module.exports = collect

function collect (stream) {
  if (stream._collected) return

  stream._collected = true
  stream.pause()

  stream.on('data', save)
  stream.on('end', save)
  var buf = []
  function save (b) {
    if (typeof b === 'string') b = new Buffer(b)
    if (Buffer.isBuffer(b) && !b.length) return
    buf.push(b)
  }

  stream.on('entry', saveEntry)
  var entryBuffer = []
  function saveEntry (e) {
    collect(e)
    entryBuffer.push(e)
  }

  stream.on('proxy', proxyPause)
  function proxyPause (p) {
    p.pause()
  }

  // replace the pipe method with a new version that will
  // unlock the buffered stuff.  if you just call .pipe()
  // without a destination, then it'll re-play the events.
  stream.pipe = (function (orig) {
    return function (dest) {
      // console.error(' === open the pipes', dest && dest.path)

      // let the entries flow through one at a time.
      // Once they're all done, then we can resume completely.
      var e = 0
      ;(function unblockEntry () {
        var entry = entryBuffer[e++]
        // console.error(" ==== unblock entry", entry && entry.path)
        if (!entry) return resume()
        entry.on('end', unblockEntry)
        if (dest) dest.add(entry)
        else stream.emit('entry', entry)
      })()

      function resume () {
        stream.removeListener('entry', saveEntry)
        stream.removeListener('data', save)
        stream.removeListener('end', save)

        stream.pipe = orig
        if (dest) stream.pipe(dest)

        buf.forEach(function (b) {
          if (b) stream.emit('data', b)
          else stream.emit('end')
        })

        stream.resume()
      }

      return dest
    }
  })(stream.pipe)
}