text: /*
   * Copyright 2017-2020 Amazon.com, Inc. or its affiliates. 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.
   * A copy of the License is located at
   *
   *     http://aws.amazon.com/apache2.0/
   *
   * or in the "license" file accompanying this file. This file 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.
   */
  
  #ifndef AACE_AUDIO_AUDIO_STREAM_H
  #define AACE_AUDIO_AUDIO_STREAM_H
  
  #include <iostream>
  #include <vector>
  #include <string>
  
  #include "AudioFormat.h"
  
  /** @file */
  
  namespace aace {
  namespace audio {
  
  class AudioStreamProperty;
  
  class AudioStream {
  public:
      using AudioFormat = aace::audio::AudioFormat;
      using Encoding = AudioFormat::Encoding;
  
      /**
       * An enum representing @c MediaType value.
       */
      enum class MediaType {
          /// MPEG media type.
          MPEG,
  
          /// WAV media type.
          WAV,
  
          /// The media type is unknown.
          UNKNOWN
      };
  
      virtual ~AudioStream();
  
      /**
       * Reads audio data from the stream when available. Audio data will be
       * available while @c isClosed() returns false.
       *
       * @param [out] data The buffer where audio data should be copied
       * @param [in] size The size of the buffer
       * @return The number of bytes read, 0 if the end of stream is reached or data is not currently available,
       * or -1 if an error occurred
       */
      virtual ssize_t read(char* data, const size_t size) = 0;
  
      /**
       * Checks if the audio stream from the no more data available to read.
       *
       * @return @c true if the audio stream is closed, @c false if more data
       * will be available
       */
  
      virtual bool isClosed() = 0;
  
      /**
       * Returns the encoding format of the @c AudioStream. If the encoding is not known
       * then @c Encoding::UNKNOWN will be returned.
       *
       * @return @c Encoding format of the @c AudioStream
       * @deprecated Use @c getAudioFormat to return the audio stream encoding and additional
       * audio format properties.
       */
      virtual Encoding getEncoding();
  
      /**
       * Returns the audio format properties of this stream, including the audio encoding type.
       *
       * @return @c AudioFormat specified for this stream.
       */
      virtual AudioFormat getAudioFormat();
  
      /**
       * Returns the media type of the @c AudioStream. If the type is not known
       * then @c MediaType::UNKNOWN will be returned.
       *
       * @return @c MediaType specified for this stream.
       */
      virtual MediaType getMediaType();
  
      /**
       * Returns optional meta-data properties for the @c AudioStream.
       *
       * @return List of meta-data properties for the @c AudioStream.
       */
      virtual std::vector<AudioStreamProperty> getProperties();
  };
  
  /**
   * Key/value type for providing meta-data with the AudioStream.
   */
  class AudioStreamProperty {
  public:
      /**
       * AudioStreamProperty constructor
       *
       * @param  key The property key
       * @param  value The property value
       */
      AudioStreamProperty(const std::string& key, const std::string& value) : m_key{key}, m_value{value} {
      }
  
      /**
       * AudioStreamProperty copy constructor
       *
       * @param  prop The @c AudioStreamProperty being copied
       */
      AudioStreamProperty(const AudioStreamProperty& other) {
          *this = other;
      }
  
      /**
       * AudioStreamProperty copy constructor
       *
       * @param  other The @c AudioStreamProperty being assigned
       */
      AudioStreamProperty& operator=(const AudioStreamProperty& other) = default;
  
      /**
       * @return The property key
       */
      std::string getKey() {
          return m_key;
      }
  
      /**
       * @return The property value
       */
      std::string getValue() {
          return m_value;
      }
  
  private:
      std::string m_key;
      std::string m_value;
  };
  
  }  // namespace audio
  }  // namespace aace
  
  #endif  // AACE_AUDIO_AUDIO_STREAM_H
  