from django.conf import settings
from django.utils.html import strip_tags, strip_spaces_between_tags
from email.MIMEMultipart import MIMEMultipart
from email.MIMEText import MIMEText
from email.Header import Header
import smtplib, rfc822

class BadHeaderError(ValueError):
    pass

class SafeMIMEMultipart(MIMEMultipart):
    def __setitem__(self, name, val):
        "Forbids multi-line headers, to prevent header injection."
        if '\n' in val or '\r' in val:
            raise BadHeaderError, "Header values can't contain
newlines (got %r for header %r)" % (val, name)
        if name == "Subject":
            val = Header(val, settings.DEFAULT_CHARSET)
        MIMEText.__setitem__(self, name, val)

def send_mass_mail(datatuple, fail_silently=False,
auth_user=settings.EMAIL_HOST_USER,
auth_password=settings.EMAIL_HOST_PASSWORD):
    """
    Given a datatuple of (subject, message, from_email, recipient_list), sends
    each message to each recipient list. Returns the number of e-mails sent.

    If from_email is None, the DEFAULT_FROM_EMAIL setting is used.
    If auth_user and auth_password are set, they're used to log in.
    """
    # We prepare the server to send messages.
    try:
        server = smtplib.SMTP(settings.EMAIL_HOST, settings.EMAIL_PORT)
        if auth_user and auth_password:
            server.login(auth_user, auth_password)
    except:
        #print 'Server preparation did not work'
        if fail_silently:
            return
        raise
    num_sent = 0
    # We prepare the message to be sent.
    for subject, message, from_email, recipient_list in datatuple:
        if not recipient_list:
            continue
        from_email = from_email or settings.DEFAULT_FROM_EMAIL
        # Create the root message and fill in the basic headers
        msgRoot = MIMEMultipart('related')
        msgRoot['Subject'] = subject
        msgRoot['From'] = from_email
        msgRoot['To'] = ', '.join(recipient_list)
        msgRoot['Date'] = rfc822.formatdate()
        msgRoot.preamble = 'This is a multi-part message in MIME format.'
        # Encapsulate the plain and HTML versions of the message body in an
        # 'alternative' part, so message agents can decide which they
want to display.
        msgAlternative = MIMEMultipart('alternative')
        msgRoot.attach(msgAlternative)
        # This is the html message.
        msgText = MIMEText(message, 'html', settings.DEFAULT_CHARSET)
        msgAlternative.attach(msgText)
        # This is the alternative plain text message.
        msgText =
MIMEText(strip_spaces_between_tags(strip_tags(message)), 'plain',
settings.DEFAULT_CHARSET)
        msgAlternative.attach(msgText)
        # We send the actual message
        try:
            server.sendmail(from_email, recipient_list, msgRoot.as_string())
            num_sent += 1
        except:
            if not fail_silently:
                raise
    # We quit elegantly
    try:
        server.quit()
    except:
        if fail_silently:
            return
        raise
    return num_sent