/**
 * @file
 *
 * Provides a pair of byte streams that can be used to buffer bi-directional
 * stream traffic between two endpoints.
 */

/******************************************************************************
 *
 *
 * Copyright (c) 2009-2011, 2014, AllSeen Alliance. All rights reserved.
 *
 *    Permission to use, copy, modify, and/or distribute this software for any
 *    purpose with or without fee is hereby granted, provided that the above
 *    copyright notice and this permission notice appear in all copies.
 *
 *    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 ******************************************************************************/

#ifndef _QCC_BYTESTREAMPAIR_H
#define _QCC_BYTESTREAMPAIR_H

#include <qcc/platform.h>
#include <qcc/String.h>
#include <qcc/Pipe.h>
#include <qcc/Stream.h>

namespace qcc {

/**
 * Stream implementation returned by ByteStreamPair
 */
class ByteStream : public Stream {
  public:

    /** Construct an ByteStream */
    ByteStream() : source(NULL) { };

    /**
     * Virtual destructor for derivable class.
     */
    virtual ~ByteStream() { }

    /**
     * Get the source.
     *
     * @return Underlying source
     */
    Source* GetSource() { return &pipe; }

    /**
     * Set the source.
     *
     * @param source  Incomming byte source.
     */
    void SetSource(Source* source) { this->source = source; }

    /**
     * Pull bytes from the ByteStream
     * The source is exhausted when ER_EOF is returned.
     *
     * @param buf          Buffer to store pulled bytes
     * @param reqBytes     Number of bytes requested to be pulled from source.
     * @param actualBytes  Actual number of bytes retrieved from source.
     * @return   ER_OK if successful. ER_EOF if source is exhausted. Otherwise an error.
     */
    QStatus PullBytes(void* buf, size_t reqBytes, size_t& actualBytes)
    {
        QStatus status = ER_FAIL;

        if (source) {
            status = source->PullBytes(buf, reqBytes, actualBytes);
        }
        return status;
    }

    /**
     * Push bytes into the sink.
     *
     * @param buf          Buffer to store pulled bytes
     * @param numBytes     Number of bytes from buf to send to sink.
     * @param numSent      Number of bytes actually consumed by sink.
     * @return   ER_OK if successful.
     */
    QStatus PushBytes(const void* buf, size_t numBytes, size_t& numSent)
    {
        return pipe.PushBytes(buf, numBytes, numSent);
    }

  private:
    Source* source;
    Pipe pipe;
};


/**
 * Provides a pair of byte streams that can be used to buffer bi-directional
 * stream traffic between two endpoints.
 */
class ByteStreamPair {
  public:

    /**
     * Construct an ByteStreamPair
     */
    ByteStreamPair()
    {
        first.SetSource(second.GetSource());
        second.SetSource(first.GetSource());
    }

    /**
     * Virtual destructor for derivable class.
     */
    virtual ~ByteStreamPair() { }

    /**
     * Get "first" Stream.
     *
     * @return  Reference to "first" stream.
     */
    Stream& GetFirstStream() { return first; }

    /**
     * Get "first" Stream.
     *
     * @return  Reference to "second" stream.
     */
    Stream& GetSecondStream() { return second; }

  private:

    ByteStream first;    /**< "First" side byte stream */
    ByteStream second;   /**< "Second" side byte stream */
};

}  /* namespace */

#endif