import os
import json
import smtplib
from email.mime.text import MIMEText

def read_file(filename):
    """ Read contents of file. """
    f = open(filename)
    contents = f.read()
    f.close()
    return contents

def parse_email(filename):
    """ --------------------
        String -> Dictionary
        --------------------
        Read given json file, and parse it.
    """
    return json.loads(read_file(filename))

def send_email(msg_data):
    """ Given message data, send email. Expects the following:
        username, password, subject, message, sender, recipient
    """
    # Sender, recipient, and message content
    msg = MIMEText(msg_data['message'])
    msg['Subject'] = msg_data['subject']
    msg['From'] = msg_data['sender']
    msg['To'] = msg_data['recipient']

    # Login to account, and send email.
    username = msg_data['username']
    password = msg_data['password']

    server = smtplib.SMTP('smtp.gmail.com:587')
    server.starttls()
    server.login(username, password)
    server.sendmail(msg['From'], msg['To'], msg.as_string())
    server.quit()

def process_email(filename):
    """ --------------------------------------------------------
        String -> SideEffect(Send email) | Print failure message
        --------------------------------------------------------
        Given json file containing email information, either send
        email, or print out an error message.
    """
    try:
        email_data = json.loads(read_file(filename))
    except:
        print "Couldn't parse: {}. Check that it has these fields: username, password, subject, message, sender, recipient".format(filename)
        return 1
    try:
        send_email(email_data)
        print "Sent email for {}".format(filename)
    except:
        print "Couldn't send email for {}. Is your password right?".format(filename)
        return 1
    return 0

# Get email files
email_files = filter(lambda f: f.endswith('.json'), os.listdir('.'))

map(process_email, email_files)

# { "username": "dela3499"
# , "password": "bsvrvrzoelmfasj2" # app-specific password from Google
# , "sender": "dela3499@gmail.com"
# , "recipient": "dela3499+test@gmail.com"
# , "subject": "Test 3"
# , "message": "This is a test."
# }