/* -*- C++ -*-

 * gui/xml.h - Part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

#include <iostream>

#include <string>

#include <vector>

#include <list>

#include <map>

#include <lemon/error.h>

#include <lemon/xy.h>

namespace lemon {

  class XmlIo 

  {

    bool _writeMode;

  public:

    ///Check if XmlIo is in write mode.

    bool write() { return _writeMode;}

    ///Check if XmlIo is in read mode.

    bool read() { return !_writeMode;}

    std::ostream& os;

    int level;

  protected:

    void indent(int level) {

      os << std::endl;

      for(int i=0;i<level;i++) os << ' ';

    }

    void tag(const std::string &_tag) {

      os << '<' << _tag << '>';

    }

    void etag(const std::string &_tag) {

      os << "</" << _tag << '>';

    }

    void itag(const std::string &_tag) { indent();tag(_tag); }

    void ietag(const std::string &_tag) { indent();etag(_tag); }

    void beginTag(const std::string &_tag) {

      itag(_tag);

      level++;

    }

    void endTag(const std::string &_tag) {

      level--;

      ietag(_tag);

    }

  public:

    ///Indent the line according to its level.

    ///\warning It can only be used in write mode.

    ///

    void indent()

    {

      if(write())

	if(level>=0) indent(level);

	else level=0;

      else throw LogicError();	

    }

    ///Read/write a tag

    ///Read/write a tag.

    ///In write mode it does not start a new line.

    class ContTag

    {

      XmlIo &ix;

      const std::string _tag;

    public:

      ///\e

      ///\e

      ///

      ContTag(XmlIo &_ix,const std::string &_t) :

	ix(_ix), _tag(_t)

      {

	if(ix.write()) ix.tag(_tag);

	else ix.useTag(_tag);

      }

      ~ContTag() { 

	if(ix.write()) ix.etag(_tag);

	else if(!std::uncaught_exception()) ix.useTag('/'+_tag);      

      }

    };

    ///Read/write a tag

    ///Read/write a tag.

    ///The whole <foo> ... </foo> will be places in a single line.

    class LineTag

    {

      XmlIo &ix;

      const std::string _tag;

    public:

      ///\e

      ///\e

      ///

      LineTag(XmlIo &_ix,const std::string &_t) :

	ix(_ix), _tag(_t)

      {

	if(ix.write()) ix.itag(_tag);

	else ix.useTag(_tag);

      }

      ~LineTag() { 

	if(ix.write()) ix.etag(_tag);

	else if(!std::uncaught_exception()) ix.useTag('/'+_tag);

      }

    };

    ///Read/write a tag

    ///Read/write a tag.

    ///

    class Tag

    {

      XmlIo &ix;

      const std::string _tag;

    public:

      ///\e

      ///\e

      ///

      Tag(XmlIo &_ix,const std::string &_t) :

	ix(_ix), _tag(_t)

      {

	if(ix.write()) ix.beginTag(_tag);

	else ix.useTag(_tag);

      }

      ~Tag() {

	if(ix.write()) ix.endTag(_tag);

	else if(!std::uncaught_exception()) ix.useTag('/'+_tag);

      }

    };

  private:

    std::istream& is;

    std::string next_tag;

    int line_number;

    void skipWhiteSpaces()

    {

      if(write()) throw LogicError();

      {

	char c;

	while (is.get(c) && std::isspace(c,is.getloc()))

	  if(c=='\n') line_number++;

	is.unget();

      }

    }

  protected:

    /// Use the next tag.

    ///\e

    ///

    void useTag() {next_tag.clear();}

    ///Use the next tag and check if it is equal with \c _tag

    ///\e

    ///

    void useTag(const std::string &_tag) {

      if(nextTag()==_tag) useTag();

      else throw DataFormatError("",line_number,"Unexpected token name");

    }

  public:

    ///Return the next tag (if a tag follows on the stream).

    ///\warning It can only be used in read mode.

    ///

    const std::string &nextTag() 

    {

      if(write()) throw LogicError();

      else if(next_tag.empty()) {

	char c;

	skipWhiteSpaces();

	if(!is.get(c) || c!='<')

	  throw DataFormatError("",line_number,"Bad format");

	next_tag.clear();

	while (is.get(c) && c!='>') next_tag.push_back(c);

	if(c!='>')

	  throw DataFormatError("",line_number,"Bad format");

      }

      return next_tag;

    }

    /**********************************************************************/

    ///\e

    ///\e

    ///

    XmlIo(std::ostream& _os) : _writeMode(true), os(_os),

			       level(-1),

			       is(*(std::istream*)(NULL)) {}

    ///\e

    ///

    XmlIo(std::istream& _is) : _writeMode(false),

			       os(*(std::ostream*)(NULL)), is(_is),

			       line_number(1) {}

    ~XmlIo() { if(write()) os<< std::endl; }

    XmlIo &operator()(const int &v) 

    { 

      if(write()) os << v;

      else {

	skipWhiteSpaces();

	if(!(is >> const_cast<int &>(v))) 

	  throw DataFormatError("",line_number,"Not an 'int'");

      }

      return *this;

    }

    XmlIo &operator()(const double &v) 

    {

      if(write()) os << v;

      else {

	skipWhiteSpaces();

	if(!(is >> const_cast<double &>(v))) 

	  throw DataFormatError("",line_number,"Not an 'double'");

      }

      return *this;

    }

    XmlIo &operator()(const std::string &v)

    {

      if(write())

	for(std::string::const_iterator i=v.begin();i!=v.end();++i)

	  switch(*i) {

	  case '\\':

	    os << "\\\\";

	    break;

	  case '<':

	    os << "\\<";

	    break;

	  case '&':

	    os << "\\&";

	    break;

	  case '\n':

	    os << "\\n";

	    break;

	  default:

	    os<<*i;

	    break;

	  }

      else {

	std::string &w = const_cast<std::string &>(v);

	w.clear();

	char c;

	while (is.get(c) && c!='<')

	  if(c=='\\')

	    if(!is.get(c))

	      throw DataFormatError("",line_number,"Bad string");

	    else switch(c) {

	    case 'n':

	      w.push_back('\n');

	      break;

	    default:

	      w.push_back(c);

	      break;

	    }

	  else {

	    if(c=='\n') line_number++;

	    w.push_back(c);

	  }

	if(c!='<')

	  throw DataFormatError("",line_number,"Unexpected eof");

	is.unget();

      }

      return *this;

    }

    XmlIo &operator()(const std::string &_tag,const int &v) 

    { 

      LineTag t(*this,_tag);

      (*this)(v);

      return *this;

    }

    XmlIo &operator()(const std::string &_tag,const double &v) 

    {

      LineTag t(*this,_tag);

      (*this)(v);

      return *this;

    }

    XmlIo &operator()(const std::string &_tag,const std::string &v)

    {

      LineTag t(*this,_tag);

      (*this)(v);

      return *this;

    }

    ///\e

    ///\e

    ///

    template<class V>

    XmlIo &operator()(const std::string &_tag,const V &v)

    {

      Tag t(*this,_tag);

      xml(*this,const_cast<V &>(v));

      return *this;

    }

    ///\e

    ///\e

    ///

    template<class V>

    XmlIo &operator()(const V &v)

    {

      xml(*this,const_cast<V &>(v));

      return *this;

    }

    };

  //////////////////////////////////////////////////////////////////////

  //////////////////////////////////////////////////////////////////////

  ///\e

  ///\relates XmlIo

  ///

  template<class A>

  void xml(XmlIo &x,std::auto_ptr<A> &v)

  {

    if(x.write()) v=new A;

    x(*v);

  }

  ///\e

  ///\relates XmlIo

  ///

  template<class A,class B>

  void xml(XmlIo &x,std::pair<A,B> &v)

  {

    x("first",v.first);

    x("second",v.second);

  }

  ///\e

  ///\relates XmlIo

  ///

  template<class T>

  void xml(XmlIo &x,std::list<T> &v)

  {

    if(x.write())

      for(typename std::list<T>::const_iterator it=v.begin();

	  it!=v.end();++it) x("item",*it);

    else while(x.nextTag()=="item")

      {

	v.push_back(T());

	x("item",v.back());

      }

  }

  ///\e

  ///\relates XmlIo

  ///

  template<class T>

  void xml(XmlIo &x,std::vector<T> &v)

  {

    if(x.write())

      for(typename std::vector<T>::const_iterator it=v.begin();

	  it!=v.end();++it) x("item",*it);

    else while(x.nextTag()=="item")

      {

	v.push_back(T());

	x("item",v.back());      

      }

  }

  ///\e

  ///\relates XmlIo

  ///

  template<class K,class V>

  void xml(XmlIo &x,std::map<K,V> &v)

  {

    if(x.write()) 

      for(typename std::map<K,V>::const_iterator it=v.begin();

	  it!=v.end();++it) x("item",*it);

    else while(x.nextTag()=="item")

      {

	typename std::map<K,V>::value_type it;

	x("item",it);

	v.insert(it);

      }

  }

  ///\e

  ///\relates XmlIo

  ///

  template<class T>

  void xml(XmlIo &x,lemon::xy<T> &v)

  {

    { XmlIo::LineTag t(x,"x"); x(v.x); }

    { XmlIo::ContTag t(x,"y"); x(v.y); }

  }

  ///\e

  ///\relates XmlIo

  ///

  template<class T>

  void xml(XmlIo &x,lemon::BoundingBox<T> &v)

  {

    if(x.write()) {

      if(!v.empty()) {

	x("point",v.bottomLeft());

	if(v.bottomLeft()!=v.topRight()) x("point",v.topRight());

      }

    }

    else {

      v.clear();

      while(x.nextTag()=="point") {

	lemon::xy<T> co;

	x("point",co);

	v.add(co);

      }

    }

  }

}