/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2006 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 "HttpHeader.h"
#include "Range.h"
#include "util.h"
#include "A2STR.h"
#include "DownloadFailureException.h"
#include "array_fun.h"

namespace aria2 {

HttpHeader::HttpHeader()
  : statusCode_(0)
{}

HttpHeader::~HttpHeader() {}

void HttpHeader::put(int hdKey, const std::string& value)
{
  std::multimap<int, std::string>::value_type vt(hdKey, value);
  table_.insert(vt);
}

bool HttpHeader::defined(int hdKey) const
{
  return table_.count(hdKey);
}

const std::string& HttpHeader::find(int hdKey) const
{
  std::multimap<int, std::string>::const_iterator itr = table_.find(hdKey);
  if(itr == table_.end()) {
    return A2STR::NIL;
  } else {
    return (*itr).second;
  }
}

std::vector<std::string> HttpHeader::findAll(int hdKey) const
{
  std::vector<std::string> v;
  std::pair<std::multimap<int, std::string>::const_iterator,
            std::multimap<int, std::string>::const_iterator> itrpair =
    table_.equal_range(hdKey);
  while(itrpair.first != itrpair.second) {
    v.push_back((*itrpair.first).second);
    ++itrpair.first;
  }
  return v;
}

std::pair<std::multimap<int, std::string>::const_iterator,
          std::multimap<int, std::string>::const_iterator>
HttpHeader::equalRange(int hdKey) const
{
  return table_.equal_range(hdKey);
}

Range HttpHeader::getRange() const
{
  const std::string& rangeStr = find(CONTENT_RANGE);
  if(rangeStr.empty()) {
    const std::string& clenStr = find(CONTENT_LENGTH);
    if(clenStr.empty()) {
      return Range();
    } else {
      int64_t contentLength;
      if(!util::parseLLIntNoThrow(contentLength, clenStr) ||
         contentLength < 0) {
        throw DL_ABORT_EX("Content-Length must be positive integer");
      } else if(contentLength > std::numeric_limits<off_t>::max()) {
        throw DOWNLOAD_FAILURE_EXCEPTION
          (fmt(EX_TOO_LARGE_FILE, contentLength));
      } else if(contentLength == 0) {
        return Range();
      } else {
        return Range(0, contentLength - 1, contentLength);
      }
    }
  }
  // we expect that rangeStr looks like 'bytes 100-199/100'
  // but some server returns '100-199/100', omitting bytes-unit sepcifier
  // 'bytes'.
  std::string::const_iterator byteRangeSpec =
    std::find(rangeStr.begin(), rangeStr.end(), ' ');
  if(byteRangeSpec == rangeStr.end()) {
    // we assume bytes-unit specifier omitted.
    byteRangeSpec = rangeStr.begin();
  } else {
    while(byteRangeSpec != rangeStr.end() &&
          (*byteRangeSpec == ' ' || *byteRangeSpec == '\t')) {
      ++byteRangeSpec;
    }
  }
  std::string::const_iterator slash =
    std::find(byteRangeSpec, rangeStr.end(), '/');
  if(slash == rangeStr.end() || slash+1 == rangeStr.end() ||
     (byteRangeSpec+1 == slash && *byteRangeSpec == '*') ||
     (slash+2 == rangeStr.end() && *(slash+1) == '*')) {
    // If byte-range-resp-spec or instance-length is "*", we returns
    // empty Range. The former is usually sent with 416 (Request range
    // not satisfiable) status.
    return Range();
  }
  std::string::const_iterator minus = std::find(byteRangeSpec, slash, '-');
  if(minus == slash) {
    return Range();
  }
  int64_t startByte, endByte, entityLength;
  if(!util::parseLLIntNoThrow(startByte, std::string(byteRangeSpec, minus)) ||
     !util::parseLLIntNoThrow(endByte, std::string(minus+1, slash)) ||
     !util::parseLLIntNoThrow(entityLength,
                              std::string(slash+1, rangeStr.end())) ||
     startByte < 0 || endByte < 0 || entityLength < 0) {
    throw DL_ABORT_EX("byte-range-spec must be positive");
  }
  if(startByte > std::numeric_limits<off_t>::max()) {
    throw DOWNLOAD_FAILURE_EXCEPTION(fmt(EX_TOO_LARGE_FILE, startByte));
  }
  if(endByte > std::numeric_limits<off_t>::max()) {
    throw DOWNLOAD_FAILURE_EXCEPTION(fmt(EX_TOO_LARGE_FILE, endByte));
  }
  if(entityLength > std::numeric_limits<off_t>::max()) {
    throw DOWNLOAD_FAILURE_EXCEPTION(fmt(EX_TOO_LARGE_FILE, entityLength));
  }
  return Range(startByte, endByte, entityLength);
}

void HttpHeader::setVersion(const std::string& version)
{
  version_ = version;
}

void HttpHeader::setMethod(const std::string& method)
{
  method_ = method;
}

void HttpHeader::setRequestPath(const std::string& requestPath)
{
  requestPath_ = requestPath;
}

void HttpHeader::clearField()
{
  table_.clear();
}

int HttpHeader::getStatusCode() const
{
  return statusCode_;
}

void HttpHeader::setStatusCode(int code)
{
  statusCode_ = code;
}

const std::string& HttpHeader::getVersion() const
{
  return version_;
}

const std::string& HttpHeader::getMethod() const
{
  return method_;
}

const std::string& HttpHeader::getRequestPath() const
{
  return requestPath_;
}

const std::string& HttpHeader::getReasonPhrase() const
{
  return reasonPhrase_;
}

void HttpHeader::setReasonPhrase(const std::string& reasonPhrase)
{
  reasonPhrase_ = reasonPhrase;
}

bool HttpHeader::fieldContains(int hdKey, const char* value)
{
  std::pair<std::multimap<int, std::string>::const_iterator,
            std::multimap<int, std::string>::const_iterator> range =
    equalRange(hdKey);
  for(std::multimap<int, std::string>::const_iterator i = range.first;
      i != range.second; ++i) {
    std::vector<Scip> values;
    util::splitIter((*i).second.begin(), (*i).second.end(),
                    std::back_inserter(values),
                    ',',
                    true // doStrip
                    );
    for(std::vector<Scip>::const_iterator j = values.begin(),
          eoj = values.end(); j != eoj; ++j) {
      if(util::strieq((*j).first, (*j).second, value)) {
        return true;
      }
    }
  }
  return false;
}

bool HttpHeader::isKeepAlive() const
{
  const std::string& connection = find(CONNECTION);
  return !util::strieq(connection, "close") &&
    (version_ == "HTTP/1.1" || util::strieq(connection, "keep-alive"));
}

namespace {
const char* INTERESTING_HEADER_NAMES[] = {
  "accept-encoding",
  "access-control-request-headers",
  "access-control-request-method",
  "authorization",
  "connection",
  "content-disposition",
  "content-encoding",
  "content-length",
  "content-range",
  "content-type",
  "digest",
  "infohash",
  "last-modified",
  "link",
  "location",
  "origin",
  "port",
  "retry-after",
  "sec-websocket-key",
  "sec-websocket-version",
  "set-cookie",
  "transfer-encoding",
  "upgrade",
};
} // namespace

int idInterestingHeader(const char* hdName)
{
  const char** i = std::lower_bound(vbegin(INTERESTING_HEADER_NAMES),
                                    vend(INTERESTING_HEADER_NAMES),
                                    hdName, util::strless);
  if(i != vend(INTERESTING_HEADER_NAMES) && strcmp(*i, hdName) == 0 ) {
    return i - vbegin(INTERESTING_HEADER_NAMES);
  } else {
    return HttpHeader::MAX_INTERESTING_HEADER;
  }
}

} // namespace aria2