room-frame.html",
  "create.js": "wai-app-create.js",
  "model.js": "wai-app-model.js",
  "index.html": "index.html",
  "runtime.json": "wai-app-runtime.json",
  "pkg/wai_app.js": "pkg/wai_app.js",
};
const APP_FILES = ["wai-app-app.js", "wai-app-renderer.js", "wai-app-components.js", "wai-app-session.js", "wai-app.css", "wai-app-room-frame.html", "pkg/wai_app.js", "pkg/wai_app_bg.wasm"];
const FRAME_CLIENT = "../../../joule-code/joule-code-rs/crates/joule-moq-web/web/room/app.js";

// The room client's served name for each file of joule-moq-web/web it is made of.
function servedName(rel) {
  const fixed = {
    "room/app.js": "room/wai-app-room-client.js",
    "pkg/joule_moq_web.js": "room/moq/pkg/wai_app_room_moq.js",
    "pkg/joule_moq_web_e2ee.js": "room/moq-e2ee/pkg/wai_app_room_moq_e2ee.js",
    "pkg/wai_live_web.js": "room/live/pkg/wai_app_room_live.js",
  };
  if (fixed[rel]) return fixed[rel];
  const m = rel.match(/^(room|moq)\/([a-z0-9-]+)\.js$/);
  if (m) return `room/wai-app-room-${m[2]}.js`;
  return null;
}

const SPEC = /(["'`])(\.{1,2}\/[^"'`\s]*)\1/g;
const sha256 = (b) => crypto.createHash("sha256").update(b).digest("hex");

function layRoomClient() {
  const todo = ["room/app.js"];
  const done = new Set();
  while (todo.length) {
    const rel = todo.pop();
    if (done.has(rel)) continue;
    done.add(rel);
    const served = servedName(rel);
    const text = fs.readFileSync(path.join(WEB, rel), "utf8");
    const rewritten = text.replace(SPEC, (all, q, spec) => {
      const target = path.posix.normalize(path.posix.join(path.posix.dirname(rel), spec));
      const to = servedName(target);
      if (!to) throw new Error(`runtime: ${rel} names ${spec} (${target}), which the room client's layout does not map`);
      if (!target.startsWith("pkg/")) todo.push(target);
      let r = path.posix.relative(path.posix.dirname(served), to);
      if (!r.startsWith(".")) r = `./${r}`;
      return `${q}${r}${q}`;
    });
    const header = `// joule-moq-web/web/${rel} (Apache-2.0), sha256 ${sha256(text)}; its imports renamed by wai/wai-app/web/runtime.mjs.\n`;
    fs.mkdirSync(path.join(OUT, path.dirname(served)), { recursive: true });
    fs.writeFileSync(path.join(OUT, served), header + rewritten);
  }
  return [...done].sort();
}

// wai-app's files under their served names, each relative path in them (an import, a
// stylesheet, a frame, a data attribute) rewritten to those names; one the table does not
// map fails the layout. The room frame loads the room client laid out beside it.
function layCreate() {
  const dir = path.join(OUT, "create");
  fs.mkdirSync(dir, { recursive: true });
  for (const [src, served] of Object.entries(CREATE_FILES)) {
    if (src === "runtime.json" || src.startsWith("pkg/")) continue;
    let text = fs.readFileSync(path.join(HERE, src), "utf8");
    if (src === "room-frame.html") {
      if (!text.includes(`src="${FRAME_CLIENT}"`)) throw new Error("runtime: room-frame.html does not load the room client by its source path");
      text = text.replace(`src="${FRAME_CLIENT}"`, 'src="../room/wai-app-room-client.js"');
    }
    text = text.replace(/(["'`])\.\/([a-z0-9_./-]+)\1/gi, (all, q, rel) => {
      if (rel === "recorded/") return all;
      const to = CREATE_FILES[rel];
      if (!to) throw new Error(`runtime: ${src} names ./${rel}, which the layout does not map`);
      return `${q}./${to}${q}`;
    });
    fs.writeFileSync(path.join(dir, served), text);
  }
  fs.mkdirSync(path.join(dir, "recorded"), { recursive: true });
  for (const f of fs.readdirSync(path.join(HERE, "recorded"))) fs.copyFileSync(path.join(HERE, "recorded", f), path.join(dir, "recorded", f));
}

function walk(d, base, acc) {
  if (!fs.existsSync(d)) return acc;
  for (const e of fs.readdirSync(d, { withFileTypes: true }).sort((a, b) => (a.name < b.name ? -1 : 1))) {
    const p = path.join(d, e.name);
    if (e.isDirectory()) walk(p, base, acc);
    else acc.push(path.relative(base, p).split(path.sep).join("/"));
  }
  return acc;
}

const room = layRoomClient();
layCreate();
const files = [];
for (const f of APP_FILES) {
  const p = path.join(OUT, "create", f);
  if (!fs.existsSync(p)) throw new Error(`runtime: create/${f} is missing (build wai-app's WebAssembly package into ${path.join(OUT, "create/pkg")} first)`);
  files.push(`create/${f}`);
}
for (const f of walk(path.join(OUT, "room"), OUT, [])) files.push(f);
const listed = files.map((f) => ({ path: f, sha256: sha256(fs.readFileSync(path.join(OUT, f))) }));
fs.writeFileSync(path.join(OUT, "create/wai-app-runtime.json"), JSON.stringify({ note: "The runtime an app made with Create carries under vendor/, by path, with each file's SHA-256.", files: listed }, null, 1) + "\n");
console.log(`runtime: ${room.length} room client file(s), ${listed.length} runtime file(s) listed in create/wai-app-runtime.json`);