#!/usr/bin/env node
/*
 * Emit `static-dist/askama-common.css` from the SvelteKit design-token
 * source of truth (`src/lib/styles/base/variables.css`) plus the auth-page
 * component styles (`src/lib/styles/askama-common.css`).
 *
 * WHY A POST-BUILD SCRIPT:
 *   Vite's `writeBundle` hooks fire mid-build, before
 *   `@sveltejs/adapter-static` copies the finalised site to
 *   `../static-dist/`. Anything written to that directory during
 *   Vite gets wiped when adapter-static runs. A `postbuild` script
 *   runs after everything the SvelteKit build owns, so its output
 *   survives — one predictable moment, no ordering trap.
 *
 * WHAT IT PRODUCES:
 *   A single stable-named CSS file at `static-dist/askama-common.css`
 *   containing:
 *     1. Every design token declared in `base/variables.css` (:root,
 *        `light-dark(...)`, dark-mode blocks, etc.)
 *     2. The auth-page component rules from `askama-common.css`
 *   Concatenated, prefixed with a "do not edit" header, written UTF-8.
 *
 * SINGLE SOURCE OF TRUTH:
 *   If a token changes in `variables.css`, one rebuild propagates it to
 *   both the SPA (via Svelte's normal build pipeline) AND the askama
 *   templates (via this file). Two consumers, one source. No manual
 *   sync step.
 *
 * SERVER SIDE:
 *   Server-rendered askama templates reference:
 *     <link rel="stylesheet" href="/askama-common.css">
 *   The Rust web layer serves `static-dist/askama-common.css` at that
 *   URL through the same ServeDir the SPA uses. No route wiring needed.
 */

import { readFileSync, writeFileSync, mkdirSync } from 'node:fs';
import { dirname, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = dirname(fileURLToPath(import.meta.url));
const stylesDir = resolve(__dirname, '../src/lib/styles');
const outputFile = resolve(__dirname, '../../static-dist/askama-common.css');

const header =
	'/* Auto-generated by frontend/scripts/emit-askama-common.mjs.\n' +
	' * Do NOT edit by hand — regenerated on every `npm run build`.\n' +
	' * Sources: src/lib/styles/base/variables.css (design tokens)\n' +
	' *          src/lib/styles/askama-common.css (auth components)\n' +
	' */\n\n';

const tokens = readFileSync(resolve(stylesDir, 'base/variables.css'), 'utf8');
const components = readFileSync(resolve(stylesDir, 'askama-common.css'), 'utf8');

mkdirSync(dirname(outputFile), { recursive: true });
writeFileSync(outputFile, header + tokens + '\n' + components, 'utf8');

const bytes = Buffer.byteLength(header + tokens + '\n' + components, 'utf8');
console.log(`emit-askama-common: wrote ${bytes} bytes → ${outputFile}`);