/*
 * (C) Copyright 1996-2016 ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 * In applying this licence, ECMWF does not waive the privileges and immunities
 * granted to it by virtue of its status as an intergovernmental organisation nor
 * does it submit to any jurisdiction.
 */

/*! \file XmlReader.cc
    \brief Implementation of the Reader for Xml.

    Magics Team - ECMWF 2005

    Started: 2005

    Changes:

*/

#include "XmlReader.h"
#include "MagException.h"
#include "MagLog.h"
#include "expat.h"
using namespace magics;

XmlReader::XmlReader(bool tag) : dataAsTag_(tag) {}


XmlReader::~XmlReader() {}

static void XMLCALL startElementHandler(void* data, const char* name, const char** atts) {
    XmlReader* reader = (XmlReader*)data;
    map<string, string> def;
    while (*atts) {
        def.insert(std::make_pair(*atts, *(atts + 1)));
        atts += 2;
    }
    reader->newElement(name, def);
}


static void XMLCALL endElementHandler(void* data, const char* tag) {
    XmlReader* reader = (XmlReader*)data;
    reader->endElement(tag);
}

static bool empty(const string& value) {
    for (string::const_iterator c = value.begin(); c != value.end(); ++c) {
        if (!isspace(*c))
            return false;
    }
    return true;
}

static void XMLCALL dataHandler(void* data, const char* value, int len) {
    string stringval = string(value, len);
    if (empty(stringval))
        return;
    XmlReader* reader = (XmlReader*)data;

    if (reader->dataAsTag()) {
        map<string, string> def;
        def["data"] = stringval;
        reader->newElement("data", def);
        reader->endElement("data");
    }
    else
        reader->addData(stringval);
}


static int externalEntityRefHandler(XML_Parser,  //	 parser,
                                    const XML_Char* context, const XML_Char* base, const XML_Char* systemID,
                                    const XML_Char* publicID) {
    // MagLog::dev()<< "context--->" << context << endl;
    // MagLog::dev()<< "base--->" << base << endl;
    // MagLog::dev()<< "systemID--->" << systemID << endl;
    // MagLog::dev()<< "publicID--->" << publicID << endl;
    return 0;
}


void XmlReader::newElement(const string& name, const map<string, string>& def) {
    // Here we create a XmlNode you put in the tree...
    XmlNode* parent = tree_->getParent(name);
    if (parent) {
        // MagLog::dev()<< "push-->empty " << name << endl;
        push(parent);
    }
    if (empty())
        push(tree_->root());
    XmlNode* node = tree_->newNode(name, def);
    top()->push_back(node);
    push(node);
}

void XmlReader::endElement(const string& tag) {
    tree_->endElement(tag);
    pop();
    // MagLog::dev()<< "pop-->" << tag << endl;
    if (tag == "definition") {
        pop();
        // MagLog::dev()<< "pop-->empty" << tag << endl;
    }
    if (tag == "magics") {
        pop();
        // MagLog::dev()<< "pop-->empty" << tag << endl;
    }
}

void XmlReader::addData(const string& data) {
    top()->setData(data);
}


void XmlReader::interpret(const string& xml, XmlTree* tree) {
    tree_ = tree;
    char buf[BUFSIZ];
    XML_Parser parser = XML_ParserCreate(NULL);
    int done;
    XML_SetUserData(parser, this);
    XML_SetParamEntityParsing(parser, XML_PARAM_ENTITY_PARSING_ALWAYS);
    XML_SetElementHandler(parser, startElementHandler, endElementHandler);
    XML_SetCharacterDataHandler(parser, dataHandler);

    FILE* in = fopen(xml.c_str(), "r");

    if (!in) {
        MagLog::dev() << "XmlDecoder: can not open file " << xml << endl;
        MagLog::error() << "XmlDecoder: can not open file " << xml << endl;
        return;
    }

    do {
        size_t len = fread(buf, 1, sizeof(buf), in);
        done       = len < sizeof(buf);
        if (XML_Parse(parser, buf, len, done) == XML_STATUS_ERROR) {
            ostringstream s;
            s << "XmlMagException : " << XML_ErrorString(XML_GetErrorCode(parser)) << " at line  "
              << XML_GetCurrentLineNumber(parser) << ends;
            cerr << s.str() << "\n";
        }
    } while (!done);
    XML_ParserFree(parser);
    fclose(in);
}

int XmlReader::decode(const string& xml, XmlTree* tree) {
    tree_ = tree;
    //	char buf[BUFSIZ];
    XML_Parser parser = XML_ParserCreate(NULL);
    //	int done;
    XML_SetUserData(parser, this);
    XML_SetParamEntityParsing(parser, XML_PARAM_ENTITY_PARSING_ALWAYS);
    XML_SetElementHandler(parser, startElementHandler, endElementHandler);
    XML_SetCharacterDataHandler(parser, dataHandler);

    if (XML_Parse(parser, xml.c_str(), xml.size(), true) == XML_STATUS_ERROR) {
        ostringstream s;
        s << "XmlMagException : " << XML_ErrorString(XML_GetErrorCode(parser)) << " at line  "
          << XML_GetCurrentLineNumber(parser) << ends;
        return -1;
    }
    XML_ParserFree(parser);
    return 0;
}


/*!
 Class information are given to the output-stream.
*/
void XmlReader::print(ostream& out) const {
    out << "XmlReader[";
    out << "]";
}
