#!/usr/bin/env node
/**
 * Fail-loud check for stale ecosystem aliases and old `App.<Capitalized>`
 * references in `src/`. The point is to keep documentation honest after
 * the rename to full-word aliases (`$cache` / `$session` / etc.) and
 * the move from capitalized service slots (`App.Cache`) to lowercase
 * declarable services (`App.cache`).
 *
 * Allowed capitalised names on `App.*` are the ecosystem core:
 * `Logger`, `Bus`, `Timers`, `Orca`. Everything else is lowercase.
 *
 * Run: `node scripts/check-aliases.mjs`
 * Exit code: 0 when clean, 1 when any forbidden token is found.
 */

import { readFileSync, readdirSync, statSync } from 'node:fs';
import { join, relative, sep } from 'node:path';
import { fileURLToPath } from 'node:url';

const HERE = fileURLToPath(new URL('.', import.meta.url));
const ROOT = join(HERE, '..');
const SRC = join(ROOT, 'src');

const STALE_ALIAS_PATTERNS = [
	{ rx: /\$cach[^e]/g, hint: '$cach* → $cache*' },
	{ rx: /\$sess[^i]/g, hint: '$sess* → $session*' },
	{ rx: /\$conn[^e]/g, hint: '$conn* → $connection*' },
	{ rx: /\$timr\b/g, hint: '$timr → $timer' },
	{ rx: /\$logr\b/g, hint: '$logr → $logger' },
	{ rx: /\$fmts\b/g, hint: '$fmts → $format' },
	{ rx: /\$stor[^a]/g, hint: '$stor* → $storage*' },
	{ rx: /\$aapp\b/g, hint: '$aapp → $active-app' },
	{ rx: /\$buss\b/g, hint: '$buss → $bus' },
	{ rx: /\$libs\/buss\b/g, hint: '$libs/buss → $libs/bus' },
	{ rx: /\$libs\/logr\b/g, hint: '$libs/logr → $libs/logger' },
	{ rx: /\$libs\/timr\b/g, hint: '$libs/timr → $libs/timer' },
	{ rx: /\$libs\/cach[^e]/g, hint: '$libs/cach* → $libs/cache*' }
];

const APP_FORBIDDEN_CAPITALS = [
	'Cache',
	'Sess',
	'Sium',
	'Storage',
	'Format',
	'Frontend',
	'Lang',
	'Auth',
	'Perms',
	'Http',
	'Dom'
];
const APP_PATTERN = new RegExp(`\\bApp\\.(${APP_FORBIDDEN_CAPITALS.join('|')})\\b`, 'g');

const SKIP_DIRS = new Set(['node_modules', '.svelte-kit', '.git', 'build', 'dist']);
const SCAN_EXTENSIONS = new Set([
	'.ts',
	'.svelte',
	'.svelte.ts',
	'.js',
	'.mjs',
	'.md',
	'.txt'
]);

/** Files where the references are deliberately historical. */
const ALLOWLIST = new Set([
	join('arts', 'active-app', 'types.ts').replaceAll('/', sep)
]);

function* walk(dir) {
	for (const entry of readdirSync(dir)) {
		if (SKIP_DIRS.has(entry)) continue;
		const full = join(dir, entry);
		const st = statSync(full);
		if (st.isDirectory()) {
			yield* walk(full);
			continue;
		}
		if (!st.isFile()) continue;
		const lower = entry.toLowerCase();
		if (!Array.from(SCAN_EXTENSIONS).some((ext) => lower.endsWith(ext))) continue;
		yield full;
	}
}

function scanFile(file) {
	const text = readFileSync(file, 'utf8');
	const findings = [];
	for (const { rx, hint } of STALE_ALIAS_PATTERNS) {
		rx.lastIndex = 0;
		const matches = text.match(rx);
		if (matches) findings.push({ kind: 'alias', hint, count: matches.length });
	}
	APP_PATTERN.lastIndex = 0;
	const appMatches = text.match(APP_PATTERN);
	if (appMatches) {
		findings.push({
			kind: 'app',
			hint: `App.<lowercase> required for non-core services (${[...new Set(appMatches)].join(', ')})`,
			count: appMatches.length
		});
	}
	return findings;
}

let exit = 0;
const offenders = [];
for (const file of walk(SRC)) {
	const rel = relative(SRC, file);
	if (ALLOWLIST.has(rel)) continue;
	const findings = scanFile(file);
	if (findings.length === 0) continue;
	offenders.push({ rel, findings });
	exit = 1;
}

if (offenders.length === 0) {
	console.log('aliases: clean');
} else {
	console.log('aliases: found stale references');
	for (const { rel, findings } of offenders) {
		console.log(`  ${rel}`);
		for (const f of findings) console.log(`    - ${f.hint} (x${f.count})`);
	}
	console.log(
		'\nFix: run a search/replace using the canonical aliases in svelte.config.js'
	);
}

process.exit(exit);