"""The public buyer sign-up form.

This is the only place on the platform a password minimum is enforced — the
realm has no password policy set and no mail service exists — so the rules live
here and are deliberately plain: long enough, not the email or the company name,
and typed twice the same. The form is also the first line of duplicate-email
handling; Keycloak refuses a second account with the same address, and the view
turns that into the same sentence.
"""
from django import forms

from apps.users.models import User

MIN_PASSWORD_LENGTH = 12

DUPLICATE_EMAIL_MESSAGE = "An account with this email already exists — sign in instead."


class BuyerSignupForm(forms.Form):
    full_name = forms.CharField(
        max_length=255,
        label="Full name",
        widget=forms.TextInput(attrs={"class": "form-control", "autocomplete": "name"}),
    )
    company_name = forms.CharField(
        max_length=255,
        label="Company name",
        widget=forms.TextInput(attrs={"class": "form-control", "autocomplete": "organization"}),
    )
    email = forms.EmailField(
        label="Email",
        widget=forms.EmailInput(attrs={"class": "form-control", "autocomplete": "email"}),
    )
    password = forms.CharField(
        label="Password",
        widget=forms.PasswordInput(attrs={"class": "form-control", "autocomplete": "new-password"}),
        help_text=f"At least {MIN_PASSWORD_LENGTH} characters.",
    )
    confirm_password = forms.CharField(
        label="Confirm password",
        widget=forms.PasswordInput(attrs={"class": "form-control", "autocomplete": "new-password"}),
    )

    def clean_email(self):
        email = self.cleaned_data["email"].strip().lower()
        if User.objects.filter(email__iexact=email).exists():
            raise forms.ValidationError(DUPLICATE_EMAIL_MESSAGE)
        return email

    def clean(self):
        cleaned = super().clean()
        password = cleaned.get("password")
        confirm = cleaned.get("confirm_password")
        if password and confirm and password != confirm:
            self.add_error("confirm_password", "The two passwords do not match.")
        if password:
            if len(password) < MIN_PASSWORD_LENGTH:
                self.add_error(
                    "password",
                    f"Use at least {MIN_PASSWORD_LENGTH} characters.",
                )
            email = (cleaned.get("email") or "").strip().lower()
            company = (cleaned.get("company_name") or "").strip().lower()
            if password.lower() in (email, company) and password:
                self.add_error(
                    "password",
                    "Choose a password that is not your email address or company name.",
                )
        return cleaned