#ifndef __creaImageIOSQLiteTreeHandler_h_INCLUDED__
#define __creaImageIOSQLiteTreeHandler_h_INCLUDED__

#include <creaImageIOTreeHandler.h>

class CppSQLite3DB;

namespace creaImageIO
{

/**
	* \ingroup Model
	*/
  //=======================================================================
  /// Concrete TreeHandler which manages a tree stored in a sqlite database
  class SQLiteTreeHandler : virtual public TreeHandler
  {
  public:
    ///====================================================================
    /// Ctor with database file name 
    SQLiteTreeHandler(const std::string& filename);
    /// Dtor
    virtual ~SQLiteTreeHandler();
    ///====================================================================

    ///====================================================================
    /// Returns the sqlite db file name 
    const std::string& GetFileName() const { return mFileName; }
    ///====================================================================
 
    ///====================================================================
    /// QUERY METHODS
    /// Is the 'source' readable ?
    virtual bool IsReadable() { return true; }
    /// Is the 'source' writable ?
    virtual bool IsWritable() { return true; }
    ///====================================================================


    ///====================================================================
    /// INITIALIZATION / FINALIZATION
    ///====================================================================

    ///====================================================================
    /// Opens an existing 'source' 
    /// Default mode is read only 
    /// If IsWritable and writable==true then opens in read/write mode
    virtual bool Open(bool writable = false);
    /// Closes the 'source'
    virtual bool Close();
    /// Creates a new 'source' 
    /// Default mode is read only 
    /// If IsWritable and writable==true then opens in read/write mode
    virtual bool Create(bool writable = false);
    /// Destroys the 'source'
    virtual bool Destroy();
    ///====================================================================


    ///====================================================================
    // READ METHODS
    ///====================================================================


    ///====================================================================
    /// Returns the number of children of the Node *WITHOUT LOADING THEM*
    /// REM : The Tree itself is a Node and asking for its number of 
    ///       children returns the number of children of level 1.
    virtual unsigned int GetNumberOfChildren(tree::Node* n);
    ///====================================================================

    ///====================================================================
    /// Recursively loads the children of node 'parent' until maxlevel 
    /// is reached.
    /// If parent == NULL or parent == tree then starts with the 'children' of 
    /// the tree itself.
    /// Returns the total number of children loaded.
    virtual int LoadChildren(tree::Node* parent, int maxlevel);
    ///====================================================================

    ///====================================================================
    /// Unloads the Node and its descendants
    /// WITHOUT altering the source, e.g. the database
    virtual void UnLoad(tree::Node* n);
    ///====================================================================


    ///====================================================================
    /// WRITE METHODS : WORK ONLY IN WRITE MODE
    ///====================================================================
    /// Adds a branch in the tree with the attributes provided
    /// returns the Level in the tree where the branch was connected 
    /// (-1 for error, 0 for top level, etc. ) 
    /// Of course the branch is loaded on exit
    virtual int AddBranch( const AttributeMapType& attr );
    /// Removes the node and its descendants 
    virtual bool Remove(tree::Node*);
    //====================================================================
    

    
  protected:
    //======================================================================
    /// Open the database
    bool DBOpen();
    /// Import the Tree::Description from database (verifies the structure)
    bool DBImportTreeDescription();
    //======================================================================
    //======================================================================
    // Creation
    /// Creates a new database on disk and the tables
    bool DBCreate();
    /// Appends to string s the SQL command to create the attributes of a given level
    void AppendAttributesSQLDefinition(int level, std::string& s);
    //======================================================================

    //======================================================================
    tree::Node* DBGetParent( const AttributeMapType& attr);
    //======================================================================

    //======================================================================
    int DBLoadChildren( tree::Node* parent, int numberoflevels = 1);
    //======================================================================

    /*
    /// 
    int DBQueryNumberOfChildren(tree::Node* n);
    
    // Insertion
    bool DBInsert(tree::Node* alien_node) ; //, UpdateSummary& summary);
    
    //
    std::string DBGetNodeId(tree::Node* node, const std::string& parent_id);

    tree::Node* GetNodeFromTypeId(int level, 
				  const std::string& id);

    // 
    tree::Node* DBGetOrCreateNode(tree::Node* alien_node, 
				      tree::Node* internal_parent,
				      std::string parentid,
				  std::string& created_id);
    //				      UpdateSummary& summary);
    
    tree::Node* DBGetOrCreateParent(tree::Node* alien_node,
				    std::string& parent_id);
				    //				   UpdateSummary& summary);
    
    void DBRecursiveGetOrCreateNode(tree::Node* alien_node, 
					 tree::Node* parent, 
				    const std::string& parent_id);
    //					 UpdateSummary& summary);
    

    // 
    void DBRecursiveRemoveNode(tree::Node* node);


    void BuildSQLFieldsValues(tree::Node* n,
			      std::string& str);


    tree::Node* GetChildrenLike(tree::Node* internal_parent,
			       tree::Node* alien_node);
    */
  private:
    /// The DB
    CppSQLite3DB* mDB;
   /// The physical location associated to the DicomDatabase (directory, db file...)
    std::string mFileName;
    /// Is the DB writable ?
    bool mWritable;
    void SetWritable(bool w) { mWritable; }
    bool GetWritable() const { return mWritable; }

    /*
    struct TypeId
    {
      int type;
      std::string id;
      bool operator< (const TypeId& o) const 
      {
	return ((type<o.type) ||
		((type==o.type)&&id<o.id));
      }
    };
    
    typedef std::map<TypeId,tree::Node*> TypeIdToNodeMapType;
    TypeIdToNodeMapType mTypeIdToNodeMap;
    */
  };
  // EO class SQLiteTreeHandler
  //=======================================================================


} // EO namespace creaImageIO

// EOF
#endif