import * as pty from 'node-pty'
import { EventEmitter } from 'events'

export class PTYManager extends EventEmitter {
  private ptyProcess: pty.IPty | null = null
  private resolvedShell: string

  constructor() {
    super()
    this.resolvedShell = this.resolveShell('claude')
  }

  start(_shell: string = 'claude', args: string[] = []) {
    this.ptyProcess = pty.spawn(this.resolvedShell, args, {
      name: 'xterm-color',
      cols: 80,
      rows: 24,
      cwd: process.env.HOME,
      env: process.env as { [key: string]: string },
    })

    this.ptyProcess.onData((data: string) => {
      this.emit('data', data)
    })

    this.ptyProcess.onExit(({ exitCode }) => {
      this.emit('exit', exitCode)
    })

    return this.ptyProcess
  }

  write(data: string) {
    if (this.ptyProcess) {
      this.ptyProcess.write(data)
    }
  }

  resize(cols: number, rows: number) {
    if (this.ptyProcess) {
      this.ptyProcess.resize(cols, rows)
    }
  }

  kill() {
    if (this.ptyProcess) {
      this.ptyProcess.kill()
      this.ptyProcess = null
    }
  }

  private resolveShell(shell: string): string {
    if (shell === 'claude') {
      const { execSync } = require('child_process')
      try {
        return execSync('which claude', { encoding: 'utf8' }).trim()
      } catch {
        throw new Error(
          'Claude CLI not found. Please install it: https://claude.ai/download'
        )
      }
    }
    return shell
  }
}