import csv
import email
import getpass
import imaplib

EMAIL_SERVER = 'imap.gmail.com'


def split_addresses(addr_list):
    # split an address list into list of tuples of (name,address)
    if not addr_list:
        return []
    out_q = True
    cut = -1
    res = []
    for i in range(len(addr_list)):
        if addr_list[i] == '"':
            out_q = not out_q
        if out_q and addr_list[i] == ',':
            res.append(email.utils.parseaddr(addr_list[cut + 1:i]))
            cut = i
    res.append(email.utils.parseaddr(addr_list[cut + 1:i + 1]))
    return res


def authenticate_to_gmail(username):
    mail = imaplib.IMAP4_SSL(EMAIL_SERVER)
    password = getpass.getpass()
    mail.login(username, password)
    mail.select("INBOX")
    return mail


def get_messages(username):
    mail = authenticate_to_gmail(username)
    result, data = mail.search(None, "ALL")
    message_ids = data[0].split()
    return mail.fetch(','.join(message_ids), '(BODY.PEEK[HEADER])')[1][0::2]


def main():
    username = raw_input("Username: ")
    messages = get_messages(username)

    with open('emails.csv', 'w') as f:
        writer = csv.writer(f)
        writer.writerow(['Name', 'Email'])

        for msg in (email.message_from_string(raw_msg) for _, raw_msg in messages):
            if 'to' in msg:
                if username in msg['to']:
                    for addr in split_addresses(msg['from']):
                        writer.writerow(list(addr))

            if 'from' in msg:
                if msg['from'] == username:
                    for addr in split_addresses(msg['to']):
                        writer.writerow(list(addr))


if __name__ == "__main__":
    main()