/*
 * Copyright 2017, gRPC Authors All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import Foundation

// The I/O code below is derived from Apple's swift-protobuf project.
// https://github.com/apple/swift-protobuf
// BEGIN swift-protobuf derivation

#if os(Linux)
import Glibc
#else
import Darwin.C
#endif

enum PluginError: Error {
  /// Raised for any errors reading the input
  case readFailure
}

// Alias clib's write() so Stdout.write(bytes:) can call it.
private let _write = write

enum Stdin {
  static func readall() throws -> Data {
    let fd: Int32 = 0
    let buffSize = 32
    var buff = [UInt8]()
    while true {
      var fragment = [UInt8](repeating: 0, count: buffSize)
      let count = read(fd, &fragment, buffSize)
      if count < 0 {
        throw PluginError.readFailure
      }
      if count < buffSize {
        buff += fragment[0 ..< count]
        return Data(buff)
      }
      buff += fragment
    }
  }
}

enum Stdout {
  static func write(bytes: Data) {
    bytes.withUnsafeBytes { (p: UnsafeRawBufferPointer) in
      _ = _write(1, p.baseAddress, p.count)
    }
  }
}

// END swift-protobuf derivation