from socket import *
import ssl
import base64
import argparse as ap
import getpass as gp

parser = ap.ArgumentParser(description='A test SMTP client with TLS')
parser.add_argument('-u', '--username', dest='username', required=True, metavar='<username>')
parser.add_argument('-f', '--from', dest='fromMail', required=True, metavar='<sender_email>')
parser.add_argument('-t', '--to', dest='toMail', required=True, metavar='<recipient_email>')

args = parser.parse_args()

# Message to send
msg = '\nI love computer networks!\n'
endmsg = '\n.\n'

#Credentials
# Remember to DELETE THE PASSWORD before you hand-in the code!!!
username = args.username
password = gp.getpass(prompt='Password: ')

# Choose a mail server (Office365 for your student accounts or NTNU's student SMTP) and call it mailserver
# You'll have to search the web for the address
#mailserver = 'smtp.office365.com'
mailserver = 'smtp.stud.ntnu.no'
# Create socket called clientSocket and establish a TCP connection with mailserver
clientSocket = socket(AF_INET, SOCK_STREAM)

# Port number may change according to the mail server
# You'll have to search the web to find the corresponding port. Remember that we are using TLS.
clientSocket.connect((mailserver, 587))
#clientSocket.connect((mailserver, 2500))
recv = clientSocket.recv(1024)
recv = recv.decode()
print(recv)
if recv[:3] != '220':
    print('220 reply not received from server.')

# Send HELO command and print(server response.)
# Can use EHLO instead since HELO is obsolete, but can still be used
heloCommand = 'HELO {}\n'.format(clientSocket.getsockname()[0])
print(clientSocket.getsockname()[0])
clientSocket.send(heloCommand.encode())
recv1 = clientSocket.recv(1024)
recv1 = recv1.decode()
print(recv1)
if recv1[:3] != '250':
    print('250 reply not received from server.')

# Send STARTTLS command to start a secure connection and get server response.
quitcommand = 'STARTTLS\n'
clientSocket.send(quitcommand.encode())
recv2 = clientSocket.recv(1024)
recv2 = recv2.decode()
print(recv2)
if recv2[:3] != '220':
    print('220 reply not received from server.')

# Wrap the clientSocket with a TLS secure socket
clientSocketSSL = ssl.wrap_socket(clientSocket, ssl_version=ssl.PROTOCOL_SSLv23)

# Send HELO command and print(server response.)
# Can use EHLO instead since HELO is obsolete, but the latter can still be used
heloCommand = 'EHLO Hey\n'
clientSocketSSL.send(heloCommand.encode())
recv3 = clientSocketSSL.recv(1024)
recv3 = recv3.decode()
print(recv3)
if recv3[:3] != '250':
    print('250 reply not received from server.')

# Send AUTH command and print(server response.)
authCommand = 'AUTH LOGIN\n'
clientSocketSSL.send(authCommand.encode())
recv4 = clientSocketSSL.recv(1024)
recv4 = recv4.decode()
print(recv4)
# The code in this response is in plain text (should be 334), but
# the message is in base64. Have to decode it before printing.
print(recv4.split()[0] + ' ' + base64.b64decode(recv4.split()[1]).decode() + '\n')
if recv4[:3] != '334':
    print('334 reply not received from server.')

# Send username in base64 command and print(server response.)
# Remember to add \n after the username
loginCommand = base64.b64encode(username.encode()).decode() + '\n'
clientSocketSSL.send(loginCommand.encode())
# In bytes, have to decode to string
recv5 = clientSocketSSL.recv(1024)
recv5 = recv5.decode()
# The code in this response is in plain text (should be 334), but
# the message is in base64. Have to decode it before printing.
print(recv5.split()[0] + ' ' + base64.b64decode(recv5.split()[1]).decode() + '\n')
if recv5[:3] != '334':
    print('334 reply not received from server.')

# Send your password in base64 command and print(server response.)
# Remember to add \n after the password
passCommand = base64.b64encode(password.encode()).decode() + '\n'
clientSocketSSL.send(passCommand.encode())
recv6 = clientSocketSSL.recv(1024)
recv6 = recv6.decode()
print(recv6)
if recv6[:3] != '235':
    print('235 reply not received from server.')

# Send MAIL FROM command and print(server response.)
mailfrom = 'MAIL FROM: <{}>\n'.format(args.fromMail)
clientSocketSSL.send(mailfrom.encode())
recv7 = clientSocketSSL.recv(1024)
recv7 = recv7.decode()
print(recv7)
if recv7[:3] != '250':
    print('250 reply not received from server.')

# Send RCPT TO command and print(server response.)
rcptto = 'RCPT TO: <{}>\n'.format(args.toMail)
clientSocketSSL.send(rcptto.encode())
recv8 = clientSocketSSL.recv(1024)
recv8 = recv8.decode()
print(recv8)
if recv8[:3] != '250':
    print('250 reply not received from server.')

# Send DATA command and print(server response.)
data = 'DATA\n'
clientSocketSSL.send(data.encode())
recv9 = clientSocketSSL.recv(1024)
recv9 = recv9.decode()
print(recv9)
if recv9[:3] != '354':
    print('354 reply not received from server.')

# Send message data.
clientSocketSSL.send('Subject:Greeting To you!\n'.encode())
clientSocketSSL.send('\ntest again\n'.encode())
clientSocketSSL.send(msg.encode())

# Message ends with a single period.
clientSocketSSL.send(endmsg.encode())
recv10 = clientSocketSSL.recv(1024)
recv10 = recv10.decode()
print(recv10)
if recv10[:3] != '250':
    print('250 reply not received from server.')

# If you get here and receive the proper code response from the server,
# the code is correct. The mailserver has commited to deliver the mail.
# Keep in mind that the mail may still be blocked at the receiver side (spam)
# but that does not mean that your code is wrong.

# Send QUIT command and get server response.
quitcommand = 'QUIT\n'
clientSocketSSL.send(quitcommand.encode())
recv11 = clientSocketSSL.recv(1024)
recv11 = recv11.decode()
print(recv11)
if recv11[:3] != '221':
    print('221 reply not received from server.')