detect.ts

import fs from 'node:fs'
import path from 'node:path'
import { execaCommand } from 'execa'
import { findUp } from 'find-up'
import terminalLink from 'terminal-link'
import prompts from '@posva/prompts'
import type { Agent } from './agents'
import { AGENTS, INSTALL_PAGE, LOCKS } from './agents'
import { cmdExists } from './utils'

export interface DetectOptions {
  autoInstall?: boolean
  programmatic?: boolean
  cwd?: string
}

export async function detect({ autoInstall, programmatic, cwd }: DetectOptions = {}) {
  let agent: Agent | null = null
  let version: string | null = null

  const lockPath = await findUp(Object.keys(LOCKS), { cwd })
  let packageJsonPath: string | undefined

  if (lockPath)
    packageJsonPath = path.resolve(lockPath, '../package.json')
  else
    packageJsonPath = await findUp('package.json', { cwd })

  // read `packageManager` field in package.json
  if (packageJsonPath && fs.existsSync(packageJsonPath)) {
    try {
      const pkg = JSON.parse(fs.readFileSync(packageJsonPath, 'utf8'))
      if (typeof pkg.packageManager === 'string') {
        const [name, ver] = pkg.packageManager.split('@')
        version = ver
        if (name === 'yarn' && parseInt(ver) > 1)
          agent = 'yarn@berry'
        else if (name === 'pnpm' && parseInt(ver) < 7)
          agent = 'pnpm@6'
        else if (name in AGENTS)
          agent = name
        else if (!programmatic)
          console.warn('[ni] Unknown packageManager:', pkg.packageManager)
      }
    }
    catch {}
  }

  // detect based on lock
  if (!agent && lockPath)
    agent = LOCKS[path.basename(lockPath)]

  // auto install
  if (agent && !cmdExists(agent.split('@')[0]) && !programmatic) {
    if (!autoInstall) {
      console.warn(`[ni] Detected ${agent} but it doesn't seem to be installed.\n`)

      if (process.env.CI)
        process.exit(1)

      const link = terminalLink(agent, INSTALL_PAGE[agent])
      const { tryInstall } = await prompts({
        name: 'tryInstall',
        type: 'confirm',
        message: `Would you like to globally install ${link}?`,
      })
      if (!tryInstall)
        process.exit(1)
    }

    await execaCommand(`npm i -g ${agent}${version ? `@${version}` : ''}`, { stdio: 'inherit', cwd })
  }

  return agent
}