from django import forms
from django.conf import settings
from django.contrib.admin.widgets import AdminDateWidget
from django.forms import ModelForm, ChoiceField, RadioSelect, BooleanField, CharField, EmailField
from django.forms.renderers import DjangoTemplates
from django.utils.html import format_html
from django.utils.safestring import mark_safe

from .models import (
    TYPE_CHOICES,
    Project,
    ProjectCategory,
    WikimediaProject,
    ConcreteVolunteer,
    ConcreteExtern,
    IFG,
    Library,
    ELiterature,
    Software,
    HonoraryCertificate,
    Travel,
    Email,
    Literature,
    List,
    BusinessCard,
)


class TableFormRenderer(DjangoTemplates):
    form_template_name = 'django/forms/table.html'


class FdbForm(ModelForm):
    '''this base class provides the required css class for all forms'''
    required_css_class = 'required'


class CommonOrderMixin(forms.Form):
    """
    Ensures a consistent field order for all forms that inherit from this mixin.

    The goal is to always render:
      - "realname" and "email" fields at the top,
      - all other fields in the middle (in the order Django provides),
      - "check" (terms/privacy checkbox) at the bottom.

    This keeps the UX consistent across all forms without repeating field_order logic.
    """

    # Fields that should always appear first in the form
    field_order_head = ('realname', 'email')

    # Fields that should always appear last in the form
    field_order_tail = ('check',)  # rename if your checkbox field is called differently

    def __init__(self, *args, **kwargs):
        """
        Override the default form initialization to reorder fields.

        The method:
          1. Put the 'head' fields first.
          2. Put all other fields in the middle.
          3. Put the 'tail' fields last.

        Non-existing fields are ignored by `order_fields`.
        """

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

        ordered = {*self.field_order_head, *self.field_order_tail}

        self.order_fields([
            *self.field_order_head,
            *[field for field in self.fields if field not in ordered],
            *self.field_order_tail,
        ])


class ExternForm(FdbForm):
    choice = ChoiceField(choices=TYPE_CHOICES.items(), widget=RadioSelect,
                         label='Was möchtest Du beantragen?')

    check = BooleanField(required=True,
                         label=format_html("Ich stimme den <a href='{}' target='_blank' rel='noopener'>Datenschutzbestimmungen</a> und der<br> <a href='{}' target='_blank' rel='noopener'>Richtlinie zur Förderung der Communitys</a> zu",
                         settings.DATAPROTECTION, settings.FOERDERRICHTLINIEN))

    class Meta:
        model = ConcreteExtern
        exclude = ('username', 'granted', 'granted_date', 'survey_mail_send', 'service_id', 'survey_mail_date', 'mail_state')


INTERN_CHOICES = {
    'PRO': 'Projektsteckbrief',
    'HON': 'Ehrenamtsbescheinigung, Akkreditierung oder Redaktionsbestätigung',
    'TRAV': 'Reisekostenerstattung',
}


class InternForm(FdbForm):
    choice = ChoiceField(choices=INTERN_CHOICES.items(), widget=RadioSelect,
                         label='Was möchtest Du eingeben?')

    class Meta:
        model = ConcreteVolunteer
        exclude = ('granted', 'granted_date', 'survey_mail_send', 'survey_mail_date', 'mail_state')


class BaseApplicationForm(FdbForm):
    """
    Base form for all external applications.

    - Adds standard fields that must appear in every form:
      * realname (applicant's full name)
      * email (contact address for notifications)
      * check (confirmation of data protection and funding policy)
    - Ensures consistency across all application types.
    """
    realname = CharField(
        label='Realname',
        required=True,
        help_text='Bitte gib deinen Vor- und Nachnamen ein.'
    )
    email = EmailField(
        label='E-Mail-Adresse',
        required=True,
        help_text='Bitte gib deine E-Mail-Adresse ein, damit dich <br> Wikimedia Deutschland bei Rückfragen oder für <br> die Zusage kontaktieren kann.'
    )
    check = BooleanField(required=True,
                         label=format_html(
                             "Ich stimme den <a href='{}' target='_blank' rel='noopener'>Datenschutzbestimmungen</a> und der<br> <a href='{}' target='_blank' rel='noopener'>Richtlinie zur Förderung der Communitys</a> zu",
                             settings.DATAPROTECTION, settings.FOERDERRICHTLINIEN))


PROJECT_COST_GT_1000_MESSAGE = format_html(
    """Bitte beachte, dass für Projektkosten über 1.000 € ein öffentlicher Projektplan erforderlich
       ist (siehe <a href="{0}" target="blank_">Wikipedia:Förderung/Projektplanung)</a>.""",
    'https://de.wikipedia.org/wiki/Wikipedia:F%C3%B6rderung/Projektplanung'
)


class BaseProjectForm(ModelForm):
    categories = {
        'categories': ProjectCategory,
        'wikimedia_projects': WikimediaProject,
    }

    class Media:
        js = ('dropdown/js/otrs_link.js', 'js/project-categories.js')

    def clean(self):
        cleaned_data = ModelForm.clean(self)

        if self.errors:
            return cleaned_data

        for field, model in self.categories.items():
            field_other = f'{field}_other'
            values = cleaned_data[field]

            if model.other in values:
                if not cleaned_data[field_other]:
                    self.add_error(field_other, f'Bitte gib einen Wert an oder deselektiere "{model.OTHER}".')
            else:
                cleaned_data[field_other] = ''

        return cleaned_data


class ProjectForm(CommonOrderMixin, BaseProjectForm, BaseApplicationForm):
    OPTIONAL_FIELDS = {
        'categories_other',
        'wikimedia_projects_other',
        'page',
        'group',
        'location',
        'insurance',
        'notes',
    }

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

        for field in set(self.fields) - self.OPTIONAL_FIELDS:
            self.fields[field].required = True

    class Meta:
        model = Project
        fields = [
            'name',
            'description',
            'categories',
            'categories_other',
            'wikimedia_projects',
            'wikimedia_projects_other',
            'start',
            'end',
            'participants_estimated',
            'page',
            'group',
            'location',
            'cost',
            'insurance',
            'notes',
        ]
        widgets = {
            'start': AdminDateWidget,
            'end': AdminDateWidget,
        }

    class Media:
        css = {
            'all': ('css/dateFieldNoNowShortcutInTravels.css',)
        }

    def clean_cost(self):
        cost = self.cleaned_data['cost']

        if cost > 1000:
            raise forms.ValidationError(PROJECT_COST_GT_1000_MESSAGE, code='cost-gt-1000')

        return cost


HOTEL_CHOICES = {
    'TRUE': mark_safe('Hotelzimmer benötigt'),
    'FALSE': mark_safe('Kein Hotelzimmer benötigt'),
}


class TravelForm(BaseApplicationForm, CommonOrderMixin):
    # TODO: add some javascript to show/hide other-field

    hotel = ChoiceField(label='Hotelzimmer benötigt:', choices=HOTEL_CHOICES.items(), widget=RadioSelect())

    # this is the code, to change required to false if needed
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['project_name'].required = True
        self.fields['transport'].required = True
        self.fields['travelcost'].required = True
        self.fields['checkin'].required = True
        self.fields['checkout'].required = True
        self.fields['hotel'].required = True

    class Meta:
        model = Travel
        fields = ['project_name', 'transport', 'travelcost', 'checkin', 'checkout', 'hotel', 'notes']
        exclude = ('granted', 'granted_date', 'survey_mail_send', 'realname', 'email', 'survey_mail_date', 'project',
                   'request_url', 'payed_for_hotel_by', 'payed_for_travel_by', 'intern_notes', 'mail_state')
        widgets = {
            'checkin': AdminDateWidget,
            'checkout': AdminDateWidget,
        }

    class Media:
        js = ('dropdown/js/otrs_link.js',)
        css = {
            'all': ('css/dateFieldNoNowShortcutInTravels.css',)
        }


class LibraryForm(BaseApplicationForm, CommonOrderMixin):

    class Meta:
        model = Library
        fields = ['cost', 'library', 'duration', 'notes', 'survey_mail_send']
        exclude = ['intern_notes', 'survey_mail_send', 'mail_state']

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

        self.fields['library'].label = self._meta.model.LIBRARY_LABEL
        self.fields['library'].help_text = self._meta.model.LIBRARY_HELP_TEXT
        self.fields['duration'].help_text = self._meta.model.DURATION_HELP_TEXT


class ELiteratureForm(LibraryForm):

    class Meta(LibraryForm.Meta):
        model = ELiterature


class SoftwareForm(LibraryForm):

    class Meta(LibraryForm.Meta):
        model = Software


class HonoraryCertificateForm(FdbForm):

    class Meta:
        model = HonoraryCertificate
        fields = ['request_url', 'project']
        exclude = ['intern_notes']

    class Media:
        js = ('dropdown/js/otrs_link.js',)


class IFGForm(BaseApplicationForm, CommonOrderMixin):
    class Meta:
        model = IFG
        fields = ['cost', 'url', 'notes']
        exclude = ['intern_notes', 'survey_mail_send', 'mail_state']


class CheckForm(FdbForm):
    termstoaccept = settings.NUTZUNGSBEDINGUNGEN

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

        # Check if the model field 'terms_accepted' is present
        if 'terms_accepted' in self.fields:
            # Make the field required (HTML5 validation)
            self.fields['terms_accepted'].required = True
            # Set custom label with link to terms
            self.fields['terms_accepted'].label = format_html(
                "Ich stimme den <a href='{}'>Nutzungsbedingungen</a> zu",
                self.termstoaccept
            )


class LiteratureForm(BaseApplicationForm, CommonOrderMixin):
    termstoaccept = settings.NUTZUNGSBEDINGUNGEN_LITERATURSTIPENDIUM

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['selfbuy_give_data'].required = True

    class Meta:
        model = Literature
        fields = ['cost', 'info', 'source', 'notes', 'selfbuy', 'selfbuy_data', 'selfbuy_give_data', 'terms_accepted']
        exclude = ['intern_notes', 'survey_mail_send', 'mail_state']

    class Media:
        js = ('dropdown/js/literature.js',)


ADULT_CHOICES = {
    'TRUE': mark_safe('Ich bin volljährig.'),
    'FALSE': mark_safe('Ich bin noch nicht volljährig.'),
}


class EmailForm(BaseApplicationForm, CommonOrderMixin):
    termstoaccept = settings.NUTZUNGSBEDINGUNGEN_EMAIL_SERVICE

    # this is the code, to change required to false if needed
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['adult'].required = True
        self.fields['other'].required = True

    adult = ChoiceField(label='Volljährigkeit', choices=ADULT_CHOICES.items(), widget=RadioSelect())

    # TODO: add some javascript to show/hide other-field
    class Meta:
        model = Email
        fields = ['domain', 'address', 'other', 'adult', 'terms_accepted']
        exclude = ['intern_notes', 'survey_mail_send', 'mail_state']

    class Media:
        js = ('dropdown/js/mail.js',)


class BusinessCardForm(BaseApplicationForm, CommonOrderMixin):
    termstoaccept = settings.NUTZUNGSBEDINGUNGEN_VISITENKARTEN

    # this is the code, to change required to false if needed
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['url_of_pic'].required = True
        self.fields['send_data_to_print'].required = True

    class Meta:
        model = BusinessCard
        exclude = ['intern_notes', 'survey_mail_send', 'mail_state']
        fields = ['project', 'data', 'variant', 'url_of_pic', 'send_data_to_print', 'sent_to', 'terms_accepted']

    class Media:
        js = ('dropdown/js/businessCard.js',)


class ListForm(BaseApplicationForm, CommonOrderMixin):
    termstoaccept = settings.NUTZUNGSBEDINGUNGEN_MAILINGLISTEN

    class Meta:
        model = List
        fields = ['domain', 'address', 'terms_accepted']
        exclude = ['intern_notes', 'survey_mail_send', 'mail_state']

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

        self.fields['address'].initial = ''