import { EventEmitter } from 'node:events'
import { realpath } from 'node:fs/promises'
import { basename, dirname } from 'node:path'
import { fileURLToPath } from 'node:url'
import { afterEach, describe, expect, it, vi } from 'vitest'
import {
  detectAgentRuntimes,
  detectRuntimeBinary,
  validateRuntimeVersion,
  type RuntimeVersionProcess
} from './runtime-discovery'

const originalPath = process.env.PATH
const originalPathCase = process.env.Path

afterEach(() => {
  if (originalPath === undefined) {
    delete process.env.PATH
  } else {
    process.env.PATH = originalPath
  }
  if (originalPathCase === undefined) {
    delete process.env.Path
  } else {
    process.env.Path = originalPathCase
  }
})

describe('runtime discovery', () => {
  it('launches a detached POSIX version probe and awaits bounded tree cleanup', async () => {
    const child =
      new EventEmitter() as RuntimeVersionProcess & EventEmitter
    child.exitCode = null
    child.pid = 2718
    child.kill = vi.fn()
    child.stdout = new EventEmitter()
    child.stderr = new EventEmitter()
    const spawnProcess = vi.fn(() => child)
    let releaseCleanup!: () => void
    const cleanupBlocked = new Promise<void>((resolve) => {
      releaseCleanup = resolve
    })
    const terminateProcessTree = vi.fn(async () => {
      await cleanupBlocked
    })

    const validation = validateRuntimeVersion('runtime', {
      platform: 'linux',
      spawnProcess,
      terminateProcessTree,
      outputLimit: 4,
      terminationWaitMs: 25
    })
    ;(child.stdout as EventEmitter).emit('data', '12345')
    let completed = false
    void validation.then(() => {
      completed = true
    })
    await Promise.resolve()

    expect(completed).toBe(false)
    expect(spawnProcess).toHaveBeenCalledWith(
      'runtime',
      ['--version'],
      expect.objectContaining({ detached: true })
    )
    expect(terminateProcessTree).toHaveBeenCalledWith(child, {
      platform: 'linux',
      processGroup: true,
      signal: 'SIGKILL',
      waitMs: 25
    })

    releaseCleanup()
    await expect(validation).resolves.toEqual({ valid: false })
  })

  it('canonicalizes and validates a configured ordinary file first', async () => {
    process.env.PATH = ''
    process.env.Path = ''

    const detection = await detectRuntimeBinary({
      binaryPath: process.execPath,
      binaryNames: ['binary-that-does-not-exist'],
      label: 'Test CLI'
    })

    expect(detection).toMatchObject({
      available: true,
      path: await realpath(process.execPath),
      source: 'configured'
    })
    expect(detection.version).toMatch(/^\d+\.\d+\.\d+/u)
  })

  it('rejects relative configured paths without resolving them from cwd', async () => {
    process.env.PATH = ''
    process.env.Path = ''

    await expect(
      detectRuntimeBinary({
        binaryPath: 'relative/runtime',
        binaryNames: ['goodbuddy-runtime-that-does-not-exist'],
        label: 'Test CLI'
      })
    ).resolves.toEqual({
      available: false,
      detail: expect.stringContaining('必须为绝对路径')
    })
  })

  it('finds executable names from absolute PATH directories', async () => {
    process.env.PATH = dirname(process.execPath)
    process.env.Path = dirname(process.execPath)

    const detection = await detectRuntimeBinary({
      binaryPath: '',
      binaryNames: [basename(process.execPath)],
      label: 'Test CLI'
    })

    expect(detection).toMatchObject({
      available: true,
      path: await realpath(process.execPath),
      source: 'automatic'
    })
  })

  it('prefers a configured binary over the bundled runtime', async () => {
    const detection = await detectRuntimeBinary({
      binaryPath: process.execPath,
      bundledPath: process.execPath,
      binaryNames: ['goodbuddy-runtime-that-does-not-exist'],
      label: 'Test CLI'
    })

    expect(detection).toMatchObject({
      available: true,
      path: await realpath(process.execPath),
      source: 'configured'
    })
    expect(detection.detail).not.toContain('内置')
  })

  it('prefers a bundled runtime over PATH discovery', async () => {
    process.env.PATH = dirname(process.execPath)
    process.env.Path = dirname(process.execPath)

    const detection = await detectRuntimeBinary({
      binaryPath: '',
      bundledPath: process.execPath,
      binaryNames: [basename(process.execPath)],
      label: 'Test CLI'
    })

    expect(detection).toMatchObject({
      available: true,
      path: await realpath(process.execPath),
      source: 'bundled'
    })
    expect(detection.detail).toContain('内置')
  })

  it('allows a bundled script to defer execution validation to its host adapter', async () => {
    process.env.PATH = ''
    process.env.Path = ''
    const bundledScript = fileURLToPath(import.meta.url)

    const detection = await detectRuntimeBinary({
      binaryPath: '',
      bundledPath: bundledScript,
      bundledValidation: 'canonical-file',
      bundledVersion: '1.5.47',
      binaryNames: ['goodbuddy-runtime-that-does-not-exist'],
      label: 'Script Runtime'
    })

    expect(detection).toMatchObject({
      available: true,
      path: await realpath(bundledScript),
      version: '1.5.47',
      source: 'bundled'
    })
    expect(detection.detail).toBe(
      '内置 Script Runtime 1.5.47 已就绪'
    )
  })

  it('accepts a controlled bundled harness when no custom host is configured', async () => {
    const bundledScript = fileURLToPath(import.meta.url)
    const detection = await detectRuntimeBinary({
      binaryPath: '',
      bundledPath: bundledScript,
      bundledValidation: 'canonical-file',
      bundledVersion: '0.1.0-rc.8',
      binaryNames: [],
      label: 'GoodBuddy DeepSeek Harness Host'
    })

    expect(detection).toMatchObject({
      available: true,
      path: await realpath(bundledScript),
      version: '0.1.0-rc.8',
      source: 'bundled'
    })
    expect(detection.detail).toContain('内置')
  })

  it('does not discover arbitrary DeepSeek Harness hosts from PATH', async () => {
    process.env.PATH = dirname(process.execPath)
    process.env.Path = dirname(process.execPath)

    await expect(
      detectRuntimeBinary({
        binaryPath: '',
        allowAutomaticDiscovery: false,
        binaryNames: [basename(process.execPath)],
        label: 'GoodBuddy DeepSeek Harness Host'
      })
    ).resolves.toEqual({
      available: false,
      detail: expect.stringContaining('未自动检测到')
    })
  })

  it('returns both runtime detections without exposing PATH contents', async () => {
    const privatePathValue = `${dirname(process.execPath)}-private-path-value`
    process.env.PATH = privatePathValue
    process.env.Path = privatePathValue

    const result = await detectAgentRuntimes({
      opencodeBinaryPath: process.execPath,
      continueBinaryPath: process.execPath
    })

    expect(result.opencode).toMatchObject({
      available: true,
      path: await realpath(process.execPath)
    })
    expect(result.continue).toMatchObject({
      available: true,
      path: await realpath(process.execPath)
    })
    expect(result.deepseekHarness.available).toBe(false)
    expect(JSON.stringify(result)).not.toContain(privatePathValue)
  })
})