/* <!-- 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 "MetalinkParserStateV3Impl.h"

#include <cstring>

#include "MetalinkParserStateMachine.h"
#include "RecoverableException.h"
#include "MetalinkResource.h"
#include "util.h"
#include "XmlAttr.h"

namespace aria2 {

const char METALINK3_NAMESPACE_URI[] = "http://www.metalinker.org/";

namespace {
bool checkNsUri(const char* nsUri)
{
  return nsUri && strcmp(nsUri, METALINK3_NAMESPACE_URI) == 0;
}
} // namespace

void MetalinkMetalinkParserState::beginElement(
    MetalinkParserStateMachine* psm, const char* localname, const char* prefix,
    const char* nsUri, const std::vector<XmlAttr>& attrs)
{
  if (checkNsUri(nsUri) && strcmp(localname, "files") == 0) {
    psm->setFilesState();
  }
  else {
    psm->setSkipTagState();
  }
}

void FilesMetalinkParserState::beginElement(MetalinkParserStateMachine* psm,
                                            const char* localname,
                                            const char* prefix,
                                            const char* nsUri,
                                            const std::vector<XmlAttr>& attrs)
{
  if (checkNsUri(nsUri) && strcmp(localname, "file") == 0) {
    psm->setFileState();
    auto itr = findAttr(attrs, "name", METALINK3_NAMESPACE_URI);
    if (itr != attrs.end()) {
      std::string name((*itr).value, (*itr).valueLength);
      if (name.empty() || util::detectDirTraversal(name)) {
        return;
      }
      psm->newEntryTransaction();
      psm->setFileNameOfEntry(name);
    }
  }
  else {
    psm->setSkipTagState();
  }
}

void FileMetalinkParserState::beginElement(MetalinkParserStateMachine* psm,
                                           const char* localname,
                                           const char* prefix,
                                           const char* nsUri,
                                           const std::vector<XmlAttr>& attrs)
{
  if (!checkNsUri(nsUri)) {
    psm->setSkipTagState();
  }
  else if (strcmp(localname, "size") == 0) {
    psm->setSizeState();
  }
  else if (strcmp(localname, "version") == 0) {
    psm->setVersionState();
  }
  else if (strcmp(localname, "language") == 0) {
    psm->setLanguageState();
  }
  else if (strcmp(localname, "os") == 0) {
    psm->setOSState();
  }
  else if (strcmp(localname, "verification") == 0) {
    psm->setVerificationState();
  }
  else if (strcmp(localname, "resources") == 0) {
    psm->setResourcesState();
    int maxConnections;
    auto itr = findAttr(attrs, "maxconnections", METALINK3_NAMESPACE_URI);
    if (itr == attrs.end()) {
      maxConnections = -1;
    }
    else {
      if (!util::parseIntNoThrow(
              maxConnections, std::string((*itr).value, (*itr).valueLength)) ||
          maxConnections <= 0) {
        maxConnections = -1;
      }
    }
    psm->setMaxConnectionsOfEntry(maxConnections);
  }
  else {
    psm->setSkipTagState();
  }
}

void FileMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                         const char* localname,
                                         const char* prefix, const char* nsUri,
                                         std::string characters)
{
  psm->commitEntryTransaction();
}

void SizeMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                         const char* localname,
                                         const char* prefix, const char* nsUri,
                                         std::string characters)
{
  // current metalink specification doesn't require size element.
  int64_t size;
  if (util::parseLLIntNoThrow(size, characters) && size >= 0 &&
      size <= std::numeric_limits<a2_off_t>::max()) {
    psm->setFileLengthOfEntry(size);
  }
}

void VersionMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                            const char* localname,
                                            const char* prefix,
                                            const char* nsUri,
                                            std::string characters)
{
  psm->setVersionOfEntry(std::move(characters));
}

void LanguageMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                             const char* localname,
                                             const char* prefix,
                                             const char* nsUri,
                                             std::string characters)
{
  psm->setLanguageOfEntry(std::move(characters));
}

void OSMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                       const char* localname,
                                       const char* prefix, const char* nsUri,
                                       std::string characters)
{
  psm->setOSOfEntry(std::move(characters));
}

void VerificationMetalinkParserState::beginElement(
    MetalinkParserStateMachine* psm, const char* localname, const char* prefix,
    const char* nsUri, const std::vector<XmlAttr>& attrs)
{
  if (!checkNsUri(nsUri)) {
    psm->setSkipTagState();
  }
  else if (strcmp(localname, "hash") == 0) {
    psm->setHashState();
    auto itr = findAttr(attrs, "type", METALINK3_NAMESPACE_URI);
    if (itr == attrs.end()) {
      return;
    }
    else {
      psm->newChecksumTransaction();
      psm->setTypeOfChecksum(std::string((*itr).value, (*itr).valueLength));
    }
  }
  else if (strcmp(localname, "pieces") == 0) {
    psm->setPiecesState();
    uint32_t length;
    {
      auto itr = findAttr(attrs, "length", METALINK3_NAMESPACE_URI);
      if (itr == attrs.end()) {
        return;
      }
      else {
        if (!util::parseUIntNoThrow(
                length, std::string((*itr).value, (*itr).valueLength))) {
          return;
        }
      }
    }
    std::string type;
    {
      auto itr = findAttr(attrs, "type", METALINK3_NAMESPACE_URI);
      if (itr == attrs.end()) {
        return;
      }
      else {
        type.assign((*itr).value, (*itr).valueLength);
      }
    }
    psm->newChunkChecksumTransaction();
    psm->setLengthOfChunkChecksum(length);
    psm->setTypeOfChunkChecksum(type);
  }
  else if (strcmp(localname, "signature") == 0) {
    psm->setSignatureState();
    auto itr = findAttr(attrs, "type", METALINK3_NAMESPACE_URI);
    if (itr == attrs.end()) {
      return;
    }
    else {
      psm->newSignatureTransaction();
      psm->setTypeOfSignature(std::string((*itr).value, (*itr).valueLength));
      auto itr = findAttr(attrs, "file", METALINK3_NAMESPACE_URI);
      if (itr != attrs.end()) {
        std::string file((*itr).value, (*itr).valueLength);
        if (!util::detectDirTraversal(file)) {
          psm->setFileOfSignature(file);
        }
      }
    }
  }
  else {
    psm->setSkipTagState();
  }
}

void HashMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                         const char* localname,
                                         const char* prefix, const char* nsUri,
                                         std::string characters)
{
  psm->setHashOfChecksum(std::move(characters));
  psm->commitChecksumTransaction();
}

void PiecesMetalinkParserState::beginElement(MetalinkParserStateMachine* psm,
                                             const char* localname,
                                             const char* prefix,
                                             const char* nsUri,
                                             const std::vector<XmlAttr>& attrs)
{
  if (checkNsUri(nsUri) && strcmp(localname, "hash") == 0) {
    psm->setPieceHashState();
    auto itr = findAttr(attrs, "piece", METALINK3_NAMESPACE_URI);
    if (itr == attrs.end()) {
      psm->cancelChunkChecksumTransaction();
    }
    else {
      uint32_t idx;
      if (util::parseUIntNoThrow(
              idx, std::string((*itr).value, (*itr).valueLength))) {
        psm->createNewHashOfChunkChecksum(idx);
      }
      else {
        psm->cancelChunkChecksumTransaction();
      }
    }
  }
  else {
    psm->setSkipTagState();
  }
}

void PiecesMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                           const char* localname,
                                           const char* prefix,
                                           const char* nsUri,
                                           std::string characters)
{
  psm->commitChunkChecksumTransaction();
}

void PieceHashMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                              const char* localname,
                                              const char* prefix,
                                              const char* nsUri,
                                              std::string characters)
{
  psm->setMessageDigestOfChunkChecksum(std::move(characters));
  psm->addHashOfChunkChecksum();
}

void SignatureMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                              const char* localname,
                                              const char* prefix,
                                              const char* nsUri,
                                              std::string characters)
{
  psm->setBodyOfSignature(std::move(characters));
  psm->commitSignatureTransaction();
}

void ResourcesMetalinkParserState::beginElement(
    MetalinkParserStateMachine* psm, const char* localname, const char* prefix,
    const char* nsUri, const std::vector<XmlAttr>& attrs)
{
  if (!checkNsUri(nsUri)) {
    psm->setSkipTagState();
  }
  else if (strcmp(localname, "url") == 0) {
    psm->setURLState();
    std::string type;
    {
      auto itr = findAttr(attrs, "type", METALINK3_NAMESPACE_URI);
      if (itr == attrs.end()) {
        return;
      }
      type.assign((*itr).value, (*itr).valueLength);
    }
    std::string location;
    {
      auto itr = findAttr(attrs, "location", METALINK3_NAMESPACE_URI);
      if (itr != attrs.end()) {
        location.assign((*itr).value, (*itr).valueLength);
      }
    }
    int preference;
    {
      auto itr = findAttr(attrs, "preference", METALINK3_NAMESPACE_URI);
      if (itr == attrs.end()) {
        preference = MetalinkResource::getLowestPriority();
      }
      else if (util::parseIntNoThrow(
                   preference, std::string((*itr).value, (*itr).valueLength)) &&
               preference >= 0) {
        // In Metalink3Spec, highest preference value is 100.  We
        // use Metalink4Spec priority unit system in which 1 is
        // highest.
        preference = 101 - preference;
      }
      else {
        preference = MetalinkResource::getLowestPriority();
      }
    }
    int maxConnections;
    {
      auto itr = findAttr(attrs, "maxconnections", METALINK3_NAMESPACE_URI);
      if (itr == attrs.end()) {
        maxConnections = -1;
      }
      else if (!util::parseIntNoThrow(
                   maxConnections,
                   std::string((*itr).value, (*itr).valueLength)) ||
               maxConnections <= 0) {
        maxConnections = -1;
      }
    }
    psm->newResourceTransaction();
    psm->setTypeOfResource(type);
    psm->setLocationOfResource(location);
    psm->setPriorityOfResource(preference);
    psm->setMaxConnectionsOfResource(maxConnections);
  }
  else {
    psm->setSkipTagState();
  }
}

void URLMetalinkParserState::endElement(MetalinkParserStateMachine* psm,
                                        const char* localname,
                                        const char* prefix, const char* nsUri,
                                        std::string characters)
{
  psm->setURLOfResource(std::move(characters));
  psm->commitResourceTransaction();
}

} // namespace aria2