/******************************************************************************
 *
 * Project:  KML Driver
 * Purpose:  Class for reading, parsing and handling a kmlfile.
 * Author:   Jens Oberender, j.obi@troja.net
 *
 ******************************************************************************
 * Copyright (c) 2007, Jens Oberender
 * Copyright (c) 2008-2013, Even Rouault <even dot rouault at spatialys.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/
#include "kmlnode.h"
#include "kml.h"

#include <cstring>
#include <cstdio>
#include <exception>
#include <iostream>
#include <string>

#include "cpl_conv.h"
#include "cpl_error.h"
#ifdef HAVE_EXPAT
#  include "expat.h"
#endif


KML::KML() :
    poTrunk_(nullptr),
    nNumLayers_(-1),
    papoLayers_(nullptr),
    nDepth_(0),
    validity(KML_VALIDITY_UNKNOWN),
    pKMLFile_(nullptr),
    poCurrent_(nullptr),
    oCurrentParser(nullptr),
    nDataHandlerCounter(0),
    nWithoutEventCounter(0)
{}

KML::~KML()
{
    if( nullptr != pKMLFile_ )
        VSIFCloseL(pKMLFile_);
    CPLFree(papoLayers_);

    delete poTrunk_;
}

bool KML::open(const char * pszFilename)
{
    if( nullptr != pKMLFile_ )
        VSIFCloseL( pKMLFile_ );

    pKMLFile_ = VSIFOpenL( pszFilename, "r" );
    return pKMLFile_ != nullptr;
}

bool KML::parse()
{
    if( nullptr == pKMLFile_ )
    {
        sError_ = "No file given";
        return false;
    }

    if(poTrunk_ != nullptr) {
        delete poTrunk_;
        poTrunk_ = nullptr;
    }

    if(poCurrent_ != nullptr)
    {
        delete poCurrent_;
        poCurrent_ = nullptr;
    }

    XML_Parser oParser = OGRCreateExpatXMLParser();
    XML_SetUserData(oParser, this);
    XML_SetElementHandler(oParser, startElement, endElement);
    XML_SetCharacterDataHandler(oParser, dataHandler);
    oCurrentParser = oParser;
    nWithoutEventCounter = 0;

    int nDone = 0;
    int nLen = 0;
    char aBuf[BUFSIZ] = { 0 };
    bool bError = false;

    do
    {
        nDataHandlerCounter = 0;
        nLen = (int)VSIFReadL( aBuf, 1, sizeof(aBuf), pKMLFile_ );
        nDone = VSIFEofL(pKMLFile_);
        if (XML_Parse(oParser, aBuf, nLen, nDone) == XML_STATUS_ERROR)
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                      "XML parsing of KML file failed : %s at line %d, "
                      "column %d",
                      XML_ErrorString(XML_GetErrorCode(oParser)),
                      static_cast<int>(XML_GetCurrentLineNumber(oParser)),
                      static_cast<int>(XML_GetCurrentColumnNumber(oParser)));
            bError = true;
            break;
        }
        nWithoutEventCounter ++;
    } while (!nDone && nLen > 0 && nWithoutEventCounter < 10);

    XML_ParserFree(oParser);
    VSIRewindL(pKMLFile_);

    if (nWithoutEventCounter == 10)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Too much data inside one element. File probably corrupted");
        bError = true;
    }

    if( bError )
    {
        if( poCurrent_ != nullptr )
        {
            while( poCurrent_ )
            {
                KMLNode* poTemp = poCurrent_->getParent();
                delete poCurrent_;
                poCurrent_ = poTemp;
            }
            // No need to destroy poTrunk_ : it has been destroyed in
            // the last iteration
        }
        else
        {
            // Case of invalid content after closing element matching
            // first <kml> element
            delete poTrunk_;
        }
        poTrunk_ = nullptr;
        return false;
    }

    poCurrent_ = nullptr;
    return true;
}

void KML::checkValidity()
{
    if(poTrunk_ != nullptr)
    {
        delete poTrunk_;
        poTrunk_ = nullptr;
    }

    if(poCurrent_ != nullptr)
    {
        delete poCurrent_;
        poCurrent_ = nullptr;
    }

    if(pKMLFile_ == nullptr)
    {
        sError_ = "No file given";
        return;
    }

    XML_Parser oParser = OGRCreateExpatXMLParser();
    XML_SetUserData(oParser, this);
    XML_SetElementHandler(oParser, startElementValidate, nullptr);
    XML_SetCharacterDataHandler(oParser, dataHandlerValidate);
    int nCount = 0;

    oCurrentParser = oParser;

    int nDone = 0;
    int nLen = 0;
    char aBuf[BUFSIZ] = { 0 };

    // Parses the file until we find the first element.
    do
    {
        nDataHandlerCounter = 0;
        nLen = static_cast<int>(VSIFReadL( aBuf, 1, sizeof(aBuf), pKMLFile_ ));
        nDone = VSIFEofL(pKMLFile_);
        if (XML_Parse(oParser, aBuf, nLen, nDone) == XML_STATUS_ERROR)
        {
            if (nLen <= BUFSIZ-1)
                aBuf[nLen] = 0;
            else
                aBuf[BUFSIZ-1] = 0;
            if( strstr(aBuf, "<?xml") && (
                    strstr(aBuf, "<kml") ||
                    (strstr(aBuf, "<Document") && strstr(aBuf, "/kml/2.")) ) )
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                        "XML parsing of KML file failed : %s at line %d, column %d",
                        XML_ErrorString(XML_GetErrorCode(oParser)),
                        (int)XML_GetCurrentLineNumber(oParser),
                        (int)XML_GetCurrentColumnNumber(oParser));
            }

            validity = KML_VALIDITY_INVALID;
            XML_ParserFree(oParser);
            VSIRewindL(pKMLFile_);
            return;
        }

        nCount ++;
        /* After reading 50 * BUFSIZE bytes, and not finding whether the file */
        /* is KML or not, we give up and fail silently */
    } while ( !nDone && nLen > 0 &&
              validity == KML_VALIDITY_UNKNOWN && nCount < 50 );

    XML_ParserFree(oParser);
    VSIRewindL(pKMLFile_);
    poCurrent_ = nullptr;
}

void XMLCALL KML::startElement( void* pUserData, const char* pszName,
                                const char** ppszAttr )
{
  KML* poKML = static_cast<KML*>(pUserData);
  try
  {
    poKML->nWithoutEventCounter = 0;

    const char* pszColumn = strchr(pszName, ':');
    if( pszColumn)
        pszName = pszColumn + 1;

    if(poKML->poTrunk_ == nullptr
    || (poKML->poCurrent_ != nullptr &&
        poKML->poCurrent_->getName().compare("description") != 0))
    {
        if (poKML->nDepth_ == 1024)
        {
            CPLError( CE_Failure, CPLE_AppDefined,
                      "Too big depth level (%d) while parsing KML.",
                      poKML->nDepth_ );
            XML_StopParser(poKML->oCurrentParser, XML_FALSE);
            return;
        }

        KMLNode* poMynew = new KMLNode();
        poMynew->setName(pszName);
        poMynew->setLevel(poKML->nDepth_);

        for( int i = 0; ppszAttr[i]; i += 2 )
        {
            Attribute* poAtt = new Attribute();
            poAtt->sName = ppszAttr[i];
            poAtt->sValue = ppszAttr[i + 1];
            poMynew->addAttribute(poAtt);
        }

        if(poKML->poTrunk_ == nullptr)
            poKML->poTrunk_ = poMynew;
        if(poKML->poCurrent_ != nullptr)
            poMynew->setParent(poKML->poCurrent_);
        poKML->poCurrent_ = poMynew;

        poKML->nDepth_++;
    }
    else if( poKML->poCurrent_ != nullptr )
    {
        std::string sNewContent = "<";
        sNewContent += pszName;
        for( int i = 0; ppszAttr[i]; i += 2 )
        {
            sNewContent += " ";
            sNewContent += ppszAttr[i];
            sNewContent += "=\"";
            sNewContent += ppszAttr[i + 1];
            sNewContent += "\"";
        }
        sNewContent += ">";
        if(poKML->poCurrent_->numContent() == 0)
            poKML->poCurrent_->addContent(sNewContent);
        else
            poKML->poCurrent_->appendContent(sNewContent);
    }
  }
  catch(const std::exception& ex)
  {
    CPLError(CE_Failure, CPLE_AppDefined,
             "KML: libstdc++ exception : %s", ex.what());
    XML_StopParser(poKML->oCurrentParser, XML_FALSE);
  }
}

void XMLCALL KML::startElementValidate( void* pUserData, const char* pszName,
                                        const char** ppszAttr )
{
    KML* poKML = static_cast<KML *>(pUserData);

    if (poKML->validity != KML_VALIDITY_UNKNOWN)
        return;

    poKML->validity = KML_VALIDITY_INVALID;

    const char* pszColumn = strchr(pszName, ':');
    if( pszColumn)
        pszName = pszColumn + 1;

    if(strcmp(pszName, "kml") == 0 || strcmp(pszName, "Document") == 0)
    {
        // Check all Attributes
        for( int i = 0; ppszAttr[i]; i += 2 )
        {
            // Find the namespace and determine the KML version
            if(strcmp(ppszAttr[i], "xmlns") == 0)
            {
                // Is it KML 2.2?
                if((strcmp(ppszAttr[i + 1], "http://earth.google.com/kml/2.2") == 0) ||
                   (strcmp(ppszAttr[i + 1], "http://www.opengis.net/kml/2.2") == 0))
                {
                    poKML->validity = KML_VALIDITY_VALID;
                    poKML->sVersion_ = "2.2";
                }
                else if(strcmp(ppszAttr[i + 1], "http://earth.google.com/kml/2.1") == 0)
                {
                    poKML->validity = KML_VALIDITY_VALID;
                    poKML->sVersion_ = "2.1";
                }
                else if(strcmp(ppszAttr[i + 1], "http://earth.google.com/kml/2.0") == 0)
                {
                    poKML->validity = KML_VALIDITY_VALID;
                    poKML->sVersion_ = "2.0";
                }
                else
                {
                    CPLDebug("KML",
                             "Unhandled xmlns value : %s. Going on though...",
                             ppszAttr[i]);
                    poKML->validity = KML_VALIDITY_VALID;
                    poKML->sVersion_ = "?";
                }
            }
        }

        if (poKML->validity == KML_VALIDITY_INVALID)
        {
            CPLDebug( "KML",
                      "Did not find xmlns attribute in <kml> element. "
                      "Going on though..." );
            poKML->validity = KML_VALIDITY_VALID;
            poKML->sVersion_ = "?";
        }
    }
}

void XMLCALL KML::dataHandlerValidate( void * pUserData,
                                       const char * /* pszData */,
                                       int /* nLen */ )
{
    KML* poKML = static_cast<KML *>(pUserData);

    poKML->nDataHandlerCounter ++;
    if (poKML->nDataHandlerCounter >= BUFSIZ)
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "File probably corrupted (million laugh pattern)" );
        XML_StopParser(poKML->oCurrentParser, XML_FALSE);
    }
}

void XMLCALL KML::endElement(void* pUserData, const char* pszName)
{
  KML* poKML = static_cast<KML *>(pUserData);

  try
  {
    poKML->nWithoutEventCounter = 0;

    const char* pszColumn = strchr(pszName, ':');
    if( pszColumn)
        pszName = pszColumn + 1;

    if(poKML->poCurrent_ != nullptr &&
       poKML->poCurrent_->getName().compare(pszName) == 0)
    {
        poKML->nDepth_--;
        KMLNode* poTmp = poKML->poCurrent_;
        // Split the coordinates
        if(poKML->poCurrent_->getName().compare("coordinates") == 0 &&
           poKML->poCurrent_->numContent() == 1)
        {
            const std::string sData = poKML->poCurrent_->getContent(0);
            std::size_t nPos = 0;
            const std::size_t nLength = sData.length();
            const char* pszData = sData.c_str();
            while( true )
            {
                // Cut off whitespaces
                while( nPos < nLength &&
                       (pszData[nPos] == ' ' || pszData[nPos] == '\n'
                        || pszData[nPos] == '\r' || pszData[nPos] == '\t' ) )
                    nPos++;

                if (nPos == nLength)
                    break;

                const std::size_t nPosBegin = nPos;

                // Get content
                while(nPos < nLength &&
                      pszData[nPos] != ' ' && pszData[nPos] != '\n' &&
                      pszData[nPos] != '\r' &&
                      pszData[nPos] != '\t')
                    nPos++;

                if(nPos - nPosBegin > 0)
                {
                    std::string sTmp(pszData + nPosBegin, nPos - nPosBegin);
                    poKML->poCurrent_->addContent(sTmp);
                }
            }
            if(poKML->poCurrent_->numContent() > 1)
                poKML->poCurrent_->deleteContent(0);
        }
        else if (poKML->poCurrent_->numContent() == 1)
        {
            const std::string sData = poKML->poCurrent_->getContent(0);
            std::string sDataWithoutNL;
            std::size_t nPos = 0;
            const std::size_t nLength = sData.length();
            const char* pszData = sData.c_str();
            std::size_t nLineStartPos = 0;
            bool bLineStart = true;

            // Re-assemble multi-line content by removing leading spaces for
            // each line.  I am not sure why we do that. Should we preserve
            // content as such?
            while(nPos < nLength)
            {
                const char ch = pszData[nPos];
                if( bLineStart && (ch == ' ' || ch == '\t' || ch == '\n' ||
                                   ch == '\r') )
                    nLineStartPos ++;
                else if( ch == '\n' || ch == '\r' )
                {
                    if( !bLineStart )
                    {
                        std::string sTmp( pszData + nLineStartPos,
                                          nPos - nLineStartPos);
                        if( !sDataWithoutNL.empty() )
                            sDataWithoutNL += " ";
                        sDataWithoutNL += sTmp;
                        bLineStart = true;
                    }
                    nLineStartPos = nPos + 1;
                }
                else
                {
                    bLineStart = false;
                }
                nPos++;
            }

            if( nLineStartPos > 0 )
            {
                if (nLineStartPos < nPos)
                {
                    std::string sTmp( pszData + nLineStartPos,
                                      nPos - nLineStartPos);
                    if( !sDataWithoutNL.empty() )
                        sDataWithoutNL += " ";
                    sDataWithoutNL += sTmp;
                }

                poKML->poCurrent_->deleteContent(0);
                poKML->poCurrent_->addContent(sDataWithoutNL);
            }
        }

        if(poKML->poCurrent_->getParent() != nullptr)
            poKML->poCurrent_ = poKML->poCurrent_->getParent();
        else
            poKML->poCurrent_ = nullptr;

        if(!poKML->isHandled(pszName))
        {
            CPLDebug("KML", "Not handled: %s", pszName);
            delete poTmp;
            if( poKML->poCurrent_ == poTmp )
                poKML->poCurrent_ = nullptr;
            if( poKML->poTrunk_ == poTmp )
                poKML->poTrunk_ = nullptr;
        }
        else
        {
            if(poKML->poCurrent_ != nullptr)
                poKML->poCurrent_->addChildren(poTmp);
        }
    }
    else if(poKML->poCurrent_ != nullptr)
    {
        std::string sNewContent = "</";
        sNewContent += pszName;
        sNewContent += ">";
        if(poKML->poCurrent_->numContent() == 0)
            poKML->poCurrent_->addContent(sNewContent);
        else
            poKML->poCurrent_->appendContent(sNewContent);
    }
  }
  catch(const std::exception& ex)
  {
        CPLError(CE_Failure, CPLE_AppDefined,
             "KML: libstdc++ exception : %s", ex.what());
    XML_StopParser(poKML->oCurrentParser, XML_FALSE);
  }
}

void XMLCALL KML::dataHandler(void* pUserData, const char* pszData, int nLen)
{
    KML* poKML = static_cast<KML *>(pUserData);

    poKML->nWithoutEventCounter = 0;

    if(nLen < 1 || poKML->poCurrent_ == nullptr)
        return;

    poKML->nDataHandlerCounter ++;
    if (poKML->nDataHandlerCounter >= BUFSIZ)
    {
        CPLError( CE_Failure, CPLE_AppDefined,
                  "File probably corrupted (million laugh pattern)" );
        XML_StopParser(poKML->oCurrentParser, XML_FALSE);
    }

    try
    {
        std::string sData(pszData, nLen);

        if(poKML->poCurrent_->numContent() == 0)
            poKML->poCurrent_->addContent(sData);
        else
            poKML->poCurrent_->appendContent(sData);
    }
    catch(const std::exception& ex)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
             "KML: libstdc++ exception : %s", ex.what());
        XML_StopParser(poKML->oCurrentParser, XML_FALSE);
    }
}

bool KML::isValid()
{
    checkValidity();

    if( validity == KML_VALIDITY_VALID )
        CPLDebug( "KML", "Valid: %d Version: %s",
                  validity == KML_VALIDITY_VALID, sVersion_.c_str());

    return validity == KML_VALIDITY_VALID;
}

std::string KML::getError() const
{
    return sError_;
}

int KML::classifyNodes()
{
    if( poTrunk_ == nullptr )
        return false;
    return poTrunk_->classify(this);
}

void KML::eliminateEmpty()
{
    if( poTrunk_ != nullptr )
        poTrunk_->eliminateEmpty(this);
}

void KML::print(unsigned short nNum)
{
    if( poTrunk_ != nullptr )
        poTrunk_->print(nNum);
}

bool KML::isHandled(std::string const& elem) const
{
    return isLeaf(elem) || isFeature(elem) || isFeatureContainer(elem)
        || isContainer(elem) || isRest(elem);
}

bool KML::isLeaf( std::string const& /* elem */ ) const
{
    return false;
}

bool KML::isFeature( std::string const& /* elem */ ) const
{
    return false;
}

bool KML::isFeatureContainer( std::string const& /* elem */ ) const
{
    return false;
}

bool KML::isContainer( std::string const& /* elem */ ) const
{
    return false;
}

bool KML::isRest( std::string const& /* elem */ ) const
{
    return false;
}

void KML::findLayers( KMLNode* /* poNode */, int /* bKeepEmptyContainers */ )
{
    // idle
}

bool KML::hasOnlyEmpty() const
{
    return poTrunk_->hasOnlyEmpty();
}

int KML::getNumLayers() const
{
    return nNumLayers_;
}

bool KML::selectLayer(int nNum) {
    if( nNumLayers_ < 1 || nNum >= nNumLayers_ )
        return false;
    poCurrent_ = papoLayers_[nNum];
    return true;
}

std::string KML::getCurrentName() const
{
    std::string tmp;
    if( poCurrent_ != nullptr )
    {
        tmp = poCurrent_->getNameElement();
    }
    return tmp;
}

Nodetype KML::getCurrentType() const
{
    if(poCurrent_ != nullptr)
        return poCurrent_->getType();

    return Unknown;
}

int KML::is25D() const
{
    if(poCurrent_ != nullptr)
        return poCurrent_->is25D();

    return Unknown;
}

int KML::getNumFeatures()
{
    if(poCurrent_ == nullptr)
        return -1;

    return static_cast<int>(poCurrent_->getNumFeatures());
}

Feature* KML::getFeature(std::size_t nNum, int& nLastAsked, int &nLastCount)
{
    if(poCurrent_ == nullptr)
        return nullptr;

    return poCurrent_->getFeature(nNum, nLastAsked, nLastCount);
}

void KML::unregisterLayerIfMatchingThisNode(KMLNode* poNode)
{
    for(int i=0;i<nNumLayers_;)
    {
        if( papoLayers_[i] == poNode )
        {
            if( i < nNumLayers_ - 1 )
            {
                memmove( papoLayers_ + i, papoLayers_ + i + 1,
                        (nNumLayers_ - 1 - i) * sizeof(KMLNode*) );
            }
            nNumLayers_ --;
            break;
        }
        i++;
    }
}
