"""

John Rachlin
DS 2000: Intro to Programming with Data

Filename: network.py
    
Description: A simple social network

    
"""

class Network:
    
    def __init__(self):
        """ Constructor """
        self.dict = {} # state variable "attribute" of Network
    
    
    def add_person(self, name):
        """ Adds a new person to the network """
        if name not in self.dict:
            self.dict[name] = []
        
    
    
    def friend(self, name1, name2):
        """ Make two people MUTUAL friends """
        self.add_person(name1)
        self.add_person(name2)
        
        if name2 not in self.get_friends(name1):
            self.dict[name1].append(name2)
            
        if name1 not in self.get_friends(name2):
            self.dict[name2].append(name1)
        
    
    def get_friends(self, name):
        """ Return all the friends of <name> as a list"""
        self.add_person(name)
        return self.dict[name]
    
    def recommend(self, name):
        """ Return friends of friends
        Exclude existing friends.
        Exclude name him/herself
        Dont recommend a person more than once """
        
        recs = []
        
        friends = self.get_friends(name) # immediate friends
        for friend in friends:
            friendsfriends = self.get_friends(friend)
            for f in friendsfriends:
                if f != name and f not in recs and f not in friends:
                    recs.append(f)
        return recs
            
        


def main():
    
    net = Network()
    
    #net.add_person("John")
    #net.add_person("Laney")
    
    #print("Before: ", net.dict)
    net.friend("John", "Laney")   
    net.friend("John", "Emma")
    net.friend("John", "Dachuan")
    net.friend("Laney", "Leilani")
 
    #print("After : ", net.dict)

    print("Friends of Leilani: ", net.get_friends("Leilani"))
    print("Recommendations   : ", net.recommend("Leilani"))
    
    
    
if __name__ == '__main__':
    main()