networking.py

import socket, os, json, pdb

class Client:
    """ This class allwos the user to connect to a server and receive a textfile
    """
 
    #constructor + Type hinting adr:str appears whe creating object
    def __init__(self,adr: str, port: int):
        """Arguments:
            adr:  str - Name of domain or IP
            port: int _ between 0 and 65535
        """
        self.adr     = adr
        self.port   = port
        
    #shutdown/ close server from client side
    def close_server(self):
        msg = 'shutdown'
        try: 
            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            s.settimeout(10.0)
        except Exception as err:
            print(err) #print Exception to terminal
            return
        
        # resolve hostname
        if type(self.adr) is not str: #raise exception if adr is not string
            raise Exception('adr must be of type String')    
        try:
            ip = socket.gethostbyname(self.adr)
        except Exception as err:
            print('Exception using socket.gethostbyname():\n', err)
            return
        #try to connect to destination
        if type(self.port) is not int: #raise exception if port is not int
            raise Exception('ip must be of type integer')
        elif self.port < 0 or self.port > 65535:
            raise Exception('Port must be between 0 and 65535')
        try:
            s.connect((ip,self.port))
            #print('connected to: %s\n' %(ip))
        except Exception as err:
            print(err)
            s.close()
            return
        try:            
            s.send(msg.encode())
        except Exception as err:
            print('s.send(msg.encode())\n', err)
            
    def get_file(self):
        """
            Receives a file from given server
        """
        msg = 'file request'
        try: 
            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            s.settimeout(10.0)
        except Exception as err:
            print(err) #print Exception to terminal
            return
        
        # resolve hostname
        if type(self.adr) is not str: #raise exception if adr is not string
            raise Exception('adr must be of type String')    
        try:
            ip = socket.gethostbyname(self.adr)
        except Exception as err:
            print('Exception using socket.gethostbyname():\n', err)
            return
        #try to connect to destination
        if type(self.port) is not int: #raise exception if port is not int
            raise Exception('ip must be of type integer')
        elif self.port < 0 or self.port > 65535:
            raise Exception('Port must be between 0 and 65535')
        try:
            s.connect((ip,self.port))
            #print('connected to: %s\n' %(ip))
        except Exception as err:
            print(err)
            s.close()
            return
        try:            
            s.send(msg.encode())
        except Exception as err:
            print('s.send(msg.encode())\n', err)
        try:   
            msg = s.recv(4096).decode()                        
        except Exception as err:
            print('msg = s.recv(4096).decode()\n', err)
        s.close()

        try:
            fileJson = json.loads(msg)
        except Exception as err:
            print('fileJson = json.loads(msg)',err)
        file = open(fileJson['name']+'copy.txt','w')
        file.write(fileJson['content'])
        file.close()
        return fileJson
        #print(msg)

class Server:

    def __init__(self,adr: str, port: int):
        self.port = port
        self.adr  = adr
        
    def close_server(self):
        try:
            self.s.close()
        except Exception as err:
            print('self.s.close()',err)
            return
    def close_connection(self):
        try:
            self.c.close()
        except Exception as err:
            print('self.s.close()',err)

    def launch(self):
        if type(self.adr) is not str: #raise exception if adr is not string
            raise Exception('adr must be of type String')
        if type(self.port) is not int: #raise exception if port is not int
            raise Exception('ip must be of type integer')
        elif self.port < 0 or self.port > 65535:
            raise Exception('Port must be between 0 and 65535')
        try:
            self.s.bind((self.adr, self.port))
            print("socket binded to %s" %(self.port))
        except Exception as err:
            print('Exception cathed when executing self.s.bind((adr,port))\n',err)
            return
        # put the socket into listening mode - 5 scokets can be in queue, 6th is refused
        try:
            self.s.listen(5)
            print("socket is listening\n")
        except Exception as err:
            print('self.s.listen(5)',err)
            return

    def send_file(self, fileName: str):

        #create socket
        try: 
            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        except Exception as err:
            print(err) #print Exception to terminal
            return
        
        #Validate arguments
        if type(self.adr) is not str: #raise exception if adr is not string
            raise Exception('adr must be of type String')
        if type(self.port) is not int: #raise exception if port is not int
            raise Exception('ip must be of type integer')
        elif self.port < 0 or self.port > 65535:
            raise Exception('Port must be between 0 and 65535')
        
        #bind to adress and port
        try:
            s.bind((self.adr, self.port))
            print("socket binded to %s" %(self.port))
        except Exception as err:
            print('Exception cathed when executing self.s.bind((adr,port))\n',err)
            return

        # put the socket into listening mode - 5 scokets can be in queue, 6th is refused
        try:
            s.listen(5)
            print("socket is listening\n")
        except Exception as err:
            print('self.s.listen(5)',err)
            return

        while True:
            
            
            
            #accept connections
            try:
                c, cAdr = s.accept()
                print('Got connection from\n', cAdr)
            except Exception as err:
                print('self.c, cAdr = self.s.accept()',err)
                return

            #receive message
            response = c.recv(4096).decode()
            
            if response == 'shutdown':
                #shut down server from client side
                s.close()
                print('server closed by client:\n',cAdr)
                break
            else:
                # read file
                if type(fileName) is not str:
                    raise Exception('fileName must be String')
                # load file
                fileJson ={}
                try:
                    file = open(fileName,'r')
                except Exception as err:
                    print('file = open(fileName,\'r\'\n', err)
                    return
                fileJson['name'] = file.name
                fileJson['content'] = file.read()
                file.close()
                msg = json.dumps(fileJson)
                #send file and close connection if empty response
                c.send(msg.encode())
                c.close()
            print(response)

        

    def send(self, msg):
        try:
            self.c.send(msg)
        except Exception as err:
            print('self.s.send(msg)\n',err)

    def close_server(self):
        try:
            self.s.close()
        except Exception as err:
            print('self.s.close()',err)
            return
    def close_connection(self):
        try:
            self.c.close()
        except Exception as err:
            print('self.s.close()',err)