from django import forms
from django.core.exceptions import ValidationError
from django.db import models
from django.db.models import Min, Prefetch, Q, UniqueConstraint
from django.utils import timezone
from django.utils.html import mark_safe
from django.utils.translation import gettext_lazy as _
from grapple.helpers import register_query_field, register_singular_query_field
from grapple.models import (
    GraphQLBoolean,
    GraphQLCollection,
    GraphQLForeignKey,
    GraphQLImage,
    GraphQLRichText,
    GraphQLStreamfield,
    GraphQLString,
)
from modelcluster.fields import ParentalKey, ParentalManyToManyField
from modelcluster.models import ClusterableModel
from wagtail.admin.panels import (
    FieldPanel,
    FieldRowPanel,
    HelpPanel,
    InlinePanel,
    MultiFieldPanel,
    MultipleChooserPanel,
    TitleFieldPanel,
)
from wagtail.fields import RichTextField
from wagtail.models import Orderable, Page, PageManager, PageQuerySet
from wagtail.search import index
from wagtail.snippets.models import register_snippet
from wagtail_headless_preview.models import HeadlessMixin

from associations.widgets import AssociationChooserWidget
from dnscms.fields import CommonStreamField
from dnscms.options import ALL_PIGS
from dnscms.wordpress.models import WPImportedPageMixin
from venues.models import VenuePage


@register_singular_query_field("eventIndex")
class EventIndex(HeadlessMixin, Page):
    max_count = 1
    subpage_types = ["events.EventPage"]

    def future_events(self, info, **kwargs):
        return (
            EventPage.objects.live()
            .future()
            .order_by("next_occurrence")
            .select_related("featured_image")
            .prefetch_related(
                Prefetch(
                    "occurrences",
                    queryset=EventOccurrence.objects.select_related("venue"),
                ),
                "categories",
                Prefetch(
                    "organizers",
                    queryset=EventOrganizer.objects.select_related("association"),
                ),
            )
        )

    graphql_fields = [
        GraphQLCollection(
            GraphQLForeignKey,
            "future_events",
            "events.EventPage",
            required=True,
            item_required=True,
            is_queryset=True,
        ),
    ]

    search_fields = []


@register_snippet
@register_query_field("eventCategory", "eventCategories")
class EventCategory(models.Model):
    name = models.CharField(
        max_length=100,
        null=False,
        blank=False,
    )
    slug = models.SlugField(
        verbose_name=_("slug"),
        max_length=255,
        help_text=_("The name of the category as it will appear in URLs."),
    )
    show_in_filters = models.BooleanField(
        default=False,
        help_text=_("Should this category be available as a filter in the event programme?"),
    )

    PIG_CHOICES = [
        ("", _("None")),
    ] + ALL_PIGS

    pig = models.CharField(
        max_length=32,
        choices=PIG_CHOICES,
        default="",
        blank=True,
        help_text=_("Default pig for events of this kind."),
    )

    panels = [
        TitleFieldPanel("name"),
        FieldPanel("slug"),
        FieldPanel("show_in_filters"),
        FieldPanel("pig", heading=_("Pig")),
    ]

    graphql_fields = [
        GraphQLString("name", required=True),
        GraphQLString("slug", required=True),
        GraphQLBoolean("show_in_filters", required=True),
        GraphQLString("pig", required=True),
    ]

    class Meta:
        verbose_name = _("event category")
        verbose_name_plural = _("event categories")
        ordering = ["name"]

    def __str__(self):
        return self.name


class EventOrganizerLink(Orderable):
    event = ParentalKey(
        "events.EventPage", on_delete=models.CASCADE, related_name="organizer_links"
    )
    organizer = models.ForeignKey(
        "events.EventOrganizer",
        on_delete=models.PROTECT,
        related_name="organized_events",
        help_text="",
    )

    panels = [FieldPanel("organizer", heading="", help_text="")]

    graphql_fields = [
        GraphQLForeignKey("organizer", "events.EventOrganizer"),
    ]

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

    class Meta:
        verbose_name = _("organizer")
        verbose_name_plural = _("organizers")
        constraints = [
            UniqueConstraint(
                "event", "organizer", name="event_organizer_link_event_organizer_unique"
            )
        ]


@register_snippet
@register_query_field("eventOrganizer", "eventOrganizers")
class EventOrganizer(ClusterableModel):
    name = models.CharField(
        max_length=100,
        null=False,
        blank=False,
    )
    slug = models.SlugField(
        verbose_name=_("slug"),
        max_length=255,
        help_text=_("The name of the organizer as it will appear in URLs."),
    )

    association = models.ForeignKey(
        "associations.AssociationPage",
        null=True,
        blank=True,
        on_delete=models.PROTECT,
        related_name="organizers",
        help_text=_("If a DNS association or committee is behind it, choose it here."),
    )

    external_url = models.URLField(
        blank=True,
        max_length=512,
        help_text=_("Link to the external organizer's website"),
    )

    panels = [
        TitleFieldPanel("name"),
        FieldPanel("slug"),
        FieldPanel(
            "association",
            widget=AssociationChooserWidget(linked_fields={"association": "#id_association"}),
            heading=_("Internal organizer"),
        ),
        MultiFieldPanel(
            heading=_("External organizer"),
            children=[
                FieldPanel(
                    "external_url",
                    heading=_("Website"),
                    help_text=_("Leave this empty if the organizer exists in the list above."),
                ),
            ],
        ),
    ]

    graphql_fields = [
        GraphQLString("name", required=True),
        GraphQLString("slug", required=True),
        GraphQLForeignKey("association", "associations.AssociationPage", required=False),
        GraphQLString("external_url"),
    ]

    class Meta:
        verbose_name = _("event organizer")
        verbose_name_plural = _("event organizers")
        ordering = ["name"]

    def __str__(self):
        return self.name


class EventPageQuerySet(PageQuerySet):
    def future(self):
        now = timezone.now()
        today_start = timezone.localtime(now).replace(hour=0, minute=0, second=0, microsecond=0)
        next_occurrence = Min("occurrences__start", filter=Q(occurrences__start__gte=today_start))
        return self.filter(occurrences__start__gte=today_start).annotate(
            next_occurrence=next_occurrence
        )


EventPageManager = PageManager.from_queryset(EventPageQuerySet)


class EventPage(HeadlessMixin, WPImportedPageMixin, Page):
    subpage_types = []
    parent_page_types = ["events.EventIndex"]
    show_in_menus = False

    objects = EventPageManager()

    featured_image = models.ForeignKey(
        "images.CustomImage",
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="+",
        help_text=_(
            "Choose an image for use in the programme and other surfaces. "
            "Should be a photo or an illustration without too much text "
            "– don't reuse a Facebook cover uncritically!"
        ),
    )

    subtitle = models.CharField(
        blank=True,
        max_length=128,
        help_text=_(
            "A short text that appears right below the title. "
            "Feel free to leave it empty if you fit most of it in the main title."
        ),
    )
    lead = RichTextField(features=["italic", "link"], blank=True)
    body = CommonStreamField

    categories = ParentalManyToManyField(
        "events.EventCategory",
        blank=True,
    )

    organizers = models.ManyToManyField(
        "events.EventOrganizer", through="events.EventOrganizerLink"
    )

    PIG_CHOICES = [
        ("", _("None")),
        ("automatic", _("Automatic")),
    ] + ALL_PIGS

    pig = models.CharField(
        max_length=32,
        choices=PIG_CHOICES,
        default="automatic",
        blank=True,
        help_text=_(
            "The pig that hangs out on the event page. "
            "Automatic causes one to be chosen based on the event's category."
        ),
    )

    ticket_url = models.URLField(
        blank=True,
        max_length=1024,
        help_text=_("Direct link to ticket purchase, e.g. TicketCo, Billetto or Ticketmaster"),
    )
    facebook_url = models.URLField(
        blank=True,
        max_length=1024,
        help_text=_("Direct link to the event on Facebook"),
    )

    free = models.BooleanField(null=False, default=False)
    price_regular = models.CharField(max_length=32, blank=True)
    price_student = models.CharField(max_length=32, blank=True)
    price_member = models.CharField(max_length=32, blank=True)

    ticket_panels = [
        FieldPanel("free", heading=_("Free"), help_text=_("Is this event free for everyone?")),
        MultiFieldPanel(
            children=[
                FieldRowPanel(
                    children=[
                        FieldPanel("price_regular", heading=_("Regular price")),
                        FieldPanel("price_student", heading=_("Price for students")),
                        FieldPanel("price_member", heading=_("Price for DNS members")),
                    ],
                    help_text="",
                ),
                HelpPanel(
                    content=mark_safe(
                        _(
                            "Write <strong>0</strong> for free. "
                            "An empty field hides the price category. "
                            "If possible, write digits only."
                        )
                    )
                ),
            ],
            attrs={"id": "specific_pricing_panel"},
        ),
        FieldPanel("ticket_url", heading=_("Ticket purchase link")),
    ]

    content_panels = Page.content_panels + [
        FieldPanel("subtitle", heading=_("Subtitle")),
        FieldPanel("featured_image"),
        FieldPanel("lead", heading=_("Lead")),
        FieldPanel("body"),
        FieldPanel("categories", widget=forms.CheckboxSelectMultiple),
        MultiFieldPanel(
            heading=_("Organizers"),
            children=[
                HelpPanel(
                    content=_("Who is behind the event?"),
                ),
                MultipleChooserPanel(
                    "organizer_links", chooser_field_name="organizer", label=_("Organizer")
                ),
            ],
        ),
        FieldPanel("pig", heading=_("Pig")),
        FieldPanel(
            "facebook_url",
            heading=_("Facebook link"),
            help_text=_("Direct link to the event on Facebook."),
        ),
        MultiFieldPanel(heading=_("Pricing and tickets"), children=ticket_panels),
        MultiFieldPanel(
            heading=_("Date, time and venue"),
            children=[
                HelpPanel(
                    content=_(
                        "If the event spans several days, add each day as a separate occurrence."
                    ),
                ),
                InlinePanel("occurrences", min_num=1, label=_("Occurrence")),
            ],
        ),
    ]

    graphql_fields = [
        GraphQLString("subtitle"),
        GraphQLImage("featured_image"),
        GraphQLRichText("lead"),
        GraphQLStreamfield("body"),
        GraphQLString("pig", required=True),
        GraphQLString("ticket_url"),
        GraphQLString("facebook_url"),
        GraphQLBoolean("free"),
        GraphQLString("price_regular"),
        GraphQLString("price_student"),
        GraphQLString("price_member"),
        GraphQLCollection(
            GraphQLForeignKey,
            "categories",
            "events.EventCategory",
            required=True,
            item_required=True,
        ),
        GraphQLCollection(
            GraphQLForeignKey,
            "occurrences",
            "events.EventOccurrence",
            required=True,
            item_required=True,
        ),
        GraphQLCollection(
            GraphQLForeignKey,
            "organizers",
            "events.EventOrganizer",
            required=True,
            item_required=True,
        ),
    ]

    search_fields = Page.search_fields + [index.SearchField("body")]

    class Meta:
        verbose_name = _("event")
        verbose_name_plural = _("events")

    def clean(self):
        super().clean()

        # remove duped organizers based on name
        organizers = [x.organizer.name for x in self.organizer_links.all()]
        if len(organizers) != len(set(organizers)):
            seen_organizers = set()
            for link in self.organizer_links.all():
                if link.organizer.name in seen_organizers:
                    self.organizer_links.remove(link)
                else:
                    seen_organizers.add(link.organizer.name)

        # if the event is free, all specific pricing is unset
        if self.free:
            self.price_regular = ""
            self.price_student = ""
            self.price_member = ""

    def import_wordpress_data(self, data):
        import datetime
        import html
        from zoneinfo import ZoneInfo

        from django.core.validators import URLValidator

        validate_url = URLValidator(schemes=["http", "https"])

        def fix_url(url):
            if not url:
                return None
            url = url.strip()
            try:
                validate_url(url)
            except Exception:
                print(f"Bogus URL for {self.wp_post_id}: {url}")
                return None
            return url

        # Wagtail page model fields
        self.title = html.unescape(data["title"])
        self.slug = data["slug"]
        self.first_published_at = data["first_published_at"]
        self.last_published_at = data["last_published_at"]
        self.latest_revision_created_at = data["latest_revision_created_at"]
        self.search_description = data["search_description"]

        # debug fields
        self.wp_post_id = data["wp_post_id"]
        self.wp_post_type = data["wp_post_type"]
        self.wp_link = data["wp_link"]
        self.wp_raw_content = data["wp_raw_content"]
        self.wp_block_json = data["wp_block_json"]
        self.wp_processed_content = data["wp_processed_content"]
        self.wp_normalized_styles = data["wp_normalized_styles"]
        self.wp_post_meta = data["wp_post_meta"]

        # own model fields
        self.body = data["body"] or ""

        # categories (organizers and event types)
        wp_categories = data["wp_categories"]

        # organizers
        organizer_cats = [x for x in wp_categories if x["domain"] == "event_organizer"]
        organizers = []
        for x in organizer_cats:
            try:
                organizer = EventOrganizer.objects.get(slug=x["nicename"])
            except EventOrganizer.DoesNotExist:
                organizer = EventOrganizer.objects.create(name=x["name"], slug=x["nicename"])
            organizers.append(organizer)

        self.organizer_links.set(
            [EventOrganizerLink(event=self, organizer=organizer) for organizer in organizers]
        )

        ## event types
        # type_cats = [x for x in wp_categories if x["domain"] == "event_type"]
        # event_categories = []
        # for x in type_cats:
        #     try:
        #         event_category = EventCategory.objects.get(slug=x["nicename"])
        #     except EventCategory.DoesNotExist:
        #         event_category = EventCategory.objects.create(
        #             name=x["name"], slug=x["nicename"], show_in_filters=False
        #         )
        #     event_categories.append(event_category)
        # self.categories.set(event_categories)

        meta = data["wp_post_meta"]

        start_ts = meta.get("neuf_events_starttime") or 1337
        end_ts = meta.get("neuf_events_endtime")
        tz = ZoneInfo("Europe/Oslo")
        start = start_ts and datetime.datetime.fromtimestamp(start_ts, datetime.UTC).replace(
            tzinfo=tz
        )
        end = end_ts and datetime.datetime.fromtimestamp(end_ts, datetime.UTC).replace(tzinfo=tz)
        venue_id = meta.get("neuf_events_venue_id")
        venue_custom = meta.get("neuf_events_venue")
        venue = None
        if venue_id:
            venue = VenuePage.objects.get(wp_post_id=venue_id)
            venue_custom = ""
        else:
            venue_custom = venue_custom or ""

        occurrence = EventOccurrence(
            event=self, start=start, end=end, venue=venue, venue_custom=venue_custom
        )
        self.occurrences.set([occurrence])

        self.ticket_url = fix_url(meta.get("neuf_events_bs_url")) or ""
        self.facebook_url = fix_url(meta.get("neuf_events_fb_url")) or ""

        def parse_price(price):
            if price is None:
                return ""
            if type(price) is int:
                return price
            p = price.strip()
            if p == "":
                return ""
            try:
                return int(p)
            except ValueError:
                pass
            free = ["gratis", "free", "gratis/free", "free/gratis"]
            if p.lower() in free:
                return 0
            return price

        price_regular = parse_price(meta.get("neuf_events_price_regular"))
        price_member = parse_price(meta.get("neuf_events_price_member"))
        if not price_regular and not price_member:
            self.free = True
        else:
            self.price_regular = parse_price(meta.get("neuf_events_price_regular"))
            self.price_member = parse_price(meta.get("neuf_events_price_member"))


class EventOccurrence(Orderable):
    event = ParentalKey(EventPage, on_delete=models.CASCADE, related_name="occurrences")
    start = models.DateTimeField()
    end = models.DateTimeField(null=True, blank=True)
    venue = models.ForeignKey(
        VenuePage,
        on_delete=models.PROTECT,
        related_name="event_occurrences",
        blank=True,
        null=True,
    )
    venue_custom = models.CharField(
        blank=True,
        max_length=128,
        help_text=mark_safe(
            _(
                "Use this <em>if none of the venues that can be selected on the left</em> fit. "
                "E.g. <em>Frederikkeplassen</em> or <em>Sirkusteltet</em>."
            )
        ),
    )

    panels = [
        FieldRowPanel(
            children=[
                FieldPanel("start", heading=_("Start")),
                FieldPanel("end", heading=_("End")),
            ],
        ),
        FieldRowPanel(
            children=[
                FieldPanel("venue", heading=_("Venue")),
                FieldPanel("venue_custom", heading=_("Venue as free text")),
            ],
        ),
    ]

    graphql_fields = [
        GraphQLString("start", required=True),
        GraphQLString("end"),
        GraphQLForeignKey("venue", "venues.VenuePage"),
        GraphQLString("venue_custom"),
    ]

    def clean(self):
        if self.venue and self.venue_custom:
            raise ValidationError(
                {
                    "venue_custom": _(
                        "You can't both pick a venue and write something in this field."
                    )
                }
            )
        if not self.venue and not self.venue_custom:
            raise ValidationError({"venue": _("Venue is required.")})

    def __str__(self):
        return f"{self.start}--{self.end}"

    class Meta:
        verbose_name = _("occurrence")
        verbose_name_plural = _("occurrences")