#!/usr/bin/env node
/**
 * Generates src/lib/edit-on-github-routes.js by scanning src/pages for .mdx files.
 * Used by Layout.jsx so "Edit on GitHub" links point to .../index.mdx for index
 * routes, and so GitHub links render only on routes backed by a real MDX file
 * (e.g. not on the prerendered 404/500 pages, where pathname is /_error).
 * Run automatically with dev and build.
 */

import fs from 'fs'
import path from 'path'
import { fileURLToPath } from 'url'

const __dirname = path.dirname(fileURLToPath(import.meta.url))
const ROOT = path.join(__dirname, '..')
const PAGES_DIR = path.join(ROOT, 'src/pages')
const OUT_PATH = path.join(ROOT, 'src/lib/edit-on-github-routes.js')

function findMdxRoutes(dir, basePath = '') {
  const entries = fs.readdirSync(dir, { withFileTypes: true })
  const indexRoutes = []
  const allRoutes = []
  for (const e of entries) {
    const rel = basePath ? `${basePath}/${e.name}` : e.name
    if (e.isDirectory()) {
      const nested = findMdxRoutes(path.join(dir, e.name), rel)
      indexRoutes.push(...nested.indexRoutes)
      allRoutes.push(...nested.allRoutes)
    } else if (e.name === 'index.mdx') {
      indexRoutes.push('/' + basePath)
      allRoutes.push('/' + basePath)
    } else if (e.name.endsWith('.mdx')) {
      allRoutes.push('/' + rel.replace(/\.mdx$/, ''))
    }
  }
  return { indexRoutes, allRoutes }
}

const { indexRoutes, allRoutes } = findMdxRoutes(PAGES_DIR)
const routes = indexRoutes.filter((r) => r !== '/').sort() // ignore root index if any
const mdxRoutes = allRoutes.filter((r) => r !== '/').sort()

const content = `// Auto-generated by scripts/generate-github-routes.mjs – do not edit
/** Pathnames served by src/pages/.../index.mdx (Edit on GitHub must link to /index.mdx). */
export const EDIT_ON_GITHUB_INDEX_ROUTES = new Set(${JSON.stringify(routes)});
/** Every pathname backed by an .mdx file under src/pages. GitHub links are hidden elsewhere. */
export const MDX_PAGE_ROUTES = new Set(${JSON.stringify(mdxRoutes)});
`

fs.mkdirSync(path.dirname(OUT_PATH), { recursive: true })
fs.writeFileSync(OUT_PATH, content, 'utf8')
console.log('Generated', OUT_PATH, 'with', routes.length, 'index routes,', mdxRoutes.length, 'mdx routes')