import test from 'brittle'
import fs from 'fs'
import path from 'path'
import os from 'os'
import {
  discoverCgroupContainers,
  readCgroupCpu,
  readCgroupMemory,
  isDockerCollectorEnabled,
  resolveDockerSocket,
} from '../server/services/collectors/docker.js'
import {
  makeDockerCpuChart,
  makeDockerMemChart,
  DOCKER_CONTAINERS_CHART,
} from '../shared/metrics.js'

function writeFixtureCgroup(root, id) {
  const dir = path.join(root, `docker-${id}.scope`)
  fs.mkdirSync(dir, { recursive: true })
  fs.writeFileSync(
    path.join(dir, 'cpu.stat'),
    'usage_usec 5000000\nuser_usec 4000000\nsystem_usec 1000000\n'
  )
  fs.writeFileSync(path.join(dir, 'memory.current'), String(64 * 1024 * 1024))
  fs.writeFileSync(path.join(dir, 'memory.max'), String(256 * 1024 * 1024))
  return dir
}

test('docker chart helpers', (t) => {
  t.is(DOCKER_CONTAINERS_CHART.id, 'docker.containers')
  const cpu = makeDockerCpuChart('abc123def456', 'nginx')
  t.is(cpu.id, 'docker.cpu.abc123def456')
  t.is(cpu.context, 'docker.cpu')
  t.is(cpu.title, 'nginx · CPU')
  t.is(cpu.family, 'nginx')
  const mem = makeDockerMemChart('abc123def456', 'nginx')
  t.is(mem.id, 'docker.mem.abc123def456')
  t.is(mem.title, 'nginx · memory')
  t.ok(mem.dimensions.find((d) => d.id === 'usage'))
})

test('isDockerCollectorEnabled', (t) => {
  const prev = process.env.PEARDATA_DOCKER
  delete process.env.PEARDATA_DOCKER
  t.absent(isDockerCollectorEnabled())
  process.env.PEARDATA_DOCKER = '1'
  t.ok(isDockerCollectorEnabled())
  if (prev == null) delete process.env.PEARDATA_DOCKER
  else process.env.PEARDATA_DOCKER = prev
})

test('resolveDockerSocket prefers existing preferred path', (t) => {
  const fallback = resolveDockerSocket('/nonexistent-docker-sock-peardata-test')
  t.ok(typeof fallback === 'string')
  t.ok(fallback.includes('docker.sock') || fallback.includes('podman.sock'))
})

test('readCgroupCpu / memory from fixture', (t) => {
  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'peardata-cgroup-'))
  const slice = path.join(tmp, 'system.slice')
  fs.mkdirSync(slice, { recursive: true })
  const id = 'a'.repeat(64)
  const cgroupPath = writeFixtureCgroup(slice, id)

  const cpu = readCgroupCpu(cgroupPath)
  t.ok(cpu)
  t.is(cpu.usageNs, 5000000 * 1000)

  const mem = readCgroupMemory(cgroupPath)
  t.ok(mem)
  t.is(mem.usage, 64 * 1024 * 1024)
  t.is(mem.limit, 256 * 1024 * 1024)

  t.ok(typeof discoverCgroupContainers === 'function')

  fs.rmSync(tmp, { recursive: true, force: true })
})