/**
 * Fails when the Docker Compose scheduler and the Helm CronJobs disagree.
 *
 * Both deployments must run the same background jobs on the same schedules, or
 * a feature silently works on one and not the other — the exact class of drift
 * that left Compose without a scheduler for as long as it did.
 *
 * Sources of truth:
 *   docker/crontab            — one line per job for Docker Compose
 *   helm/sim/values.yaml      — cronjobs.jobs.<name>.{path,schedule} for Kubernetes
 */
import { readFileSync } from 'node:fs'
import { dirname, join } from 'node:path'
import { fileURLToPath } from 'node:url'

const repoRoot = join(dirname(fileURLToPath(import.meta.url)), '..')

/** Parses `*​/5 * * * * curl ... "$SIM_URL/api/foo"` into its schedule and path. */
function parseCrontab(contents: string): Map<string, string> {
  const jobs = new Map<string, string>()
  for (const rawLine of contents.split('\n')) {
    const line = rawLine.trim()
    if (!line || line.startsWith('#') || !line.includes('curl')) continue
    const schedule = line.split(/\s+/).slice(0, 5).join(' ')
    const pathMatch = line.match(/\$SIM_URL(\/api\/[^"']+)/)
    if (!pathMatch) {
      throw new Error(`docker/crontab line has no $SIM_URL/api/... target:\n  ${line}`)
    }
    jobs.set(pathMatch[1], schedule)
  }
  return jobs
}

/**
 * Pulls the `schedule`/`path` pairs out of the `cronjobs.jobs` block.
 *
 * Deliberately dependency-free rather than using a YAML parser: this runs in the
 * chart-validation CI job, which otherwise installs nothing — and a full install
 * there drags in native modules that have no business building for a lint job.
 * The block has a fixed shape, and an empty result is treated as an error, so a
 * structural change fails loudly instead of silently passing.
 */
function parseHelmJobs(contents: string): Map<string, string> {
  const lines = contents.split('\n')
  const start = lines.findIndex((l) => l.startsWith('cronjobs:'))
  if (start === -1) throw new Error('helm/sim/values.yaml has no top-level `cronjobs:` block')

  const jobs = new Map<string, string>()
  let schedule: string | null = null

  for (const line of lines.slice(start + 1)) {
    // A new top-level key ends the cronjobs block.
    if (/^[a-zA-Z]/.test(line)) break
    const scheduleMatch = line.match(/^\s+schedule:\s*"([^"]+)"/)
    if (scheduleMatch) {
      schedule = scheduleMatch[1]
      continue
    }
    const pathMatch = line.match(/^\s+path:\s*"([^"]+)"/)
    if (pathMatch) {
      if (!schedule) throw new Error(`path "${pathMatch[1]}" has no preceding schedule`)
      jobs.set(pathMatch[1], schedule)
      schedule = null
    }
  }

  if (jobs.size === 0) {
    throw new Error('parsed no jobs from cronjobs.jobs — the values.yaml shape likely changed')
  }
  return jobs
}

const crontab = parseCrontab(readFileSync(join(repoRoot, 'docker/crontab'), 'utf8'))
const helm = parseHelmJobs(readFileSync(join(repoRoot, 'helm/sim/values.yaml'), 'utf8'))

const errors: string[] = []

for (const [path, schedule] of helm) {
  if (!crontab.has(path)) {
    errors.push(`${path} is a Helm CronJob but is missing from docker/crontab`)
  } else if (crontab.get(path) !== schedule) {
    errors.push(`${path} schedule differs — helm: "${schedule}", crontab: "${crontab.get(path)}"`)
  }
}

for (const path of crontab.keys()) {
  if (!helm.has(path)) {
    errors.push(`${path} is in docker/crontab but has no matching Helm CronJob`)
  }
}

if (errors.length > 0) {
  console.error('Scheduler parity check failed:\n')
  for (const error of errors) console.error(`  - ${error}`)
  console.error(
    '\nKeep docker/crontab and helm/sim/values.yaml cronjobs.jobs in sync so both deployments run the same jobs.'
  )
  process.exit(1)
}

console.log(`Scheduler parity OK — ${helm.size} jobs match across Docker Compose and Helm.`)