class Hierarchy:
    def __init__(self,name,subsections=None):
        self._parent = None
        self._name=name 
        self._sections = []
        if subsections is not None:
           for s in subsections:
             self.addSection(s)

    @property
    def parent(self):
        return(self._parent)

    @property
    def sections(self):
        return(self._sections)

    def addSection(self,section):
        self._sections.append(section)

    @property
    def hasChildren(self):
        return(len(self._sections)>0)

    @property
    def name(self):
        return(self._name)



class Document:
    def __init__(self,runid,date):
        self._runid = runid 
        self._date = date 
        self._sections = []

    @property
    def runid(self):
        return(self._runid)

    @property
    def date(self):
        return(self._date)

    @property
    def sections(self):
        return(self._sections)

    def addSection(self,section):
        self._sections.append(section)

    def accept(self, visitor):
      visitor.visitDocument(self)
      for element in self._sections:
          element.accept(visitor)   
      visitor.leaveDocument(self)

class Section(Hierarchy):
  def __init__(self,name):
      super(Section, self).__init__(name)
      self._tables = []

  def addTable(self,table):
      self._tables.append(table)

  @property
  def hasContent(self):
      return(len(self._tables) > 0 or any([x.hasContent for x in self.sections]))


  def accept(self, visitor):
      if self.hasContent:
         visitor.visitSection(self)
         for element in self.sections:
             element.accept(visitor) 
         for element in self._tables:
             element.accept(visitor)    
         visitor.leaveSection(self)   

class Table:
    def __init__(self,params,cores):
       self._params=params
       self._cores=cores
       self._rows=[] 

    def addRow(self,row):
       self._rows.append(row)

    @property
    def columns(self):
       return(self._params + self._cores)

    @property
    def params(self):
       return(self._params)

    @property
    def cores(self):
       return(self._cores)

    @property
    def rows(self):
       return(self._rows)

    def accept(self, visitor):
      visitor.visitTable(self)