from abc import ABC, abstractmethod

class IContent(ABC):
    def __init__(self, text):
        self.text = text
        
    @abstractmethod
    def format(self):
        pass
    
class MyContent(IContent):
    def format(self):
        return ''.join(['', self.text, ''])
        
class IProtocol(ABC):
    def __init__(self, text):
        self.text = text
        
    @abstractmethod
    def format(self):
        pass
    
class MyProtocol(IProtocol):
    def format(self):
        return ''.join(["I'm" , self.text])
    

class IEmail(ABC):
    
    @abstractmethod
    def set_sender(self, sender):
        pass
    
    @abstractmethod
    def set_receiver(self, receiver):
        pass
    
    @abstractmethod
    def set_content(self, content):
        pass
    
class Email(IEmail):
    def __init__(self, protocol):
        self.protocol = protocol
        self.__sender = None
        self.__receiver = None
        self.__content = None
        
    def set_sender(self, sender):
        self.__sender = sender.format()
            
    def set_receiver(self, receiver):
        self.__receiver = receiver.format()
            
    def set_content(self, content):
        self.__content = content.format()
            
    def __repr__(self):
        
        template = "Sender: {sender}\nReceiver: {receiver}\nContent: \n{content}"
        
        return template.format(sender = self.__sender, receiver = self.__receiver, content = self.__content)
        
email = Email('IM')
email.set_sender('qmal')
email.set_receiver('james')
content = MyContent('Hello, there!')
email.set_content(content)
print(email)