/**
 * Pear often runs without `process.stdin` / `process.stdout`; Holepunch uses `bare-stdio`
 * on fds 0–2 (same idea as pear-terminal's stdio singleton).
 */

import { bindReplDebugStream, isReplDebug, replDbg } from './debug-repl.js'

/**
 * @returns {Promise<{ stdin: import('stream').Readable | null, stdout: import('stream').Writable | null }>}
 */
export async function resolveStdio() {
  const p = globalThis.process
  if (p?.stdin && p?.stdout) {
    if (isReplDebug()) {
      bindReplDebugStream(p.stdout)
      replDbg(
        'resolve-stdio',
        'process stdin/stdout',
        JSON.stringify({
          stdinIsTTY: p.stdin.isTTY,
          stdoutColumns: p.stdout.columns,
          hasCursorTo: typeof p.stdout.cursorTo,
          hasClearLine: typeof p.stdout.clearLine
        })
      )
    }
    return { stdin: p.stdin, stdout: p.stdout }
  }
  try {
    const mod = await import('bare-stdio')
    const io = mod.default?.in ? mod.default : mod
    if (io?.in && io?.out) {
      if (isReplDebug()) {
        bindReplDebugStream(io.out)
        replDbg(
          'resolve-stdio',
          'bare-stdio',
          JSON.stringify({
            stdinIsTTY: io.in.isTTY,
            stdoutColumns: io.out.columns,
            hasCursorTo: typeof io.out.cursorTo,
            hasClearLine: typeof io.out.clearLine
          })
        )
      }
      return { stdin: io.in, stdout: io.out }
    }
  } catch (e) {
    if (isReplDebug())
      replDbg('resolve-stdio', 'bare-stdio unavailable', String(e))
  }
  if (isReplDebug()) replDbg('resolve-stdio', 'no stdin/stdout')
  return { stdin: null, stdout: null }
}