# L-24 MCS 260 Mon 24 Oct 2007 : class People

class People:
   """
   The class People collects information of
   all librarians and patrons of the library.
   """
   whoswho = []
   current = ''

   def __init__(self):
      "Creates a root user."
      import classperson
      root = classperson.Person() 
      root.create(name='root',PIN=0,status=True)
      self.whoswho = [root]

   def search(self,name):
      """
      Returns -1 if name not in self.whoswho,
      else the person object is returned.
      """
      for p in self.whoswho:
         if p.name == name:
            return p
      else:
         return -1

   def logon(self):
      """
      Prompts for name and PIN, and returns
       -1 if access is not granted;
        0 if the user is a patron;
       +1 if the user is a librarian.
      """
      name = raw_input('Give your name : ')
      member = self.search(name)
      if member.PIN < 0:
         print 'you are not a member'
         return -1
      else:
         PIN = input('Give your PIN : ')
         if PIN == member.PIN:
            print 'welcome ' + member.name
            self.current = member
            if member.librarian:
               return +1
            else:
               return 0
         else:
            print 'wrong PIN'
            return -1

   def who(self):
      "Shows who is currently logged in."
      if self.current == '':
         print 'nobody is logged in'
      else:
         print self.current.name + ' is logged in'

   def logoff(self):
      "The current user is logged off."
      if self.current != '':
         print 'bye bye, ' + self.current.name
         self.current = ''

   def add(self):
      "Adds a new person to the collection."
      import classperson
      p = classperson.Person()
      p.create()
      self.whoswho.append(p)

   def delete(self):
      "Prompts for a name and then deletes."
      name = raw_input('Give name : ')
      for k in range(0,len(self.whoswho)):
         p = self.whoswho[k]
         if p.name == name:
            d = self.whoswho.pop(k)
            d.show()
            print 'has been deleted'           
            break