"""
Provides a form to send an email to the blog-owner.

If you make any changes to this plugin, please send a patch to 
<sa+pyblosxom at c-area dot ch> so I can incorporate them.
Thanks!


To install:
1) Put contact.py in your plugin directory.
2) In config.py add 'contact' to py['load_plugins']
3) Add the following variables to config.py:
    py['contact_urltrigger'] = "/contact" # optional, this is the default
    py['contact_smtp_server'] = "localhost" # required
    py['contact_smtp_to'] = "you@example.com" # required
4) Optionally create a template named contact.<flavour> in your flavour directory.
   If no contact.<flavour> exists a simple default is used. See _default_template below.


Dependencies:
    - My compatibility plugin if you're not using pyblosxom 1.2+.


$Id: contact.py,v 1.6 2005/08/25 13:21:48 sar Exp $
"""
__author__ = "Steven Armstrong <sa at c-area dot ch>"
__version__ = "$Revision: 1.6 $ $Date: 2005/08/25 13:21:48 $"
__url__ = "http://www.c-area.ch/code/"
__description__ = "Provides a form to send an email to the blog-owner."
__license__ = "GPL 2+"


# Python imports
import urlparse

# Pyblosxom imports
from Pyblosxom.renderers.blosxom import Renderer
from Pyblosxom import tools


# Variables
TRIGGER = "/contact"
TRIGGER_KEY = "contact_urltrigger"
INIT_KEY = "contact_initiated"
MESSAGE_KEY = "contact_error_message"
_form_fields = ['name', 'email', 'subject', 'message']

_default_template = """
<div>
<h2>Contact me</h2>
<div style="display:block;">$contact_error_message</div>
<form name="contactForm" id="contactForm" method="post" action="$base_url$contact_urltrigger">
<div class="contactLine">
  <label class="contactLine" for="name" title="Your name">Name</label>
  <input type="text" name="name" id="name" value="$contact_name" /><br />
</div>
<div class="contactLine">
  <label class="contactLine" for="email" title="Your email address">Email</label>
  <input type="text" name="email" id="email" value="$contact_email" /><br />
</div>
<div class="contactLine">
  <label class="contactLine" for="subject" title="Subject of your message">Subject</label>
  <input class="contactLine" type="text" name="subject" id="subject" value="$contact_subject" /><br />
</div>
<div class="contactText">
  <label class="contactText" for="message" title="Your message">Message</label>
  <textarea name="message" id="message" style="height:150px;">$contact_message</textarea><br />
</div>
<div class="contactSubmit">
  <input class="contactSubmit" type="submit" value="Send" style="width:auto; margin-right:0;" />
  <input class="contactSubmit" type="reset" value="Reset" style="width:auto; margin-right:0;" />
</div>
</form>
</div>
"""

################################################################################
##
## Helper functions
##
################################################################################

rfc822_specials = '()<>@,;:\\"[]'

def isAddressValid(addr):
    '''
    Taken from

    http://www.secureprogramming.com/?action=view&feature=recipes&recipeid=1

    Posted by Matt Messier on Tue, Sep 02, 2003 (06:19 PM) GMT

    >>> isAddressValid('djfhdfh')
    0
    >>> isAddressValid('djfhdfh@test.com')
    8
    >>> isAddressValid('dj@fhdfh@test.com')
    0
    >>> isAddressValid('dj\@fhdfh@test.com')
    0
    >>> isAddressValid('dj"@"fhdfh@test.com')
    0
    >>> isAddressValid('dj" "fhdfh@test.com')
    0
    >>> isAddressValid('dj\" \"fhdfh@test.com')
    0
    >>> isAddressValid('dj." ".fhdfh@test.com')
    13
    >>> isAddressValid('dj."@ ".fhdfh@test.com')
    14
    >>> isAddressValid('dj."@<> ".fhdfh@test.com')
    16
    >>> isAddressValid('dj."@<>ü ".fhdfh@test.com')
    0
    >>> isAddressValid('dj<>fhdfh@test.com')
    0
    >>> isAddressValid('dj\<\>fhdfh@test.com')
    0
    >>> isAddressValid('dj\ fhdfh@test.com')
    0
    >>> isAddressValid('dj\\ fhdfh@test.com')
    0
    >>> isAddressValid('djfhdfh@test.com.de')
    8
    >>> isAddressValid('djfhdfh@test.co<m.de')
    0
    '''
    # Ported from Recipe 3.9 in Secure Programming Cookbook for C and C++ by
    # John Viega and Matt Messier (O'Reilly 2003)

    # First we validate the name portion (name@domain)
    c = 0
    while c < len(addr):
        if addr[c] == '"' and (not c or addr[c - 1] == '.' or addr[c - 1] == '"'):
            c = c + 1
            while c < len(addr):
                if addr[c] == '"':
                    c = c + 1
                    break
                if addr[c] == '\\' and addr[c + 1] == ' ':
                    c = c + 2
                    continue
                if ord(addr[c]) < 32 or ord(addr[c]) >= 127: return 0
                c = c + 1
            else: return 0
            if addr[c] == '@': break
            if addr[c] != '.': return 0
            c = c + 1
            continue
        if addr[c] == '@': break
        if ord(addr[c]) <= 32 or ord(addr[c]) >= 127: return 0
        if addr[c] in rfc822_specials: return 0
        c = c + 1
    if not c or addr[c - 1] == '.': return 0

    # Next we validate the domain portion (name@domain)
    domain = c = c + 1
    if domain >= len(addr): return 0
    count = 0
    while c < len(addr):
        if addr[c] == '.':
            if c == domain or addr[c - 1] == '.': return 0
            count = count + 1
        if ord(addr[c]) <= 32 or ord(addr[c]) >= 127: return 0
        if addr[c] in rfc822_specials: return 0
        c = c + 1

    ## The final return statement was modified to return the split point
    ## (position of @) so that the email can split in its two subsections.
    if count >= 1:
        return domain


def verify_installation(request):
    config = request.getConfiguration()
    retval = 1

    if not 'contact_urltrigger' in config:
        print "Missing optional property: 'contact_urltrigger'"
        print "Using the default of '%s'" % TRIGGER
    
    _required = ['contact_smtp_server', 'contact_smtp_to']
    for prop in _required:
        if not prop in config:
            print "Missing required property: '%s'" % prop
            retval = 0
    
    return retval



class ContactRenderer(Renderer):
    
    def render(self, header=1):
        config = self._request.getConfiguration()
        data = self._request.getData()

        # root_datadir is normaly set after the cb_pathinfo callback.
        # but if a plugin implements cb_handle (as this one does), 
        # cb_pathinfo is never called.
        # if root_datadir is not set and flavourdir is not set in config.py
        # an exception is thrown in BlosxomRenderer._getFlavour.
        # so set root_datadir here explicitly to prevent that.
        if not 'root_datadir' in data:
            data['root_datadir'] = config['datadir']

        # initialize flavour
        self.flavour = self._getFlavour(data.get('flavour', 'html'))
        data['content-type'] = self.flavour['content_type'].strip()
        if header:
            self.addHeader("Status", "200 OK")
            if self._needs_content_type and data['content-type'] != "":
                self.addHeader('Content-type', '%s; charset=%s' % (data['content-type'], config.get('blog_encoding', 'iso-8859-1')))
            self.showHeaders()

        d = {}
        d.update(config)
        d.update(data)

        if 'head' in self.flavour:
            self._outputFlavour(d, 'head')

        if not 'contact' in self.flavour:
            self.flavour['contact'] = _default_template
        self._outputFlavour(d, 'contact')

        if 'foot' in self.flavour: 
            self._outputFlavour(d, 'foot')                
        
        self.rendered = 1



def _update_config(config):
    if TRIGGER_KEY in config:
        global TRIGGER
        TRIGGER = config[TRIGGER_KEY]
    else:
        # set this explicitly so it's available in templates
        config[TRIGGER_KEY] = TRIGGER


def _handle_post(request):
    form = request.getForm()
    data = request.getData()
    http = request.getHttp()
    config = request.getConfiguration()

    email = {}
    error = False
    error_messages = []

    if not 'HTTP_REFERER' in http or \
           not http['HTTP_REFERER'].startswith('://'.join(urlparse.urlsplit(config['base_url'])[0:1])):
        data[MESSAGE_KEY] = "Posting from foreign hosts not allowed.<br />\nUse the form below to send your message."
        return

    for field in _form_fields:
        if not field in form:
            error_messages.append("Missing required field '%s'." % field)
            error = True
        else:
            # strip markup
            parser = tools.Stripper()
            parser.feed(form[field].value)
            email[field] = parser.gettext()

    if 'email' in email.keys() and not isAddressValid(email['email']):
            error = True
	    error_messages.append("Invalid email address '%s'. Cannot deliver your message!" % email['email'])

    if error:
        data[MESSAGE_KEY] = "<br />\n".join(error_messages)
        _remember_email(email, data)
    else:
        success, data[MESSAGE_KEY] = _send_email(email, config)
        if success:
            _forget_email(data)
        else:
            _remember_email(email, data)


def _remember_email(email, data):
    """
    Stores form fields in the data dict so they can be used to 
    populate the form in the template.
    """
    for key in email:
        data["contact_%s" % key] = email[key]


def _forget_email(data):
    """
    Resets/forgets any stored form field values.
    """
    for key in _form_fields:
        key = "contact_%s" % key
        if key in data:
            del data[key]


def _send_email(email, config):
    try:
        try: from email.Utils import formatdate
        except ImportError: from rfc822 import formatdate
        import smtplib
    
        smtp = smtplib.SMTP(config['contact_smtp_server'])

        email['to'] = config["contact_smtp_to"]
        email['date'] = formatdate(localtime=True)

        msg = """\
From: %(name)s <%(email)s>
To: %(to)s
Date: %(date)s
Subject: %(subject)s

%(message)s

""" % email

        smtp.sendmail(
            from_addr=email['email'],
            to_addrs=config['contact_smtp_to'],
            msg=msg
        )
        smtp.quit()
    except:
        if hasattr(tools, "log_exception"):
            tools.log_exception()
        return (False, "Error: Problem sending email.")
    else:
        return (True, "Thanks for feeding my mailbox ;-)")




#******************************
# Callbacks
#******************************

def cb_start(args):
    request = args['request']
    http = request.getHttp()
    config = request.getConfiguration()
    _update_config(config)

    if http['PATH_INFO'].startswith(TRIGGER):
        data = request.getData()
        data[INIT_KEY] = True


def cb_handle(args):
    request = args['request']
    data = request.getData()

    if INIT_KEY in data:
        http = request.getHttp()
        if http['REQUEST_METHOD'].upper() == "POST":
            _handle_post(request)
        else:
            _forget_email(data)

        ContactRenderer(request, request.getResponse()).render()

        return 1


def cb_end(args):
    # cleanup
    request = args['request']
    data = request.getData()
    if INIT_KEY in data:
        del data[INIT_KEY]
    if MESSAGE_KEY in data:
        del data[MESSAGE_KEY]