/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2009 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 "HttpServer.h"

#include <sstream>

#include "HttpHeader.h"
#include "SocketCore.h"
#include "HttpHeaderProcessor.h"
#include "DlAbortEx.h"
#include "message.h"
#include "util.h"
#include "LogFactory.h"
#include "Logger.h"
#include "Base64.h"
#include "a2functional.h"
#include "fmt.h"
#include "SocketRecvBuffer.h"
#include "TimeA2.h"

namespace aria2 {

HttpServer::HttpServer
(const SharedHandle<SocketCore>& socket,
 DownloadEngine* e)
 : socket_(socket),
   socketRecvBuffer_(new SocketRecvBuffer(socket_)),
   socketBuffer_(socket),
   e_(e),
   headerProcessor_(new HttpHeaderProcessor()),
   keepAlive_(true),
   gzip_(false),
   acceptsPersistentConnection_(true),
   acceptsGZip_(false)
{}

HttpServer::~HttpServer() {}

SharedHandle<HttpHeader> HttpServer::receiveRequest()
{
  if(socketRecvBuffer_->bufferEmpty()) {
    if(socketRecvBuffer_->recv() == 0 &&
       !socket_->wantRead() && !socket_->wantWrite()) {
      throw DL_ABORT_EX(EX_EOF_FROM_PEER);
    }
  }
  headerProcessor_->update(socketRecvBuffer_->getBuffer(),
                           socketRecvBuffer_->getBufferLength());
  if(headerProcessor_->eoh()) {
    SharedHandle<HttpHeader> header = headerProcessor_->getHttpRequestHeader();
    size_t putbackDataLength = headerProcessor_->getPutBackDataLength();
    A2_LOG_INFO(fmt("HTTP Server received request\n%s",
                    headerProcessor_->getHeaderString().c_str()));
    socketRecvBuffer_->shiftBuffer
      (socketRecvBuffer_->getBufferLength()-putbackDataLength);
    lastRequestHeader_ = header;
    lastBody_.clear();
    lastBody_.str("");
    lastContentLength_ =
      lastRequestHeader_->getFirstAsUInt(HttpHeader::CONTENT_LENGTH);
    headerProcessor_->clear();

    std::string connection =
      util::toLower(lastRequestHeader_->getFirst(HttpHeader::CONNECTION));
    acceptsPersistentConnection_ =
      connection.find(HttpHeader::CLOSE) == std::string::npos &&
      (lastRequestHeader_->getVersion() == HttpHeader::HTTP_1_1 ||
       connection.find("keep-alive") != std::string::npos);

    std::vector<std::string> acceptEncodings;
    util::split(lastRequestHeader_->getFirst(HttpHeader::ACCEPT_ENCODING),
                std::back_inserter(acceptEncodings), A2STR::COMMA_C, true);
    acceptsGZip_ =
      std::find(acceptEncodings.begin(), acceptEncodings.end(), "gzip")
      != acceptEncodings.end();
    return header;
  } else {
    socketRecvBuffer_->clearBuffer();
    return SharedHandle<HttpHeader>();
  }
}

bool HttpServer::receiveBody()
{
  if(lastContentLength_ == 0) {
    return true;
  }
  if(socketRecvBuffer_->bufferEmpty()) {
    if(socketRecvBuffer_->recv() == 0 &&
       !socket_->wantRead() && !socket_->wantWrite()) {
      throw DL_ABORT_EX(EX_EOF_FROM_PEER);
    }
  }
  size_t length =
    std::min(socketRecvBuffer_->getBufferLength(),
             static_cast<size_t>(lastContentLength_-lastBody_.tellg()));
  lastBody_.write(reinterpret_cast<const char*>(socketRecvBuffer_->getBuffer()),
                  length);
  socketRecvBuffer_->shiftBuffer(length);
  return lastContentLength_ == static_cast<uint64_t>(lastBody_.tellp());
}

std::string HttpServer::getBody() const
{
  return lastBody_.str();
}

const std::string& HttpServer::getMethod() const
{
  return lastRequestHeader_->getMethod();
}

const std::string& HttpServer::getRequestPath() const
{
  return lastRequestHeader_->getRequestPath();
}

void HttpServer::feedResponse(const std::string& text, const std::string& contentType)
{
  feedResponse("200 OK", "", text, contentType);
}

void HttpServer::feedResponse(const std::string& status,
                              const std::string& headers,
                              const std::string& text,
                              const std::string& contentType)
{
  std::string httpDate = Time().toHTTPDate();
  std::string header = "HTTP/1.1 ";
  strappend(header, status, "\r\n",
            "Date: ", httpDate, "\r\n",
            "Content-Type: ", contentType, "\r\n");
  strappend(header, "Content-Length: ", util::uitos(text.size()), "\r\n",
            "Expires: ", httpDate, "\r\n",
            "Cache-Control: no-cache\r\n");
  if(supportsGZip()) {
    header += "Content-Encoding: gzip\r\n";
  }
  if(!supportsPersistentConnection()) {
    header += "Connection: close\r\n";
  }
  if(!headers.empty()) {
    header += headers;
    if(!util::endsWith(headers, "\r\n")) {
      header += "\r\n";
    }
  }

  header += "\r\n";
  A2_LOG_DEBUG(fmt("HTTP Server sends response:\n%s", header.c_str()));
  socketBuffer_.pushStr(header);
  socketBuffer_.pushStr(text);
}

ssize_t HttpServer::sendResponse()
{
  return socketBuffer_.send();
}

bool HttpServer::sendBufferIsEmpty() const
{
  return socketBuffer_.sendBufferIsEmpty();
}

bool HttpServer::authenticate()
{
  if(username_.empty()) {
    return true;
  }

  std::string authHeader = lastRequestHeader_->getFirst("Authorization");
  if(authHeader.empty()) {
    return false;
  }
  std::pair<std::string, std::string> p;
  util::divide(p, authHeader, ' ');
  if(p.first != "Basic") {
    return false;
  }
  std::string userpass = Base64::decode(p.second);
  std::pair<std::string, std::string> userpassPair;
  util::divide(userpassPair, userpass, ':');
  return username_ == userpassPair.first && password_ == userpassPair.second;
}

void HttpServer::setUsernamePassword
(const std::string& username, const std::string& password)
{
  username_ = username;
  password_ = password;
}

} // namespace aria2