# -*- coding: utf-8 -*-
import re
from datetime import timedelta

from django.core.cache import cache
from django.core.exceptions import ValidationError
from django.core.validators import RegexValidator
from django.db import models
from django.utils import timezone
from django.utils.text import format_lazy, slugify
from django.utils.translation import gettext_lazy as _
from taggit.managers import TaggableManager as TaggitTaggableManager
from taggit.models import GenericTaggedItemBase, TagBase

from babybuddy.site_settings import NapSettings
from core.utils import random_color


def validate_date(date, field_name):
    """
    Confirm that a date is not in the future.
    :param date: a timezone aware date instance.
    :param field_name: the name of the field being checked.
    :return:
    """
    if date and date > timezone.localdate():
        raise ValidationError(
            {field_name: _("Date can not be in the future.")}, code="date_invalid"
        )


def validate_duration(model, max_duration=timedelta(hours=24)):
    """
    Basic sanity checks for models with a duration
    :param model: a model instance with 'start' and 'end' attributes
    :param max_duration: maximum allowed duration between start and end time
    :return:
    """
    if model.start and model.end:
        if model.start > model.end:
            raise ValidationError(
                _("Start time must come before end time."), code="end_before_start"
            )
        if model.end - model.start > max_duration:
            raise ValidationError(_("Duration too long."), code="max_duration")


def validate_unique_period(queryset, model):
    """
    Confirm that model's start and end date do not intersect with other
    instances.
    :param queryset: a queryset of instances to check against.
    :param model: a model instance with 'start' and 'end' attributes
    :return:
    """
    if model.id:
        queryset = queryset.exclude(id=model.id)
    if model.start and model.end:
        if queryset.filter(start__lt=model.end, end__gt=model.start):
            raise ValidationError(
                _("Another entry intersects the specified time period."),
                code="period_intersection",
            )


def validate_time(time, field_name):
    """
    Confirm that a time is not in the future.
    :param time: a timezone aware datetime instance.
    :param field_name: the name of the field being checked.
    :return:
    """
    if time and time > timezone.localtime():
        raise ValidationError(
            {field_name: _("Date/time can not be in the future.")}, code="time_invalid"
        )


class Tag(TagBase):
    DARK_COLOR = "#101010"
    LIGHT_COLOR = "#EFEFEF"

    color = models.CharField(
        verbose_name=_("Color"),
        max_length=32,
        default=random_color,
        validators=[RegexValidator(r"^#[0-9a-fA-F]{6}$")],
    )
    last_used = models.DateTimeField(
        verbose_name=_("Last used"),
        default=timezone.now,
        blank=False,
    )

    class Meta:
        verbose_name = _("Tag")
        verbose_name_plural = _("Tags")

    @property
    def complementary_color(self):
        if not self.color:
            return self.DARK_COLOR

        r, g, b = [int(x, 16) for x in re.match("#(..)(..)(..)", self.color).groups()]
        yiq = ((r * 299) + (g * 587) + (b * 114)) // 1000
        if yiq >= 128:
            return self.DARK_COLOR
        else:
            return self.LIGHT_COLOR


class Tagged(GenericTaggedItemBase):
    tag = models.ForeignKey(
        Tag,
        verbose_name=_("Tag"),
        on_delete=models.CASCADE,
        related_name="%(app_label)s_%(class)s_items",
    )

    def save_base(self, *args, **kwargs):
        """
        Update last_used of the used tag, whenever it is used in a
        save-operation.
        """
        self.tag.last_used = timezone.now()
        self.tag.save()
        return super().save_base(*args, **kwargs)


class TaggableManager(TaggitTaggableManager):
    pass


class BMI(models.Model):
    model_name = "bmi"
    child = models.ForeignKey(
        "Child", on_delete=models.CASCADE, related_name="bmi", verbose_name=_("Child")
    )
    bmi = models.FloatField(blank=False, null=False, verbose_name=_("BMI"))
    date = models.DateField(
        blank=False, default=timezone.localdate, null=False, verbose_name=_("Date")
    )
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-date"]
        verbose_name = _("BMI")
        verbose_name_plural = _("BMI")

    def __str__(self):
        return str(_("BMI"))

    def clean(self):
        validate_date(self.date, "date")


class Child(models.Model):
    model_name = "child"
    first_name = models.CharField(max_length=255, verbose_name=_("First name"))
    last_name = models.CharField(
        blank=True, max_length=255, verbose_name=_("Last name")
    )
    birth_date = models.DateField(blank=False, null=False, verbose_name=_("Birth date"))
    slug = models.SlugField(
        allow_unicode=True,
        blank=False,
        editable=False,
        max_length=100,
        unique=True,
        verbose_name=_("Slug"),
    )
    picture = models.ImageField(
        blank=True, null=True, upload_to="child/picture/", verbose_name=_("Picture")
    )

    objects = models.Manager()

    cache_key_count = "core.child.count"

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["last_name", "first_name"]
        verbose_name = _("Child")
        verbose_name_plural = _("Children")

    def __str__(self):
        return self.name()

    def save(self, *args, **kwargs):
        self.slug = slugify(self, allow_unicode=True)
        super(Child, self).save(*args, **kwargs)
        cache.set(self.cache_key_count, Child.objects.count(), None)

    def delete(self, using=None, keep_parents=False):
        super(Child, self).delete(using, keep_parents)
        cache.set(self.cache_key_count, Child.objects.count(), None)

    def name(self, reverse=False):
        if not self.last_name:
            return self.first_name
        if reverse:
            return "{}, {}".format(self.last_name, self.first_name)
        return "{} {}".format(self.first_name, self.last_name)

    @classmethod
    def count(cls):
        """Get a (cached) count of total number of Child instances."""
        return cache.get_or_set(cls.cache_key_count, Child.objects.count, None)


class DiaperChange(models.Model):
    model_name = "diaperchange"
    child = models.ForeignKey(
        "Child",
        on_delete=models.CASCADE,
        related_name="diaper_change",
        verbose_name=_("Child"),
    )
    time = models.DateTimeField(
        blank=False, default=timezone.localtime, null=False, verbose_name=_("Time")
    )
    wet = models.BooleanField(verbose_name=_("Wet"))
    solid = models.BooleanField(verbose_name=_("Solid"))
    color = models.CharField(
        blank=True,
        choices=[
            ("black", _("Black")),
            ("brown", _("Brown")),
            ("green", _("Green")),
            ("yellow", _("Yellow")),
        ],
        max_length=255,
        verbose_name=_("Color"),
    )
    amount = models.FloatField(blank=True, null=True, verbose_name=_("Amount"))
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-time"]
        verbose_name = _("Diaper Change")
        verbose_name_plural = _("Diaper Changes")

    def __str__(self):
        return str(_("Diaper Change"))

    def attributes(self):
        attributes = []
        if self.wet:
            attributes.append(self._meta.get_field("wet").verbose_name)
        if self.solid:
            attributes.append(self._meta.get_field("solid").verbose_name)
        if self.color:
            attributes.append(self.get_color_display())
        return attributes

    def clean(self):
        validate_time(self.time, "time")


class Feeding(models.Model):
    model_name = "feeding"
    child = models.ForeignKey(
        "Child",
        on_delete=models.CASCADE,
        related_name="feeding",
        verbose_name=_("Child"),
    )
    start = models.DateTimeField(
        blank=False,
        default=timezone.localtime,
        null=False,
        verbose_name=_("Start time"),
    )
    end = models.DateTimeField(
        blank=False, default=timezone.localtime, null=False, verbose_name=_("End time")
    )
    duration = models.DurationField(
        editable=False, null=True, verbose_name=_("Duration")
    )
    type = models.CharField(
        choices=[
            ("breast milk", _("Breast milk")),
            ("formula", _("Formula")),
            ("fortified breast milk", _("Fortified breast milk")),
            ("solid food", _("Solid food")),
        ],
        max_length=255,
        verbose_name=_("Type"),
    )
    method = models.CharField(
        choices=[
            ("bottle", _("Bottle")),
            ("left breast", _("Left breast")),
            ("right breast", _("Right breast")),
            ("both breasts", _("Both breasts")),
            ("parent fed", _("Parent fed")),
            ("self fed", _("Self fed")),
        ],
        max_length=255,
        verbose_name=_("Method"),
    )
    amount = models.FloatField(blank=True, null=True, verbose_name=_("Amount"))
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-start"]
        verbose_name = _("Feeding")
        verbose_name_plural = _("Feedings")

    def __str__(self):
        return str(_("Feeding"))

    def save(self, *args, **kwargs):
        if self.start and self.end:
            self.duration = self.end - self.start
        super(Feeding, self).save(*args, **kwargs)

    def clean(self):
        validate_time(self.start, "start")
        validate_duration(self)
        validate_unique_period(Feeding.objects.filter(child=self.child), self)


class HeadCircumference(models.Model):
    model_name = "head_circumference"
    child = models.ForeignKey(
        "Child",
        on_delete=models.CASCADE,
        related_name="head_circumference",
        verbose_name=_("Child"),
    )
    head_circumference = models.FloatField(
        blank=False, null=False, verbose_name=_("Head Circumference")
    )
    date = models.DateField(
        blank=False, default=timezone.localdate, null=False, verbose_name=_("Date")
    )
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-date"]
        verbose_name = _("Head Circumference")
        verbose_name_plural = _("Head Circumference")

    def __str__(self):
        return str(_("Head Circumference"))

    def clean(self):
        validate_date(self.date, "date")


class Height(models.Model):
    model_name = "height"
    child = models.ForeignKey(
        "Child",
        on_delete=models.CASCADE,
        related_name="height",
        verbose_name=_("Child"),
    )
    height = models.FloatField(blank=False, null=False, verbose_name=_("Height"))
    date = models.DateField(
        blank=False, default=timezone.localdate, null=False, verbose_name=_("Date")
    )
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-date"]
        verbose_name = _("Height")
        verbose_name_plural = _("Height")

    def __str__(self):
        return str(_("Height"))

    def clean(self):
        validate_date(self.date, "date")


class Note(models.Model):
    model_name = "note"
    child = models.ForeignKey(
        "Child", on_delete=models.CASCADE, related_name="note", verbose_name=_("Child")
    )
    note = models.TextField(verbose_name=_("Note"))
    time = models.DateTimeField(
        blank=False, default=timezone.localtime, verbose_name=_("Time")
    )
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-time"]
        verbose_name = _("Note")
        verbose_name_plural = _("Notes")

    def __str__(self):
        return str(_("Note"))


class Pumping(models.Model):
    model_name = "pumping"
    child = models.ForeignKey(
        "Child",
        on_delete=models.CASCADE,
        related_name="pumping",
        verbose_name=_("Child"),
    )
    amount = models.FloatField(blank=False, null=False, verbose_name=_("Amount"))
    time = models.DateTimeField(
        blank=False, default=timezone.localtime, null=False, verbose_name=_("Time")
    )
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-time"]
        verbose_name = _("Pumping")
        verbose_name_plural = _("Pumping")

    def __str__(self):
        return str(_("Pumping"))

    def clean(self):
        validate_time(self.time, "time")


class Sleep(models.Model):
    model_name = "sleep"
    child = models.ForeignKey(
        "Child", on_delete=models.CASCADE, related_name="sleep", verbose_name=_("Child")
    )
    start = models.DateTimeField(
        blank=False,
        default=timezone.localtime,
        null=False,
        verbose_name=_("Start time"),
    )
    end = models.DateTimeField(
        blank=False, default=timezone.localtime, null=False, verbose_name=_("End time")
    )
    nap = models.BooleanField(null=False, blank=True, verbose_name=_("Nap"))
    duration = models.DurationField(
        editable=False, null=True, verbose_name=_("Duration")
    )
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()
    settings = NapSettings(_("Nap settings"))

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-start"]
        verbose_name = _("Sleep")
        verbose_name_plural = _("Sleep")

    def __str__(self):
        return str(_("Sleep"))

    def save(self, *args, **kwargs):
        if self.nap is None:
            self.nap = (
                Sleep.settings.nap_start_min
                <= timezone.localtime(self.start).time()
                <= Sleep.settings.nap_start_max
            )
        if self.start and self.end:
            self.duration = self.end - self.start
        super(Sleep, self).save(*args, **kwargs)

    def clean(self):
        validate_time(self.start, "start")
        validate_time(self.end, "end")
        validate_duration(self)
        validate_unique_period(Sleep.objects.filter(child=self.child), self)


class Temperature(models.Model):
    model_name = "temperature"
    child = models.ForeignKey(
        "Child",
        on_delete=models.CASCADE,
        related_name="temperature",
        verbose_name=_("Child"),
    )
    temperature = models.FloatField(
        blank=False, null=False, verbose_name=_("Temperature")
    )
    time = models.DateTimeField(
        blank=False, default=timezone.localtime, null=False, verbose_name=_("Time")
    )
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-time"]
        verbose_name = _("Temperature")
        verbose_name_plural = _("Temperature")

    def __str__(self):
        return str(_("Temperature"))

    def clean(self):
        validate_time(self.time, "time")


class Timer(models.Model):
    model_name = "timer"
    child = models.ForeignKey(
        "Child",
        blank=True,
        null=True,
        on_delete=models.CASCADE,
        related_name="timers",
        verbose_name=_("Child"),
    )
    name = models.CharField(
        blank=True, max_length=255, null=True, verbose_name=_("Name")
    )
    start = models.DateTimeField(
        default=timezone.now, blank=False, verbose_name=_("Start time")
    )
    active = models.BooleanField(default=True, editable=False, verbose_name=_("Active"))
    user = models.ForeignKey(
        "auth.User",
        on_delete=models.CASCADE,
        related_name="timers",
        verbose_name=_("User"),
    )

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-start"]
        verbose_name = _("Timer")
        verbose_name_plural = _("Timers")

    def __str__(self):
        return self.name or str(format_lazy(_("Timer #{id}"), id=self.id))

    @property
    def title_with_child(self):
        """Get Timer title with child name in parenthesis."""
        title = str(self)
        # Only actually add the name if there is more than one Child instance.
        if title and self.child and Child.count() > 1:
            title = format_lazy("{title} ({child})", title=title, child=self.child)
        return title

    @property
    def user_username(self):
        """Get Timer user's name with a preference for the full name."""
        if self.user.get_full_name():
            return self.user.get_full_name()
        return self.user.get_username()

    def duration(self):
        return timezone.now() - self.start

    def restart(self):
        """Restart the timer."""
        self.start = timezone.now()
        self.save()

    def stop(self):
        """Stop (delete) the timer."""
        self.delete()

    def save(self, *args, **kwargs):
        self.name = self.name or None
        super(Timer, self).save(*args, **kwargs)

    def clean(self):
        validate_time(self.start, "start")


class TummyTime(models.Model):
    model_name = "tummytime"
    child = models.ForeignKey(
        "Child",
        on_delete=models.CASCADE,
        related_name="tummy_time",
        verbose_name=_("Child"),
    )
    start = models.DateTimeField(
        blank=False,
        default=timezone.localtime,
        null=False,
        verbose_name=_("Start time"),
    )
    end = models.DateTimeField(
        blank=False, default=timezone.localtime, null=False, verbose_name=_("End time")
    )
    duration = models.DurationField(
        editable=False, null=True, verbose_name=_("Duration")
    )
    milestone = models.CharField(
        blank=True, max_length=255, verbose_name=_("Milestone")
    )
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-start"]
        verbose_name = _("Tummy Time")
        verbose_name_plural = _("Tummy Time")

    def __str__(self):
        return str(_("Tummy Time"))

    def save(self, *args, **kwargs):
        if self.start and self.end:
            self.duration = self.end - self.start
        super(TummyTime, self).save(*args, **kwargs)

    def clean(self):
        validate_time(self.start, "start")
        validate_time(self.end, "end")
        validate_duration(self)
        validate_unique_period(TummyTime.objects.filter(child=self.child), self)


class Weight(models.Model):
    model_name = "weight"
    child = models.ForeignKey(
        "Child",
        on_delete=models.CASCADE,
        related_name="weight",
        verbose_name=_("Child"),
    )
    weight = models.FloatField(blank=False, null=False, verbose_name=_("Weight"))
    date = models.DateField(
        blank=False, default=timezone.localdate, null=False, verbose_name=_("Date")
    )
    notes = models.TextField(blank=True, null=True, verbose_name=_("Notes"))
    tags = TaggableManager(blank=True, through=Tagged)

    objects = models.Manager()

    class Meta:
        default_permissions = ("view", "add", "change", "delete")
        ordering = ["-date"]
        verbose_name = _("Weight")
        verbose_name_plural = _("Weight")

    def __str__(self):
        return str(_("Weight"))

    def clean(self):
        validate_date(self.date, "date")