// vocab_node drives datetime.js's vocabulary resolution in plain Node
// against a stub page: a document whose lang is en, no
// self.fiestaStrings, and a field with no attributes, so the only
// vocabulary left is the script's own English. It reads back one JSON
// object: "words", the vocabulary the field resolved to; "parsed",
// each phrase on stdin to the ISO instant the parser read it as (null
// for no reading), at a fixed now of 2026-10-28 10:30 local; and
// "malformed", the vocabulary a field with an attribute that is not
// JSON resolves to on a Spanish page with the Spanish table loaded.
//
//	echo '{"phrases":["tomorrow","next fri 9am","in 2 weeks"]}' |
//	  node node/vocab_node.mjs
//
// check/datetime_test.go is the only caller. It holds the words to
// i18n/en.json's date-words and wants every phrase read, which is what
// the README promises of an English page that loads no table.
import { readFileSync } from "node:fs";
import vm from "node:vm";

const src = readFileSync(new URL("../../js/datetime.js", import.meta.url), "utf8");

const chunks = [];
for await (const chunk of process.stdin) chunks.push(chunk);
const { phrases = [] } = JSON.parse(Buffer.concat(chunks).toString("utf8") || "{}");

// load evaluates the script in a fresh context: the least DOM it
// touches on load, a loading document whose root carries lang, and a
// self holding strings as its registry. It returns what the script
// exported.
function load(lang, strings) {
  const root = { lang, getAttribute: (k) => (k === "lang" ? lang : null) };
  const document = {
    readyState: "loading",
    documentElement: root,
    addEventListener() {},
    querySelectorAll: () => [],
  };
  const self = { fiestaStrings: strings };
  const module = { exports: {} };
  vm.runInNewContext(src, { document, self, window: self, module, exports: module.exports, setTimeout, clearTimeout }, { filename: "datetime.js" });
  return module.exports;
}

// An element with attributes and nothing else.
const element = (attrs) => ({ getAttribute: (k) => (Object.prototype.hasOwnProperty.call(attrs, k) ? attrs[k] : null) });

const { vocabulary, parse, tables } = load("en", {});
if (typeof vocabulary !== "function") {
  process.stderr.write("datetime.js does not export vocabulary\n");
  process.exit(1);
}
// A field with no attributes at all, on an English page with no table.
const words = vocabulary(element({}));

// A Spanish page whose table is the shipped i18n/es.json, and a field
// whose attribute is not JSON: the attribute is as good as absent, so
// the vocabulary must be the table's, not English.
const es = JSON.parse(readFileSync(new URL("../../i18n/es.json", import.meta.url), "utf8"));
const malformed = load("es", { es }).vocabulary(element({ "data-rst-date-words": "{not json" }));
const now = new Date(2026, 9, 28, 10, 30);
const tbl = tables("en");
const parsed = {};
for (const phrase of phrases) {
  let read = null;
  try {
    read = parse(phrase, words, tbl, now, {});
  } catch (e) {
    read = null;
  }
  parsed[phrase] = read && read.date ? read.date.toISOString() : null;
}
process.stdout.write(JSON.stringify({ words, parsed, malformed }));