from django import forms
from django.contrib.auth.models import Group, User
from django.db import models
from django.forms import CheckboxSelectMultiple
from wagtail.admin.panels import FieldPanel
from wagtail.fields import RichTextField, StreamField
from wagtail.models import Page
from wagtail.models.copying import ParentalManyToManyField


class EmptyPage(Page):
    pass


class HomePage(Page):
    body = RichTextField(blank=True)

    content_panels = Page.content_panels + ["body"]


class CoursePage(Page):
    body = RichTextField(blank=True)
    course_image = models.ForeignKey(
        "wagtailimages.Image",
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="+",
    )
    allowed_groups = ParentalManyToManyField(
        Group,
        related_name="course_pages",
        help_text="Select a group to restrict access to this course. Non-members will be prompted to purchase the course to view modules.",
    )

    def _user_has_access(self, user):
        if not user.is_authenticated:
            return False
        user_group_ids = user.groups.values_list("id", flat=True)
        return self.allowed_groups.filter(id__in=user_group_ids).exists()

    def get_context(self, request):
        context = super().get_context(request)
        context["user_has_access"] = self._user_has_access(request.user)
        return context

    content_panels = Page.content_panels + [
        FieldPanel("course_image"),
        FieldPanel("body"),
        FieldPanel("allowed_groups", widget=CheckboxSelectMultiple),
    ]


class CourseModulePage(Page):
    body = RichTextField(blank=True)

    @property
    def course(self):
        if hasattr(self, "get_parent"):
            parent = self.get_parent()
            if parent and hasattr(parent, "specific"):
                return parent.specific
        return None

    @property
    def full_title(self):
        course = self.course
        if course:
            return f"{course.title} - {self.title}"
        return self.title

    content_panels = Page.content_panels + ["body"]


class EventPage(Page):
    image = models.ForeignKey(
        "wagtailimages.Image",
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="+",
    )
    start = models.DateTimeField()
    end = models.DateTimeField()

    # TODO: use google maps here
    location = models.CharField(max_length=255, blank=True)

    description = RichTextField(blank=True)
    hosts = ParentalManyToManyField(
        User,
        related_name="hosted_events",
        help_text="Select users who will be listed as hosts of this event.",
    )

    content_panels = Page.content_panels + [
        FieldPanel("image"),
        FieldPanel("start"),
        FieldPanel("end"),
        FieldPanel("location"),
        FieldPanel("hosts", widget=CheckboxSelectMultiple),
        FieldPanel("description"),
    ]