## $Id: utils.py 7382 2011-12-18 15:32:10Z uli $
##
## Copyright (C) 2011 Uli Fouquet & Henrik Bettermann
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
##
"""General helper utilities for SIRP.
"""
import grok
import smtplib
import string
from random import SystemRandom as r
from email.mime.text import MIMEText
from waeup.sirp.interfaces import ISIRPUtils

from email.Header import Header
from email.Utils import parseaddr, formataddr


class SIRPUtils(grok.GlobalUtility):
    """A collection of methods subject to customization.
    """
    grok.implements(ISIRPUtils)

    def sendMail(self,fullname,username,usertype,portal,body,
                 email_from,email_to,subject):
        """Send an email with data provided by forms.
        """
        config = grok.getSite()['configuration']
        text = """Fullname: %s
User Id: %s
User Type: %s
Portal: %s

%s
"""
        msg = MIMEText(text % (fullname,username,usertype,portal,body))
        msg['From'] = '%s <%s>' % (fullname,email_from)
        msg['To'] = email_to
        msg['Subject'] = subject
        server = smtplib.SMTP(config.smtp_server)
        if config.smtp_requires_login:
            server.login(config.smtp_username,config.smtp_password)
        try:
            server.sendmail(email_from,email_to,msg.as_string())
        except:
            return False
        server.quit()
        return True

    def fullname(self,firstname,lastname,middlename=None):
        # We do not necessarily have the middlename attribute
        if middlename:
            return string.capwords(
                '%s %s %s' % (firstname, middlename, lastname))
        else:
            return string.capwords(
                '%s %s' % (firstname, lastname))

    def genPassword(self, length=8, chars=string.letters + string.digits):
        return ''.join([r().choice(chars) for i in range(length)])

    def sendPassword(self,fullname,msg,username,password,login_url,
                 email_to,subject):
        """Send an email with user credentials.

        XXX: While this method is unicode-proof (i.e. it can handle
             non-plain-ASCII chars in names and messages) other
             methods inhere are not and will fail silently. Some
             reorganization of SMPT-related code is needed here.
        """
        config = grok.getSite()['configuration']
        header_charset = 'ISO-8859-1'
        text = """Dear %s,

%s
Student Registration and Information Portal of
%s.

Your user name: %s
Your password: %s
Login page: %s

Please remember your user name and keep
your password secret!

Please also note that passwords are case-sensitive.

Regards
"""
        from_ = '%s <%s>' % (config.name_admin,config.email_admin)
        from_name, from_addr = parseaddr(from_)
        rcpt_name, rcpt_addr = parseaddr(email_to)
        from_name = str(Header(unicode(from_name), header_charset))
        rcpt_name = str(Header(unicode(rcpt_name), header_charset))
        from_addr = from_addr.encode('ascii')
        rpct_addr = rcpt_addr.encode('ascii')

        body = text % (
                fullname, msg,config.name,username,password,login_url)
        for body_charset in ['US-ASCII', 'ISO-8859-1', 'UTF-8']:
            try:
                body.encode(body_charset)
            except UnicodeError:
                print "FAILED: ", body_charset, text
                pass
            else:
                break

        msg = MIMEText(body.encode(body_charset), 'plain', body_charset)
        msg['From'] = formataddr((from_name, from_addr))
        msg['To'] = formataddr((rcpt_name, rcpt_addr))
        msg['Subject'] = Header(unicode(subject), header_charset)
        server = smtplib.SMTP(config.smtp_server)
        if config.smtp_requires_login:
            server.login(config.smtp_username,config.smtp_password)
        try:
            server.sendmail(config.email_admin,email_to,msg.as_string())
        except Exception, e:
            # XXX: log error message
            return False
        server.quit()
        return True