import datetime

from django.core.exceptions import ObjectDoesNotExist
from django.contrib.auth import get_user_model
from django.db import models
from django.utils.translation import ugettext_lazy as _

from symposion.managers import DefaultSelectRelatedManager
from symposion.text_parser import parse
from symposion.proposals.models import ProposalBase
from symposion.conference.models import Section
from symposion.speakers.models import Speaker

User = get_user_model()


class Schedule(models.Model):
    objects = DefaultSelectRelatedManager()

    section = models.OneToOneField(
        Section,
        verbose_name=_("Section"),
        on_delete=models.CASCADE,
    )
    published = models.BooleanField(default=True, verbose_name=_("Published"))
    hidden = models.BooleanField(_("Hide schedule from overall conference view"), default=False)

    def __str__(self):
        return "%s Schedule" % self.section

    class SymposionMeta:
        select_related = ('section', )

    class Meta:
        ordering = ["section"]
        verbose_name = _('Schedule')
        verbose_name_plural = _('Schedules')


class Day(models.Model):
    objects = DefaultSelectRelatedManager()


    schedule = models.ForeignKey(
        Schedule,
        verbose_name=_("Schedule"),
        on_delete=models.CASCADE,
    )
    date = models.DateField(verbose_name=_("Date"))

    def __str__(self):
        return "%s: %s" % (self.schedule.section.name, self.date)

    class SymposionMeta:
        select_related = ('schedule__section', )

    class Meta:
        unique_together = [("schedule", "date")]
        ordering = ["date"]
        verbose_name = _("date")
        verbose_name_plural = _("dates")


class Room(models.Model):

    schedule = models.ForeignKey(
        Schedule,
        verbose_name=_("Schedule"),
        on_delete=models.CASCADE,
    )
    name = models.CharField(max_length=65, verbose_name=_("Name"))
    order = models.PositiveIntegerField(verbose_name=_("Order"))

    def __unicode__(self):
        return self.name

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = _("Room")
        verbose_name_plural = _("Rooms")


class Track(models.Model):
    name = models.CharField(max_length=80, verbose_name=_("Track"))
    room = models.ForeignKey(Room, on_delete=models.CASCADE)
    day = models.ForeignKey(Day, on_delete=models.CASCADE)

    def __str__(self):
        return self.name

    class Meta:
        unique_together = [('room', 'day')]
        verbose_name = _("Track")
        verbose_name_plural = _("Tracks")


class SlotKind(models.Model):
    """
    A slot kind represents what kind a slot is. For example, a slot can be a
    break, lunch, or X-minute talk.
    """

    schedule = models.ForeignKey(
        Schedule,
        verbose_name=_("schedule"),
        on_delete=models.CASCADE,
    )
    label = models.CharField(max_length=50, verbose_name=_("Label"))

    def __str__(self):
        return ": ".join((self.schedule.section.name, self.label))

    class Meta:
        verbose_name = _("Slot kind")
        verbose_name_plural = _("Slot kinds")


class Slot(models.Model):
    objects = DefaultSelectRelatedManager()

    name = models.CharField(max_length=512, editable=False)
    day = models.ForeignKey(
        Day,
        verbose_name=_("Day"),
        on_delete=models.CASCADE,
    )
    kind = models.ForeignKey(
        SlotKind,
        verbose_name=_("Kind"),
        on_delete=models.CASCADE,
    )
    start = models.TimeField(verbose_name=_("Start"))
    end = models.TimeField(verbose_name=_("End"))
    exclusive = models.BooleanField(
        default=False,
        help_text=_("Set to true if this is the only event during this "
                    "timeslot"),
    )
    content_override = models.TextField(blank=True, verbose_name=_("Content override"))
    content_override_html = models.TextField(blank=True)

    def assign(self, content):
        """
        Assign the given content to this slot and if a previous slot content
        was given we need to unlink it to avoid integrity errors.
        """
        self.unassign()
        content.slot = self
        content.save()

    def unassign(self):
        """
        Unassign the associated content with this slot.
        """
        content = self.content
        if content and content.slot_id:
            content.slot = None
            content.save()

    @property
    def content(self):
        """
        Return the content this slot represents.
        @@@ hard-coded for presentation for now
        """
        try:
            return self.content_ptr
        except ObjectDoesNotExist:
            return None

    @property
    def start_datetime(self):
        return datetime.datetime(
            self.day.date.year,
            self.day.date.month,
            self.day.date.day,
            self.start.hour,
            self.start.minute)

    @property
    def end_datetime(self):
        return datetime.datetime(
            self.day.date.year,
            self.day.date.month,
            self.day.date.day,
            self.end.hour,
            self.end.minute)

    @property
    def length_in_minutes(self):
        return int(
            (self.end_datetime - self.start_datetime).total_seconds() / 60)

    @property
    def rooms(self):
        return Room.objects.filter(pk__in=self.slotroom_set.values("room"))

    def save(self, *args, **kwargs):
        roomlist = ' '.join(map(str, self.rooms))
        self.name = "%s %s (%s - %s) %s" % (self.day.date, self.kind.label, self.start, self.end, roomlist)
        self.content_override_html = parse(self.content_override)
        super(Slot, self).save(*args, **kwargs)

    def __str__(self):
        return "%s: %s" % (self.day.schedule.section.name, self.name)

    class SymposionMeta:
        select_related = ('kind__schedule__section', 'day')

    class Meta:
        ordering = ["day__schedule__section__name", "day", "start" ]
        verbose_name = _("slot")
        verbose_name_plural = _("slots")


class SlotRoom(models.Model):
    """
    Links a slot with a room.
    """

    slot = models.ForeignKey(
        Slot,
        verbose_name=_("Slot"),
        on_delete=models.CASCADE,
    )
    room = models.ForeignKey(
        Room,
        verbose_name=_("Room"),
        on_delete=models.CASCADE,
    )

    def __str__(self):
        return "%s %s" % (self.room, self.slot)

    class Meta:
        unique_together = [("slot", "room")]
        ordering = ["slot", "room__order"]
        verbose_name = _("Slot room")
        verbose_name_plural = _("Slot rooms")


class Presentation(models.Model):
    objects = DefaultSelectRelatedManager()

    slot = models.OneToOneField(
        Slot,
        null=True,
        blank=True,
        related_name="content_ptr",
        verbose_name=_("Slot"),
        on_delete=models.CASCADE,
    )
    title = models.CharField(max_length=100, verbose_name=_("Title"))
    abstract = models.TextField(verbose_name=_("Abstract"))
    abstract_html = models.TextField(blank=True)
    speaker = models.ForeignKey(
        Speaker,
        related_name="presentations",
        verbose_name=_("Speaker"),
        on_delete=models.CASCADE,
    )
    additional_speakers = models.ManyToManyField(Speaker, related_name="copresentations",
                                                 blank=True, verbose_name=_("Additional speakers"))
    unpublish = models.BooleanField(
        default=False,
        verbose_name=_("Do not publish"),
    )
    cancelled = models.BooleanField(default=False, verbose_name=_("Cancelled"))
    proposal_base = models.OneToOneField(
        ProposalBase,
        related_name="presentation",
        verbose_name=_("Proposal base"),
        on_delete=models.CASCADE,
    )
    section = models.ForeignKey(
        Section,
        related_name="presentations",
        verbose_name=_("Section"),
        on_delete=models.CASCADE,
    )

    def save(self, *args, **kwargs):
        self.abstract_html = parse(self.abstract)
        return super(Presentation, self).save(*args, **kwargs)

    @property
    def number(self):
        return self.proposal.number

    @property
    def proposal(self):
        if self.proposal_base_id is None:
            return None
        return ProposalBase.objects.get_subclass(pk=self.proposal_base_id)

    def speakers(self):
        yield self.speaker
        for speaker in self.additional_speakers.all():
            if speaker.user:
                yield speaker

    def __str__(self):
        return "#%s %s (%s)" % (self.number, self.title, self.speaker)

    class Meta:
        ordering = ["slot"]
        verbose_name = _("presentation")
        verbose_name_plural = _("presentations")


class Session(models.Model):

    day = models.ForeignKey(
        Day,
        related_name="sessions",
        verbose_name=_("Day"),
        on_delete=models.CASCADE,
    )
    slots = models.ManyToManyField(Slot, related_name="sessions", verbose_name=_("Slots"))

    def sorted_slots(self):
        return self.slots.order_by("start")

    def start(self):
        slots = self.sorted_slots()
        if slots:
            return list(slots)[0].start
        else:
            return None

    def end(self):
        slots = self.sorted_slots()
        if slots:
            return list(slots)[-1].end
        else:
            return None

    def chair(self):
        for role in self.sessionrole_set.all():
            if role.role == SessionRole.SESSION_ROLE_CHAIR:
                return role
        return None

    @property
    def rooms(self):
        return Room.objects.filter(slotroom__slot__in=self.slots.all()).distinct()

    @property
    def room_names(self):
        return ', '.join(room.name for room in self.rooms)

    def __str__(self):
        start = self.start()
        end = self.end()
        rooms = ', '.join(room.name for room in self.rooms)
        if start and end:
            return "%s: %s - %s in %s" % (
                self.day.date.strftime("%a"),
                start.strftime("%X"),
                end.strftime("%X"),
                rooms
            )
        return ""

    class Meta:
        verbose_name = _("Session")
        verbose_name_plural = _("Sessions")


class SessionRole(models.Model):

    SESSION_ROLE_CHAIR = 1
    SESSION_ROLE_RUNNER = 2

    SESSION_ROLE_TYPES = [
        (SESSION_ROLE_CHAIR, _("Session Chair")),
        (SESSION_ROLE_RUNNER, _("Session Runner")),
    ]

    session = models.ForeignKey(
        Session,
        verbose_name=_("Session"),
        on_delete=models.CASCADE,
    )
    user = models.ForeignKey(
        User,
        verbose_name=_("User"),
        on_delete=models.CASCADE,
    )
    role = models.IntegerField(choices=SESSION_ROLE_TYPES, verbose_name=_("Role"))
    status = models.NullBooleanField(verbose_name=_("Status"))

    submitted = models.DateTimeField(default=datetime.datetime.now)

    class Meta:
        unique_together = [("session", "user", "role")]
        verbose_name = _("Session role")
        verbose_name_plural = _("Session roles")

    def __str__(self):
        return "%s %s: %s" % (self.user, self.session,
                              self.SESSION_ROLE_TYPES[self.role - 1][1])