#! /usr/bin/python

import socket
import sys
import time

def readline(fd):
    line = fd.readline()
    if line == None:
        raise EOFError()
    #sys.stdout.write(line)
    return line.rstrip() #remove trailing CRLF

def checkOK(fd):
    line = readline(fd)
    if line[0] == '-':
        raise RuntimeError("server errored")

whitespace = " \t"

pop3_host = "pop3.shellmix.com"
pop3_port = 110
pop3_user = ""
pop3_pass = ""

sock_fd = None
fd = None
try:
    sock_fd = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock_fd.connect((pop3_host, pop3_port))
    fd = sock_fd.makefile()
    print("connected")
    checkOK(fd)

    sock_fd.send("USER " + pop3_user + "\r\n")
    checkOK(fd)

    sock_fd.send("PASS " + pop3_pass + "\r\n")
    checkOK(fd)

    sock_fd.send("LIST\r\n")
    checkOK(fd)
    message_list = []
    while True:
        line = readline(fd)
        if len(line) == 1 and line[0] == ".":
            break
        message_list.append(line.split(" ")[0])

    finished = False
    for msg in message_list:
        sock_fd.send("RETR " + msg + "\r\n")
        checkOK(fd)
        email_finished = False
        #loop for email headers
        while True:
            line = readline(fd)
            if len(line) == 1 and line[0] == ".":
                email_finished = True
                break
            if len(line) == 0: #end of headers
                break
            if whitespace.find(line[0]) != -1: #the first character is whitespace
                print("-> " + line.strip())
            else:
                keyval = line.split(":")
                keyval[0] = keyval[0].strip()
                keyval[1] = keyval[1].strip()
                print("key=\"" + keyval[0] + "\" val=\"" + keyval[1] + "\"")

        #loop for email body
        while not email_finished:
            line = readline(fd)
            if len(line) == 1 and line[0] == ".":
                break


    sock_fd.send("QUIT\r\n")
    checkOK(fd)
finally:
    time.sleep(1)
    print("cleaning up")
    if fd != None:
        fd.close()
        fd = None
    if sock_fd != None:
        sock_fd.shutdown(socket.SHUT_RDWR)
        sock_fd.close()
        sock_fd = None