#include "preXmlManager.hh"
#include "xmlToolDir.hh"

#include <fstream>
#include <iostream>
#include <ExpatInterface/Element.h>
#include <ExpatInterface/Document.h>

void preXml::Manager::_mandatoryInitialisation() {
  // Here we could check here that we have a preXml-Xml file.
  // May put that in later.


  //Want to be absolutely certain of these:
  this->_geometry        = NULL;
  this->_geometryManager = NULL;
  this->_sectionManager  = NULL;

  _geometryManager 
    = new xmlTool::Directory(this->_doc,
			  std::string("geometry"),
			  std::string("name") );

  // We's better stop if that failed.
  assert(_geometryManager);
};

preXml::Manager::~Manager() {
  if (this->_geometryManager) delete this->_geometryManager;
  if (this->_sectionManager)  delete this->_sectionManager;
  // Note - we most definitely do not delete _geometry !
};

preXml::Manager::Manager(const std::string & preXmlFileName) {
  std::cout << "Atempting to open "<<preXmlFileName<<" ... "<<flush;
  std::ifstream in(preXmlFileName.c_str());
  assert(in);
  std::cout << "done." << endl;
  _doc.load(in);
  this->_mandatoryInitialisation();
};
 
preXml::Manager::Manager(std::istream & preXmlInputStream) {
  _doc.load(preXmlInputStream);
  this->_mandatoryInitialisation();
};

xmlTool::Directory & preXml::Manager::geoManager() const {
  // We are guaranteed that the _geometryManager exists
  // by the constructors of preXml::Manager,
  // so we can just say:
  return *(this->_geometryManager);
};

void preXml::Manager::setGeometry() {
  // Must check that we are at the end of a geometry branch.
  if (this->_geometryManager->getDirNames().size() !=0 ) {
    std::cerr << "You've tried to set the geometry in "
	      << this->_geometryManager->getCurDirName()
	      << " but there are still further sub-geometries "
	      << "to chose from. "
	      << (this->_geometryManager->getDirNames())[0]
	      << " for example." << endl;
  }
  assert(this->_geometryManager->getDirNames().size()==0 );

  // Good.  Let's set things up!
  this->_geometry = &(this->_geometryManager->getCurDirElt());
  // and check that that did something
  assert(this->_geometry);

  // So now that the geometry is chosen, 
  // let's fire up the secManager
  this->_sectionManager 
    = new xmlTool::Directory(*(this->_geometry),
			  string("section"),
			  string("name"));

  // Better check that that worked.
  assert(this->_sectionManager);
};

xmlTool::Directory & preXml::Manager::secManager() const {
  // Must check that a valid geometry exists.
  if (!this->_geometry) {
    std::cerr << "You've tried to start messing about in "
	      << "sections long before having chosen and set "
	      << "the directory.  Set the geometry with "
	      << "setGeometry() which is a preXml method."
	      << endl;
  }
  assert(this->_geometry);

  // O.K.  The existence of the geometry ensures
  // the existence of the sectionManager, so:
  return *(this->_sectionManager);
};

void preXml::Manager::fill(preXml::Quantity & quantity, const xml::Element & elt) const {
  // cout << "Hey, I am Simple Filler." << endl;
  // Check that we have indeed been given a param.
  assert(elt.getTagName()==string("param"));

  // That's good.  Let's examine elt's children.
  const xml::Element::ElementCollection & children = elt.getChildren();

  // All good params should have exactly one child.
  assert(children.size()==1);

  // For clarity, let's now identify this only child
  const xml::Element & child = *(children[0]);

  // And now we read into "quantity" the information stored in "elt".
  quantity.readFrom(child);
};

void preXml::Manager::fill(preXml::Quantity & quantity, 
			   const std::string & paramName) {
  // Only allowed to start doing this once a geometry has been chosen.
  // However, the call to secManager will sort that check out.

  // Let's find the element corresponding to the name
  const xml::Element & elt = 
    this->_finder.findUnderTheUniqueElement(this->secManager().getCurDirElt(),
					   string("param"),
					   string("name"),
					   paramName);

  // Well, if that didn't complain, then the elt was found.
  this->fill(quantity, elt);
};