from django.contrib.auth.models import User

from django.contrib.auth import authenticate

from django.contrib.auth.tokens import default_token_generator

from django.contrib.sites.models import Site

from django.template import Context, loader

from django import forms

from django.utils.translation import ugettext_lazy as _

from django.utils.http import int_to_base36

class UserCreationForm(forms.ModelForm):

    """

    A form that creates a user, with no privileges, from the given username and password.

    """

    username = forms.RegexField(label=_("Username"), max_length=30, regex=r'^\w+$',

        help_text = _("Required. 30 characters or fewer. Alphanumeric characters only (letters, digits and underscores)."),

        error_message = _("This value must contain only letters, numbers and underscores."))

    password1 = forms.CharField(label=_("Password"), widget=forms.PasswordInput)

    password2 = forms.CharField(label=_("Password confirmation"), widget=forms.PasswordInput)

    class Meta:

        model = User

        fields = ("username",)

    def clean_username(self):

        username = self.cleaned_data["username"]

        try:

            User.objects.get(username=username)

        except User.DoesNotExist:

            return username

        raise forms.ValidationError(_("A user with that username already exists."))

    def clean_password2(self):

        password1 = self.cleaned_data.get("password1", "")

        password2 = self.cleaned_data["password2"]

        if password1 != password2:

            raise forms.ValidationError(_("The two password fields didn't match."))

        return password2

    def save(self, commit=True):

        user = super(UserCreationForm, self).save(commit=False)

        user.set_password(self.cleaned_data["password1"])

        if commit:

            user.save()

        return user

class UserChangeForm(forms.ModelForm):

    username = forms.RegexField(label=_("Username"), max_length=30, regex=r'^\w+$',

        help_text = _("Required. 30 characters or fewer. Alphanumeric characters only (letters, digits and underscores)."),

        error_message = _("This value must contain only letters, numbers and underscores."))

    class Meta:

        model = User

class AuthenticationForm(forms.Form):

    """

    Base class for authenticating users. Extend this to get a form that accepts

    username/password logins.

    """

    username = forms.CharField(label=_("Username"), max_length=30)

    password = forms.CharField(label=_("Password"), widget=forms.PasswordInput)

    def __init__(self, request=None, *args, **kwargs):

        """

        If request is passed in, the form will validate that cookies are

        enabled. Note that the request (a HttpRequest object) must have set a

        cookie with the key TEST_COOKIE_NAME and value TEST_COOKIE_VALUE before

        running this validation.

        """

        self.request = request

        self.user_cache = None

        super(AuthenticationForm, self).__init__(*args, **kwargs)

    def clean(self):

        username = self.cleaned_data.get('username')

        password = self.cleaned_data.get('password')

        if username and password:

            self.user_cache = authenticate(username=username, password=password)

            if self.user_cache is None:

                raise forms.ValidationError(_("Please enter a correct username and password. Note that both fields are case-sensitive."))

            elif not self.user_cache.is_active:

                raise forms.ValidationError(_("This account is inactive."))

        # TODO: determine whether this should move to its own method.

        if self.request:

            if not self.request.session.test_cookie_worked():

                raise forms.ValidationError(_("Your Web browser doesn't appear to have cookies enabled. Cookies are required for logging in."))

        return self.cleaned_data

    def get_user_id(self):

        if self.user_cache:

            return self.user_cache.id

        return None

    def get_user(self):

        return self.user_cache

class PasswordResetForm(forms.Form):

    email = forms.EmailField(label=_("E-mail"), max_length=75)

    def clean_email(self):

        """

        Validates that a user exists with the given e-mail address.

        """

        email = self.cleaned_data["email"]

        self.users_cache = User.objects.filter(email__iexact=email)

        if len(self.users_cache) == 0:

            raise forms.ValidationError(_("That e-mail address doesn't have an associated user account. Are you sure you've registered?"))

    def save(self, domain_override=None, email_template_name='registration/password_reset_email.html',

             use_https=False, token_generator=default_token_generator):

        """

        Generates a one-use only link for resetting password and sends to the user

        """

        from django.core.mail import send_mail

        for user in self.users_cache:

            if not domain_override:

                current_site = Site.objects.get_current()

                site_name = current_site.name

                domain = current_site.domain

            else:

                site_name = domain = domain_override

            t = loader.get_template(email_template_name)

            c = {

                'email': user.email,

                'domain': domain,

                'site_name': site_name,

                'uid': int_to_base36(user.id),

                'user': user,

                'token': token_generator.make_token(user),

                'protocol': use_https and 'https' or 'http',

            }

            send_mail(_("Password reset on %s") % site_name,

                t.render(Context(c)), None, [user.email])

class SetPasswordForm(forms.Form):

    """

    A form that lets a user change set his/her password without

    entering the old password

    """

    new_password1 = forms.CharField(label=_("New password"), widget=forms.PasswordInput)

    new_password2 = forms.CharField(label=_("New password confirmation"), widget=forms.PasswordInput)

    def __init__(self, user, *args, **kwargs):

        self.user = user

        super(SetPasswordForm, self).__init__(*args, **kwargs)

    def clean_new_password2(self):

        password1 = self.cleaned_data.get('new_password1')

        password2 = self.cleaned_data.get('new_password2')

        if password1 and password2:

            if password1 != password2:

                raise forms.ValidationError(_("The two password fields didn't match."))

        return password2

    def save(self, commit=True):

        self.user.set_password(self.cleaned_data['new_password1'])

        if commit:

            self.user.save()

        return self.user

class PasswordChangeForm(SetPasswordForm):

    """

    A form that lets a user change his/her password by entering

    their old password.

    """

    old_password = forms.CharField(label=_("Old password"), widget=forms.PasswordInput)

    def clean_old_password(self):

        """

        Validates that the old_password field is correct.

        """

        old_password = self.cleaned_data["old_password"]

        if not self.user.check_password(old_password):

            raise forms.ValidationError(_("Your old password was entered incorrectly. Please enter it again."))

        return old_password

PasswordChangeForm.base_fields.keyOrder = ['old_password', 'new_password1', 'new_password2']

class AdminPasswordChangeForm(forms.Form):

    """

    A form used to change the password of a user in the admin interface.

    """

    password1 = forms.CharField(label=_("Password"), widget=forms.PasswordInput)

    password2 = forms.CharField(label=_("Password (again)"), widget=forms.PasswordInput)

    def __init__(self, user, *args, **kwargs):

        self.user = user

        super(AdminPasswordChangeForm, self).__init__(*args, **kwargs)

    def clean_password2(self):

        password1 = self.cleaned_data.get('password1')

        password2 = self.cleaned_data.get('password2')

        if password1 and password2:

            if password1 != password2:

                raise forms.ValidationError(_("The two password fields didn't match."))

        return password2

    def save(self, commit=True):

        """

        Saves the new password.

        """

        self.user.set_password(self.cleaned_data["password1"])

        if commit:

            self.user.save()

        return self.user