/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2010 Tatsuhiro Tsujikawa
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
/* copyright --> */
#include "SocketBuffer.h"

#include <cassert>
#include <algorithm>

#include "SocketCore.h"
#include "DlAbortEx.h"
#include "message.h"
#include "fmt.h"
#include "LogFactory.h"
#include "a2functional.h"

namespace aria2 {

SocketBuffer::ByteArrayBufEntry::ByteArrayBufEntry
(unsigned char* bytes, size_t length,
 std::unique_ptr<ProgressUpdate> progressUpdate)
  : BufEntry(std::move(progressUpdate)), bytes_(bytes), length_(length)
{}

SocketBuffer::ByteArrayBufEntry::~ByteArrayBufEntry()
{
  delete [] bytes_;
}

ssize_t SocketBuffer::ByteArrayBufEntry::send
(const std::shared_ptr<SocketCore>& socket, size_t offset)
{
  return socket->writeData(bytes_+offset, length_-offset);
}

bool SocketBuffer::ByteArrayBufEntry::final(size_t offset) const
{
  return length_ <= offset;
}

size_t SocketBuffer::ByteArrayBufEntry::getLength() const
{
  return length_;
}

const unsigned char* SocketBuffer::ByteArrayBufEntry::getData() const
{
  return bytes_;
}

SocketBuffer::StringBufEntry::StringBufEntry
(std::string s, std::unique_ptr<ProgressUpdate> progressUpdate)
  : BufEntry(std::move(progressUpdate)), str_(std::move(s))
{}

ssize_t SocketBuffer::StringBufEntry::send
(const std::shared_ptr<SocketCore>& socket, size_t offset)
{
  return socket->writeData(str_.data()+offset, str_.size()-offset);
}

bool SocketBuffer::StringBufEntry::final(size_t offset) const
{
  return str_.size() <= offset;
}

size_t SocketBuffer::StringBufEntry::getLength() const
{
  return str_.size();
}

const unsigned char* SocketBuffer::StringBufEntry::getData() const
{
  return reinterpret_cast<const unsigned char*>(str_.c_str());
}

SocketBuffer::SocketBuffer(std::shared_ptr<SocketCore> socket)
  : socket_(std::move(socket)), offset_(0)
{}

SocketBuffer::~SocketBuffer() {}

void SocketBuffer::pushBytes(unsigned char* bytes, size_t len,
                             std::unique_ptr<ProgressUpdate> progressUpdate)
{
  if(len > 0) {
    bufq_.push_back(make_unique<ByteArrayBufEntry>
                    (bytes, len, std::move(progressUpdate)));
  }
}

void SocketBuffer::pushStr(std::string data,
                           std::unique_ptr<ProgressUpdate> progressUpdate)
{
  if(!data.empty()) {
    bufq_.push_back(make_unique<StringBufEntry>
                    (std::move(data), std::move(progressUpdate)));
  }
}

ssize_t SocketBuffer::send()
{
  a2iovec iov[A2_IOV_MAX];
  size_t totalslen = 0;
  while(!bufq_.empty()) {
    size_t num;
    size_t bufqlen = bufq_.size();
    ssize_t amount = 24_k;
    ssize_t firstlen = bufq_.front()->getLength() - offset_;
    amount -= firstlen;
    iov[0].A2IOVEC_BASE =
      reinterpret_cast<char*>(const_cast<unsigned char*>
                              (bufq_.front()->getData() + offset_));
    iov[0].A2IOVEC_LEN = firstlen;
    num = 1;
    for(auto i = std::begin(bufq_)+1, eoi = std::end(bufq_);
        i != eoi && num < A2_IOV_MAX && num < bufqlen && amount > 0;
        ++i, ++num) {

      ssize_t len = (*i)->getLength();

      if(amount < len) {
        break;
      }

      amount -= len;
      iov[num].A2IOVEC_BASE =
        reinterpret_cast<char*>(const_cast<unsigned char*>((*i)->getData()));
      iov[num].A2IOVEC_LEN = len;
    }
    ssize_t slen = socket_->writeVector(iov, num);
    if(slen == 0 && !socket_->wantRead() && !socket_->wantWrite()) {
      throw DL_ABORT_EX(fmt(EX_SOCKET_SEND, "Connection closed."));
    }
    // A2_LOG_NOTICE(fmt("num=%zu, amount=%d, bufq.size()=%zu, SEND=%d",
    //                   num, amount, bufq_.size(), slen));
    totalslen += slen;

    if(firstlen > slen) {
      offset_ += slen;
      bufq_.front()->progressUpdate(slen, false);
      if (socket_->wantRead() || socket_->wantWrite()) {
        goto fin;
      }
      continue;
    }

    slen -= firstlen;
    bufq_.front()->progressUpdate(firstlen, true);
    bufq_.pop_front();
    offset_ = 0;

    for(size_t i = 1; i < num; ++i) {
      auto& buf = bufq_.front();
      ssize_t len = buf->getLength();
      if(len > slen) {
        offset_ = slen;
        bufq_.front()->progressUpdate(slen, false);
        goto fin;
      }

      slen -= len;
      bufq_.front()->progressUpdate(len, true);
      bufq_.pop_front();
    }
  }
 fin:
  return totalslen;
}

bool SocketBuffer::sendBufferIsEmpty() const
{
  return bufq_.empty();
}

} // namespace aria2
