import assert from 'node:assert/strict'
import { chmod, mkdir, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises'
import { existsSync } from 'node:fs'
import { delimiter, join, resolve } from 'node:path'
import { tmpdir } from 'node:os'
import { spawnSync } from 'node:child_process'
import test from 'node:test'

const root = resolve(import.meta.dirname, '..')
const script = resolve(root, 'deploy/scripts/deploy-blue-green-service.sh')
const shell = process.platform === 'win32' ? 'C:/Program Files/Git/bin/bash.exe' : '/bin/sh'

const dockerMock = `#!/usr/bin/env sh
set -eu
printf '%s\\n' "$*" >> "$MOCK_LOG"
command="$1"
shift
case "$command" in
  network)
    [ "$1" = inspect ] && { echo '{}'; exit 0; }
    exit 0
    ;;
  compose)
    container_name=''
    previous=''
    for argument in "$@"; do
      if [ "$previous" = --name ]; then container_name="$argument"; fi
      previous="$argument"
      if [ "$argument" = run ]; then
        action=run
      fi
    done
    if [ "\${action:-}" = run ]; then
      case "$container_name" in
        *-worker) : > "$MOCK_WORKER_EXISTS" ;;
        *) : > "$MOCK_CANDIDATE_EXISTS" ;;
      esac
      exit 0
    fi
    exit 0
    ;;
  inspect)
    target=''
    for argument in "$@"; do target="$argument"; done
    case "$target" in
      firstleg-production-file)
        [ ! -f "$MOCK_LEGACY_REMOVED" ]
        ;;
      firstleg-production-file-green)
        [ -f "$MOCK_CANDIDATE_EXISTS" ] || exit 1
        case "$*" in
          *State.Health*) printf '%s\\n' "\${MOCK_CANDIDATE_HEALTH:-healthy}" ;;
          *Config.Image*) printf '%s\\n' 'registry.local/group/file:newtag' ;;
        esac
        ;;
      firstleg-production-file-green-worker)
        [ -f "$MOCK_WORKER_EXISTS" ] || exit 1
        case "$*" in
          *State.Health*) printf '%s\\n' healthy ;;
          *Config.Image*) printf '%s\\n' 'registry.local/group/file:newtag' ;;
        esac
        ;;
      *) exit 1 ;;
    esac
    ;;
  stop)
    target=''
    for argument in "$@"; do target="$argument"; done
    [ "$target" = firstleg-production-file ] && : > "$MOCK_LEGACY_STOPPED"
    ;;
  rm)
    target=''
    for argument in "$@"; do target="$argument"; done
    case "$target" in
      firstleg-production-file) : > "$MOCK_LEGACY_REMOVED" ;;
      firstleg-production-file-green) rm -f "$MOCK_CANDIDATE_EXISTS" ;;
      firstleg-production-file-green-worker) rm -f "$MOCK_WORKER_EXISTS" ;;
    esac
    ;;
  logs) echo 'candidate logs' ;;
  *) echo "unexpected docker command: $command $*" >&2; exit 2 ;;
esac
`

async function runBlueGreen(health) {
  const temp = await mkdtemp(join(tmpdir(), 'blue-green-runtime-'))
  const bin = join(temp, 'bin')
  const docker = join(bin, 'docker')
  const sleep = join(bin, 'sleep')
  const envFile = join(temp, 'deployment.env')
  const compose = join(temp, 'compose.yml')
  const stateRoot = join(temp, 'state')
  const log = join(temp, 'docker.log')
  await mkdir(bin)
  await mkdir(stateRoot)
  await writeFile(docker, dockerMock, 'utf8')
  await writeFile(sleep, '#!/usr/bin/env sh\nexit 0\n', 'utf8')
  await chmod(docker, 0o755)
  await chmod(sleep, 0o755)
  await writeFile(envFile, 'FILE_EXPORT_CONSUMER_ENABLED=true\n', 'utf8')
  await writeFile(compose, 'services: {}\n', 'utf8')
  await writeFile(log, '', 'utf8')

  const paths = {
    candidate: join(temp, 'candidate'), stopped: join(temp, 'legacy-stopped'),
    removed: join(temp, 'legacy-removed'), worker: join(temp, 'worker')
  }
  const result = spawnSync(shell, [
    script.replaceAll('\\', '/'), 'production', 'registry.local/group', 'newtag', 'file',
    envFile.replaceAll('\\', '/'), compose.replaceAll('\\', '/'), 'firstleg-production'
  ], {
    cwd: root, encoding: 'utf8', env: {
      ...process.env,
      PATH: `${bin}${delimiter}${process.env.PATH ?? ''}`,
      BLUE_GREEN_STATE_ROOT: stateRoot,
      BLUE_GREEN_STABILIZATION_SECONDS: '0',
      BLUE_GREEN_DRAIN_SECONDS: '0',
      DEPLOY_HEALTH_TIMEOUT_SECONDS: '2',
      DEPLOY_HEALTH_POLL_SECONDS: '1',
      MOCK_LOG: log,
      MOCK_CANDIDATE_EXISTS: paths.candidate,
      MOCK_WORKER_EXISTS: paths.worker,
      MOCK_LEGACY_STOPPED: paths.stopped,
      MOCK_LEGACY_REMOVED: paths.removed,
      MOCK_CANDIDATE_HEALTH: health
    }
  })
  const output = `${result.stdout}\n${result.stderr}`
  const dockerLog = await readFile(log, 'utf8')
  const stateFile = join(stateRoot, 'firstleg-production-file.active')
  const state = existsSync(stateFile) ? await readFile(stateFile, 'utf8') : ''
  const evidence = {
    ...result, output, dockerLog, state,
    stopped: existsSync(paths.stopped), removed: existsSync(paths.removed),
    worker: existsSync(paths.worker)
  }
  await rm(temp, { recursive: true, force: true })
  return evidence
}

test('healthy candidate becomes active only after health and old instance drains', async (context) => {
  if (!existsSync(shell)) context.skip(`shell unavailable: ${shell}`)
  const result = await runBlueGreen('healthy')
  assert.equal(result.status, 0, result.output)
  assert.equal(result.stopped, true)
  assert.equal(result.removed, true)
  assert.equal(result.worker, true)
  assert.match(result.state, /^green\|firstleg-production-file-green\|19206\|registry\.local\/group\/file:newtag\|firstleg-production-file-green-worker/)
  const run = result.dockerLog.indexOf('compose --project-name firstleg-production')
  const stop = result.dockerLog.indexOf('stop --time 45 firstleg-production-file')
  assert.ok(run >= 0 && run < stop)
  assert.match(result.dockerLog,
    /network connect --alias file --alias file-service firstleg-production-routing firstleg-production-file-green/)
})

test('unhealthy candidate is removed while old instance and state remain untouched', async (context) => {
  if (!existsSync(shell)) context.skip(`shell unavailable: ${shell}`)
  const result = await runBlueGreen('unhealthy')
  assert.equal(result.status, 1, result.output)
  assert.equal(result.stopped, false)
  assert.equal(result.removed, false)
  assert.equal(result.worker, false)
  assert.equal(result.state, '')
  assert.doesNotMatch(result.dockerLog, /stop --time .*firstleg-production-file/)
})