notifications-admin/app/main/forms.py

import weakref
from datetime import datetime, timedelta
from itertools import chain
from numbers import Number

import pytz
from flask import Markup, render_template, request
from flask_login import current_user
from flask_wtf import FlaskForm as Form
from flask_wtf.file import FileAllowed
from flask_wtf.file import FileField as FileField_wtf
from flask_wtf.file import FileSize
from notifications_utils.formatters import strip_all_whitespace
from notifications_utils.insensitive_dict import InsensitiveDict
from notifications_utils.recipients import InvalidPhoneError, validate_phone_number
from werkzeug.utils import cached_property
from wtforms import (
    BooleanField,
    DateField,
    EmailField,
    FieldList,
    FileField,
    HiddenField,
    IntegerField,
    PasswordField,
)
from wtforms import RadioField as WTFormsRadioField
from wtforms import (
    SearchField,
    SelectMultipleField,
    StringField,
    TelField,
    TextAreaField,
    ValidationError,
    validators,
)
from wtforms.validators import (
    URL,
    DataRequired,
    InputRequired,
    Length,
    Optional,
    Regexp,
)

from app.formatters import (
    format_auth_type,
    format_thousands,
    guess_name_from_email_address,
)
from app.main.validators import (
    CommonlyUsedPassword,
    CsvFileValidator,
    DoesNotStartWithDoubleZero,
    LettersNumbersSingleQuotesFullStopsAndUnderscoresOnly,
    MustContainAlphanumericCharacters,
    NoCommasInPlaceHolders,
    NoEmbeddedImagesInSVG,
    NoTextInSVG,
    OnlySMSCharacters,
    ValidEmail,
    ValidGovEmail,
)
from app.models.organization import Organization
from app.utils import merge_jsonlike
from app.utils.csv import get_user_preferred_timezone
from app.utils.user_permissions import all_ui_permissions, permission_options


def get_time_value_and_label(future_time):
    preferred_tz = pytz.timezone(get_user_preferred_timezone())
    return (
        future_time.astimezone(preferred_tz).isoformat(),
        "{} at {} {}".format(
            get_human_day(future_time.astimezone(preferred_tz)),
            get_human_time(future_time.astimezone(preferred_tz)),
            get_user_preferred_timezone(),
        ),
    )


def get_human_time(time):
    return {"0": "midnight", "12": "noon"}.get(
        time.strftime("%-H"), time.strftime("%-I%p").lower()
    )


def get_human_day(time, prefix_today_with="T"):
    #  Add 1 hour to get ‘midnight today’ instead of ‘midnight tomorrow’

    preferred_tz = pytz.timezone(get_user_preferred_timezone())
    time = (time - timedelta(hours=1)).strftime("%A")
    if time == datetime.now(preferred_tz).strftime("%A"):
        return "{}oday".format(prefix_today_with)
    if time == (datetime.now(preferred_tz) + timedelta(days=1)).strftime("%A"):
        return "Tomorrow"
    return time


def get_furthest_possible_scheduled_time():
    # We want local time to find date boundaries
    preferred_tz = pytz.timezone(get_user_preferred_timezone())
    return (datetime.now(preferred_tz) + timedelta(days=4)).replace(hour=0)


def get_next_hours_until(until):
    preferred_tz = pytz.timezone(get_user_preferred_timezone())
    now = datetime.now(preferred_tz)
    hours = int((until - now).total_seconds() / (60 * 60))
    return [
        (now + timedelta(hours=i)).replace(minute=0, second=0, microsecond=0)
        for i in range(1, hours + 1)
    ]


def get_next_days_until(until):
    preferred_tz = pytz.timezone(get_user_preferred_timezone())
    now = datetime.now(preferred_tz)
    days = int((until - now).total_seconds() / (60 * 60 * 24))
    return [
        get_human_day((now + timedelta(days=i)), prefix_today_with="Later t")
        for i in range(0, days + 1)
    ]


class RadioField(WTFormsRadioField):
    def __init__(self, *args, thing="an option", **kwargs):
        super().__init__(*args, **kwargs)
        self.thing = thing
        self.validate_choice = False

    def pre_validate(self, form):
        super().pre_validate(form)
        if self.data not in dict(self.choices).keys():
            raise ValidationError(f"Select {self.thing}")


def email_address(label="Email address", gov_user=True, required=True):
    validators = [
        ValidEmail(),
    ]

    if gov_user:
        validators.append(ValidGovEmail())

    if required:
        validators.append(DataRequired(message="Cannot be empty"))

    return GovukEmailField(label, validators)


class UKMobileNumber(TelField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(UKMobileNumber, self).__init__(label, validators, **kwargs)
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        return govuk_text_input_field_widget(
            self, field, type="tel", param_extensions=param_extensions, **kwargs
        )

    def pre_validate(self, form):
        try:
            validate_phone_number(self.data)
        except InvalidPhoneError as e:
            raise ValidationError(str(e))


class InternationalPhoneNumber(TelField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(InternationalPhoneNumber, self).__init__(
            label, validators=validators, **kwargs
        )
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        return govuk_text_input_field_widget(
            self, field, type="tel", param_extensions=param_extensions, **kwargs
        )

    def pre_validate(self, form):
        try:
            if self.data:
                validate_phone_number(self.data, international=True)
        except InvalidPhoneError as e:
            raise ValidationError(str(e))


def uk_mobile_number(label="Mobile number"):
    return UKMobileNumber(label, validators=[DataRequired(message="Cannot be empty")])


def international_phone_number(label="Mobile number"):
    return InternationalPhoneNumber(
        label, validators=[DataRequired(message="Cannot be empty")]
    )


def password(label="Password"):
    return GovukPasswordField(
        label,
        validators=[
            DataRequired(message="Cannot be empty"),
            Length(8, 255, message="Must be at least 8 characters"),
            CommonlyUsedPassword(message="Choose a password that’s harder to guess"),
        ],
    )


def govuk_text_input_field_widget(
    self, field, type=None, param_extensions=None, **kwargs
):
    value = kwargs["value"] if "value" in kwargs else field.data
    value = str(value) if isinstance(value, Number) else value

    # error messages
    error_message = None
    if field.errors:
        error_message_format = (
            "html" if kwargs.get("error_message_with_html") else "text"
        )
        error_message = {
            "attributes": {
                "data-module": "track-error",
                "data-error-type": field.errors[0],
                "data-error-label": field.name,
            },
            error_message_format: field.errors[0],
        }

    # convert to parameters that usa understands
    params = {
        "errorMessage": error_message,
        "id": field.id,
        "label": {"text": field.label.text},
        "name": field.name,
        "value": value,
    }

    if type:
        params["type"] = type

    # extend default params with any sent in
    merge_jsonlike(params, self.param_extensions)
    # add any sent in through use in templates
    merge_jsonlike(params, param_extensions)

    return Markup(
        render_template("components/components/input/template.njk", params=params)
    )


class GovukTextInputField(StringField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukTextInputField, self).__init__(label, validators, **kwargs)
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, **kwargs):
        return govuk_text_input_field_widget(self, field, **kwargs)


class GovukPasswordField(PasswordField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukPasswordField, self).__init__(label, validators, **kwargs)
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        return govuk_text_input_field_widget(
            self, field, type="password", param_extensions=param_extensions, **kwargs
        )


class GovukEmailField(EmailField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukEmailField, self).__init__(label, validators=validators, **kwargs)
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        params = {
            "attributes": {"spellcheck": "false"}
        }  # email addresses don't need to be spellchecked
        merge_jsonlike(params, param_extensions)

        return govuk_text_input_field_widget(
            self, field, type="email", param_extensions=params, **kwargs
        )


class GovukSearchField(SearchField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukSearchField, self).__init__(label, validators, **kwargs)
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        params = {"classes": ""}  # email addresses don't need to be spellchecked
        merge_jsonlike(params, param_extensions)

        return govuk_text_input_field_widget(
            self, field, type="search", param_extensions=params, **kwargs
        )


class GovukDateField(DateField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukDateField, self).__init__(label, validators, **kwargs)
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        return govuk_text_input_field_widget(
            self, field, param_extensions=param_extensions, **kwargs
        )


class GovukIntegerField(IntegerField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukIntegerField, self).__init__(label, validators, **kwargs)
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        return govuk_text_input_field_widget(
            self, field, param_extensions=param_extensions, **kwargs
        )


class SMSCode(GovukTextInputField):
    validators = [
        DataRequired(message="Cannot be empty"),
        Regexp(regex=r"^\d+$", message="Numbers only"),
        Length(min=6, message="Not enough numbers"),
        Length(max=6, message="Too many numbers"),
    ]

    def __call__(self, **kwargs):
        params = {"attributes": {"pattern": "[0-9]*"}}
        if "param_extensions" in kwargs:
            merge_jsonlike(kwargs["param_extensions"], params)

        return super().__call__(type="tel", **kwargs)

    def process_formdata(self, valuelist):
        if valuelist:
            self.data = InsensitiveDict.make_key(valuelist[0])


class ForgivingIntegerField(GovukTextInputField):
    #  Actual value is 2147483647 but this is a scary looking arbitrary number
    POSTGRES_MAX_INT = 2000000000

    def __init__(self, label=None, things="items", format_error_suffix="", **kwargs):
        self.things = things
        self.format_error_suffix = format_error_suffix
        super().__init__(label, **kwargs)

    def process_formdata(self, valuelist):
        if valuelist:
            value = valuelist[0].replace(",", "").replace(" ", "")

            try:
                value = int(value)
            except ValueError:
                pass

            if value == "":
                value = 0

        return super().process_formdata([value])

    def pre_validate(self, form):
        if self.data:
            error = None
            try:
                if int(self.data) > self.POSTGRES_MAX_INT:
                    error = "Number of {} must be {} or less".format(
                        self.things,
                        format_thousands(self.POSTGRES_MAX_INT),
                    )
            except ValueError:
                error = "Enter the number of {} {}".format(
                    self.things,
                    self.format_error_suffix,
                )

            if error:
                raise ValidationError(error)

        return super().pre_validate(form)

    def __call__(self, **kwargs):
        if self.get_form().is_submitted() and not self.get_form().validate():
            return super().__call__(value=(self.raw_data or [None])[0], **kwargs)

        try:
            value = int(self.data)
            value = format_thousands(value)
        except (ValueError, TypeError):
            value = self.data if self.data is not None else ""

        return super().__call__(value=value, **kwargs)


class FieldWithNoneOption:
    # This is a special value that is specific to our forms. This is
    # more expicit than casting `None` to a string `'None'` which can
    # have unexpected edge cases
    NONE_OPTION_VALUE = "__NONE__"

    # When receiving Python data, eg when instantiating the form object
    # we want to convert that data to our special value, so that it gets
    # recognised as being one of the valid choices
    def process_data(self, value):
        self.data = self.NONE_OPTION_VALUE if value is None else value

    # After validation we want to convert it back to a Python `None` for
    # use elsewhere, eg posting to the API
    def post_validate(self, form, validation_stopped):
        if self.data == self.NONE_OPTION_VALUE and not validation_stopped:
            self.data = None


class RadioFieldWithNoneOption(FieldWithNoneOption, RadioField):
    pass


class NestedFieldMixin:
    def children(self):
        # start map with root option as a single child entry
        child_map = {
            None: [option for option in self if option.data == self.NONE_OPTION_VALUE]
        }

        # add entries for all other children
        for option in self:
            # assign all options with a NONE_OPTION_VALUE (not always None) to the None key
            if option.data == self.NONE_OPTION_VALUE:
                child_ids = [
                    folder["id"]
                    for folder in self.all_template_folders
                    if folder["parent_id"] is None
                ]
                key = self.NONE_OPTION_VALUE
            else:
                child_ids = [
                    folder["id"]
                    for folder in self.all_template_folders
                    if folder["parent_id"] == option.data
                ]
                key = option.data

            child_map[key] = [option for option in self if option.data in child_ids]

        return child_map

    # to be used as the only version of .children once radios are converted
    @cached_property
    def _children(self):
        return self.children()

    def get_items_from_options(self, field):
        items = []

        for option in self._children[None]:
            item = self.get_item_from_option(option)
            if option.data in self._children:
                item["children"] = self.render_children(
                    field.name, option.label.text, self._children[option.data]
                )
            items.append(item)

        return items

    def render_children(self, name, label, options):
        params = {
            "name": name,
            "fieldset": {"legend": {"text": label, "classes": "usa-sr-only"}},
            "formGroup": {"classes": "usa-form-group--nested"},
            "asList": True,
            "items": [],
        }
        for option in options:
            item = self.get_item_from_option(option)

            if len(self._children[option.data]):
                item["children"] = self.render_children(
                    name, option.label.text, self._children[option.data]
                )

            params["items"].append(item)

        return render_template("forms/fields/checkboxes/template.njk", params=params)


class NestedRadioField(RadioFieldWithNoneOption, NestedFieldMixin):
    pass


class NestedCheckboxesField(SelectMultipleField, NestedFieldMixin):
    NONE_OPTION_VALUE = None


class HiddenFieldWithNoneOption(FieldWithNoneOption, HiddenField):
    pass


class RadioFieldWithRequiredMessage(RadioField):
    def __init__(self, *args, required_message="Not a valid choice", **kwargs):
        self.required_message = required_message
        super().__init__(*args, **kwargs)

    def pre_validate(self, form):
        try:
            return super().pre_validate(form)
        except ValueError:
            raise ValidationError(self.required_message)


class StripWhitespaceForm(Form):
    class Meta:
        def bind_field(self, form, unbound_field, options):
            # FieldList simply doesn't support filters.
            # @see: https://github.com/wtforms/wtforms/issues/148
            no_filter_fields = (FieldList, PasswordField, GovukPasswordField)
            filters = (
                [strip_all_whitespace]
                if not issubclass(unbound_field.field_class, no_filter_fields)
                else []
            )
            filters += unbound_field.kwargs.get("filters", [])
            bound = unbound_field.bind(form=form, filters=filters, **options)
            bound.get_form = weakref.ref(
                form
            )  # GC won't collect the form if we don't use a weakref
            return bound

        def render_field(self, field, render_kw):
            render_kw.setdefault("required", False)
            return super().render_field(field, render_kw)


class StripWhitespaceStringField(GovukTextInputField):
    def __init__(self, label=None, param_extensions=None, **kwargs):
        kwargs["filters"] = tuple(
            chain(
                kwargs.get("filters", ()),
                (strip_all_whitespace,),
            )
        )
        super(GovukTextInputField, self).__init__(label, **kwargs)
        self.param_extensions = param_extensions


class LoginForm(StripWhitespaceForm):
    email_address = GovukEmailField(
        "Email address",
        validators=[
            Length(min=5, max=255),
            DataRequired(message="Cannot be empty"),
            ValidEmail(),
        ],
    )
    password = GovukPasswordField(
        "Password", validators=[DataRequired(message="Enter your password")]
    )


class RegisterUserForm(StripWhitespaceForm):
    name = GovukTextInputField(
        "Full name", validators=[DataRequired(message="Cannot be empty")]
    )
    email_address = email_address()
    mobile_number = international_phone_number()
    password = password()
    # always register as sms type
    auth_type = HiddenField("auth_type", default="sms_auth")


class RegisterUserFromInviteForm(RegisterUserForm):
    def __init__(self, invited_user):
        super().__init__(
            service=invited_user.service,
            email_address=invited_user.email_address,
            auth_type=invited_user.auth_type,
            name=guess_name_from_email_address(invited_user.email_address),
        )

    mobile_number = InternationalPhoneNumber("Mobile number", validators=[])
    service = HiddenField("service")
    email_address = HiddenField("email_address")
    auth_type = HiddenField("auth_type", validators=[DataRequired()])

    def validate_mobile_number(self, field):
        if self.auth_type.data == "sms_auth" and not field.data:
            raise ValidationError("Cannot be empty")


class RegisterUserFromOrgInviteForm(StripWhitespaceForm):
    def __init__(self, invited_org_user):
        super().__init__(
            organization=invited_org_user.organization,
            email_address=invited_org_user.email_address,
        )

    name = GovukTextInputField(
        "Full name", validators=[DataRequired(message="Cannot be empty")]
    )

    mobile_number = InternationalPhoneNumber(
        "Mobile number", validators=[DataRequired(message="Cannot be empty")]
    )
    password = password()
    organization = HiddenField("organization")
    email_address = HiddenField("email_address")
    auth_type = HiddenField("auth_type", validators=[DataRequired()])


def govuk_checkbox_field_widget(self, field, param_extensions=None, **kwargs):
    # error messages
    error_message = None
    if field.errors:
        error_message = {
            "attributes": {
                "data-module": "track-error",
                "data-error-type": field.errors[0],
                "data-error-label": field.name,
            },
            "text": field.errors[0],
        }

    params = {
        "name": field.name,
        "errorMessage": error_message,
        "items": [
            {
                "name": field.name,
                "id": field.id,
                "text": field.label.text,
                "value": "y",
                "checked": field.data,
            }
        ],
    }

    # extend default params with any sent in during instantiation
    if self.param_extensions:
        merge_jsonlike(params, self.param_extensions)

    # add any sent in though use in templates
    if param_extensions:
        merge_jsonlike(params, param_extensions)

    return Markup(render_template("forms/fields/checkboxes/macro.njk", params=params))


def govuk_checkboxes_field_widget(
    self, field, wrap_in_collapsible=False, param_extensions=None, **kwargs
):
    def _wrap_in_collapsible(field_label, checkboxes_string):
        # wrap the checkboxes HTML in the HTML needed by the collapisble JS
        result = Markup(
            f'<div class="selection-wrapper"'
            f'     data-module="collapsible-checkboxes"'
            f'     data-field-label="{field_label}">'
            f"  {checkboxes_string}"
            f"</div>"
        )

        return result

    # error messages
    error_message = None
    if field.errors:
        error_message = {
            "attributes": {
                "data-module": "track-error",
                "data-error-type": field.errors[0],
                "data-error-label": field.name,
            },
            "text": field.errors[0],
        }

    # returns either a list or a hierarchy of lists
    # depending on how get_items_from_options is implemented
    items = self.get_items_from_options(field)

    params = {
        "name": field.name,
        "fieldset": {
            "attributes": {"id": field.name},
            "legend": {
                "text": field.label.text,
            },
        },
        "asList": self.render_as_list,
        "errorMessage": error_message,
        "items": items,
    }

    # extend default params with any sent in during instantiation
    if self.param_extensions:
        merge_jsonlike(params, self.param_extensions)

    # add any sent in though use in templates
    if param_extensions:
        merge_jsonlike(params, param_extensions)

    if wrap_in_collapsible:
        # add a blank hint to act as an ARIA live-region
        params.update(
            {
                "hint": {
                    "html": '<div class="selection-summary" role="region" aria-live="polite"></div>'
                }
            }
        )

        return _wrap_in_collapsible(
            self.field_label,
            Markup(render_template("forms/fields/checkboxes/macro.njk", params=params)),
        )
    else:
        return Markup(
            render_template("forms/fields/checkboxes/macro.njk", params=params)
        )


def govuk_radios_field_widget(self, field, param_extensions=None, **kwargs):
    # error messages
    error_message = None
    if field.errors:
        error_message = {
            "attributes": {
                "data-module": "track-error",
                "data-error-type": field.errors[0],
                "data-error-label": field.name,
            },
            "text": field.errors[0],
        }

    # returns either a list or a hierarchy of lists
    # depending on how get_items_from_options is implemented
    items = self.get_items_from_options(field)

    params = {
        "name": field.name,
        "fieldset": {
            "attributes": {"id": field.name},
            "legend": {
                "text": field.label.text,
                "classes": "usa-legend text-bold",
            },
        },
        "errorMessage": error_message,
        "items": items,
    }

    # extend default params with any sent in during instantiation
    if self.param_extensions:
        merge_jsonlike(params, self.param_extensions)

    # add any sent in though use in templates
    if param_extensions:
        merge_jsonlike(params, param_extensions)

    return Markup(
        render_template("components/components/radios/template.njk", params=params)
    )


class GovukCheckboxField(BooleanField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukCheckboxField, self).__init__(
            label, validators, false_values=None, **kwargs
        )
        self.param_extensions = param_extensions

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        return govuk_checkbox_field_widget(
            self, field, param_extensions=param_extensions, **kwargs
        )


# based on work done by @richardjpope: https://github.com/richardjpope/recourse/blob/master/recourse/forms.py#L6
class GovukCheckboxesField(SelectMultipleField):
    render_as_list = False

    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukCheckboxesField, self).__init__(label, validators, **kwargs)
        self.param_extensions = param_extensions

    def get_item_from_option(self, option):
        return {
            "name": option.name,
            "id": option.id,
            "text": option.label.text,
            "value": str(option.data),  # to protect against non-string types like uuids
            "checked": option.checked,
        }

    def get_items_from_options(self, field):
        return [self.get_item_from_option(option) for option in field]

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        return govuk_checkboxes_field_widget(
            self, field, param_extensions=param_extensions, **kwargs
        )


# Wraps checkboxes rendering in HTML needed by the collapsible JS
class GovukCollapsibleCheckboxesField(GovukCheckboxesField):
    def __init__(
        self, label="", validators=None, field_label="", param_extensions=None, **kwargs
    ):
        super(GovukCollapsibleCheckboxesField, self).__init__(
            label, validators, param_extensions, **kwargs
        )
        self.field_label = field_label

    def widget(self, field, **kwargs):
        return govuk_checkboxes_field_widget(
            self, field, wrap_in_collapsible=True, param_extensions=None, **kwargs
        )


# GovukCollapsibleCheckboxesField adds an ARIA live-region to the hint and wraps the render in HTML needed by the
# collapsible JS
# NestedFieldMixin puts the items into a tree hierarchy, pre-rendering the sub-trees of the top-level items
class GovukCollapsibleNestedCheckboxesField(
    NestedFieldMixin, GovukCollapsibleCheckboxesField
):
    NONE_OPTION_VALUE = None
    render_as_list = True


class GovukRadiosField(RadioField):
    def __init__(self, label="", validators=None, param_extensions=None, **kwargs):
        super(GovukRadiosField, self).__init__(label, validators, **kwargs)
        self.param_extensions = param_extensions

    def get_item_from_option(self, option):
        return {
            "name": option.name,
            "id": option.id,
            "text": option.label.text,
            "value": str(option.data),  # to protect against non-string types like uuids
            "checked": option.checked,
        }

    def get_items_from_options(self, field):
        return [self.get_item_from_option(option) for option in field]

    # self.__call__ renders the HTML for the field by:
    # 1. delegating to self.meta.render_field which
    # 2. calls field.widget
    # this bypasses that by making self.widget a method with the same interface as widget.__call__
    def widget(self, field, param_extensions=None, **kwargs):
        return govuk_radios_field_widget(
            self, field, param_extensions=param_extensions, **kwargs
        )


class OptionalGovukRadiosField(GovukRadiosField):
    def pre_validate(self, form):
        if self.data is None:
            return
        super().pre_validate(form)


class OnOffField(GovukRadiosField):
    def __init__(self, label, choices=None, *args, **kwargs):
        choices = choices or [
            (True, "On"),
            (False, "Off"),
        ]
        super().__init__(
            label,
            *args,
            choices=choices,
            thing=f"{choices[0][1].lower()} or {choices[1][1].lower()}",
            **kwargs,
        )

    def process_formdata(self, valuelist):
        if valuelist:
            value = valuelist[0]
            self.data = (value == "True") if value in ["True", "False"] else value

    def iter_choices(self):
        for value, label in self.choices:
            # This overrides WTForms default behaviour which is to check
            # self.coerce(value) == self.data
            # where self.coerce returns a string for a boolean input
            yield (value, label, (self.data in {value, self.coerce(value)}))


class OrganizationTypeField(GovukRadiosField):
    def __init__(self, *args, include_only=None, validators=None, **kwargs):
        super().__init__(
            *args,
            choices=[
                (value, label)
                for value, label in Organization.TYPE_LABELS.items()
                if not include_only or value in include_only
            ],
            thing="the type of organization",
            validators=validators or [],
            **kwargs,
        )


class GovukRadiosFieldWithNoneOption(FieldWithNoneOption, GovukRadiosField):
    pass


# guard against data entries that aren't a known permission
def filter_by_permissions(valuelist):
    if valuelist is None:
        return None
    else:
        return [
            entry
            for entry in valuelist
            if any(entry in option for option in permission_options)
        ]


class AuthTypeForm(StripWhitespaceForm):
    auth_type = GovukRadiosField(
        "Sign in using",
        choices=[
            ("sms_auth", format_auth_type("sms_auth")),
            ("email_auth", format_auth_type("email_auth")),
        ],
    )


class BasePermissionsForm(StripWhitespaceForm):
    def __init__(self, all_template_folders=None, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.folder_permissions.choices = []
        if all_template_folders is not None:
            self.folder_permissions.all_template_folders = all_template_folders
            self.folder_permissions.choices = [
                (item["id"], item["name"])
                for item in ([{"name": "Templates", "id": None}] + all_template_folders)
            ]

    folder_permissions = GovukCollapsibleNestedCheckboxesField(
        "Folders this team member can see", field_label="folder"
    )

    login_authentication = GovukRadiosField(
        "Sign in using",
        choices=[
            ("sms_auth", "Text message code"),
            ("email_auth", "Email link"),
        ],
        thing="how this team member should sign in",
        validators=[DataRequired()],
    )

    permissions_field = GovukCheckboxesField(
        "Permissions",
        filters=[filter_by_permissions],
        choices=[(value, label) for value, label in permission_options],
        param_extensions={"hint": {"text": "All team members can see sent messages."}},
    )

    @property
    def permissions(self):
        return set(self.permissions_field.data)

    @classmethod
    def from_user(cls, user, service_id, **kwargs):
        form = cls(
            **kwargs,
            **{
                "permissions_field": (
                    user.permissions_for_service(service_id) & all_ui_permissions
                )
            },
            login_authentication=user.auth_type,
        )

        return form


class PermissionsForm(BasePermissionsForm):
    pass


class BaseInviteUserForm:
    email_address = email_address(gov_user=False)

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

    def validate_email_address(self, field):
        if current_user.platform_admin:
            return
        if field.data.lower() == self.inviter_email_address.lower():
            raise ValidationError("You cannot send an invitation to yourself")


class InviteUserForm(BaseInviteUserForm, PermissionsForm):
    pass


class InviteOrgUserForm(BaseInviteUserForm, StripWhitespaceForm):
    pass


class TwoFactorForm(StripWhitespaceForm):
    def __init__(self, validate_code_func, *args, **kwargs):
        """
        Keyword arguments:
        validate_code_func -- Validates the code with the API.
        """
        self.validate_code_func = validate_code_func
        super(TwoFactorForm, self).__init__(*args, **kwargs)

    sms_code = SMSCode("Text message code")

    def validate(self, extra_validators=None):
        if not self.sms_code.validate(self):
            return False

        is_valid, reason = self.validate_code_func(self.sms_code.data)

        if not is_valid:
            self.sms_code.errors.append(reason)
            return False

        return True


class TextNotReceivedForm(StripWhitespaceForm):
    mobile_number = international_phone_number()


class RenameServiceForm(StripWhitespaceForm):
    name = GovukTextInputField(
        "Service name",
        validators=[
            DataRequired(message="Cannot be empty"),
            MustContainAlphanumericCharacters(),
            Length(max=255, message="Service name must be 255 characters or fewer"),
        ],
    )


class RenameOrganizationForm(StripWhitespaceForm):
    name = GovukTextInputField(
        "Organization name",
        validators=[
            DataRequired(message="Cannot be empty"),
            MustContainAlphanumericCharacters(),
            Length(
                max=255, message="Organization name must be 255 characters or fewer"
            ),
        ],
    )


class OrganizationOrganizationTypeForm(StripWhitespaceForm):
    organization_type = OrganizationTypeField("What type of organization is this?")


class AdminOrganizationDomainsForm(StripWhitespaceForm):
    def populate(self, domains_list):
        for index, value in enumerate(domains_list):
            self.domains[index].data = value

    domains = FieldList(
        StripWhitespaceStringField(
            "",
            validators=[
                Optional(),
            ],
            default="",
        ),
        min_entries=20,
        max_entries=20,
        label="Domain names",
    )


class CreateServiceForm(StripWhitespaceForm):
    name = GovukTextInputField(
        "What’s your service called?",
        validators=[
            DataRequired(message="Cannot be empty"),
            MustContainAlphanumericCharacters(),
            Length(max=255, message="Service name must be 255 characters or fewer"),
        ],
    )
    organization_type = OrganizationTypeField("Where is this service run?")


class AdminNewOrganizationForm(
    RenameOrganizationForm, OrganizationOrganizationTypeForm
):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)


class AdminServiceSMSAllowanceForm(StripWhitespaceForm):
    free_sms_allowance = GovukIntegerField(
        "Numbers of text message fragments per year",
        validators=[InputRequired(message="Cannot be empty")],
    )


class AdminServiceMessageLimitForm(StripWhitespaceForm):
    message_limit = GovukIntegerField(
        "Max number of messages the service has per send",
        validators=[DataRequired(message="Cannot be empty")],
    )


class AdminServiceRateLimitForm(StripWhitespaceForm):
    rate_limit = GovukIntegerField(
        "Number of messages the service can send in a rolling 60 second window",
        validators=[DataRequired(message="Cannot be empty")],
    )


class ConfirmPasswordForm(StripWhitespaceForm):
    def __init__(self, validate_password_func, *args, **kwargs):
        self.validate_password_func = validate_password_func
        super(ConfirmPasswordForm, self).__init__(*args, **kwargs)

    password = GovukPasswordField("Enter password")

    def validate_password(self, field):
        if not self.validate_password_func(field.data):
            raise ValidationError("Invalid password")


class BaseTemplateForm(StripWhitespaceForm):
    name = GovukTextInputField(
        "Template name", validators=[DataRequired(message="Cannot be empty")]
    )

    template_content = TextAreaField(
        "Message",
        validators=[DataRequired(message="Cannot be empty"), NoCommasInPlaceHolders()],
    )
    process_type = HiddenField("normal")


class SMSTemplateForm(BaseTemplateForm):
    def validate_template_content(self, field):
        OnlySMSCharacters(template_type="sms")(None, field)


class EmailTemplateForm(BaseTemplateForm):
    subject = TextAreaField(
        "Subject", validators=[DataRequired(message="Cannot be empty")]
    )


class ForgotPasswordForm(StripWhitespaceForm):
    email_address = email_address(gov_user=False)


class NewPasswordForm(StripWhitespaceForm):
    new_password = password()


class ChangePasswordForm(StripWhitespaceForm):
    def __init__(self, validate_password_func, *args, **kwargs):
        self.validate_password_func = validate_password_func
        super(ChangePasswordForm, self).__init__(*args, **kwargs)

    old_password = password("Current password")
    new_password = password("New password")

    def validate_old_password(self, field):
        if not self.validate_password_func(field.data):
            raise ValidationError("Invalid password")


class CsvUploadForm(StripWhitespaceForm):
    file = FileField(
        "Add recipients",
        validators=[
            DataRequired(message="Please pick a file"),
            CsvFileValidator(),
            FileSize(max_size=10e6, message="File must be smaller than 10Mb"),  # 10Mb
        ],
    )


class ChangeNameForm(StripWhitespaceForm):
    new_name = GovukTextInputField("Your name")


# https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
class ChangePreferredTimezoneForm(StripWhitespaceForm):
    def __init__(self, *args, **kwargs):
        super(ChangePreferredTimezoneForm, self).__init__(*args, **kwargs)
        self.new_preferred_timezone.choices = [
            ("America/Puerto_Rico", "America/Puerto_Rico"),
            ("US/Eastern", "US/Eastern"),
            ("US/Central", "US/Central"),
            ("US/Mountain", "US/Mountain"),
            ("US/Pacific", "US/Pacific"),
            ("US/Alaska", "US/Alaska"),
            ("US/Hawaii", "US/Hawaii"),
            ("US/Aleutian", "US/Aleutian"),
            ("US/Samoa", "US/Samoa"),
        ]

    new_preferred_timezone = GovukRadiosField(
        "What timezone would you like to use?",
    )


class ChangeEmailForm(StripWhitespaceForm):
    def __init__(self, validate_email_func, *args, **kwargs):
        self.validate_email_func = validate_email_func
        super(ChangeEmailForm, self).__init__(*args, **kwargs)

    email_address = email_address()

    def validate_email_address(self, field):
        # The validate_email_func can be used to call API to check if the email address is already in
        # use. We don't want to run that check for invalid email addresses, since that will cause an error.
        # If there are any other validation errors on the email_address, we should skip this check.
        if self.email_address.errors:
            return

        is_valid = self.validate_email_func(field.data)
        if is_valid:
            raise ValidationError("The email address is already in use")


class ChangeNonGovEmailForm(ChangeEmailForm):
    email_address = email_address(gov_user=False)


class ChangeMobileNumberForm(StripWhitespaceForm):
    mobile_number = international_phone_number()


class ChooseTimeForm(StripWhitespaceForm):
    def __init__(self, *args, **kwargs):
        super(ChooseTimeForm, self).__init__(*args, **kwargs)
        self.scheduled_for.choices = [("", "Now")] + [
            get_time_value_and_label(hour)
            for hour in get_next_hours_until(get_furthest_possible_scheduled_time())
        ]
        self.scheduled_for.categories = get_next_days_until(
            get_furthest_possible_scheduled_time()
        )

    scheduled_for = GovukRadiosField(
        "When should Notify send these messages?",
        default="",
    )


class CreateKeyForm(StripWhitespaceForm):
    def __init__(self, existing_keys, *args, **kwargs):
        self.existing_key_names = [
            key["name"].lower() for key in existing_keys if not key["expiry_date"]
        ]
        super().__init__(*args, **kwargs)

    key_type = GovukRadiosField(
        "Type of key",
        thing="the type of key",
    )

    key_name = GovukTextInputField(
        "Name for this key",
        validators=[DataRequired(message="You need to give the key a name")],
    )

    def validate_key_name(self, key_name):
        if key_name.data.lower() in self.existing_key_names:
            raise ValidationError("A key with this name already exists")


class EstimateUsageForm(StripWhitespaceForm):
    volume_email = ForgivingIntegerField(
        "How many emails do you expect to send in the next year?",
        things="emails",
        format_error_suffix="you expect to send",
    )
    volume_sms = ForgivingIntegerField(
        "How many text messages do you expect to send in the next year?",
        things="text messages",
        format_error_suffix="you expect to send",
    )
    consent_to_research = GovukRadiosField(
        "Can we contact you when we’re doing user research?",
        choices=[
            ("yes", "Yes"),
            ("no", "No"),
        ],
        thing="yes or no",
        param_extensions={
            "hint": {
                "text": "You do not have to take part and you can unsubscribe at any time"
            }
        },
    )

    at_least_one_volume_filled = True

    def validate(self, *args, **kwargs):
        if self.volume_email.data == self.volume_sms.data == 0:
            self.at_least_one_volume_filled = False
            return False

        return super().validate(*args, **kwargs)


class ServiceContactDetailsForm(StripWhitespaceForm):
    contact_details_type = RadioField(
        "Type of contact details",
        choices=[
            ("url", "Link"),
            ("email_address", "Email address"),
            ("phone_number", "Phone number"),
        ],
    )

    url = GovukTextInputField("URL")
    email_address = GovukEmailField("Email address")
    # This is a text field because the number provided by the user can also be a short code
    phone_number = GovukTextInputField("Phone number")

    def validate(self, extra_validators=None):
        if self.contact_details_type.data == "url":
            self.url.validators = [DataRequired(), URL(message="Must be a valid URL")]

        elif self.contact_details_type.data == "email_address":
            self.email_address.validators = [
                DataRequired(),
                Length(min=5, max=255),
                ValidEmail(),
            ]

        elif self.contact_details_type.data == "phone_number":

            def valid_phone_number(self, num):
                try:
                    validate_phone_number(num.data, international=True)
                    return True
                except InvalidPhoneError:
                    raise ValidationError("Must be a valid phone number")

            self.phone_number.validators = [
                DataRequired(),
                Length(min=5, max=20),
                valid_phone_number,
            ]

        return super().validate(extra_validators)


class ServiceReplyToEmailForm(StripWhitespaceForm):
    email_address = email_address(label="Reply-to email address", gov_user=False)
    is_default = GovukCheckboxField("Make this email address the default")


class ServiceSmsSenderForm(StripWhitespaceForm):
    sms_sender = GovukTextInputField(
        "Text message sender",
        validators=[
            DataRequired(message="Cannot be empty"),
            Length(max=11, message="Enter 11 characters or fewer"),
            Length(min=3, message="Enter 3 characters or more"),
            LettersNumbersSingleQuotesFullStopsAndUnderscoresOnly(),
            DoesNotStartWithDoubleZero(),
        ],
    )
    is_default = GovukCheckboxField("Make this text message sender the default")


class ServiceEditInboundNumberForm(StripWhitespaceForm):
    is_default = GovukCheckboxField("Make this text message sender the default")


class AdminNotesForm(StripWhitespaceForm):
    notes = TextAreaField(validators=[])


class AdminBillingDetailsForm(StripWhitespaceForm):
    billing_contact_email_addresses = GovukTextInputField("Contact email addresses")
    billing_contact_names = GovukTextInputField("Contact names")
    billing_reference = GovukTextInputField("Reference")
    purchase_order_number = GovukTextInputField("Purchase order number")
    notes = TextAreaField(validators=[])


class ServiceOnOffSettingForm(StripWhitespaceForm):
    def __init__(self, name, *args, truthy="On", falsey="Off", **kwargs):
        super().__init__(*args, **kwargs)
        self.enabled.label.text = name
        self.enabled.choices = [
            (True, truthy),
            (False, falsey),
        ]

    enabled = OnOffField("Choices")


class ServiceSwitchChannelForm(ServiceOnOffSettingForm):
    def __init__(self, channel, *args, **kwargs):
        name = "Send {}".format(
            {
                "email": "emails",
                "sms": "text messages",
            }.get(channel)
        )

        super().__init__(name, *args, **kwargs)


class SVGFileUpload(StripWhitespaceForm):
    file = FileField_wtf(
        "Upload an SVG logo",
        validators=[
            FileAllowed(["svg"], "SVG Images only!"),
            DataRequired(message="You need to upload a file to submit"),
            NoEmbeddedImagesInSVG(),
            NoTextInSVG(),
        ],
    )


class EmailFieldInGuestList(GovukEmailField, StripWhitespaceStringField):
    pass


class InternationalPhoneNumberInGuestList(
    InternationalPhoneNumber, StripWhitespaceStringField
):
    pass


class GuestList(StripWhitespaceForm):
    def populate(self, email_addresses, phone_numbers):
        for form_field, existing_guest_list in (
            (self.email_addresses, email_addresses),
            (self.phone_numbers, phone_numbers),
        ):
            for index, value in enumerate(existing_guest_list):
                form_field[index].data = value

    email_addresses = FieldList(
        EmailFieldInGuestList("", validators=[Optional(), ValidEmail()], default=""),
        min_entries=5,
        max_entries=5,
        label="Email addresses",
    )

    phone_numbers = FieldList(
        InternationalPhoneNumberInGuestList("", validators=[Optional()], default=""),
        min_entries=5,
        max_entries=5,
        label="Mobile numbers",
    )


class DateFilterForm(StripWhitespaceForm):
    start_date = GovukDateField("Start Date", [validators.optional()])
    end_date = GovukDateField("End Date", [validators.optional()])
    include_from_test_key = GovukCheckboxField("Include test keys")


class RequiredDateFilterForm(StripWhitespaceForm):
    start_date = GovukDateField("Start Date")
    end_date = GovukDateField("End Date")


class BillingReportDateFilterForm(StripWhitespaceForm):
    start_date = GovukDateField("First day covered by report")
    end_date = GovukDateField("Last day covered by report")


class SearchByNameForm(StripWhitespaceForm):
    search = GovukSearchField(
        "Search by name",
        validators=[
            DataRequired("You need to enter full or partial name to search by.")
        ],
    )


class AdminSearchUsersByEmailForm(StripWhitespaceForm):
    search = GovukSearchField(
        "Search by name or email address",
        validators=[
            DataRequired(
                "You need to enter full or partial email address to search by."
            )
        ],
    )


class SearchUsersForm(StripWhitespaceForm):
    search = GovukSearchField("Search by name or email address")


class SearchNotificationsForm(StripWhitespaceForm):
    to = GovukSearchField()

    labels = {
        "email": "Search by email address",
        "sms": "Search by phone number",
    }

    def __init__(self, message_type, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.to.label.text = self.labels.get(
            message_type,
            "Search by phone number or email address",
        )


class SearchTemplatesForm(StripWhitespaceForm):
    search = GovukSearchField()

    def __init__(self, api_keys, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.search.label.text = (
            "Search by name or ID" if api_keys else "Search by name"
        )


class PlaceholderForm(StripWhitespaceForm):
    pass


class AdminServiceInboundNumberForm(StripWhitespaceForm):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.inbound_number.choices = kwargs["inbound_number_choices"]

    inbound_number = GovukRadiosField(
        "Set inbound number",
        thing="an inbound number",
    )


class CallbackForm(StripWhitespaceForm):
    url = GovukTextInputField(
        "URL",
        validators=[
            DataRequired(message="Cannot be empty"),
            Regexp(regex="^https.*", message="Must be a valid https URL"),
        ],
    )
    bearer_token = GovukPasswordField(
        "Bearer token",
        validators=[
            DataRequired(message="Cannot be empty"),
            Length(min=10, message="Must be at least 10 characters"),
        ],
    )

    def validate(self, extra_validators=None):
        return super().validate(extra_validators) or self.url.data == ""


class SMSPrefixForm(StripWhitespaceForm):
    enabled = OnOffField("")  # label is assigned on instantiation


def get_placeholder_form_instance(
    placeholder_name,
    dict_to_populate_from,
    template_type,
    allow_international_phone_numbers=False,
):
    if (
        InsensitiveDict.make_key(placeholder_name) == "emailaddress"
        and template_type == "email"
    ):
        field = email_address(label=placeholder_name, gov_user=False)
    elif (
        InsensitiveDict.make_key(placeholder_name) == "phonenumber"
        and template_type == "sms"
    ):
        if allow_international_phone_numbers:
            field = international_phone_number(
                label=placeholder_name
            )  # TODO: modify as necessary for non-us numbers
        else:
            field = uk_mobile_number(
                label=placeholder_name
            )  # TODO: replace with us_mobile_number
    else:
        field = GovukTextInputField(
            placeholder_name, validators=[DataRequired(message="Cannot be empty")]
        )

    PlaceholderForm.placeholder_value = field

    return PlaceholderForm(
        placeholder_value=dict_to_populate_from.get(placeholder_name, "")
    )


class SetSenderForm(StripWhitespaceForm):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.sender.choices = kwargs["sender_choices"]
        self.sender.label.text = kwargs["sender_label"]

    sender = GovukRadiosField()


class SetTemplateSenderForm(StripWhitespaceForm):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.sender.choices = kwargs["sender_choices"]
        self.sender.label.text = "Select your sender"

    sender = GovukRadiosField()


class AdminSetOrganizationForm(StripWhitespaceForm):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.organizations.choices = kwargs["choices"]

    organizations = GovukRadiosField(
        "Select an organization", validators=[DataRequired()]
    )


class AdminServiceAddDataRetentionForm(StripWhitespaceForm):
    notification_type = GovukRadiosField(
        "What notification type?",
        choices=[
            ("email", "Email"),
            ("sms", "SMS"),
        ],
        thing="notification type",
    )
    days_of_retention = GovukIntegerField(
        label="Days of retention",
        validators=[
            validators.NumberRange(min=3, max=90, message="Must be between 3 and 90")
        ],
    )


class AdminServiceEditDataRetentionForm(StripWhitespaceForm):
    days_of_retention = GovukIntegerField(
        label="Days of retention",
        validators=[
            validators.NumberRange(min=3, max=90, message="Must be between 3 and 90")
        ],
    )


class TemplateFolderForm(StripWhitespaceForm):
    def __init__(self, all_service_users=None, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if all_service_users is not None:
            self.users_with_permission.all_service_users = all_service_users
            self.users_with_permission.choices = [
                (item.id, item.name) for item in all_service_users
            ]

    users_with_permission = GovukCollapsibleCheckboxesField(
        "Team members who can see this folder", field_label="team member"
    )
    name = GovukTextInputField(
        "Folder name", validators=[DataRequired(message="Cannot be empty")]
    )


def required_for_ops(*operations):
    operations = set(operations)

    def validate(form, field):
        if form.op not in operations and any(field.raw_data):
            # super weird
            raise validators.StopValidation("Must be empty")
        if form.op in operations and not any(field.raw_data):
            raise validators.StopValidation("Cannot be empty")

    return validate


class TemplateAndFoldersSelectionForm(Form):
    """
    This form expects the form data to include an operation, based on which submit button is clicked.
    If enter is pressed, unknown will be sent by a hidden submit button at the top of the form.
    The value of this operation affects which fields are required, expected to be empty, or optional.

    * unknown
        currently not implemented, but in the future will try and work out if there are any obvious commands that can be
        assumed based on which fields are empty vs populated.
    * move-to-existing-folder
        must have data for templates_and_folders checkboxes, and move_to radios
    * move-to-new-folder
        must have data for move_to_new_folder_name, cannot have data for move_to_existing_folder_name
    * add-new-folder
        must have data for move_to_existing_folder_name, cannot have data for move_to_new_folder_name
    """

    ALL_TEMPLATES_FOLDER = {
        "name": "Templates",
        "id": RadioFieldWithNoneOption.NONE_OPTION_VALUE,
    }

    def __init__(
        self,
        all_template_folders,
        template_list,
        available_template_types,
        allow_adding_copy_of_template,
        *args,
        **kwargs,
    ):
        super().__init__(*args, **kwargs)

        self.available_template_types = available_template_types

        self.templates_and_folders.choices = template_list.as_id_and_name

        self.op = None
        self.is_move_op = self.is_add_folder_op = self.is_add_template_op = False

        self.move_to.all_template_folders = all_template_folders
        self.move_to.choices = [
            (item["id"], item["name"])
            for item in ([self.ALL_TEMPLATES_FOLDER] + all_template_folders)
        ]

        self.add_template_by_template_type.choices = list(
            filter(
                None,
                [
                    # ('email', 'Email') if 'email' in available_template_types else None,
                    ("sms", "Start with a blank template")
                    if "sms" in available_template_types
                    else None,
                    ("copy-existing", "Copy an existing template")
                    if allow_adding_copy_of_template
                    else None,
                ],
            )
        )

    @property
    def trying_to_add_unavailable_template_type(self):
        return all(
            (
                self.is_add_template_op,
                self.add_template_by_template_type.data,
                self.add_template_by_template_type.data
                not in self.available_template_types,
            )
        )

    def is_selected(self, template_folder_id):
        return template_folder_id in (self.templates_and_folders.data or [])

    def validate(self, extra_validators=None):
        self.op = request.form.get("operation")

        self.is_move_op = self.op in {"move-to-existing-folder", "move-to-new-folder"}
        self.is_add_folder_op = self.op in {"add-new-folder", "move-to-new-folder"}
        self.is_add_template_op = self.op in {"add-new-template"}

        if not (self.is_add_folder_op or self.is_move_op or self.is_add_template_op):
            return False

        return super().validate(extra_validators)

    def get_folder_name(self):
        if self.op == "add-new-folder":
            return self.add_new_folder_name.data
        elif self.op == "move-to-new-folder":
            return self.move_to_new_folder_name.data
        return None

    templates_and_folders = GovukCheckboxesField(
        "Choose templates or folders",
        validators=[required_for_ops("move-to-new-folder", "move-to-existing-folder")],
        choices=[],  # added to keep order of arguments, added properly in __init__
        param_extensions={"fieldset": {"legend": {"classes": "usa-sr-only"}}},
    )
    # if no default set, it is set to None, which process_data transforms to '__NONE__'
    # this means '__NONE__' (self.ALL_TEMPLATES option) is selected when no form data has been submitted
    # set default to empty string so process_data method doesn't perform any transformation
    move_to = NestedRadioField(
        "Choose a folder",
        default="",
        validators=[required_for_ops("move-to-existing-folder"), Optional()],
    )
    add_new_folder_name = GovukTextInputField(
        "Folder name", validators=[required_for_ops("add-new-folder")]
    )
    move_to_new_folder_name = GovukTextInputField(
        "Folder name", validators=[required_for_ops("move-to-new-folder")]
    )

    add_template_by_template_type = RadioFieldWithRequiredMessage(
        "New template",
        validators=[
            required_for_ops("add-new-template"),
            Optional(),
        ],
        required_message="Select the type of template you want to add",
    )


class AdminClearCacheForm(StripWhitespaceForm):
    model_type = GovukCheckboxesField(
        "What do you want to clear today",
    )

    def validate_model_type(self, field):
        if not field.data:
            raise ValidationError("Select at least one option")


class ChangeSecurityKeyNameForm(StripWhitespaceForm):
    security_key_name = GovukTextInputField(
        "Name of key",
        validators=[
            DataRequired(message="Cannot be empty"),
            MustContainAlphanumericCharacters(),
            Length(max=255, message="Name of key must be 255 characters or fewer"),
        ],
    )