#!/usr/bin/env node
/**
 * Generates src/lib/last-updated-routes.js by scanning src/pages for .mdx files
 * and reading the last commit date for each from git. Used by Layout.jsx to
 * render an "Updated <date>" line in the right rail.
 *
 * Skips src/pages/ipa/resources/ — those are auto-generated from the OpenAPI
 * spec, so their git date reflects generator runs, not real content edits.
 *
 * Run automatically with dev and build.
 */

import fs from 'fs'
import path from 'path'
import { fileURLToPath } from 'url'
import { buildGitDateMap } from './git-dates.mjs'

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/last-updated-routes.mjs')
const SKIP_PREFIX = 'ipa/resources'

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

const entries = findMdxRoutes(PAGES_DIR)
  .filter((r) => r.route !== '/' && r.route !== '')
  .sort((a, b) => a.route.localeCompare(b.route))

const gitDates = buildGitDateMap()
const map = {}
for (const { route, filePath } of entries) {
  const date = gitDates.get(path.relative(ROOT, filePath))
  if (date) map[route] = date
}

const content = `// Auto-generated by scripts/generate-last-updated.mjs – do not edit
/** Last commit date (YYYY-MM-DD) keyed by Next.js router.pathname. */
export const LAST_UPDATED_BY_ROUTE = ${JSON.stringify(map, null, 2)};
`

fs.mkdirSync(path.dirname(OUT_PATH), { recursive: true })
fs.writeFileSync(OUT_PATH, content, 'utf8')
console.log('Generated', OUT_PATH, 'with', Object.keys(map).length, 'dated routes')

if (Object.keys(map).length === 0) {
  const msg =
    '[last-updated] no routes received a date, git history is unavailable or the clone is shallow'
  // Hard-fail only where full history is guaranteed (the GitHub workflow
  // checks out with fetch-depth: 0). Other CI environments like Vercel
  // shallow-clone by design, so there a missing map is expected: warn and
  // ship pages without "Updated" dates instead of breaking the deploy.
  if (process.env.GITHUB_ACTIONS) {
    console.error(
      `${msg}. Failing the build: the workflow checks out with fetch-depth: 0, so an empty map means something is broken.`
    )
    process.exit(1)
  }
  console.warn(`${msg}. Pages will render without an "Updated" date.`)
}