import { spawn, spawnSync } from 'node:child_process'
import { getErrorMessage } from '@sim/utils/errors'
import type { Detection } from '../detect.ts'
import { ensureDocker } from '../docker.ts'
import { generateSecret, ROOT } from '../env-files.ts'
import { SetupError } from '../errors.ts'
import { waitFor } from '../probes.ts'
import * as p from '../prompter.ts'
import { chatFlagValues, mothershipOverride, promptCopilotKey } from '../steps.ts'
import { glyph, theme } from '../theme.ts'

const APP_URL = 'http://localhost:3000'
const RELEASE = 'sim-dev'
const NAMESPACE = 'sim-dev'
const LOCAL_CONTEXT_PREFIXES = ['kind-', 'docker-desktop', 'minikube', 'orbstack']

/**
 * `input` is piped on stdin rather than passed as arguments — argv is readable
 * by any process on the machine, so secrets must never travel that way.
 */
function run(command: string, args: string[], failMessage: string, input?: string): string {
  // `helm upgrade --install ./helm/sim` uses chart paths relative to the repo
  // root, so pin cwd regardless of where the wizard was invoked from.
  const result = spawnSync(command, args, { encoding: 'utf8', input, cwd: ROOT })
  if (result.status !== 0) {
    throw new Error(`${failMessage}: ${result.stderr.trim() || result.stdout.trim()}`)
  }
  return result.stdout
}

function isLocalContext(context: string): boolean {
  return LOCAL_CONTEXT_PREFIXES.some((prefix) => context === prefix || context.startsWith(prefix))
}

const LOCAL_SERVER_HOSTS = new Set([
  '127.0.0.1',
  'localhost',
  '0.0.0.0',
  '::1',
  'kubernetes.docker.internal',
  'host.docker.internal',
])

/** True when a context's API server is a loopback/host address — i.e. a local cluster. */
export function isLocalKubeContext(context: string): boolean {
  const server = contextServerHost(context)
  return server !== null && LOCAL_SERVER_HOSTS.has(server)
}

/**
 * Liveness probe — a kubeconfig entry can outlive a stopped or deleted cluster
 * (kind clusters are Docker containers that don't restart on their own), so a
 * context looking local is no guarantee its API server answers.
 */
function clusterReachable(context: string): boolean {
  return (
    spawnSync('kubectl', ['cluster-info', '--context', context, '--request-timeout=5s'], {
      stdio: 'ignore',
    }).status === 0
  )
}

/** The API server host a context points at, or null if kubectl can't resolve it. */
function contextServerHost(context: string): string | null {
  const result = spawnSync(
    'kubectl',
    [
      'config',
      'view',
      '--minify',
      '--context',
      context,
      '-o',
      'jsonpath={.clusters[0].cluster.server}',
    ],
    { encoding: 'utf8' }
  )
  if (result.status !== 0) return null
  try {
    return new URL(result.stdout.trim()).hostname
  } catch {
    return null
  }
}

/**
 * POSIX-quote a value for a copyable shell hint. A kube-context passes only a
 * prefix check, so it can still contain whitespace or shell metacharacters that
 * would break the `--context` argument (or run embedded syntax) when copied.
 * Ordinary context names stay bare; only unsafe ones get single-quoted.
 */
function shq(value: string): string {
  if (/^[A-Za-z0-9._/-]+$/.test(value)) return value
  return `'${value.replace(/'/g, `'\\''`)}'`
}

async function ensureLocalContext(detection: Detection): Promise<string> {
  if (!detection.binaries.helm || !detection.binaries.kubectl) {
    throw new SetupError('kubernetes mode needs kubectl and helm on PATH.', [
      `install them: ${theme.command('brew install kubectl helm')}`,
    ])
  }
  const context = detection.kubeContext
  if (context && isLocalContext(context)) {
    // The name is only a hint — a remote cluster can be named like a local one
    // (e.g. "kind-prod"). Verify the API server is a loopback/host address before
    // defaulting to "yes", so generated secrets can't silently ship to a remote
    // cluster on a blind Enter.
    const server = contextServerHost(context)
    if (server && LOCAL_SERVER_HOSTS.has(server)) {
      if (!clusterReachable(context)) {
        // The context is local but its cluster isn't answering — stopped or
        // deleted. Don't offer it (helm would just fail); fall through to the
        // kind path, which starts a stopped "sim" cluster or creates one.
        p.log.warn(
          `Context "${context}" points at a local cluster that isn't responding — it looks stopped or deleted. The wizard will start or recreate a kind cluster instead.`
        )
      } else {
        const useIt = await p.confirm({
          message: `Use current kube context "${context}"?`,
          initialValue: true,
        })
        if (useIt) return context
      }
    } else {
      p.log.warn(
        `Context "${context}" is named like a local cluster, but its API server${server ? ` (${server})` : ''} does not look local. Continuing would deploy the generated secrets there.`
      )
      const useIt = await p.confirm({
        message: `Deploy to "${context}" anyway?`,
        initialValue: false,
      })
      if (useIt) return context
    }
  } else if (context) {
    p.log.warn(
      `Current context "${context}" does not look like a local cluster. Deploying to remote clusters is not supported by the wizard yet — switch to a kind/docker-desktop context, or drive helm directly (see helm/sim/examples/values-production.yaml).`
    )
  }
  if (!detection.binaries.kind) {
    throw new SetupError('no local cluster available.', [
      `install kind: ${theme.command('brew install kind')} — the wizard creates the cluster for you`,
      'or enable Kubernetes in Docker Desktop settings, then re-run',
    ])
  }
  await ensureDocker(true)
  const clusters = run('kind', ['get', 'clusters'], 'kind get clusters failed')
    .trim()
    .split('\n')
    .filter(Boolean)
  if (clusters.includes('sim')) {
    run('kind', ['export', 'kubeconfig', '--name', 'sim'], 'kind export kubeconfig failed')
    if (clusterReachable('kind-sim')) {
      p.log.step('Reusing existing kind cluster "sim"')
    } else {
      // The cluster exists in kind but isn't answering — its node containers are
      // stopped (a Docker/machine restart). Start them and wait for the API.
      const spin = p.spinner()
      spin.start('kind cluster "sim" is stopped — starting it…')
      const nodes = run('kind', ['get', 'nodes', '--name', 'sim'], 'kind get nodes failed')
        .trim()
        .split('\n')
        .filter(Boolean)
      for (const node of nodes) spawnSync('docker', ['start', node], { stdio: 'ignore' })
      const up = await waitFor(() => Promise.resolve(clusterReachable('kind-sim')), 60_000, 2000)
      if (!up) {
        spin.stop(`${glyph.fail} kind cluster "sim" would not start`)
        throw new SetupError('the kind cluster "sim" exists but will not come up.', [
          `inspect it: ${theme.command('docker ps -a --filter name=sim-control-plane')}`,
          `recreate it: ${theme.command('kind delete cluster --name sim')}, then re-run ${theme.command('bun run setup')}`,
        ])
      }
      spin.stop('kind cluster "sim" started')
    }
  } else {
    const spin = p.spinner()
    spin.start('Creating kind cluster "sim"…')
    run('kind', ['create', 'cluster', '--name', 'sim'], 'kind create cluster failed')
    spin.stop('kind cluster "sim" ready')
  }
  return 'kind-sim'
}

interface PodProgress {
  ready: number
  total: number
  detail: string
}

/**
 * One-line summary of what the cluster is doing, for the install spinner. Only
 * long-running workloads count — the chart's CronJobs spawn short-lived pods
 * that finish as Completed, and counting those makes "ready" jitter downward
 * for reasons that have nothing to do with the install.
 */
function podProgress(context: string): PodProgress | null {
  const result = spawnSync(
    'kubectl',
    [
      'get',
      'pods',
      '--context',
      context,
      '-n',
      NAMESPACE,
      '-o',
      'jsonpath={range .items[*]}{.status.phase}{"\\t"}{.metadata.ownerReferences[0].kind}{"\\t"}{range .status.containerStatuses[*]}{.ready},{.state.waiting.reason}{" "}{end}{"\\n"}{end}',
    ],
    { encoding: 'utf8' }
  )
  if (result.status !== 0) return null
  const rows = result.stdout.split('\n').filter(Boolean)
  if (rows.length === 0) return null

  let ready = 0
  let total = 0
  let pulling = 0
  let crashing = 0
  for (const row of rows) {
    const [, ownerKind = '', containers = ''] = row.split('\t')
    if (ownerKind === 'Job') continue
    total++
    if (containers.includes('true,')) ready++
    if (containers.includes('ContainerCreating') || containers.includes('PodInitializing'))
      pulling++
    if (containers.includes('CrashLoopBackOff') || containers.includes('ImagePullBackOff'))
      crashing++
  }
  if (total === 0) return null
  const notes: string[] = []
  if (pulling > 0) notes.push(`${pulling} starting`)
  // Restarts while Postgres comes up are normal on a cold cluster; say so rather
  // than let a silent spinner imply nothing is happening.
  if (crashing > 0) notes.push(`${crashing} restarting`)
  return { ready, total, detail: notes.join(' · ') }
}

/**
 * `helm --wait` blocks for minutes with no output, so a slow image pull is
 * indistinguishable from a wedged install — the reason the old spinner was
 * unsatisfying. Run helm asynchronously and poll the cluster so the spinner
 * reports what is actually happening.
 */
async function helmInstall(
  args: string[],
  input: string,
  context: string,
  spin: ReturnType<typeof p.spinner>
): Promise<void> {
  const child = spawn('helm', args, { cwd: ROOT, stdio: ['pipe', 'pipe', 'pipe'] })
  child.stdin.write(input)
  child.stdin.end()

  let stderr = ''
  let stdout = ''
  child.stdout.on('data', (chunk) => {
    stdout += chunk
  })
  child.stderr.on('data', (chunk) => {
    stderr += chunk
  })

  const ticker = setInterval(() => {
    const progress = podProgress(context)
    if (!progress) return
    const suffix = progress.detail ? ` · ${progress.detail}` : ''
    spin.message(`${progress.ready}/${progress.total} pods ready${suffix}`)
  }, 3000)

  const code = await new Promise<number>((resolve) => {
    child.once('close', (status) => resolve(status ?? 1))
  })
  clearInterval(ticker)

  if (code !== 0) {
    throw new Error(`helm upgrade --install failed: ${stderr.trim() || stdout.trim()}`)
  }
}

interface ReleaseValues {
  app?: { env?: Record<string, string> }
  postgresql?: { auth?: { password?: string } }
}

function existingReleaseValues(context: string): ReleaseValues | null {
  const scope = ['--kube-context', context, '-n', NAMESPACE]
  const status = spawnSync('helm', ['status', RELEASE, ...scope], { stdio: 'ignore' })
  if (status.status !== 0) return null
  return JSON.parse(
    run('helm', ['get', 'values', RELEASE, ...scope, '-o', 'json'], 'helm get values failed')
  ) as ReleaseValues
}

/**
 * The previous release's secrets, or `null` when any are missing — a partial set
 * cannot be reused, since regenerating only some of them invalidates sessions
 * and stored credentials encrypted under the originals.
 */
function reusableSecrets(values: ReleaseValues | null): Record<string, string> | null {
  const env = values?.app?.env ?? {}
  const password = values?.postgresql?.auth?.password
  if (
    !env.BETTER_AUTH_SECRET ||
    !env.ENCRYPTION_KEY ||
    !env.INTERNAL_API_SECRET ||
    !env.CRON_SECRET ||
    !password
  ) {
    return null
  }
  return {
    BETTER_AUTH_SECRET: env.BETTER_AUTH_SECRET,
    ENCRYPTION_KEY: env.ENCRYPTION_KEY,
    INTERNAL_API_SECRET: env.INTERNAL_API_SECRET,
    CRON_SECRET: env.CRON_SECRET,
    POSTGRES_PASSWORD: password,
  }
}

/**
 * Values document piped to helm on stdin instead of `--set`. `JSON.stringify`
 * quotes and escapes each value — JSON is a subset of YAML, so a secret
 * containing `#`, `:`, or a leading `*` can neither break the document nor be
 * reinterpreted as YAML syntax.
 */
function secretValues(secrets: Record<string, string>): string {
  const { POSTGRES_PASSWORD, ...appEnv } = secrets
  const env = Object.entries(appEnv)
    .map(([key, value]) => `    ${key}: ${JSON.stringify(value)}`)
    .join('\n')
  return `app:\n  env:\n${env}\npostgresql:\n  auth:\n    password: ${JSON.stringify(POSTGRES_PASSWORD)}\n`
}

export async function runK8sMode(detection: Detection): Promise<void> {
  // Pin every subsequent call to the context we validated: the ambient context
  // can change between detection and deploy, which would send generated
  // credentials to an unintended cluster.
  const context = await ensureLocalContext(detection)

  const releaseValues = existingReleaseValues(context)
  const reused = reusableSecrets(releaseValues)
  const secrets = reused ?? {
    BETTER_AUTH_SECRET: generateSecret(),
    ENCRYPTION_KEY: generateSecret(),
    INTERNAL_API_SECRET: generateSecret(),
    CRON_SECRET: generateSecret(),
    POSTGRES_PASSWORD: generateSecret().slice(0, 24),
  }
  if (reused) p.log.step('Reusing secrets from the existing release')

  // Before the key is minted: a half-set override mints against one environment
  // and validates against the other, and warning afterwards is too late — the
  // bad key is already deployed.
  const overrides = mothershipOverride()
  const copilotKey = await promptCopilotKey(releaseValues?.app?.env?.COPILOT_API_KEY)

  // `helm upgrade` without `--reuse-values` keeps only what this document
  // carries, so a key the user chose to keep has to be re-supplied here.
  const appEnv: Record<string, string> = {
    ...secrets,
    ...overrides,
    ...(copilotKey ? { COPILOT_API_KEY: copilotKey } : {}),
    ...chatFlagValues(copilotKey),
  }

  const spin = p.spinner()
  spin.start('helm upgrade --install (first run pulls images — this can take several minutes)…')
  try {
    await helmInstall(
      [
        'upgrade',
        '--install',
        RELEASE,
        './helm/sim',
        '--kube-context',
        context,
        '--namespace',
        NAMESPACE,
        '--create-namespace',
        '--values',
        './helm/sim/examples/values-development.yaml',
        '--values',
        '-',
        '--wait',
        '--timeout',
        '15m',
      ],
      secretValues(appEnv),
      context,
      spin
    )
  } catch (error) {
    spin.stop(`${glyph.fail} helm install failed`)
    throw new SetupError(getErrorMessage(error), [
      `pod status: ${theme.command(`kubectl --context ${shq(context)} -n ${NAMESPACE} get pods`)}`,
      `stuck pods: ${theme.command(`kubectl --context ${shq(context)} -n ${NAMESPACE} describe pod <name> | tail -20`)}`,
      'ImagePullBackOff on ghcr.io/simstudioai/* usually means the chart appVersion tag was never published — check Chart.yaml against ghcr',
    ])
  }
  spin.stop('Release deployed, all pods ready')

  const testSpin = p.spinner()
  testSpin.start('Running helm test…')
  const test = spawnSync('helm', ['test', RELEASE, '--kube-context', context, '-n', NAMESPACE], {
    encoding: 'utf8',
    cwd: ROOT,
  })
  if (test.status !== 0) {
    testSpin.stop(`${glyph.fail} helm test failed`)
    throw new SetupError(`helm test failed:\n${test.stdout}${test.stderr}`, [
      `pod status: ${theme.command(`kubectl --context ${shq(context)} -n ${NAMESPACE} get pods`)}`,
      `app logs: ${theme.command(`kubectl --context ${shq(context)} -n ${NAMESPACE} logs deploy/${RELEASE}-app --tail 50`)}`,
    ])
  }
  testSpin.stop('helm test passed')

  p.note(
    [
      `open ${APP_URL} (needs both forwards below)`,
      `pods:      kubectl --context ${shq(context)} -n ${NAMESPACE} get pods`,
      `app logs:  kubectl --context ${shq(context)} -n ${NAMESPACE} logs deploy/${RELEASE}-app --tail 50`,
      // Both, always: the app alone loads but the editor's socket has nothing to
      // reach, which is the reconnect failure this change set exists to fix.
      ...forwardCommands(context).map(
        (command, index) => `${index === 0 ? 'forward:  ' : '          '} ${command}`
      ),
      `tear down: helm uninstall ${RELEASE} --kube-context ${shq(context)} -n ${NAMESPACE}`,
    ].join('\n'),
    'Reach your cluster'
  )

  await offerPortForward(context)
}

/**
 * Both forwards, in the order a user should run them. Kept in one place so the
 * printed instructions and what the wizard actually runs cannot drift — the app
 * alone leaves the editor's socket dead.
 */
export function forwardCommands(context: string): string[] {
  const scope = `kubectl --context ${shq(context)} -n ${NAMESPACE} port-forward`
  return [`${scope} svc/${RELEASE}-app 3000:3000`, `${scope} svc/${RELEASE}-realtime 3002:3002`]
}

/**
 * The services are ClusterIP, so a healthy release is still unreachable from the
 * host — "Sim is ready" with nothing on :3000 is the least satisfying way to end
 * a setup. Offer the forward the same way dev mode offers to start the server,
 * and run it in the foreground so Ctrl-C ends it.
 *
 * Realtime needs its own forward (one resource per invocation) or the editor's
 * socket fails; it runs as a child in this process group, so the terminal's
 * Ctrl-C reaches it too, and it is killed explicitly once the app forward exits.
 */
async function offerPortForward(context: string): Promise<void> {
  const forward = await p.confirm({
    message: `Port-forward now so you can open ${APP_URL}?`,
    initialValue: true,
  })
  if (!forward) {
    p.log.info(
      theme.muted(
        `Skipped — run both forwards when you want to reach it (the second keeps the editor's socket alive):\n${forwardCommands(
          context
        )
          .map((command) => `  ${command}`)
          .join('\n')}`
      )
    )
    return
  }

  const scope = ['--context', context, '-n', NAMESPACE]
  const realtime = spawn(
    'kubectl',
    [...scope, 'port-forward', `svc/${RELEASE}-realtime`, '3002:3002'],
    // stderr is kept so a failure can be explained; a silently dead second
    // forward looks exactly like a working setup until the editor won't connect.
    { stdio: ['ignore', 'ignore', 'pipe'] }
  )
  let realtimeError = ''
  realtime.stderr?.on('data', (chunk) => {
    realtimeError += chunk
  })
  // Only an exit we did not ask for is a problem — the kill below also fires this.
  let stopping = false
  realtime.once('exit', (code) => {
    if (stopping || code === 0) return
    p.log.warn(
      `The realtime forward (:3002) stopped — the editor's socket will not connect. ${
        realtimeError.trim() || `Check that :3002 is free and svc/${RELEASE}-realtime exists.`
      }`
    )
  })

  p.log.step(`Forwarding ${APP_URL} (app) and :3002 (realtime) — Ctrl-C to stop`)
  spawnSync('kubectl', [...scope, 'port-forward', `svc/${RELEASE}-app`, '3000:3000'], {
    stdio: 'inherit',
  })
  stopping = true
  realtime.kill()
}