#ifndef TXmlOdb_hxx_seen
#define TXmlOdb_hxx_seen

/// Acknowledgements: This class derives from the XML ODB access class developed by 
///
///   Konstantin Olchanski 
///
/// in the rootana package which is part of the Midas Data
/// Acquisition:-
/// 
///     https://midas.psi.ch/
///
/// The code has been snchronised with  revision 66 of Subversion repository:-
///      svn://ladd00.triumf.ca/rootana/trunk rootana
/// The T2K group should monitor changes to that code looking for enhancements
/// and should report back any code improvements we make to Konstantin. 

#include <string>

#include "TXMLNode.h"
#include "TXMLAttr.h"
#include "TDOMParser.h"

namespace COMET {
    class IXmlOdb;
};

/// Access to ODB saved in XML format inside midas .mid files

class COMET::IXmlOdb
{
  TDOMParser* fParser; ///< XML parser for the XML-encoded ODB data
  TXMLNode*   fOdb;    ///< Pointer to the root of the ODB tree

public:

  /// Contructor from a string
  IXmlOdb(const char*buf,Int_t bufLength);

  /// Contructor from a file
  IXmlOdb(const char* filename);

  /// Destructor
  virtual ~IXmlOdb();

  /// Validity check
  Bool_t IsValid() const { return fParser; }

  //  Print methods
  //  *************

  /// Print out the contents of the ODB subtree
  void DumpTree(TXMLNode*node, Int_t print_level, Int_t dir_level, std::string node_path) const;

  /// Print out contents of the ODB
  void Print(const Option_t* opt = "") const;

  //  Navigation methods
  //  ******************

  /// Get ROOT node
  TXMLNode* GetRootNode() const { return fOdb; }

  /// Same as FindPath(), but also index into an array
  TXMLNode* FindArrayPath(TXMLNode*node,const char* path,const char* type,Int_t index) const;

  /// Find node with given name anywhere inside the given ODB tree
  TXMLNode* FindNode(TXMLNode*node,const char*name) const;

  /// Follow the ODB path through the XML DOM tree
  TXMLNode* FindPath(TXMLNode*node,const char* path) const;

  //  Value retrevial methods
  //  ***********************

  /// Return the value of the named attribute
  const char* GetAttrValue(const TXMLNode*node,const char*attrName) const;

  //  Navigation + value retrevial methods
  //  ************************************

  Int_t       odbReadAny(      const char*path, Int_t index, Int_t tid,void* buf, Int_t bufsize=0) const;
  Int_t       odbReadArraySize(const char*path) const;
  Bool_t      odbReadBool(     const char*path, Bool_t      defaultValue = false,Int_t index=0) const;
  double      odbReadDouble(   const char*path, double      defaultValue = 0.,   Int_t index=0) const;
  Int_t       odbReadInt(      const char*path, Int_t       defaultValue = 0,    Int_t index=0) const;
  UInt_t      odbReadUint32(   const char*path, UInt_t      defaultValue = 0,    Int_t index=0) const;
  const char* odbReadString(   const char*path, const char* defaultValue = "",   Int_t index=0) const;

private:

  std::string Indent(Int_t level) const;

  /// Clear ODB statistics.
  void ClearStats() const;

  /// ODB statistics.  Multable, only defined after and used by call to Print()
  mutable Int_t fStatsNumDir;
  mutable Int_t fStatsNumKey;
  mutable Int_t fStatsNumKeyArray;
  mutable Int_t fStatsNumText;
  mutable Int_t fStatsNumValue;
  mutable Int_t fStatsNumOther;

  /// Release XML parser
  void ReleaseXMLParser() {
    delete fParser;
    fParser = NULL;
    fOdb    = NULL;
  }
};

#endif