from django import forms
from django.contrib.auth import password_validation

from .models import Invitation, User, normalize_email


class LoginForm(forms.Form):
    email = forms.EmailField(label="E-Mail", widget=forms.EmailInput(attrs={"autocomplete": "email", "autofocus": True}))
    password = forms.CharField(label="Passwort", strip=False, widget=forms.PasswordInput(attrs={"autocomplete": "current-password"}))

    def clean_email(self):
        return normalize_email(self.cleaned_data["email"])


class SetPasswordMixin(forms.Form):
    """Two password fields validated with Django's password validators."""

    password1 = forms.CharField(
        label="Neues Passwort",
        strip=False,
        widget=forms.PasswordInput(attrs={"autocomplete": "new-password"}),
        help_text="Mindestens 10 Zeichen, nicht nur Ziffern, kein gängiges Passwort.",
    )
    password2 = forms.CharField(
        label="Passwort wiederholen", strip=False, widget=forms.PasswordInput(attrs={"autocomplete": "new-password"})
    )

    def password_user(self):
        """User instance the new password is checked against (similarity validator)."""
        return None

    def clean(self):
        cleaned = super().clean()
        p1, p2 = cleaned.get("password1"), cleaned.get("password2")
        if p1 and p2 and p1 != p2:
            self.add_error("password2", "Die Passwörter stimmen nicht überein.")
        elif p1:
            try:
                password_validation.validate_password(p1, self.password_user())
            except forms.ValidationError as error:
                self.add_error("password1", error)
        return cleaned


class RegistrationForm(SetPasswordMixin):
    email = forms.EmailField(label="E-Mail", widget=forms.EmailInput(attrs={"autocomplete": "email"}))
    display_name = forms.CharField(label="Anzeigename", max_length=80, widget=forms.TextInput(attrs={"autocomplete": "nickname"}))

    field_order = ["email", "display_name", "password1", "password2"]

    def __init__(self, *args, invitation: Invitation, **kwargs):
        super().__init__(*args, **kwargs)
        self.invitation = invitation
        if invitation.email:
            self.fields["email"].initial = invitation.email
            self.fields["email"].disabled = True

    def clean_email(self):
        email = normalize_email(self.invitation.email or self.cleaned_data["email"])
        if User.objects.filter(email=email).exists():
            raise forms.ValidationError("Für diese E-Mail-Adresse gibt es bereits ein Konto.")
        return email

    def password_user(self):
        return User(email=self.cleaned_data.get("email", ""), display_name=self.cleaned_data.get("display_name", ""))


class UserPasswordForm(SetPasswordMixin):
    def __init__(self, *args, user, **kwargs):
        super().__init__(*args, **kwargs)
        self.user = user

    def password_user(self):
        return self.user


class PasswordChangeForm(UserPasswordForm):
    old_password = forms.CharField(
        label="Aktuelles Passwort", strip=False, widget=forms.PasswordInput(attrs={"autocomplete": "current-password"})
    )
    field_order = ["old_password", "password1", "password2"]

    def clean_old_password(self):
        password = self.cleaned_data["old_password"]
        if not self.user.check_password(password):
            raise forms.ValidationError("Das aktuelle Passwort ist falsch.")
        return password


class ProfileForm(forms.ModelForm):
    class Meta:
        model = User
        fields = ["display_name"]


class InvitationForm(forms.ModelForm):
    valid_days = forms.IntegerField(label="Gültig (Tage)", min_value=1, max_value=60, initial=7)

    class Meta:
        model = Invitation
        fields = ["email", "role", "note"]

    def clean_email(self):
        email = normalize_email(self.cleaned_data["email"])
        if email and User.objects.filter(email=email).exists():
            raise forms.ValidationError("Für diese E-Mail-Adresse gibt es bereits ein Konto.")
        return email