import re

from django import forms
from django.conf import settings
from django.core.exceptions import ValidationError
from django.forms import ModelForm
from django.db import models
from django.contrib.auth.models import User
from django.utils.html import mark_safe
from django.core.urlresolvers import reverse as urlreverse

from unidecode import unidecode

import debug                            # pyflakes:ignore

from ietf.person.models import Person, Email
from ietf.mailinglists.models import Whitelisted


class RegistrationForm(forms.Form):
    email = forms.EmailField(label="Your email (lowercase)")

    def clean_email(self):
        email = self.cleaned_data.get('email', '')
        if not email:
            return email
        if email.lower() != email:
            raise forms.ValidationError('The supplied address contained uppercase letters.  Please use a lowercase email address.')
        if User.objects.filter(username=email).exists():
            raise forms.ValidationError('An account with the email address you provided already exists.')
        return email


class PasswordForm(forms.Form):
    password = forms.CharField(widget=forms.PasswordInput)
    password_confirmation = forms.CharField(widget=forms.PasswordInput,
                                            help_text="Enter the same password as above, for verification.")

    def clean_password_confirmation(self):
        password = self.cleaned_data.get("password", "")
        password_confirmation = self.cleaned_data["password_confirmation"]
        if password != password_confirmation:
            raise forms.ValidationError("The two password fields didn't match.")
        return password_confirmation


def ascii_cleaner(supposedly_ascii):
    outside_printable_ascii_pattern = r'[^\x20-\x7F]'
    if re.search(outside_printable_ascii_pattern, supposedly_ascii):
        raise forms.ValidationError("Only unaccented Latin characters are allowed.")
    return supposedly_ascii

def prevent_at_symbol(name):
    if "@" in name:
        raise forms.ValidationError("Please fill in name - this looks like an email address (@ is not allowed in names).")

def prevent_system_name(name):
    name_without_spaces = name.replace(" ", "").replace("\t", "")
    if "(system)" in name_without_spaces.lower():
        raise forms.ValidationError("Please pick another name - this name is reserved.")

def get_person_form(*args, **kwargs):

    exclude_list = ['time', 'user', 'photo_thumb', 'photo', ]

    person = kwargs['instance']
    roles = person.role_set.all()
    if not roles:
        exclude_list += ['biography', 'photo', ]

    class PersonForm(ModelForm):
        class Meta:
            model = Person
            exclude = exclude_list

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

            # blank ascii if it's the same as name
            self.fields["ascii"].required = self.fields["ascii"].widget.is_required = False
            self.fields["ascii"].help_text += " " + "Leave blank to use auto-reconstructed Latin version of name."

            if self.initial.get("ascii") == self.initial.get("name"):
                self.initial["ascii"] = ""

            self.unidecoded_ascii = False

            if self.data and not self.data.get("ascii", "").strip():
                self.data = self.data.copy()
                name = self.data["name"]
                reconstructed_name = unidecode(name)
                self.data["ascii"] = reconstructed_name
                self.unidecoded_ascii = name != reconstructed_name

        def clean_name(self):
            name = self.cleaned_data.get("name") or u""
            prevent_at_symbol(name)
            prevent_system_name(name)
            return name

        def clean_ascii(self):
            if self.unidecoded_ascii:
                raise forms.ValidationError("Name contained non-ASCII characters, and was automatically reconstructed using only Latin characters. Check the result - if you are happy, just hit Submit again.")

            name = self.cleaned_data.get("ascii") or u""
            prevent_at_symbol(name)
            prevent_system_name(name)
            return ascii_cleaner(name)

        def clean_ascii_short(self):
            name = self.cleaned_data.get("ascii_short") or u""
            prevent_at_symbol(name)
            prevent_system_name(name)
            return ascii_cleaner(name)

    return PersonForm(*args, **kwargs)


class NewEmailForm(forms.Form):
    new_email = forms.EmailField(label="New email address", required=False)

    def clean_new_email(self):
        email = self.cleaned_data.get("new_email", "")
        if email:
            existing = Email.objects.filter(address=email).first()
            if existing:
                raise forms.ValidationError("Email address '%s' is already assigned to account '%s' (%s)" % (existing, existing.person and existing.person.user, existing.person))

        for pat in settings.EXLUDED_PERSONAL_EMAIL_REGEX_PATTERNS:
            if re.search(pat, email):
                raise ValidationError("This email address is not valid in a datatracker account")

        return email


class RoleEmailForm(forms.Form):
    email = forms.ModelChoiceField(label="Role email", queryset=Email.objects.all())

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

        f = self.fields["email"]
        f.label = u"%s in %s" % (role.name, role.group.acronym.upper())
        f.help_text = u"Email to use for <i>%s</i> role in %s" % (role.name, role.group.name)
        f.queryset = f.queryset.filter(models.Q(person=role.person_id) | models.Q(role=role)).distinct()
        f.initial = role.email_id
        f.choices = [(e.pk, e.address if e.active else u"({})".format(e.address)) for e in f.queryset]


class ResetPasswordForm(forms.Form):
    username = forms.EmailField(label="Your email (lowercase)")

    def clean_username(self):
        import ietf.ietfauth.views
        username = self.cleaned_data["username"]
        if not User.objects.filter(username=username).exists():
            raise forms.ValidationError(mark_safe("Didn't find a matching account. If you don't have an account yet, you can <a href=\"{}\">create one</a>.".format(urlreverse(ietf.ietfauth.views.create_account))))
        return username


class TestEmailForm(forms.Form):
    email = forms.EmailField(required=False)

class WhitelistForm(ModelForm):
    class Meta:
        model = Whitelisted
        exclude = ['by', 'time' ]