from google.appengine.api import urlfetch, users
from google.appengine.ext import db
from google.appengine.ext.webapp import RequestHandler, WSGIApplication, template
from google.appengine.ext.db import djangoforms
from urllib import urlencode
from wsgiref.handlers import CGIHandler

try:
    from django import newforms as forms
except ImportError:
    from django import forms

try:
    from django.contrib.localflavor.us.forms import USPhoneNumberField
except ImportError:
    from django.contrib.localflavor.usa.forms import USPhoneNumberField

import logging, os, re

logging.getLogger().setLevel(logging.DEBUG)

CLICK2CALL_URL = 'https://secure.click2callu.com/tpcc/makecall'

def vonageize_number(number):
    number = re.sub(r'\D', '', number)
    if len(number) == 0:
        raise forms.ValidationError('Please enter a telephone number.')
    if number[0] == '1':
        number = number[1:]
    if len(number) != 10:
        raise forms.ValidationError('Please enter a 10-digit US telephone '
                                    'number.')
    return '1' + number

class VonageUSNumberProperty(db.PhoneNumberProperty):
    def validate(self, value):
        return vonageize_number(value)

class VonageNumber(db.Model):
    label = db.StringProperty()
    username = db.StringProperty(required=True)
    password = db.StringProperty(required=True)
    number = VonageUSNumberProperty(required=True)

class AllowedUser(db.Model):
    user = db.UserProperty(required=True)

def login_required(f):
    def handle(self):
        user = users.get_current_user()
        if user is None:
            return self.redirect(users.create_login_url(self.request.uri))
        if AllowedUser.gql('WHERE user = :1', user).get() is None:
            if users.is_current_user_admin():
                AllowedUser(user=user).put()
            else:
                email = user.email()
                logging.error('Denied access to ' + email)
                return self.unavailable(
                    'Your account <b>%s</b> does not have permission to use '
                    'this service.' % email)
        return f(self)
    return handle

def admin_required(f):
    def handle(self):
        if not users.is_current_user_admin():
            return self.unavailable(
                'This function requires you to be an administrator.')
        return f(self)
    return handle

class NumberForm(djangoforms.ModelForm):
    password = forms.CharField(widget=forms.widgets.PasswordInput)
    number = USPhoneNumberField(label='Vonage number')

    class Meta:
        model = VonageNumber
        exclude = ['label']

class BasePage(RequestHandler):
    def render(self, **kw):
        self.response.out.write(template.render(self.template_path, kw))

    def unavailable(self, msg):
        self.render(unavailable=msg,
                    logout_url=users.create_logout_url(self.request.uri))

class NumbersPage(BasePage):
    template_path = os.path.join(os.path.dirname(__file__), 'numbers.html')

    @admin_required
    def get(self):
        self.render(form=NumberForm(instance=VonageNumber.all().get()))

    @admin_required
    def post(self):
        form = NumberForm(data=self.request.POST,
                          instance=VonageNumber.all().get())
        if not form.is_valid():
            return self.render(form=form)
        try:
            form.save()
        except Exception, e:
            return self.render(form=form, error=e.message)
        self.redirect('/')

class MainPage(BasePage):
    template_path = os.path.join(os.path.dirname(__file__), 'index.html')

    def error(self, msg, **kw):
        self.render(error=msg, tonumber=self.request.get('tonumber', ''), **kw)

    def failure(self, msg):
        logging.error('TPCC server error: ' + msg)
        self.error('The Vonage Click2Call server could not complete your call.',
                   failure=msg)

    def no_number(self):
        if users.is_current_user_admin():
            return self.redirect('/numbers')
        self.unavailable('No phone numbers have been configured. Please ask an '
                         'administrator to log in and add a phone number.')

    @login_required
    def get(self):
        if VonageNumber.all().get() is None:
            return self.no_number()
        self.render()

    @login_required
    def post(self):
        fromnumber = VonageNumber.all().get()
        if fromnumber is None:
            return self.no_number()

        try:
            tonumber = vonageize_number(self.request.get('tonumber', ''))
        except Exception, e:
            return self.error(e.message)

        body = urlencode(
            dict(username=fromnumber.username, password=fromnumber.password,
                 fromnumber=fromnumber.number, tonumber=tonumber))
        try:
            response = urlfetch.fetch(CLICK2CALL_URL + '?' + body)
            # get random auth errors with body, urlfetch.POST)
        except urlfetch.Error, e:
            return self.failure(e.message)

        if response.status_code != 200 or response.content[:3] != '000':
            return self.failure(response.content)

        logging.info('Dialing %s' % tonumber)
        return self.render(
            message='Dialing. Please answer your phone when it rings.')

def main():
    CGIHandler().run(WSGIApplication([('/', MainPage),
                                      ('/numbers', NumbersPage)], debug=True))

if __name__ == "__main__":
    main()