# Create your models here.

from django.utils.text import slugify
from grapple.helpers import register_query_field
from wagtail.api import APIField
from wagtail.core.blocks import StreamBlock
from wagtail.core.fields import StreamField
from wagtail.core.models import Page, Orderable
from wagtail.snippets.models import register_snippet

from vbv_lernwelt.learnpath.models_competences import *
from vbv_lernwelt.learnpath.models_learning_unit_content import WebBasedTrainingBlock, VideoBlock


@register_query_field("learning_path")
class LearningPath(Page):
    # PageChooserPanel('related_page', 'demo.PublisherPage'),

    content_panels = Page.content_panels + [
        InlinePanel('topics', label="Topics"),
    ]

    subpage_types = ['learnpath.Circle']


    class Meta:
        verbose_name = "Learning Path"

    def __str__(self):
        return f"{self.title}"


class Topic(Orderable):
    title = models.TextField(default='')
    is_visible = models.BooleanField(default=True)

    learning_path = ParentalKey('learnpath.LearningPath',
                                null=True,
                                blank=True,
                                on_delete=models.CASCADE,
                                related_name='topics',
                                )

    panels = [FieldPanel('title'),
              FieldPanel('is_visible'),
              ]

    api_fields = [
        APIField('title'),
        APIField('is_visible'),
    ]


    # content_panels = Page.content_panels + [
    #     FieldPanel('is_visible', classname="full"),
    #     PageChooserPanel('learning_path',  'learnpath.LearningPath'),
    # ]

    # parent_page_types = ['learnpath.LearningPath']
    # subpage_types = ['learnpath.Circle']

    def full_clean(self, *args, **kwargs):
        self.slug = find_available_slug(Topic, slugify(self.title, allow_unicode=True))
        super(Topic, self).full_clean(*args, **kwargs)

    class Meta:
        verbose_name = "Topic"

    def __str__(self):
        return f"{self.title}"


class Circle(Page):
    description = models.TextField(default="", blank=True)
    goals = models.TextField(default="", blank=True)

    topic = models.ForeignKey(
        'learnpath.Topic',
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name='circles'
    )

    parent_page_types = ['learnpath.LearningPath']
    subpage_types = ['learnpath.LearningUnit']

    content_panels = Page.content_panels + [
        FieldPanel('description'),
        FieldPanel('goals'),
        InlinePanel('learning_sequences', label="Learning Sequences"),
    ]

    api_fields = [
        APIField('title'),
        APIField('description'),
        APIField('topic'),
        APIField('learning_sequences'),
    ]

    def full_clean(self, *args, **kwargs):
        self.slug = find_available_slug(Circle, slugify(self.title, allow_unicode=True))
        super(Circle, self).full_clean(*args, **kwargs)

    class Meta:
        verbose_name = "Circle"

    def __str__(self):
        return f"{self.title}"


@register_snippet
class LearningSequence(Orderable):
    # TODO: How to do a icon choice field?
    title = models.CharField(max_length=256, default='')

    circle = ParentalKey(
        'learnpath.Circle',
        null=True,
        blank=True,
        on_delete=models.CASCADE,
        related_name='learning_sequences',
    )

    panels = [FieldPanel('title'), FieldPanel('circle')]

    api_fields = [
        APIField('title'),
        APIField('category'),
        APIField('learning_packages'),
    ]

    class Meta:
        verbose_name = "Learning Sequence"

    def __str__(self):
        return f"{self.title}"

    def full_clean(self, *args, **kwargs):
        super(LearningSequence, self).full_clean(*args, **kwargs)


class LearningUnit(Page):
    """
    This is a group of contents, with the übung and test it is one unit. ... more of a structural charactacter.

    """
    # TODO: Review model architecture, is the stream field the right thing here?
    parent_page_types = ['learnpath.Circle']
    learning_sequence = models.ForeignKey(
        'learnpath.LearningSequence',
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name='learning_units',
    )

    content_blocks = [
        ('web_based_training', WebBasedTrainingBlock()),
        ('video', VideoBlock()),
    ]

    contents = StreamField(
        StreamBlock(content_blocks), null=True, blank=True, min_num=1, max_num=1
    )

    content_panels = [
        FieldPanel('title', classname="full title"),
        FieldPanel('learning_sequence'),
        StreamFieldPanel('contents'),
    ]

    api_fields = [
        APIField('title'),
        APIField('contents'),
        APIField('content_blocks'),
    ]

    subpage_types = []

    class Meta:
        verbose_name = "Learning Unit"

    def full_clean(self, *args, **kwargs):
        self.slug = find_available_slug(LearningUnit, slugify(self.title, allow_unicode=True))
        super(LearningUnit, self).full_clean(*args, **kwargs)

    def __str__(self):
        return f"{self.title}"


def find_available_slug(model, requested_slug, ignore_page_id=None):
    """
    Finds an available slug within the specified parent.

    If the requested slug is not available, this adds a number on the end, for example:

     - 'requested-slug'
     - 'requested-slug-1'
     - 'requested-slug-2'

    And so on, until an available slug is found.

    The `ignore_page_id` keyword argument is useful for when you are updating a page,
    you can pass the page being updated here so the page's current slug is not
    treated as in use by another page.
    """

    # TODO: In comparison ot wagtails own function, I look for the same model  instead of the parent
    pages = model.objects.filter(slug__startswith=requested_slug)

    if ignore_page_id:
        pages = pages.exclude(id=ignore_page_id)

    existing_slugs = set(pages.values_list("slug", flat=True))
    slug = requested_slug
    number = 1

    while slug in existing_slugs:
        slug = requested_slug + "-" + str(number)
        number += 1

    return slug