package oisoft.togetherx.scripts.SQL.impl;

import java.util.Enumeration;

import oisoft.togetherx.scriptapi.UML.UMLClass;
//import oisoft.togetherx.scriptapi.UML.UMLAttribute;
//import oisoft.togetherx.scriptapi.UML.UMLAssociation;
import oisoft.togetherx.scriptapi.UML.enums.UMLAttributeEnumeration;
//import oisoft.togetherx.scriptapi.UML.enums.UMLAssociationEnumeration;

//import oisoft.togetherx.scripts.SQL.SQLTable;
import oisoft.togetherx.scripts.SQL.SQLForeignKey;

class ColumnEnumeration implements Enumeration{
  private UMLAttributeEnumeration myAttributes;
//  private ForeignKeyEnumeration myForeignKeys;
  private Enumeration myForeignKeys;
  private TableImpl myTable;
  private Enumeration myForeignColumns = new EmptyEnumeration();
  private boolean myPrimaryKeyOnly;
  private Object myCurrent;

//  private QryAttribute myLastAttribute;

//  private Table myForeignTable = null;
/**@associates <b>ColumnEnumeration</b>*/
//  private Enumeration myForeignKeys = new EmptyEnumeration();

  ColumnEnumeration(TableImpl table, SQLModelImpl model){
    this(table,model,true);
  }

  ColumnEnumeration(TableImpl table, SQLModelImpl model, boolean showForeignKeys){
    this(table,model,showForeignKeys,false);
  }

  ColumnEnumeration(TableImpl table, SQLModelImpl model, boolean showForeignKeys, boolean primaryKeyOnly){
    myAttributes = table.getUMLClass().getAttributes();
    myPrimaryKeyOnly = primaryKeyOnly;
    myTable = table;
    if( showForeignKeys ){
      myForeignKeys = new ForeignKeyEnumeration(table,model,primaryKeyOnly);
    }
    else{
      myForeignKeys = new EmptyEnumeration();
    }
    advance();
  }

  public Object nextElement(){
    Object result = myCurrent;
    advance();
    return result;
  }

  public boolean hasMoreElements(){
    return myCurrent != null;
  }

  private void advance(){
    myCurrent = null;
    while( myAttributes.hasMoreElements() ){
      ColumnImpl tmp = (ColumnImpl)myTable.getColumn(myAttributes.getNextUMLAttribute());
      if(!myPrimaryKeyOnly || tmp.isPrimaryKey()){
        myCurrent = tmp;
        break;
      }
    }
    if(myCurrent == null){
      while(!myForeignColumns.hasMoreElements() && myForeignKeys.hasMoreElements() ){
        myForeignColumns = ((SQLForeignKey)myForeignKeys.nextElement()).getColumns();
      }
      if( myForeignColumns.hasMoreElements() ){
        myCurrent = myForeignColumns.nextElement();
      }
    }
  }

}