/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2012 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 "Xml2XmlParser.h"

#include <cassert>
#include <cstring>

#include "a2io.h"
#include "ParserStateMachine.h"
#include "A2STR.h"
#include "a2functional.h"
#include "XmlAttr.h"

namespace aria2 {

namespace xml {

namespace {
void mlStartElement(void* userData, const xmlChar* localname,
                    const xmlChar* prefix, const xmlChar* nsUri,
                    int numNamespaces, const xmlChar** namespaces, int numAttrs,
                    int numDefaulted, const xmlChar** attrs)
{
  SessionData* sd = reinterpret_cast<SessionData*>(userData);
  std::vector<XmlAttr> xmlAttrs;
  const char** pattrs = reinterpret_cast<const char**>(attrs);
  for (size_t i = 0, max = numAttrs * 5; i < max; i += 5) {
    XmlAttr xmlAttr;
    assert(pattrs[i]);
    xmlAttr.localname = pattrs[i];
    if (pattrs[i + 1]) {
      xmlAttr.prefix = pattrs[i + 1];
    }
    if (attrs[i + 2]) {
      xmlAttr.nsUri = pattrs[i + 2];
    }
    xmlAttr.value = pattrs[i + 3];
    xmlAttr.valueLength = pattrs[i + 4] - xmlAttr.value;
    xmlAttrs.push_back(xmlAttr);
  }
  sd->psm->beginElement(reinterpret_cast<const char*>(localname),
                        reinterpret_cast<const char*>(prefix),
                        reinterpret_cast<const char*>(nsUri), xmlAttrs);
  if (sd->psm->needsCharactersBuffering()) {
    sd->charactersStack.push_front(A2STR::NIL);
  }
}
} // namespace

namespace {
void mlEndElement(void* userData, const xmlChar* localname,
                  const xmlChar* prefix, const xmlChar* nsUri)
{
  SessionData* sd = reinterpret_cast<SessionData*>(userData);
  std::string characters;
  if (sd->psm->needsCharactersBuffering()) {
    characters = std::move(sd->charactersStack.front());
    sd->charactersStack.pop_front();
  }
  sd->psm->endElement(reinterpret_cast<const char*>(localname),
                      reinterpret_cast<const char*>(prefix),
                      reinterpret_cast<const char*>(nsUri), characters);
}
} // namespace

namespace {
void mlCharacters(void* userData, const xmlChar* ch, int len)
{
  SessionData* sd = reinterpret_cast<SessionData*>(userData);
  if (sd->psm->needsCharactersBuffering()) {
    sd->charactersStack.front().append(&ch[0], &ch[len]);
  }
}
} // namespace

namespace {
xmlSAXHandler mySAXHandler = {
    nullptr,         // internalSubsetSAXFunc
    nullptr,         // isStandaloneSAXFunc
    nullptr,         // hasInternalSubsetSAXFunc
    nullptr,         // hasExternalSubsetSAXFunc
    nullptr,         // resolveEntitySAXFunc
    nullptr,         // getEntitySAXFunc
    nullptr,         // entityDeclSAXFunc
    nullptr,         // notationDeclSAXFunc
    nullptr,         // attributeDeclSAXFunc
    nullptr,         // elementDeclSAXFunc
    nullptr,         //   unparsedEntityDeclSAXFunc
    nullptr,         //   setDocumentLocatorSAXFunc
    nullptr,         //   startDocumentSAXFunc
    nullptr,         //   endDocumentSAXFunc
    nullptr,         //   startElementSAXFunc
    nullptr,         //   endElementSAXFunc
    nullptr,         //   referenceSAXFunc
    &mlCharacters,   //   charactersSAXFunc
    nullptr,         //   ignorableWhitespaceSAXFunc
    nullptr,         //   processingInstructionSAXFunc
    nullptr,         //   commentSAXFunc
    nullptr,         //   warningSAXFunc
    nullptr,         //   errorSAXFunc
    nullptr,         //   fatalErrorSAXFunc
    nullptr,         //   getParameterEntitySAXFunc
    nullptr,         //   cdataBlockSAXFunc
    nullptr,         //   externalSubsetSAXFunc
    XML_SAX2_MAGIC,  //   unsigned int        initialized
    nullptr,         //   void *      _private
    &mlStartElement, //   startElementNsSAX2Func
    &mlEndElement,   //   endElementNsSAX2Func
    nullptr,         //   xmlStructuredErrorFunc
};
} // namespace

XmlParser::XmlParser(ParserStateMachine* psm)
    : psm_(psm),
      sessionData_(psm),
      ctx_(xmlCreatePushParserCtxt(&mySAXHandler, &sessionData_, nullptr, 0,
                                   nullptr)),
      lastError_(0)
{
}

XmlParser::~XmlParser() { xmlFreeParserCtxt(ctx_); }

ssize_t XmlParser::parseUpdate(const char* data, size_t size)
{
  if (lastError_ != 0) {
    return lastError_;
  }
  int rv = xmlParseChunk(ctx_, data, size, 0);
  if (rv != 0) {
    return lastError_ = ERR_XML_PARSE;
  }
  else {
    return size;
  }
}

ssize_t XmlParser::parseFinal(const char* data, size_t size)
{
  if (lastError_ != 0) {
    return lastError_;
  }
  int rv = xmlParseChunk(ctx_, data, size, 1);
  if (rv != 0) {
    return lastError_ = ERR_XML_PARSE;
  }
  else {
    return size;
  }
}

int XmlParser::reset()
{
  psm_->reset();
  sessionData_.reset();
  int rv = xmlCtxtResetPush(ctx_, nullptr, 0, nullptr, nullptr);
  if (rv != 0) {
    return lastError_ = ERR_RESET;
  }
  else {
    return 0;
  }
}

} // namespace xml

} // namespace aria2