utility.py

import json
from operator import truediv
import socket
import time
#todo
#neighbor what if there is no +1 id
port = 45961

server_list = open('servers.json','r')

# with open('servers.json') as json_file:
#     servers = json.load(json_file)
#     print(json.dumps(servers, indent=4))




#create udp socket
def create_socket():
    udp_socket= socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    return(udp_socket)

def get_broadcast_ip():
    ip = get_ip()
    broadcast_ip = ip[:-3] + "255"
    return(broadcast_ip)

#get my ip 
def get_ip():
    hostname = socket.gethostname()
    myip = socket.gethostbyname(hostname + ".local")
    return(myip)

#listen for msg on udp
def udp_listener(leader):
    s = create_socket()
    myip = get_ip()
    # Set the socket to broadcast and enable reusing addresses
    s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    # Bind socket to address and port
    s.bind((get_ip(), port))
    print("Listening to broadcast messages")
    while True:
        data, addr = s.recvfrom(1024)
        if data:
            print("Message:", data.decode())
            #check if Iam leader
            msg_split(data.decode(), leader)

#Split mgs into receiver and msg and forward it to receiver
def msg_split(rec_msg, leader):
    msg_obj = rec_msg.split("@")
    kind= msg_obj[0]
    to = msg_obj[1]
    msg = msg_obj[2]
    sender = msg_obj[3]
    #print("send to: " + to)
    print("msg: " + msg)
    print("from: " + sender)
    

    if kind == "voting":
        msg = "voting@" + str(neighbor()) + "@" + "@" + get_ip()   
        send_msg(msg, server_ip(str(neighbor())))
    
    if leader == False:
        if kind == "updates":
            server_list = []
            with open("servers.json") as servers:
                server_list = json.load(servers)
            server_list = msg
            bla= open("servers.json", "w")
            json.dump(server_list, bla)

        if kind == "updateu":
            user_list = []
            with open("users.json") as users:
                user_list = json.load(users)
            user_list = msg
            bla= open("users.json", "w")
            json.dump(user_list, bla)
    
    if leader == True:    
        if kind == "msg":
            msg = "msg@" + to + "@" + msg + "@" + usr_name(sender)
            print(msg)
            send_msg(msg, to)
        if kind == "newu":
            add_user(sender, msg)
        if kind == "news":
            add_server(sender)

    
#find neighbor
def neighbor():
    myip = get_ip()

    with open("servers.json","r") as servers:
        server_list = json.load(servers)

    my_id = server_name(myip)
    print(my_id)
    print(len(server_list))

    if len(server_list) == int(my_id):
        neighbor = 1
    else:
        neighbor = int(my_id) + 1
    print("my neighbor is: ", neighbor) 
    return(neighbor)

#add user to list 
def add_server(ip):
    server_list = []
    with open("servers.json") as servers:
        server_list = json.load(servers)
    id = len(server_list)+ 1
    server_list.update({id: ip})
    bla= open("servers.json", "w")
    json.dump(server_list, bla)
    print("server added")

#add user to list 
def add_user(ip, name):
    user_list = []
    with open("users.json") as users:
        user_list = json.load(users)
    user_list.update({name: ip})
    bla= open("users.json", "w")
    json.dump(user_list, bla)
    print("user added")

def read_listu():
    with open("users.json") as users:
        user_list = json.load(users)
    return user_list

def read_lists():
    with open("servers.json") as servers:
        server_list = json.load(servers)
    return server_list

#Send UDP msg
def send_msg(msg, rec_ip):
    s = create_socket()
    s.sendto(msg.encode(),(rec_ip, port))
    print("msg send to: " + rec_ip)

#Send UDP msg with Port
def send_msgp(msg, rec_ip, port):
    s = create_socket()
    s.sendto(msg.encode(),(rec_ip, int(port)))
    print("msg send to: " + rec_ip)

#send broadcast
def send_broadcast(msg):
    s = create_socket()
    s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
    s.sendto(str.encode(msg), (get_broadcast_ip(), port))
    print("broadcast msg send")

#get ip of user by name
def usr_ip(name):
    with open("users.json","r") as users:
        user_list = json.load(users)
    usr_ip = user_list[name]
    print("User ip is: " + usr_ip)
    return(usr_ip)

#get name by ip
def usr_name(ip):
    with open("users.json","r") as users:
        user_list = json.load(users)
    names = list(user_list.keys())
    ips = list(user_list.values())
    return(names[ips.index(ip)])

#get server by ip
def server_name(ip):
    with open("servers.json","r") as servers:
        server_list = json.load(servers)
    ids = list(server_list.keys())
    ips = list(server_list.values())
    return(ids[ips.index(ip)])

#get ip of server by name
def server_ip(id):
    with open("servers.json","r") as server:
        server_list = json.load(server)
    server_ip = server_list[id]
    print("server ip is: " + server_ip)
    return(server_ip)

#heartbeat sender
def heartbeat():
    msgu = "updateu@bla@" + str(read_listu()) + "@" + get_ip()
    msgs = "updates@bla@" + str(read_lists()) + "@" + get_ip()
    with open("servers.json","r") as servers:
        server_list = json.load(servers)
    i = 1
    while i <= len(server_list):
        send_msgp("heartbeat@to@msg@sender", str(server_list[str(i)]), "45962")
        send_msg(msgu, str(server_list[str(i)]))
        send_msg(msgs, str(server_list[str(i)]))
        i += 1
        

    print("Hartbeat send")

#Voting ping is missing if next server is there
def voting():
    msg = "voting@" + str(neighbor()) + "@"  +"msg@" + server_name(get_ip())
    send_msg(msg, (server_ip(str(neighbor()))))