#!/usr/bin/env bun
/**
 * Navigation guard: outside the auth flow every route change must go through
 * react-router (`Link` / `useNavigate`) so the SPA never pays a full document
 * reload. Raw anchors, `href=` attributes and `window.location` writes are
 * reported as errors. Auth pages are exempt (e.g. the `#terms` anchors).
 *
 * Usage: bun scripts/lint-nav.mjs [dir]   (default: src)
 */
import { readdirSync, readFileSync, statSync } from 'node:fs'
import { dirname, join, relative, resolve } from 'node:path'
import { fileURLToPath } from 'node:url'

const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '..')
const scanRoot = resolve(process.argv[2] ?? join(repoRoot, 'src'))

const AUTH_EXEMPT = [
  'src/features/auth/',
  'src/pages/login/',
  'src/pages/sign-up/',
  'src/pages/forgot-password/',
  'src/pages/reset-password/',
  'src/pages/email-verification/',
  'src/pages/two-factor/',
]
const SKIP_DIRS = new Set(['node_modules', 'dist', '.git', 'pow-solver', 'livekit'])

const PATTERNS = [
  ['raw <a> anchor', /<a[\s>]/],
  ['href attribute', /\bhref=["'{]/],
  ['full-page navigation', /(?:window\.)?location\s*\.\s*(?:href\s*=|assign\s*\(|replace\s*\()/],
  // A reload is a browser-level refresh: route state must be changed through
  // react-router instead (see pages/workspace/model/repo-location).
  ['browser-level refresh', /(?:window\.|document\.)?location\s*\.\s*reload\s*\(/],
]

function* walk(dir) {
  for (const entry of readdirSync(dir)) {
    const path = join(dir, entry)
    if (statSync(path).isDirectory()) {
      if (!SKIP_DIRS.has(entry)) yield* walk(path)
    } else if (/\.tsx?$/.test(entry) && !entry.endsWith('.d.ts')) {
      yield path
    }
  }
}

const violations = []
for (const file of walk(scanRoot)) {
  const rel = relative(repoRoot, file).replaceAll('\\', '/')
  if (rel.startsWith('src/shared/api/') || AUTH_EXEMPT.some(prefix => rel.startsWith(prefix))) continue
  readFileSync(file, 'utf8')
    .split('\n')
    .forEach((line, i) => {
      // Fragment-only anchors (`href="#L12"`) never trigger a document reload,
      // so they are allowed outside the auth flow as in-page permalinks.
      const fragmentOnly = line.includes('href={`#') || /href=["'{]#/.test(line)
      for (const [label, re] of PATTERNS) {
        if (fragmentOnly && label !== 'full-page navigation' && label !== 'browser-level refresh') continue
        if (re.test(line)) violations.push(`${rel}:${i + 1}: ${label} — ${line.trim()}`)
      }
    })
}

if (violations.length > 0) {
  console.error('navigation guard: use <Link> / useNavigate() outside auth pages')
  for (const v of violations) console.error('  ' + v)
  process.exit(1)
}
console.log('navigation guard: OK — no href/location navigation outside auth pages')