import paramiko  # Importing the paramiko library for SSH connection
import time  # Importing the time library for measuring execution time
import getpass  # Importing the getpass library for securely inputting the password

class ssh:
    def __init__(self, host, port, username, password):
        self.host = host  # Store the host address
        self.port = port  # Store the port number
        self.user = username  # Store the username
        self.password = password  # Store the password
        self.connect()  # Establish an SSH connection upon object initialization
    
    def connect(self):
        try:
            self.client = paramiko.SSHClient()  # Create an SSH client object
            self.client.set_missing_host_key_policy(paramiko.AutoAddPolicy())  # Automatically add the host key to known_hosts
            self.client.connect(port=self.port, username=self.user, hostname=self.host, password=self.password)  # Connect to the SSH server
            self.commands()  # Start executing commands after successful connection
        except Exception as err:
            print("Error connecting: " + str(err))  # Display an error message if connection fails
        finally:
            pass
    
    def commands(self):
        try:
            while True:
                try:
                    cmd = input("Connection to " + self.host + ": ")  # Prompt for user input
                    if cmd == "exit":
                        break  # Break the loop if the user enters "exit"
                    elif cmd == "users":
                        self.stdin, self.stdout, self.stderr = self.client.exec_command("cat /etc/passwd")  # Execute the command on the SSH server
                        print("\n" + self.stdout.read().decode())  # Display the command output
                    else:
                        self.stdin, self.stdout, self.stderr = self.client.exec_command(cmd)  # Execute the command on the SSH server
                        print("\n" + self.stdout.read().decode())  # Display the command output
                except KeyboardInterrupt:
                    break  # Break the loop if the user interrupts with Ctrl+C
            self.client.close()  # Close the SSH connection
        except Exception as err:
            print("Error: " + str(err))  # Display an error message if an exception occurs

def main():
    host = input("Host: ")  # Prompt for the host address
    port = input("Port: ")  # Prompt for the port number
    username = input("Username: ")  # Prompt for the username
    password = getpass.getpass(prompt='Password: ')  # Prompt for the password without displaying it
    conn = ssh(host=host, port=port, username=username, password=password)  # Create an SSH object and establish connection
    
if __name__ == '__main__':
    start = time.time()  # Record the starting time
    main()  # Call the main function
    end = time.time()  # Record the ending time
    print("Time taken: {:.6f} seconds".format(end - start))  # Display the execution time