// bun run server.mjs
// tiny schedules api to manage argo cronworkflows/workflows via k8s CRDs
// comments intentionally lowercase per original style

import http from 'http'
import { KubeConfig, CustomObjectsApi } from '@kubernetes/client-node'

const GROUP = 'argoproj.io'
const VERSION = 'v1alpha1'
const CRON_PLURAL = 'cronworkflows'
const WF_PLURAL = 'workflows'
const NAMESPACE = process.env.NS || 'argo'

// load cluster credentials (or fallback to local kubeconfig for dev)
const kc = new KubeConfig()
try { kc.loadFromCluster() } catch { kc.loadFromDefault() }
const co = kc.makeApiClient(CustomObjectsApi)

// helper: build cron string from an iso timestamp in a tz
const cronFromISO = (iso, tz = 'America/New_York') => {
  const dt = new Date(iso)
  const parts = new Intl.DateTimeFormat('en-US', {
    timeZone: tz, year: 'numeric', month: 'numeric', day: 'numeric',
    hour: 'numeric', minute: '2-digit', hour12: false
  }).formatToParts(dt).reduce((a, p) => (a[p.type] = p.value, a), {})
  const m = Number(parts.month), d = Number(parts.day), h = Number(parts.hour), min = Number(parts.minute)
  return `${min} ${h} ${d} ${m} *`
}

// create or update a cronworkflow that runs a workflowtemplate
async function upsertCronWorkflow({
  name, when, tz = 'America/New_York', oneShot = false,
  template = { name: '', clusterScope: false },
  parameters = {}, entrypoint
}) {
  const schedule = when.cron ?? cronFromISO(when.iso, tz)
  const args = Object.entries(parameters).map(([name, value]) => ({ name, value }))

  const body = {
    apiVersion: `${GROUP}/${VERSION}`,
    kind: 'CronWorkflow',
    metadata: { name },
    spec: {
      timezone: tz,
      schedules: [schedule],
      concurrencyPolicy: 'Forbid',
      ...(oneShot ? { stopStrategy: { expression: 'cronworkflow.succeeded >= 1' } } : {}),
      workflowSpec: {
        ...(entrypoint ? { entrypoint } : {}),
        arguments: args.length ? { parameters: args } : undefined,
        workflowTemplateRef: {
          name: template.name,
          ...(template.clusterScope ? { clusterScope: true } : {})
        }
      }
    }
  }

  // try patch, else create
  try {
    await co.patchNamespacedCustomObject(
      GROUP, VERSION, NAMESPACE, CRON_PLURAL, name, body,
      undefined, undefined, undefined,
      { headers: { 'content-type': 'application/merge-patch+json' } }
    )
  } catch {
    await co.createNamespacedCustomObject(GROUP, VERSION, NAMESPACE, CRON_PLURAL, body)
  }
}

// run immediately (no schedule) by creating a workflow from the same template
async function runNow({ name, template, parameters = {}, entrypoint }) {
  const args = Object.entries(parameters).map(([name, value]) => ({ name, value }))
  const wf = {
    apiVersion: `${GROUP}/${VERSION}`,
    kind: 'Workflow',
    metadata: { generateName: `${name}-` },
    spec: {
      ...(entrypoint ? { entrypoint } : {}),
      arguments: args.length ? { parameters: args } : undefined,
      workflowTemplateRef: {
        name: template.name,
        ...(template.clusterScope ? { clusterScope: true } : {})
      }
    }
  }
  await co.createNamespacedCustomObject(GROUP, VERSION, NAMESPACE, WF_PLURAL, wf)
}

// tiny http api
const server = http.createServer(async (req, res) => {
  try {
    if (req.method === 'POST' && req.url === '/schedules') {
      const input = JSON.parse(await new Promise(r => {
        let d = ''; req.on('data', c => d += c); req.on('end', () => r(d))
      }))
      await upsertCronWorkflow(input)
      res.writeHead(201).end(JSON.stringify({ ok: true }))
      return
    }
    if (req.method === 'POST' && req.url === '/run-now') {
      const input = JSON.parse(await new Promise(r => {
        let d = ''; req.on('data', c => d += c); req.on('end', () => r(d))
      }))
      await runNow(input)
      res.writeHead(201).end(JSON.stringify({ ok: true }))
      return
    }
    if (req.method === 'DELETE' && req.url?.startsWith('/schedules/')) {
      const name = decodeURIComponent(req.url.split('/').pop())
      await co.deleteNamespacedCustomObject(GROUP, VERSION, NAMESPACE, CRON_PLURAL, name)
      res.writeHead(204).end()
      return
    }
    res.writeHead(404).end('not found')
  } catch (e) {
    res.writeHead(500).end(JSON.stringify({ ok: false, error: e.message }))
  }
})

const port = Number(process.env.PORT) || 3000
server.listen(port, () => console.log(`schedules api listening on :${port}`))