from decimal import Decimal

from django.conf import settings
from django.core.exceptions import ValidationError
from django.db import models
from django.utils import timezone
from django.utils.dateformat import format as date_format
from django.utils.translation import gettext_lazy as _
from django_hosts.resolvers import reverse
from djmoney.models.fields import MoneyField
from djmoney.settings import CURRENCIES
from docutils.core import publish_parts

from blog.models import BLOG_DOCUTILS_SETTINGS


class Office(models.Model):
    """
    An office held by a DSF Board member.

    """

    name = models.CharField(max_length=100, unique=True)

    def __str__(self):
        return self.name


class Term(models.Model):
    """
    A term in which DSF Board members served.

    """

    year = models.CharField(max_length=4, unique=True)

    def __str__(self):
        return self.year


class BoardMember(models.Model):
    """
    A DSF Board member.

    """

    account = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT)
    office = models.ForeignKey(Office, related_name="holders", on_delete=models.CASCADE)
    term = models.ForeignKey(
        Term, related_name="board_members", on_delete=models.CASCADE
    )

    def __str__(self):
        return f"{self.account.get_full_name()} ({self.office} - {self.term.year})"


class NonBoardAttendee(models.Model):
    """
    A non-Board member attending a Board meeting.

    """

    name = models.CharField(max_length=255)
    role = models.CharField(max_length=100)

    class Meta:
        verbose_name = _("Non-board attendee")
        verbose_name_plural = _("Non-board attendees")

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


class Meeting(models.Model):
    """
    A meeting of the DSF Board.

    """

    date = models.DateField()
    title = models.CharField(max_length=255)
    slug = models.SlugField()
    leader = models.ForeignKey(
        BoardMember, related_name="meetings_led", on_delete=models.CASCADE
    )
    board_attendees = models.ManyToManyField(
        BoardMember, related_name="meetings_attended"
    )
    non_board_attendees = models.ManyToManyField(
        NonBoardAttendee, related_name="meetings_attended", blank=True
    )
    treasurer_balance = MoneyField(
        max_digits=10,
        decimal_places=2,
        default_currency="USD",
        default=Decimal("0.0"),
    )
    treasurer_report = models.TextField(blank=True)
    treasurer_report_html = models.TextField(editable=False)

    def __str__(self):
        return "{}, {}".format(self.title, date_format(self.date, "F j, Y"))

    def save(self, *args, **kwargs):
        if self.treasurer_report:
            self.treasurer_report_html = publish_parts(
                source=self.treasurer_report,
                writer_name="html",
                settings_overrides=BLOG_DOCUTILS_SETTINGS,
            )["fragment"]
        super().save(*args, **kwargs)

    def get_absolute_url(self):
        return reverse(
            "foundation_meeting_detail",
            args=(),
            kwargs={
                "year": self.date.strftime("%Y"),
                "month": self.date.strftime("%b").lower(),
                "day": self.date.strftime("%d"),
                "slug": self.slug,
            },
        )


class ApprovedGrant(models.Model):
    """
    A grant approved by the DSF Board.

    """

    entity = models.CharField(max_length=255)
    amount = MoneyField(
        max_digits=10,
        decimal_places=2,
        default_currency="USD",
        default=Decimal("0.0"),
        currency_choices=[
            (c.code, c.name)
            for i, c in CURRENCIES.items()
            if c.code
            in {
                "USD",
                "EUR",
                "AUD",
                "NGN",
            }  # This set of currencies was extracted from current usage
        ],
    )
    approved_at = models.ForeignKey(
        Meeting, related_name="grants_approved", on_delete=models.CASCADE
    )

    class Meta:
        ordering = ("entity",)

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


class ApprovedIndividualMember(models.Model):
    """
    An individual DSF member approved by the Board.

    """

    name = models.CharField(max_length=255)
    approved_at = models.ForeignKey(
        Meeting, related_name="individual_members_approved", on_delete=models.CASCADE
    )

    def __str__(self):
        return self.name


class ApprovedCorporateMember(models.Model):
    """
    A corporate DSF member approved by the Board.

    """

    name = models.CharField(max_length=255)
    approved_at = models.ForeignKey(
        Meeting, related_name="corporate_members_approved", on_delete=models.CASCADE
    )

    def __str__(self):
        return self.name


class Banner(models.Model):
    """A site-wide campaign banner displayed in the billboard area.

    Only one banner can be active at a time; activating a banner automatically
    deactivates all others.

    Users with the view_banner permission can preview inactive banners on the
    live site.
    """

    title = models.CharField(max_length=512)
    body = models.TextField(
        blank=True,
        help_text=(
            "Optional banner body text. HTML is supported and will be rendered as given."
        ),
    )
    cta_label = models.CharField(
        "Call-to-action button label",
        max_length=100,
        blank=True,
        help_text=(
            "Label for the call-to-action button. Both label and URL must be provided "
            "for the button to appear."
        ),
    )
    cta_url = models.URLField(
        "Call-to-action button URL",
        blank=True,
        help_text=(
            "URL for the call-to-action button. Both label and URL must be provided "
            "for the button to appear."
        ),
    )
    is_active = models.BooleanField(
        default=False,
        help_text=(
            "Only one banner can be active at a time. Activating this banner will "
            "deactivate all others."
        ),
    )
    created_at = models.DateTimeField(default=timezone.now, editable=False)
    created_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        null=True,
        blank=True,
        editable=False,
        on_delete=models.SET_NULL,
        related_name="+",
    )
    updated_at = models.DateTimeField(auto_now=True)
    updated_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        null=True,
        blank=True,
        editable=False,
        on_delete=models.SET_NULL,
        related_name="+",
    )

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse("foundation_banner_preview", kwargs={"pk": self.pk})

    def clean(self):
        if bool(self.cta_label) != bool(self.cta_url):
            raise ValidationError(
                "Both a call-to-action label and URL must be provided, or neither."
            )

    def save(self, *args, **kwargs):
        if self.is_active:
            Banner.objects.exclude(pk=self.pk).update(is_active=False)
        super().save(*args, **kwargs)


class Business(models.Model):
    """
    Business of the DSF Board.

    """

    NEW = "new"
    ONGOING = "ongoing"

    TYPE_CHOICES = (
        (NEW, _("New")),
        (ONGOING, _("Ongoing")),
    )

    title = models.CharField(max_length=255)
    body = models.TextField()
    body_html = models.TextField(editable=False)
    business_type = models.CharField(max_length=25, choices=TYPE_CHOICES)
    meeting = models.ForeignKey(
        Meeting, related_name="business", on_delete=models.CASCADE
    )

    class Meta:
        ordering = ("title",)
        verbose_name_plural = _("Business")

    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        self.body_html = publish_parts(
            source=self.body,
            writer_name="html",
            settings_overrides=BLOG_DOCUTILS_SETTINGS,
        )["fragment"]
        super().save(*args, **kwargs)


class ActionItem(models.Model):
    """
    A task to be completed by an attendee of a DSF Board meeting.

    """

    responsible = models.CharField(max_length=255)
    task = models.TextField()
    meeting = models.ForeignKey(
        Meeting, related_name="action_items", on_delete=models.CASCADE
    )

    def __str__(self):
        return self.task


class CoreAwardCohort(models.Model):
    """
    A cohort of individuals -- such as "Q1 2021" -- receiving the Django Core
    Developer title.
    """

    name = models.CharField(
        max_length=255,
        unique=True,
        help_text=_("Name for the group being inducted, e.g. 'Q1 2021'"),
    )
    description = models.TextField(blank=True)
    cohort_date = models.DateField(
        help_text=_("Date this cohort was approved by the DSF Board"),
    )

    def __str__(self):
        return self.name


class CoreAward(models.Model):
    """An individual person awarded the Django Core Developer title."""

    cohort = models.ForeignKey(
        CoreAwardCohort,
        related_name="recipients",
        on_delete=models.CASCADE,
    )
    recipient = models.CharField(
        help_text=_("Recipient's name"), max_length=1023, unique=True
    )
    link = models.URLField(
        blank=True,
        null=True,
        help_text=_("Optional link for this recipient"),
    )
    description = models.TextField(
        blank=True,
        help_text=_(
            "Optional one-paragraph description/bio of why this person "
            "received the award"
        ),
    )

    class Meta:
        ordering = ["recipient"]

    def __str__(self):
        return self.recipient