# Copyright 2011-2012 GRNET S.A. All rights reserved.
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from urlparse import urljoin
from datetime import datetime

from django import forms
from django.utils.translation import ugettext as _
from django.contrib.auth.forms import UserCreationForm, AuthenticationForm, PasswordResetForm
from django.core.mail import send_mail
from django.contrib.auth.tokens import default_token_generator
from django.template import Context, loader
from django.utils.http import int_to_base36
from django.core.urlresolvers import reverse
from django.utils.functional import lazy
from django.utils.safestring import mark_safe
from django.contrib import messages
from django.utils.encoding import smart_str

from astakos.im.models import AstakosUser, Invitation, get_latest_terms, EmailChange
from astakos.im.settings import INVITATIONS_PER_LEVEL, DEFAULT_FROM_EMAIL, BASEURL, SITENAME, RECAPTCHA_PRIVATE_KEY, DEFAULT_CONTACT_EMAIL, RECAPTCHA_ENABLED
from astakos.im.widgets import DummyWidget, RecaptchaWidget
from astakos.im.functions import send_change_email

# since Django 1.4 use django.core.urlresolvers.reverse_lazy instead
from astakos.im.util import reverse_lazy, reserved_email, get_query

import logging
import hashlib
import recaptcha.client.captcha as captcha
from random import random

logger = logging.getLogger(__name__)

class LocalUserCreationForm(UserCreationForm):
    """
    Extends the built in UserCreationForm in several ways:

    * Adds email, first_name, last_name, recaptcha_challenge_field, recaptcha_response_field field.
    * The username field isn't visible and it is assigned a generated id.
    * User created is not active.
    """
    recaptcha_challenge_field = forms.CharField(widget=DummyWidget)
    recaptcha_response_field = forms.CharField(widget=RecaptchaWidget, label='')

    class Meta:
        model = AstakosUser
        fields = ("email", "first_name", "last_name", "has_signed_terms", "has_signed_terms")

    def __init__(self, *args, **kwargs):
        """
        Changes the order of fields, and removes the username field.
        """
        request = kwargs.get('request', None)
        if request:
            kwargs.pop('request')
            self.ip = request.META.get('REMOTE_ADDR',
                                       request.META.get('HTTP_X_REAL_IP', None))
        
        super(LocalUserCreationForm, self).__init__(*args, **kwargs)
        self.fields.keyOrder = ['email', 'first_name', 'last_name',
                                'password1', 'password2']
        if get_latest_terms():
            self.fields.keyOrder.append('has_signed_terms')
        if RECAPTCHA_ENABLED:
            self.fields.keyOrder.extend(['recaptcha_challenge_field',
                                         'recaptcha_response_field',])

        if 'has_signed_terms' in self.fields:
            # Overriding field label since we need to apply a link
            # to the terms within the label
            terms_link_html = '<a href="%s" target="_blank">%s</a>' \
                    % (reverse('latest_terms'), _("the terms"))
            self.fields['has_signed_terms'].label = \
                    mark_safe("I agree with %s" % terms_link_html)

    def clean_email(self):
        email = self.cleaned_data['email']
        if not email:
            raise forms.ValidationError(_("This field is required"))
        if reserved_email(email):
            raise forms.ValidationError(_("This email is already used"))
        return email

    def clean_has_signed_terms(self):
        has_signed_terms = self.cleaned_data['has_signed_terms']
        if not has_signed_terms:
            raise forms.ValidationError(_('You have to agree with the terms'))
        return has_signed_terms

    def clean_recaptcha_response_field(self):
        if 'recaptcha_challenge_field' in self.cleaned_data:
            self.validate_captcha()
        return self.cleaned_data['recaptcha_response_field']

    def clean_recaptcha_challenge_field(self):
        if 'recaptcha_response_field' in self.cleaned_data:
            self.validate_captcha()
        return self.cleaned_data['recaptcha_challenge_field']

    def validate_captcha(self):
        rcf = self.cleaned_data['recaptcha_challenge_field']
        rrf = self.cleaned_data['recaptcha_response_field']
        check = captcha.submit(rcf, rrf, RECAPTCHA_PRIVATE_KEY, self.ip)
        if not check.is_valid:
            raise forms.ValidationError(_('You have not entered the correct words'))

    def save(self, commit=True):
        """
        Saves the email, first_name and last_name properties, after the normal
        save behavior is complete.
        """
        user = super(LocalUserCreationForm, self).save(commit=False)
        user.renew_token()
        if commit:
            user.save()
            logger.info('Created user %s', user)
        return user

class InvitedLocalUserCreationForm(LocalUserCreationForm):
    """
    Extends the LocalUserCreationForm: email is readonly.
    """
    class Meta:
        model = AstakosUser
        fields = ("email", "first_name", "last_name", "has_signed_terms")

    def __init__(self, *args, **kwargs):
        """
        Changes the order of fields, and removes the username field.
        """
        super(InvitedLocalUserCreationForm, self).__init__(*args, **kwargs)

        #set readonly form fields
        ro = ('email', 'username',)
        for f in ro:
            self.fields[f].widget.attrs['readonly'] = True
        

    def save(self, commit=True):
        user = super(InvitedLocalUserCreationForm, self).save(commit=False)
        level = user.invitation.inviter.level + 1
        user.level = level
        user.invitations = INVITATIONS_PER_LEVEL.get(level, 0)
        user.email_verified = True
        if commit:
            user.save()
        return user

class ThirdPartyUserCreationForm(forms.ModelForm):
    class Meta:
        model = AstakosUser
        fields = ("email", "first_name", "last_name", "third_party_identifier", "has_signed_terms")
    
    def __init__(self, *args, **kwargs):
        """
        Changes the order of fields, and removes the username field.
        """
        self.request = kwargs.get('request', None)
        if self.request:
            kwargs.pop('request')
        super(ThirdPartyUserCreationForm, self).__init__(*args, **kwargs)
        self.fields.keyOrder = ['email', 'first_name', 'last_name', 'third_party_identifier']
        if get_latest_terms():
            self.fields.keyOrder.append('has_signed_terms')
        #set readonly form fields
        ro = ["third_party_identifier", "first_name", "last_name"]
        for f in ro:
            self.fields[f].widget.attrs['readonly'] = True
        
        if 'has_signed_terms' in self.fields:
            # Overriding field label since we need to apply a link
            # to the terms within the label
            terms_link_html = '<a href="%s" target="_blank">%s</a>' \
                    % (reverse('latest_terms'), _("the terms"))
            self.fields['has_signed_terms'].label = \
                    mark_safe("I agree with %s" % terms_link_html)
    
    def clean_email(self):
        email = self.cleaned_data['email']
        if not email:
            raise forms.ValidationError(_("This field is required"))
        return email
    
    def clean_has_signed_terms(self):
        has_signed_terms = self.cleaned_data['has_signed_terms']
        if not has_signed_terms:
            raise forms.ValidationError(_('You have to agree with the terms'))
        return has_signed_terms
    
    def save(self, commit=True):
        user = super(ThirdPartyUserCreationForm, self).save(commit=False)
        user.set_unusable_password()
        user.renew_token()
        user.provider = get_query(self.request).get('provider')
        if commit:
            user.save()
            logger.info('Created user %s', user)
        return user

class InvitedThirdPartyUserCreationForm(ThirdPartyUserCreationForm):
    """
    Extends the ThirdPartyUserCreationForm: email is readonly.
    """
    def __init__(self, *args, **kwargs):
        """
        Changes the order of fields, and removes the username field.
        """
        super(InvitedThirdPartyUserCreationForm, self).__init__(*args, **kwargs)

        #set readonly form fields
        ro = ('email',)
        for f in ro:
            self.fields[f].widget.attrs['readonly'] = True
    
    def save(self, commit=True):
        user = super(InvitedThirdPartyUserCreationForm, self).save(commit=False)
        level = user.invitation.inviter.level + 1
        user.level = level
        user.invitations = INVITATIONS_PER_LEVEL.get(level, 0)
        user.email_verified = True
        if commit:
            user.save()
        return user

class ShibbolethUserCreationForm(ThirdPartyUserCreationForm):
    def clean_email(self):
        email = self.cleaned_data['email']
        for user in AstakosUser.objects.filter(email = email):
            if user.provider == 'shibboleth':
                raise forms.ValidationError(_("This email is already associated with another shibboleth account."))
            elif not user.is_active:
                raise forms.ValidationError(_("This email is already associated with an inactive account. \
                                              You need to wait to be activated before being able to switch to a shibboleth account."))
        super(ShibbolethUserCreationForm, self).clean_email()
        return email

class InvitedShibbolethUserCreationForm(ShibbolethUserCreationForm, InvitedThirdPartyUserCreationForm):
    pass
    
class LoginForm(AuthenticationForm):
    username = forms.EmailField(label=_("Email"))
    recaptcha_challenge_field = forms.CharField(widget=DummyWidget)
    recaptcha_response_field = forms.CharField(widget=RecaptchaWidget, label='')
    
    def __init__(self, *args, **kwargs):
        was_limited = kwargs.get('was_limited', False)
        request = kwargs.get('request', None)
        if request:
            self.ip = request.META.get('REMOTE_ADDR',
                                       request.META.get('HTTP_X_REAL_IP', None))
        
        t = ('request', 'was_limited')
        for elem in t:
            if elem in kwargs.keys():
                kwargs.pop(elem)
        super(LoginForm, self).__init__(*args, **kwargs)
        
        self.fields.keyOrder = ['username', 'password']
        if was_limited and RECAPTCHA_ENABLED:
            self.fields.keyOrder.extend(['recaptcha_challenge_field',
                                         'recaptcha_response_field',])
    
    def clean_recaptcha_response_field(self):
        if 'recaptcha_challenge_field' in self.cleaned_data:
            self.validate_captcha()
        return self.cleaned_data['recaptcha_response_field']

    def clean_recaptcha_challenge_field(self):
        if 'recaptcha_response_field' in self.cleaned_data:
            self.validate_captcha()
        return self.cleaned_data['recaptcha_challenge_field']

    def validate_captcha(self):
        rcf = self.cleaned_data['recaptcha_challenge_field']
        rrf = self.cleaned_data['recaptcha_response_field']
        check = captcha.submit(rcf, rrf, RECAPTCHA_PRIVATE_KEY, self.ip)
        if not check.is_valid:
            raise forms.ValidationError(_('You have not entered the correct words'))

class ProfileForm(forms.ModelForm):
    """
    Subclass of ``ModelForm`` for permiting user to edit his/her profile.
    Most of the fields are readonly since the user is not allowed to change them.

    The class defines a save method which sets ``is_verified`` to True so as the user
    during the next login will not to be redirected to profile page.
    """
    renew = forms.BooleanField(label='Renew token', required=False)

    class Meta:
        model = AstakosUser
        fields = ('email', 'first_name', 'last_name', 'auth_token', 'auth_token_expires')

    def __init__(self, *args, **kwargs):
        super(ProfileForm, self).__init__(*args, **kwargs)
        instance = getattr(self, 'instance', None)
        ro_fields = ('email', 'auth_token', 'auth_token_expires')
        if instance and instance.id:
            for field in ro_fields:
                self.fields[field].widget.attrs['readonly'] = True

    def save(self, commit=True):
        user = super(ProfileForm, self).save(commit=False)
        user.is_verified = True
        if self.cleaned_data.get('renew'):
            user.renew_token()
        if commit:
            user.save()
        return user

class FeedbackForm(forms.Form):
    """
    Form for writing feedback.
    """
    feedback_msg = forms.CharField(widget=forms.Textarea, label=u'Message')
    feedback_data = forms.CharField(widget=forms.HiddenInput(), label='',
                                    required=False)

class SendInvitationForm(forms.Form):
    """
    Form for sending an invitations
    """

    email = forms.EmailField(required = True, label = 'Email address')
    first_name = forms.EmailField(label = 'First name')
    last_name = forms.EmailField(label = 'Last name')

class ExtendedPasswordResetForm(PasswordResetForm):
    """
    Extends PasswordResetForm by overriding save method:
    passes a custom from_email in send_mail.

    Since Django 1.3 this is useless since ``django.contrib.auth.views.reset_password``
    accepts a from_email argument.
    """
    def clean_email(self):
        email = super(ExtendedPasswordResetForm, self).clean_email()
        try:
            user = AstakosUser.objects.get(email=email, is_active=True)
            if not user.has_usable_password():
                raise forms.ValidationError(_("This account has not a usable password."))
        except AstakosUser.DoesNotExist, e:
            raise forms.ValidationError(_('That e-mail address doesn\'t have an associated user account. Are you sure you\'ve registered?'))
        return email
    
    def save(self, domain_override=None, email_template_name='registration/password_reset_email.html',
             use_https=False, token_generator=default_token_generator, request=None):
        """
        Generates a one-use only link for resetting password and sends to the user.
        """
        for user in self.users_cache:
            url = reverse('django.contrib.auth.views.password_reset_confirm',
                          kwargs={'uidb36':int_to_base36(user.id),
                                  'token':token_generator.make_token(user)})
            url = urljoin(BASEURL, url)
            t = loader.get_template(email_template_name)
            c = {
                'email': user.email,
                'url': url,
                'site_name': SITENAME,
                'user': user,
                'baseurl': BASEURL,
                'support': DEFAULT_CONTACT_EMAIL
            }
            from_email = DEFAULT_FROM_EMAIL
            send_mail(_("Password reset on %s alpha2 testing") % SITENAME,
                t.render(Context(c)), from_email, [user.email])

class EmailChangeForm(forms.ModelForm):
    class Meta:
        model = EmailChange
        fields = ('new_email_address',)
            
    def clean_new_email_address(self):
        addr = self.cleaned_data['new_email_address']
        if AstakosUser.objects.filter(email__iexact=addr):
            raise forms.ValidationError(_(u'This email address is already in use. Please supply a different email address.'))
        return addr
    
    def save(self, email_template_name, request, commit=True):
        ec = super(EmailChangeForm, self).save(commit=False)
        ec.user = request.user
        activation_key = hashlib.sha1(str(random()) + smart_str(ec.new_email_address))
        ec.activation_key=activation_key.hexdigest()
        if commit:
            ec.save()
        send_change_email(ec, request, email_template_name=email_template_name)

class SignApprovalTermsForm(forms.ModelForm):
    class Meta:
        model = AstakosUser
        fields = ("has_signed_terms",)

    def __init__(self, *args, **kwargs):
        super(SignApprovalTermsForm, self).__init__(*args, **kwargs)

    def clean_has_signed_terms(self):
        has_signed_terms = self.cleaned_data['has_signed_terms']
        if not has_signed_terms:
            raise forms.ValidationError(_('You have to agree with the terms'))
        return has_signed_terms

class InvitationForm(forms.ModelForm):
    username = forms.EmailField(label=_("Email"))
    
    def __init__(self, *args, **kwargs):
        super(InvitationForm, self).__init__(*args, **kwargs)
    
    class Meta:
        model = Invitation
        fields = ('username', 'realname')
    
    def clean_username(self):
        username = self.cleaned_data['username']
        try:
            Invitation.objects.get(username = username)
            raise forms.ValidationError(_('There is already invitation for this email.'))
        except Invitation.DoesNotExist:
            pass
        return username