/**
 * Copyright (C) 2015-2018 Virgil Security 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:
 *
 *     (1) Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *     (2) 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.
 *
 *     (3) Neither the name of the copyright holder 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 AUTHOR ''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 AUTHOR 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, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Lead Maintainer: Virgil Security Inc. <support@virgilsecurity.com>
 */


#if VIRGIL_CRYPTO_FEATURE_STREAM_IMPL

#include <virgil/crypto/VirgilByteArray.h>
#include <virgil/crypto/stream/VirgilStreamDataSource.h>

#include <algorithm>

using virgil::crypto::VirgilByteArray;
using virgil::crypto::stream::VirgilStreamDataSource;

static const size_t kChunkSizeMin = 32;

VirgilStreamDataSource::VirgilStreamDataSource(std::istream& in, size_t chunkSize)
        : in_(in), chunkSize_(std::max(chunkSize, kChunkSizeMin)) {
}

VirgilStreamDataSource::~VirgilStreamDataSource() noexcept {
}

bool VirgilStreamDataSource::hasData() {
    return in_.good();
}

VirgilByteArray VirgilStreamDataSource::read() {
    VirgilByteArray result(chunkSize_);
    in_.read(reinterpret_cast<std::istream::char_type*>(result.data()), chunkSize_);
    if (!in_) {
        // Only part of chunk was read, so result MUST be trimmed.
        result.resize(in_.gcount());
    }
    return result;
}

#endif /* VIRGIL_CRYPTO_FEATURE_STREAM_IMPL */