/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <xercesc/util/PlatformUtils.hpp>
#include <xercesc/parsers/AbstractDOMParser.hpp>
#include <xercesc/dom/DOMImplementation.hpp>
#include <xercesc/dom/DOMImplementationLS.hpp>
#include <xercesc/dom/DOMImplementationRegistry.hpp>
#include <xercesc/dom/DOMLSParser.hpp>
#include <xercesc/dom/DOMException.hpp>
#include <xercesc/dom/DOMDocument.hpp>
#include <xercesc/dom/DOMNodeList.hpp>
#include <xercesc/dom/DOMError.hpp>
#include <xercesc/dom/DOMLocator.hpp>
#include <xercesc/dom/DOMNamedNodeMap.hpp>
#include <xercesc/dom/DOMAttr.hpp>
#include "DOMCount.hpp"
#include <cstring>
#include <cstdlib>

#if defined(XERCES_NEW_IOSTREAMS)
#include <fstream>
#else
#include <fstream.h>
#endif

// ---------------------------------------------------------------------------
//  This is a simple program which invokes the DOMParser to build a DOM
//  tree for the specified input file. It then walks the tree and counts
//  the number of elements. The element count is then printed.
// ---------------------------------------------------------------------------
static void usage() {
  XERCES_STD_QUALIFIER cout << "\nUsage:\n"
                               "    DOMCount [options] <XML file | List file>\n\n"
                               "This program invokes the DOMLSParser, builds the DOM tree,\n"
                               "and then prints the number of elements found in each XML file.\n\n"
                               "Options:\n"
                               "    -l          Indicate the input file is a List File that has a list of xml files.\n"
                               "                Default to off (Input file is an XML file).\n"
                               "    -v=xxx      Validation scheme [always | never | auto*].\n"
                               "    -n          Enable namespace processing. Defaults to off.\n"
                               "    -s          Enable schema processing. Defaults to off.\n"
                               "    -f          Enable full schema constraint checking. Defaults to off.\n"
                               "    -locale=ll_CC specify the locale, default: en_US.\n"
                               "    -p          Print out names of elements and attributes encountered.\n"
                               "    -?          Show this help.\n\n"
                               "  * = Default if not provided explicitly.\n"
                            << XERCES_STD_QUALIFIER endl;
}

// ---------------------------------------------------------------------------
//
//  Recursively Count up the total number of child Elements under the specified Node.
//  Process attributes of the node, if any.
//
// ---------------------------------------------------------------------------
static int countChildElements(DOMNode *n, bool printOutEncounteredEles) {
  DOMNode *child;
  int count = 0;
  if (n) {
    if (n->getNodeType() == DOMNode::ELEMENT_NODE) {
      if (printOutEncounteredEles) {
        char *name = XMLString::transcode(n->getNodeName());
        XERCES_STD_QUALIFIER cout << "----------------------------------------------------------"
                                  << XERCES_STD_QUALIFIER endl;
        XERCES_STD_QUALIFIER cout << "Encountered Element : " << name << XERCES_STD_QUALIFIER endl;

        XMLString::release(&name);

        if (n->hasAttributes()) {
          // get all the attributes of the node
          DOMNamedNodeMap *pAttributes = n->getAttributes();
          const XMLSize_t nSize = pAttributes->getLength();
          XERCES_STD_QUALIFIER cout << "\tAttributes" << XERCES_STD_QUALIFIER endl;
          XERCES_STD_QUALIFIER cout << "\t----------" << XERCES_STD_QUALIFIER endl;
          for (XMLSize_t i = 0; i < nSize; ++i) {
            DOMAttr *pAttributeNode = (DOMAttr *)pAttributes->item(i);
            // get attribute name
            char *name = XMLString::transcode(pAttributeNode->getName());

            XERCES_STD_QUALIFIER cout << "\t" << name << "=";
            XMLString::release(&name);

            // get attribute type
            name = XMLString::transcode(pAttributeNode->getValue());
            XERCES_STD_QUALIFIER cout << name << XERCES_STD_QUALIFIER endl;
            XMLString::release(&name);
          }
        }
      }
      ++count;
    }
    for (child = n->getFirstChild(); child != nullptr; child = child->getNextSibling())
      count += countChildElements(child, printOutEncounteredEles);
  }
  return count;
}

// ---------------------------------------------------------------------------
//
//   main
//
// ---------------------------------------------------------------------------
int main(int argC, char *argV[]) {
  // Check command line and extract arguments.
  if (argC < 2) {
    usage();
    return 1;
  }

  const char *xmlFile = nullptr;
  AbstractDOMParser::ValSchemes valScheme = AbstractDOMParser::Val_Auto;
  bool doNamespaces = false;
  bool doSchema = false;
  bool schemaFullChecking = false;
  bool doList = false;
  bool errorOccurred = false;
  bool recognizeNEL = false;
  bool printOutEncounteredEles = false;
  char localeStr[64];
  memset(localeStr, 0, sizeof localeStr);

  int argInd;
  for (argInd = 1; argInd < argC; argInd++) {
    // Break out on first parm not starting with a dash
    if (argV[argInd][0] != '-')
      break;

    // Watch for special case help request
    if (!strcmp(argV[argInd], "-?")) {
      usage();
      return 2;
    } else if (!strncmp(argV[argInd], "-v=", 3) || !strncmp(argV[argInd], "-V=", 3)) {
      const char *const parm = &argV[argInd][3];

      if (!strcmp(parm, "never"))
        valScheme = AbstractDOMParser::Val_Never;
      else if (!strcmp(parm, "auto"))
        valScheme = AbstractDOMParser::Val_Auto;
      else if (!strcmp(parm, "always"))
        valScheme = AbstractDOMParser::Val_Always;
      else {
        XERCES_STD_QUALIFIER cerr << "Unknown -v= value: " << parm << XERCES_STD_QUALIFIER endl;
        return 2;
      }
    } else if (!strcmp(argV[argInd], "-n") || !strcmp(argV[argInd], "-N")) {
      doNamespaces = true;
    } else if (!strcmp(argV[argInd], "-s") || !strcmp(argV[argInd], "-S")) {
      doSchema = true;
    } else if (!strcmp(argV[argInd], "-f") || !strcmp(argV[argInd], "-F")) {
      schemaFullChecking = true;
    } else if (!strcmp(argV[argInd], "-l") || !strcmp(argV[argInd], "-L")) {
      doList = true;
    } else if (!strcmp(argV[argInd], "-special:nel")) {
      // turning this on will lead to non-standard compliance behaviour
      // it will recognize the unicode character 0x85 as new line character
      // instead of regular character as specified in XML 1.0
      // do not turn this on unless really necessary

      recognizeNEL = true;
    } else if (!strcmp(argV[argInd], "-p") || !strcmp(argV[argInd], "-P")) {
      printOutEncounteredEles = true;
    } else if (!strncmp(argV[argInd], "-locale=", 8)) {
      // Get out the end of line
      strcpy(localeStr, &(argV[argInd][8]));
    } else {
      XERCES_STD_QUALIFIER cerr << "Unknown option '" << argV[argInd] << "', ignoring it\n"
                                << XERCES_STD_QUALIFIER endl;
    }
  }

  //
  //  There should be only one and only one parameter left, and that
  //  should be the file name.
  //
  if (argInd != argC - 1) {
    usage();
    return 1;
  }

  // Initialize the XML4C system
  try {
    if (strlen(localeStr)) {
      XMLPlatformUtils::Initialize(localeStr);
    } else {
      XMLPlatformUtils::Initialize();
    }

    if (recognizeNEL) {
      XMLPlatformUtils::recognizeNEL(recognizeNEL);
    }
  }

  catch (const XMLException &toCatch) {
    XERCES_STD_QUALIFIER cerr << "Error during initialization! :\n"
                              << StrX(toCatch.getMessage()) << XERCES_STD_QUALIFIER endl;
    return 1;
  }

  // Instantiate the DOM parser.
  static const XMLCh gLS[] = {chLatin_L, chLatin_S, chNull};
  DOMImplementation *impl = DOMImplementationRegistry::getDOMImplementation(gLS);
  DOMLSParser *parser = ((DOMImplementationLS *)impl)->createLSParser(DOMImplementationLS::MODE_SYNCHRONOUS, nullptr);
  DOMConfiguration *config = parser->getDomConfig();

  config->setParameter(XMLUni::fgDOMNamespaces, doNamespaces);
  config->setParameter(XMLUni::fgXercesSchema, doSchema);
  config->setParameter(XMLUni::fgXercesHandleMultipleImports, true);
  config->setParameter(XMLUni::fgXercesSchemaFullChecking, schemaFullChecking);

  if (valScheme == AbstractDOMParser::Val_Auto) {
    config->setParameter(XMLUni::fgDOMValidateIfSchema, true);
  } else if (valScheme == AbstractDOMParser::Val_Never) {
    config->setParameter(XMLUni::fgDOMValidate, false);
  } else if (valScheme == AbstractDOMParser::Val_Always) {
    config->setParameter(XMLUni::fgDOMValidate, true);
  }

  // enable datatype normalization - default is off
  config->setParameter(XMLUni::fgDOMDatatypeNormalization, true);

  // And create our error handler and install it
  DOMCountErrorHandler errorHandler;
  config->setParameter(XMLUni::fgDOMErrorHandler, &errorHandler);

  //
  //  Get the starting time and kick off the parse of the indicated
  //  file. Catch any exceptions that might propogate out of it.
  //
  unsigned long duration;

  bool more = true;
  XERCES_STD_QUALIFIER ifstream fin;

  // the input is a list file
  if (doList)
    fin.open(argV[argInd]);

  if (fin.fail()) {
    XERCES_STD_QUALIFIER cerr << "Cannot open the list file: " << argV[argInd] << XERCES_STD_QUALIFIER endl;
    return 2;
  }

  while (more) {
    char fURI[1000];
    //initialize the array to zeros
    memset(fURI, 0, sizeof(fURI));

    if (doList) {
      if (!fin.eof()) {
        fin.getline(fURI, sizeof(fURI));
        if (!*fURI)
          continue;
        else {
          xmlFile = fURI;
          XERCES_STD_QUALIFIER cerr << "==Parsing== " << xmlFile << XERCES_STD_QUALIFIER endl;
        }
      } else
        break;
    } else {
      xmlFile = argV[argInd];
      more = false;
    }

    //reset error count first
    errorHandler.resetErrors();

    XERCES_CPP_NAMESPACE_QUALIFIER DOMDocument *doc = nullptr;

    try {
      // reset document pool
      parser->resetDocumentPool();

      const unsigned long startMillis = XMLPlatformUtils::getCurrentMillis();
      doc = parser->parseURI(xmlFile);
      const unsigned long endMillis = XMLPlatformUtils::getCurrentMillis();
      duration = endMillis - startMillis;
    }

    catch (const XMLException &toCatch) {
      XERCES_STD_QUALIFIER cerr << "\nError during parsing: '" << xmlFile << "'\n"
                                << "Exception message is:  \n"
                                << StrX(toCatch.getMessage()) << "\n"
                                << XERCES_STD_QUALIFIER endl;
      errorOccurred = true;
      continue;
    } catch (const DOMException &toCatch) {
      const unsigned int maxChars = 2047;
      XMLCh errText[maxChars + 1];

      XERCES_STD_QUALIFIER cerr << "\nDOM Error during parsing: '" << xmlFile << "'\n"
                                << "DOMException code is:  " << toCatch.code << XERCES_STD_QUALIFIER endl;

      if (DOMImplementation::loadDOMExceptionMsg(toCatch.code, errText, maxChars))
        XERCES_STD_QUALIFIER cerr << "Message is: " << StrX(errText) << XERCES_STD_QUALIFIER endl;

      errorOccurred = true;
      continue;
    } catch (...) {
      XERCES_STD_QUALIFIER cerr << "\nUnexpected exception during parsing: '" << xmlFile << "'\n";
      errorOccurred = true;
      continue;
    }

    //
    //  Extract the DOM tree, get the list of all the elements and report the
    //  length as the count of elements.
    //
    if (errorHandler.getSawErrors()) {
      XERCES_STD_QUALIFIER cout << "\nErrors occurred, no output available\n" << XERCES_STD_QUALIFIER endl;
      errorOccurred = true;
    } else {
      unsigned int elementCount = 0;
      if (doc) {
        elementCount = countChildElements((DOMNode *)doc->getDocumentElement(), printOutEncounteredEles);
        // test getElementsByTagName and getLength
        XMLCh xa[] = {chAsterisk, chNull};
        if (elementCount != doc->getElementsByTagName(xa)->getLength()) {
          XERCES_STD_QUALIFIER cout << "\nErrors occurred, element count is wrong\n" << XERCES_STD_QUALIFIER endl;
          errorOccurred = true;
        }
      }

      // Print out the stats that we collected and time taken.
      XERCES_STD_QUALIFIER cout << xmlFile << ": " << duration << " ms (" << elementCount << " elems)."
                                << XERCES_STD_QUALIFIER endl;
    }
  }

  //
  //  Delete the parser itself.  Must be done prior to calling Terminate, below.
  //
  parser->release();

  // And call the termination method
  XMLPlatformUtils::Terminate();

  if (doList)
    fin.close();

  if (errorOccurred)
    return 4;
  else
    return 0;
}

DOMCountErrorHandler::DOMCountErrorHandler()
    :

      fSawErrors(false) {}

DOMCountErrorHandler::~DOMCountErrorHandler() {}

// ---------------------------------------------------------------------------
//  DOMCountHandlers: Overrides of the DOM ErrorHandler interface
// ---------------------------------------------------------------------------
bool DOMCountErrorHandler::handleError(const DOMError &domError) {
  fSawErrors = true;
  if (domError.getSeverity() == DOMError::DOM_SEVERITY_WARNING)
    XERCES_STD_QUALIFIER cerr << "\nWarning at file ";
  else if (domError.getSeverity() == DOMError::DOM_SEVERITY_ERROR)
    XERCES_STD_QUALIFIER cerr << "\nError at file ";
  else
    XERCES_STD_QUALIFIER cerr << "\nFatal Error at file ";

  XERCES_STD_QUALIFIER cerr << StrX(domError.getLocation()->getURI()) << ", line "
                            << domError.getLocation()->getLineNumber() << ", char "
                            << domError.getLocation()->getColumnNumber()
                            << "\n  Message: " << StrX(domError.getMessage()) << XERCES_STD_QUALIFIER endl;

  return true;
}

void DOMCountErrorHandler::resetErrors() { fSawErrors = false; }