// Generates src/styles/tokens.gen.css from the hub frontend's design tokens.
//
// The hub's Tailwind entry (internal/webapp/frontend/src/tw.css) is the single
// source of truth for the BearDrive palette. It can't be imported directly:
// `@theme { … }` is Tailwind syntax, and this site deliberately doesn't run
// Tailwind. So we read that one block and re-emit it as plain custom
// properties on :root.
//
// This is why the docs site lives in the OSS repo. The cloud landing page sits
// in a different Go module and has to keep a *copy* of these tokens, policed by
// cloud/web/landing/scripts/check-tokens.mjs. Here there is no copy to police —
// the file below is generated, gitignored, and cannot drift.
import { readFileSync, writeFileSync, mkdirSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { dirname, resolve, relative } from "node:path";

const here = dirname(fileURLToPath(import.meta.url));
const SOURCE = resolve(here, "../../../internal/webapp/frontend/src/tw.css");
const OUT = resolve(here, "../src/styles/tokens.gen.css");

const src = readFileSync(SOURCE, "utf8");
const block = src.match(/@theme\s*\{([\s\S]*?)\n\}/);
if (!block) {
  throw new Error(`no @theme block found in ${SOURCE}`);
}

// Declarations only — comments and blank lines don't survive the trip.
const decls = block[1]
  .split("\n")
  .map((line) => line.trim())
  .filter((line) => line.startsWith("--"))
  .map((line) => `  ${line}`);

if (decls.length === 0) {
  throw new Error(`@theme block in ${SOURCE} declared no custom properties`);
}

mkdirSync(dirname(OUT), { recursive: true });
writeFileSync(
  OUT,
  [
    `/* GENERATED by scripts/tokens.mjs from ${relative(resolve(here, "../../.."), SOURCE)} — do not edit. */`,
    ":root {",
    ...decls,
    "}",
    "",
  ].join("\n"),
);

console.log(`tokens: wrote ${decls.length} properties to src/styles/tokens.gen.css`);