"""
Author: Michel Peltriaux
Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
Contact: michel.peltriaux@sgdnord.rlp.de
Created on: 16.11.20

"""

from abc import abstractmethod

from bootstrap_modal_forms.forms import BSModalModelForm, BSModalForm
from django import forms
from django.contrib.auth.models import User
from django.contrib.gis.forms import GeometryField, OSMWidget
from django.contrib.gis.geos import Polygon
from django.urls import reverse
from django.utils import timezone
from django.utils.translation import gettext_lazy as _


class BaseForm(forms.Form):
    """
    Basic form for that holds attributes needed in all other forms
    """
    action_url = None
    form_title = None
    cancel_redirect = None
    form_caption = None
    instance = None  # The data holding model object

    def __init__(self, *args, **kwargs):
        self.instance = kwargs.pop("instance", None)
        super().__init__(*args, **kwargs)

    @abstractmethod
    def save(self):
        # To be implemented in subclasses!
        pass

    def disable_form_field(self, field: str):
        """
        Disables a form field for user editing
        """
        self.fields[field].widget.attrs["readonly"] = True
        self.fields[field].disabled = True
        self.fields[field].widget.attrs["title"] = _("Not editable")

    def initialize_form_field(self, field: str, val):
        """
        Initializes a form field with a value
        """
        self.fields[field].initial = val

    def load_initial_data(self, form_data: dict, disabled_fields: list):
        """ Initializes form data from instance

        Inserts instance data into form and disables form fields

        Returns:

        """
        if self.instance is None:
            return
        for k, v in form_data.items():
            self.initialize_form_field(k, v)
        for field in disabled_fields:
            self.disable_form_field(field)


class RemoveForm(BaseForm):
    check = forms.BooleanField(
        label=_("Confirm"),
        label_suffix=_(""),
        required=True,
    )

    def __init__(self, *args, **kwargs):
        self.object_to_remove = kwargs.pop("object_to_remove", None)
        self.remove_post_url = kwargs.pop("remove_post_url", "")
        self.cancel_url = kwargs.pop("cancel_url", "")

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

        self.form_title = _("Remove")
        if self.object_to_remove is not None:
            self.form_caption = _("You are about to remove {} {}").format(self.object_to_remove.__class__.__name__, self.object_to_remove)
        self.action_url = self.remove_post_url
        self.cancel_redirect = self.cancel_url

    def is_checked(self) -> bool:
        return self.cleaned_data.get("check", False)

    def save(self, user: User):
        if self.object_to_remove is not None and self.is_checked():
            self.object_to_remove.is_active = False
            self.object_to_remove.deleted_on = timezone.now()
            self.object_to_remove.deleted_by = user
            self.object_to_remove.save()
        return self.object_to_remove


class SimpleGeomForm(BaseForm):
    """ A geometry form for rendering geometry read-only using a widget

    """
    geom = GeometryField(
        required=False,
        disabled=True,
        widget=OSMWidget(
            attrs={
                "map_width": 600,
                "map_height": 400,
            }
        )
    )

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

        # Initialize geometry
        try:
            geom = self.instance.geometry.geom
            if geom is None:
                raise AttributeError
        except AttributeError:
            # catches if no geometry has been added, yet. Replace with empty placeholder polygon.
            geom = Polygon.from_bbox([0, 0, 0, 0])
            # Zoom out to a very high level, so the user can see directly that there is no geometry for this entry
            self.fields["geom"].widget.attrs["default_zoom"] = 1
        self.initialize_form_field("geom", geom)
        self.area = geom.area


class RemoveDocumentForm(BaseForm, BSModalForm):
    confirm = forms.BooleanField(
        label=_("Confirm"),
        label_suffix=_(""),
        widget=forms.CheckboxInput(),
        required=True,
    )

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.instance = kwargs.get("instance", None)
        self.form_title = _("Remove document")
        self.form_caption = _("This will remove '{}'. Are you sure?").format(self.instance.title)