#!/usr/bin/env python

# -*- coding: UTF-8  -*-

# Copyright 2009 Pascal Volk

# See COPYING for distribution information.

__author__ = 'Pascal Volk'

__version__ = '0.1'

__date__ = '2009-11-14'

"""

Sends information about uncaught exceptions per email.

"""

import sys

import smtplib

import traceback

from os import environ as env

from time import ctime, gmtime, localtime, strftime, time

config = {# sender information

          'from_addr': '',

          'from_name': '',

          # smtp auth information (if necessary, else leave blank)

          'auth_user': '',

          'auth_pass': '',

          # recipient information

          'rcpt_addr': '',

          'rcpt_name': '',

          # smtp server information

          'smtp_host': 'localhost',

          'smtp_port': 25, # 25 smtp, 587 submission, 465 ssmtp (obsolete)

          'smtp_tls':  False, # True or False (use starttls on port 25/587)

          # subject of the email

          'subject': 'Exception Notification',

          # make sure that the web server can write to this file

          'error_log': '/tmp/mailtb_error.log'

         }

http_status = {200: 'OK',

               500: 'Internal Server Error'}

def log_mail_error(error, timestamp):

    try:

        prefix = strftime('%b %d %H:%M:%S', localtime(timestamp))

        line = error.message if len(error.message) else error.args

        logfile = open(config['error_log'], 'a')

        logfile.write('%s %s: %s\n' % (prefix, error.__class__.__name__, line))

        logfile.close()

    except:

        pass

def load_config(filename):

    from ConfigParser import ConfigParser

    cp = ConfigParser()

    if len(cp.read(filename)):

        global config

        get = cp.get

        for k in ('auth_pass', 'auth_user', 'error_log', 'from_addr',

                'from_name', 'rcpt_addr', 'rcpt_name', 'smtp_host', 'subject'):

            config[k] = get('mailtb', k)

        config['smtp_port'] = cp.getint('mailtb', 'smtp_port')

        config['smtp_tls'] = cp.getboolean('mailtb', 'smtp_tls')

def send_header(status=500, xhtml=False):

    s = status if status in http_status else 500

    write = sys.stdout.write

    if not xhtml:

        write('Content-Type: text/html; charset=utf-8\r\n')

    else:

        write('Content-Type: application/xhtml+xml; charset=utf-8\r\n')

    write('Status: %d %s\r\n\r\n' % (s, http_status[s]))

    sys.stdout.flush()

def send_error_page():

    send_header(500, True)

def send_mail(info):

    global config

    config['now'] = time()

    config['host'] = info['host'] if info['host'] != 'n/a' else 'localhost'

    config['date'] = strftime('%a, %d %b %Y %H:%M:%S +0000',

            gmtime(config['now']))

    try:

        if config['smtp_port'] != 465:

            smtp = smtplib.SMTP(config['smtp_host'], config['smtp_port'])

            if config['smtp_tls']:

                smtp.starttls()

        else:

            smtp = smtplib.SMTP_SSL(config['smtp_host'], config['smtp_port'])

        if len(config['auth_user']) and len(config['auth_pass']):

            smtp.login(config['auth_user'], config['auth_pass'])

        smtp.sendmail(config['from_addr'], config['rcpt_addr'],

    except Exception, e:

        # try to log it (fire and forget)

        log_mail_error(e, config['now'])

    finally:

        smtp.quit()

def mailtbhook(extype, exval, extb):

    info = {}

    if type(extype) is type:

        info['extype'] = extype.__name__

    else:

        info['extype'] = str(extype).split("'")[1]

    if hasattr(exval, 'message'):

        info['message'] = exval.message if len(exval.message) else 'n/a'

    else:

        info['message'] = str(exval)

    info['traceback'] = ''.join(['%s\n' % l for l in traceback.format_tb(extb)])

    info['date'] = ctime()

    for k in ('HTTP_HOST', 'HTTP_REFERER', 'HTTP_USER_AGENT', 'REMOTE_ADDR',

             'REMOTE_PORT', 'REQUEST_METHOD', 'REQUEST_URI', 'SERVER_PROTOCOL'):

        info[k.split('_')[-1].lower()] = env[k] if env.has_key(k) else 'n/a'

    send_mail(info)

def enable(filename=None):

    if filename is not None:

        load_config(filename)

    sys.excepthook = mailtbhook