/*
 * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */
package me.msfjarvis.openpgpktx.util

import android.os.ParcelFileDescriptor
import android.os.ParcelFileDescriptor.AutoCloseInputStream
import android.os.ParcelFileDescriptor.AutoCloseOutputStream
import android.util.Log
import java.io.IOException
import java.io.InputStream
import java.io.OutputStream

internal object ParcelFileDescriptorUtil {

  private const val TAG = "PFDUtils"

  @Throws(IOException::class)
  internal fun pipeFrom(inputStream: InputStream): ParcelFileDescriptor {
    val pipe = ParcelFileDescriptor.createPipe()
    val readSide = pipe[0]
    val writeSide = pipe[1]
    TransferThread(inputStream, AutoCloseOutputStream(writeSide)).start()
    return readSide
  }

  @Throws(IOException::class)
  internal fun pipeTo(outputStream: OutputStream, output: ParcelFileDescriptor?): TransferThread {
    val t = TransferThread(AutoCloseInputStream(output), outputStream)
    t.start()
    return t
  }

  internal class TransferThread(val `in`: InputStream, private val out: OutputStream) : Thread("IPC Transfer Thread") {

    override fun run() {
      val buf = ByteArray(4096)
      var len: Int
      try {
        while (`in`.read(buf).also { len = it } > 0) {
          out.write(buf, 0, len)
        }
      } catch (e: IOException) {
        Log.e(TAG, "IOException when writing to out", e)
      } finally {
        try {
          `in`.close()
        } catch (ignored: IOException) {}
        try {
          out.close()
        } catch (ignored: IOException) {}
      }
    }

    init {
      isDaemon = true
    }
  }
}