import { spawn, spawnSync, type ChildProcess } from 'child_process'
import { existsSync, mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'fs'
import { createServer, type Server } from 'node:http'
import type { AddressInfo } from 'node:net'
import { tmpdir } from 'os'
import { join } from 'path'
import { fileURLToPath } from 'url'
import { afterEach, describe, expect, it } from 'vitest'

const CLI_ROOT = fileURLToPath(new URL('..', import.meta.url))
const CLI_SOURCE = join(CLI_ROOT, 'src', 'cli.ts')
const TSX = join(CLI_ROOT, 'node_modules', 'tsx', 'dist', 'cli.mjs')
const dirs: string[] = []
const children: ChildProcess[] = []
const servers: Server[] = []

afterEach(async () => {
  for (const child of children.splice(0)) {
    if (child.exitCode === null && child.signalCode === null) child.kill('SIGKILL')
  }
  for (const server of servers.splice(0)) {
    server.closeAllConnections?.()
    await new Promise<void>((resolve) => server.close(() => resolve()))
  }
  for (const dir of dirs.splice(0)) rmSync(dir, { recursive: true, force: true })
})

/** A throwaway HOME for one CLI run; every path the CLI writes is under it. */
function freshRoot(): string {
  const root = mkdtempSync(join(tmpdir(), 'harness-cli-command-'))
  dirs.push(root)
  return root
}

function envFor(root: string, extra: NodeJS.ProcessEnv = {}): NodeJS.ProcessEnv {
  return {
    ...process.env,
    HOME: root,
    HARNESS_AUTH_DIR: join(root, 'auth'),
    ADAPTER_DATA_DIR: join(root, 'data'),
    ADAPTER_CLI_DIR: join(root, 'cli'),
    ADAPTER_COMPUTER_ID_FILE: join(root, 'computer-id'),
    ADAPTER_UPDATE_DISABLE: 'true',
    // Nothing listens on port 1. A `start` asks the daemon on PORT which account it serves and would
    // otherwise ask this machine's REAL daemon — and the backend is where a start that decided to
    // (re)start goes next, which must never be the production one.
    PORT: '1',
    BACKEND_WS_URL: 'http://127.0.0.1:1',
    ...extra,
  }
}

function run(...args: string[]) {
  return spawnSync(process.execPath, [TSX, CLI_SOURCE, ...args], { cwd: CLI_ROOT, encoding: 'utf8', env: envFor(freshRoot()) })
}

/** The same run, without blocking this process: a test that also SERVES the CLI something (a manifest on
 *  the loopback) has to keep its own event loop free while the child asks for it. */
function runAsync(root: string, args: string[], extra: NodeJS.ProcessEnv): Promise<{ status: number | null; stdout: string; stderr: string }> {
  return new Promise((resolve) => {
    const child = spawn(process.execPath, [TSX, CLI_SOURCE, ...args], { cwd: CLI_ROOT, env: envFor(root, extra), stdio: ['ignore', 'pipe', 'pipe'] })
    let stdout = ''
    let stderr = ''
    child.stdout.on('data', (chunk: Buffer) => { stdout += chunk.toString() })
    child.stderr.on('data', (chunk: Buffer) => { stderr += chunk.toString() })
    child.on('close', (status) => resolve({ status, stdout, stderr }))
  })
}

/** A signed-in computer: `start` refuses without one, before it looks at anything else. */
function seedSession(root: string): void {
  mkdirSync(join(root, 'auth'), { recursive: true })
  writeFileSync(join(root, 'auth', 'session.json'), JSON.stringify({
    version: 1, accessToken: 'tok', refreshToken: 'refresh', expiresAt: Date.now() + 3_600_000,
    autonomousEnv: 'prod', computerId: 'a'.repeat(32), machineId: 'm_seeded', updatedAt: Date.now(),
  }))
}

/** A daemon that is up, as `start` sees one: a pid file naming a live process. A child that idles,
 *  never this process — a `start` that finds the daemon on another account stops it. */
function seedRunningDaemon(root: string): { pid: number; exited: Promise<void> } {
  const child = spawn(process.execPath, ['-e', 'setInterval(() => {}, 1000)'], { stdio: 'ignore' })
  children.push(child)
  mkdirSync(join(root, 'data'), { recursive: true })
  writeFileSync(join(root, 'data', 'adapter.pid'), `${child.pid}\n`)
  return { pid: child.pid ?? -1, exited: new Promise((resolve) => child.once('exit', () => resolve())) }
}

/** The one thing `start` asks a live daemon: GET /api/status, for the machine it serves. Bound to a
 *  port of its own, which the test hands the CLI as PORT. */
async function daemonStatusServer(machineId: string): Promise<number> {
  const server = createServer((_req, res) => {
    res.setHeader('content-type', 'application/json')
    res.end(JSON.stringify({ machineId, version: '0.0.0-test', sessions: [] }))
  })
  servers.push(server)
  await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve))
  return (server.address() as AddressInfo).port
}

describe('CLI login/start command contract', () => {
  it('does not start or open SSO when start has no saved session', () => {
    const result = run('start')

    expect(result.status).toBe(1)
    expect(result.stderr).toContain('Not signed in. Run: harness login')
    expect(result.stdout).not.toContain('Sign in to Harness in your browser')
  })

  it('rejects the removed join command with the two-step migration', () => {
    const result = run('join')

    expect(result.status).toBe(1)
    expect(result.stderr).toContain('`harness join` has been removed.')
    expect(result.stderr).toContain('`harness login`, then `harness start`')
  })

  it('no longer has an analytics command (usage metering upload was removed)', () => {
    const result = run('analytics')

    expect(result.status).toBe(1)
    expect(result.stderr).toContain('Unknown command: analytics')
  })

  it('returns a nonzero status for an unknown command', () => {
    const result = run('not-a-command')

    expect(result.status).toBe(1)
    expect(result.stderr).toContain('Unknown command: not-a-command')
  })
})

describe('start --repair beside a running daemon', () => {
  // The managed runtimes live beside the bundle, not in it, and the daemon reads `current-grid` on every
  // resolve — so a grid laid down here is the one its next spawn runs, with no restart. `--repair` is the
  // one place a person WATCHES that provisioning; beside a live daemon it used to exit at "already
  // running" before reaching it, and the only way to follow a new pin was a restart.
  const key = `${process.platform}-${process.arch}`

  /** Serves a grid manifest that pins 9.9.9 to an archive nobody can fetch: the download is refused at
   *  once, which is a best-effort skip inside ensureManagedGrid — and the "installing" line has already
   *  said the step was reached, which is the whole of what this contract is about. */
  async function withManifest<T>(body: (url: string) => Promise<T>): Promise<T> {
    const server = createServer((_req, res) => {
      res.setHeader('content-type', 'application/json')
      res.end(JSON.stringify({ grid: { [key]: {
        version: '9.9.9', url: 'https://127.0.0.1:1/grid.tar.gz', sha256: '0'.repeat(64), archiveRoot: `grid-9.9.9-${key}`,
      } } }))
    })
    await new Promise<void>((resolve) => server.listen(0, '127.0.0.1', resolve))
    try {
      return await body(`http://127.0.0.1:${(server.address() as AddressInfo).port}/metadata.json`)
    } finally {
      await new Promise<void>((resolve) => server.close(() => resolve()))
    }
  }

  const noNode = 'http://127.0.0.1:9/metadata.json'   // refused at once: the Node runtime is not what is under test

  it('provisions the managed grid for the daemon that is up, and still leaves the daemon itself alone', async () => {
    const root = freshRoot()
    seedSession(root)
    seedRunningDaemon(root)
    const result = await withManifest((manifest) => runAsync(root, ['start', '--repair'], {
      ADAPTER_RUNTIME_DIR: join(root, 'runtime'), ADAPTER_RUNTIME_METADATA_URL: noNode, ADAPTER_GRID_RUNTIME_METADATA_URL: manifest,
    }))

    expect(result.status).toBe(0)
    expect(result.stdout).toContain(`installing the Harness grid runtime (9.9.9, ${key})`)
    expect(result.stdout).toContain('already running')
    expect(result.stdout).not.toContain('updated to v')   // no bundle staging beside a live daemon
  }, 20_000)

  it('a plain start beside a running daemon touches nothing', async () => {
    const root = freshRoot()
    seedSession(root)
    seedRunningDaemon(root)
    const result = await withManifest((manifest) => runAsync(root, ['start'], {
      ADAPTER_RUNTIME_DIR: join(root, 'runtime'), ADAPTER_RUNTIME_METADATA_URL: noNode, ADAPTER_GRID_RUNTIME_METADATA_URL: manifest,
    }))

    expect(result.status).toBe(0)
    expect(result.stdout).toContain('already running')
    expect(result.stdout).not.toContain('installing the Harness grid runtime')
  }, 20_000)
})

describe('start beside a daemon that serves another account', () => {
  // A forced login stops the daemon and waits for the browser, and a start that landed in that window
  // used to bring a daemon up on the OLD session (closed under the spawn lock now — loginForceRace.spec.ts).
  // "Already running" is what kept it there: `auth status` named the new machine, the socket served the
  // old one. However a daemon ends up on the wrong account, this is where it is noticed — `start` asks
  // the live daemon which machine it serves before leaving it alone.

  it('stops it and starts over on the session that is on disk', async () => {
    const root = freshRoot()
    seedSession(root)                                  // machineId m_seeded
    const daemon = seedRunningDaemon(root)
    const port = await daemonStatusServer('m_other')

    const result = await runAsync(root, ['start'], { PORT: String(port) })

    expect(result.stdout).toContain(`machine running (pid ${daemon.pid}) as another account — restarting it`)
    expect(result.stdout).not.toContain('already running')
    await daemon.exited
    expect(existsSync(join(root, 'data', 'adapter.pid'))).toBe(false)
    // The restart goes on to boot a daemon inline (a repo run) — which fails to bind, because the port
    // it was handed is this test's own status server. Past the point under test; the backend is never
    // consulted (start no longer resolves the machine when the session already names one).
    expect(result.status).toBe(1)
    expect(result.stdout + result.stderr).not.toContain('resolve-computer')
  }, 20_000)

  it('starts without the backend: a session that already names its machine never calls it', async () => {
    // Offline is the case this exists for. The backend here is port 1 — refused instantly — and the
    // only thing that stops the boot is the port clash with this test's status server, AFTER the point
    // where `start` used to abort on the resolve. No "Failed to start adapter: fetch failed".
    const root = freshRoot()
    seedSession(root)
    const port = await daemonStatusServer('m_other')

    const result = await runAsync(root, ['start'], { PORT: String(port) })

    expect(result.stderr).not.toContain('fetch failed')
    expect(result.stdout + result.stderr).not.toContain('resolve-computer')
    expect(result.stdout).toContain('dev mode — running in the foreground')
  }, 20_000)

  it('starts without the backend even when the session has no machine id yet, on the computer id', async () => {
    const root = freshRoot()
    mkdirSync(join(root, 'auth'), { recursive: true })
    writeFileSync(join(root, 'auth', 'session.json'), JSON.stringify({
      version: 1, accessToken: 'tok', refreshToken: 'refresh', expiresAt: Date.now() + 3_600_000,
      autonomousEnv: 'prod', computerId: 'a'.repeat(32), updatedAt: Date.now(),
    }))
    const port = await daemonStatusServer('m_other')

    const result = await runAsync(root, ['start'], { PORT: String(port) })

    expect(result.stdout).toContain('machine id not resolved yet')
    expect(result.stdout).toContain('dev mode — running in the foreground')
  }, 20_000)

  it('leaves one that serves this session alone', async () => {
    const root = freshRoot()
    seedSession(root)
    const daemon = seedRunningDaemon(root)
    const port = await daemonStatusServer('m_seeded')

    const result = await runAsync(root, ['start'], { PORT: String(port) })

    expect(result.status).toBe(0)
    expect(result.stdout).toContain('already running')
    expect(existsSync(join(root, 'data', 'adapter.pid'))).toBe(true)
    await expect(Promise.race([daemon.exited.then(() => 'exited'), new Promise((r) => setTimeout(() => r('alive'), 300))]))
      .resolves.toBe('alive')
  }, 20_000)
})