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

from purchase.models import CoursePurchase


class EmptyPage(Page):
    pass


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

    content_panels = Page.content_panels + ["body"]


class BlogIndexPage(Page):
    subpage_types = ["home.BlogPage"]


class CourseIndexPage(Page):
    subpage_types = ["home.CoursePage"]

    def get_context(self, request):
        context = super().get_context(request)
        all_courses = self.get_children().live()
        purchased_courses = set()
        other_courses = set()

        for course in all_courses:
            if course.specific._user_has_access(request.user):
                purchased_courses.add(course)
            else:
                other_courses.add(course)

        context["purchased_courses"] = sorted(
            purchased_courses, key=lambda c: c.title.lower()
        )
        context["other_courses"] = sorted(other_courses, key=lambda c: c.title.lower())
        return context


class BlogPage(Page):
    author = models.CharField(max_length=255)
    image = models.ForeignKey(
        "wagtailimages.Image",
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="+",
    )
    body = StreamField(
        [
            ("heading", blocks.CharBlock(classname="title")),
            ("paragraph", blocks.RichTextBlock()),
            ("image", ImageBlock()),
        ]
    )

    content_panels = Page.content_panels + [
        FieldPanel("author"),
        FieldPanel("image"),
        FieldPanel("body"),
    ]
    parent_page_types = ["home.BlogIndexPage"]


class CoursePage(Page):
    course_image = models.ForeignKey(
        "wagtailimages.Image",
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="+",
    )
    description = models.CharField(max_length=255, blank=True)
    body = RichTextField(blank=True)
    allowed_groups = ParentalManyToManyField(
        Group,
        related_name="course_pages",
        help_text="Additional groups that should have access to this course, e.g. Editors. NOTE: Users who purchase the course will be automatically added to a dedicated access group for this course, so you don't need to add that group here.",
    )

    repository_url = models.URLField(
        null=True,
        blank=True,
    )

    def _user_has_access(self, user):
        if not user.is_authenticated:
            return False

        user_group_ids = user.groups.values_list("id", flat=True)
        if self.allowed_groups.filter(id__in=user_group_ids).exists():
            return True

        return CoursePurchase.objects.filter(
            user=user, course=self, refunded=False
        ).exists()

    def _user_purchase_id(self, user):
        if not user.is_authenticated:
            return None

        purchase = CoursePurchase.objects.filter(
            user=user, course=self, refunded=False
        ).first()
        print(f"User {user} purchase for course {self}: {purchase}")
        return purchase.id if purchase else None

    def mock_purchase(self, user):
        """Mock method to simulate purchasing this course for a user."""
        if not user.is_authenticated:
            return False
        obj, created = CoursePurchase.objects.get_or_create(
            user=user, course=self, refunded=False
        )
        # Add user to dedicated access group for this course
        group_name = f"course_{self.id}_access"
        group, _ = Group.objects.get_or_create(name=group_name)
        user.groups.add(group)
        # Ensure allowed_groups only includes this access group
        if not self.allowed_groups.filter(id=group.id).exists():
            self.allowed_groups.add(group)
        return created

    def save(self, *args, **kwargs):
        if self.id is not None:
            group_name = f"course_{self.id}_access"
            group, created = Group.objects.get_or_create(name=group_name)
            if not self.allowed_groups.filter(id=group.id).exists():
                self.allowed_groups.add(group)

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

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

    content_panels = Page.content_panels + [
        FieldPanel("course_image"),
        FieldPanel("description"),
        FieldPanel("body"),
        FieldPanel("allowed_groups", widget=CheckboxSelectMultiple),
        FieldPanel(
            "repository_url",
            read_only=True,
            heading="Repository URL (auto-generated)",
        ),
    ]
    parent_page_types = ["home.CourseIndexPage"]
    subpage_types = ["home.CourseModulePage"]


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"]
    subpage_types = ["home.ModuleLessonPage"]
    parent_page_types = ["home.CoursePage"]


class ModuleLessonPage(Page):
    body = RichTextField(blank=True)
    create_gitea_repo = models.BooleanField(
        default=False,
        help_text="If enabled, a Gitea repository will be automatically created for this module when the module is published.",
    )
    gitea_repo_url = models.URLField(
        null=True,
        blank=True,
        help_text="URL of the Gitea repository for this lesson (auto-generated if 'create_gitea_repo' is enabled)",
    )

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

    content_panels = Page.content_panels + [
        FieldPanel("body"),
        FieldPanel("create_gitea_repo"),
        FieldPanel(
            "gitea_repo_url",
            read_only=True,
            heading="Gitea Repository URL",
        ),
    ]
    parent_page_types = ["home.CourseModulePage"]