import assert from "node:assert/strict"
import { readFileSync } from "node:fs"
import test from "node:test"
import { loadTypeScriptModule } from "./test-support/load-typescript-module.mjs"

const helpers = loadTypeScriptModule(new URL("./support-availability.ts", import.meta.url), {}, { Date, Intl, Set })

function inTimezone(timezone, run) {
  const previous = process.env.TZ
  process.env.TZ = timezone
  try { run() } finally {
    if (previous === undefined) delete process.env.TZ
    else process.env.TZ = previous
  }
}

test("European vacation wall times reject the spring gap and preserve both autumn occurrences", () => {
  inTimezone("Europe/Berlin", () => {
    assert.equal(helpers.localDateTimeToISO("2026-03-29T02:30"), null)
    assert.deepEqual(Array.from(helpers.localDateTimeCandidates("2026-10-25T02:30")), [
      "2026-10-25T00:30:00.000Z", "2026-10-25T01:30:00.000Z",
    ])
  })
})

test("half-hour DST overlaps expose both instants rather than assuming an hour", () => {
  inTimezone("Australia/Lord_Howe", () => {
    const values = Array.from(helpers.localDateTimeCandidates("2026-04-05T01:45"))
    assert.deepEqual(values, ["2026-04-04T14:45:00.000Z", "2026-04-04T15:15:00.000Z"])
    assert.equal(helpers.selectedLocalDateTimeISO("2026-04-05T01:45", values[1]), values[1])
  })
})

function flatten(value, prefix = "") {
  return Object.fromEntries(Object.entries(value).flatMap(([key, item]) => (
    item && typeof item === "object" ? Object.entries(flatten(item, `${prefix}${key}.`)) : [[`${prefix}${key}`, item]]
  )))
}

test("every availability translation and interpolation remains complete across Russian, English and Chinese", () => {
  const catalogs = Object.fromEntries(["en-US", "ru-RU", "zh-CN"].map(locale => [
    locale, flatten(JSON.parse(readFileSync(new URL(`../messages/${locale}.json`, import.meta.url), "utf8")).supportAvailability),
  ]))
  const reference = catalogs["en-US"]
  for (const [locale, catalog] of Object.entries(catalogs)) {
    assert.deepEqual(Object.keys(catalog).sort(), Object.keys(reference).sort(), `${locale} availability keys`)
    for (const [key, text] of Object.entries(catalog)) {
      assert.equal(typeof text, "string", `${locale}: ${key}`)
      assert.ok(text.trim(), `${locale}: ${key} is empty`)
      assert.deepEqual((text.match(/\{[^}]+\}/g) ?? []).sort(), (reference[key].match(/\{[^}]+\}/g) ?? []).sort(), `${locale}: ${key} interpolation`)
    }
  }
})