/*
 *
 * Copyright 2016, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#if SWIFT_PACKAGE
  import CgRPC
#endif
import Foundation // for String.Encoding

/// Representation of raw data that may be sent and received using gRPC
class ByteBuffer {

  /// Pointer to underlying C representation
  var b: UnsafeMutableRawPointer!

  /// The provider of data in the buffer (if needed) to ensure that it is retained.
  private var source : Any?

  /// Initializes a ByteBuffer
  ///
  /// - Parameter b: the underlying C representation
  init(b: UnsafeMutableRawPointer) {
    self.b = b
  }

  /// Initializes a ByteBuffer
  ///
  /// - Parameter string: a string to store in the buffer
  init(string: String) {
    self.b = cgrpc_byte_buffer_create_with_string(string)
    self.source = string
  }

  /// Initializes a ByteBuffer
  ///
  /// - Parameter data: data to store in the buffer
  init(data: Data) {
    data.withUnsafeBytes { (bytes) in
      self.b = cgrpc_byte_buffer_create_with_data(bytes, data.count)
    }
    self.source = data
  }

  deinit {
    cgrpc_byte_buffer_destroy(b);
  }

  /// Gets a string from the contents of the ByteBuffer
  ///
  /// - Returns: a string formed from the ByteBuffer contents
  func string() -> String {
    return String(cString:cgrpc_byte_buffer_as_string(b),
                  encoding:String.Encoding.utf8)!
  }

  /// Gets raw data from the contents of the ByteBuffer
  ///
  /// - Returns: data formed from the ByteBuffer contents
  func data() -> Data {
    var length : Int = 0
    let bytes = cgrpc_byte_buffer_as_data(b, &length)
    return Data(bytes:bytes!, count: length)
  }
}