import { test, expect } from "bun:test";
import { resolveI18n, makeT, resolveLang, translateHtml } from "../src/index.ts";

const i18n = resolveI18n(
  {
    en: { hi: "Hi {name}", nav: { home: "Home" }, ph: "Email" },
    es: { hi: "Hola {name}", nav: { home: "Inicio" } },
  },
  { default: "en" },
);

test("makeT interpolates params and nested keys", () => {
  const t = makeT(i18n, "es");
  expect(t("hi", { name: "Ana" })).toBe("Hola Ana");
  expect(t("nav.home")).toBe("Inicio");
});

test("makeT falls back to default language, then the key", () => {
  const t = makeT(i18n, "es");
  expect(t("ph")).toBe("Email"); // missing in es → en
  expect(t("nope")).toBe("nope"); // missing everywhere → key
});

test("resolveLang: cookie → Accept-Language → default", () => {
  expect(resolveLang(i18n, "es", null)).toBe("es");
  expect(resolveLang(i18n, undefined, "fr,es;q=0.8")).toBe("es");
  expect(resolveLang(i18n, "xx", "de")).toBe("en"); // invalid cookie + unsupported header
});

test("translateHtml resolves data-t text and t:attr attributes", () => {
  const t = makeT(i18n, "en");
  const out = translateHtml('<input t:placeholder="ph"><span data-t="nav.home"></span>', t);
  expect(out).toContain('placeholder="Email"');
  expect(out).toContain('<span data-t="nav.home">Home</span>');
});

test("translateHtml is a no-op without markers", () => {
  const t = makeT(i18n, "en");
  expect(translateHtml("<p>plain</p>", t)).toBe("<p>plain</p>");
});

test("translateHtml preserves authored fallback text when a key is unavailable", () => {
  const t = (key: string) => key;
  expect(translateHtml('<h1 data-t="missing.title">Readable fallback</h1>', t)).toBe(
    '<h1 data-t="missing.title">Readable fallback</h1>',
  );
  expect(translateHtml('<input t:placeholder="missing.placeholder" />', t)).toBe(
    '<input placeholder="" />',
  );
});
