import os
import random

from django.core.mail import send_mail
from django.db import models
from django.template.loader import render_to_string
from django.urls import reverse_lazy
from django.utils import timezone
from django.utils.translation import gettext_lazy as _


class Tournament(models.Model):
    """
    Store the information of a tournament.
    """

    name = models.CharField(
        max_length=255,
        verbose_name=_("name"),
    )

    organizers = models.ManyToManyField(
        'member.TFJMUser',
        related_name="organized_tournaments",
        verbose_name=_("organizers"),
        help_text=_("List of all organizers that can see and manipulate data of the tournament and the teams."),
    )

    size = models.PositiveSmallIntegerField(
        verbose_name=_("size"),
        help_text=_("Number of teams that are allowed to join the tournament."),
    )

    place = models.CharField(
        max_length=255,
        verbose_name=_("place"),
    )

    price = models.PositiveSmallIntegerField(
        verbose_name=_("price"),
        help_text=_("Price asked to participants. Free with a scholarship."),
    )

    description = models.TextField(
        verbose_name=_("description"),
    )

    date_start = models.DateField(
        default=timezone.now,
        verbose_name=_("date start"),
    )

    date_end = models.DateField(
        default=timezone.now,
        verbose_name=_("date end"),
    )

    date_inscription = models.DateTimeField(
        default=timezone.now,
        verbose_name=_("date of registration closing"),
    )

    date_solutions = models.DateTimeField(
        default=timezone.now,
        verbose_name=_("date of maximal solution submission"),
    )

    date_syntheses = models.DateTimeField(
        default=timezone.now,
        verbose_name=_("date of maximal syntheses submission for the first round"),
    )

    date_solutions_2 = models.DateTimeField(
        default=timezone.now,
        verbose_name=_("date when solutions of round 2 are available"),
    )

    date_syntheses_2 = models.DateTimeField(
        default=timezone.now,
        verbose_name=_("date of maximal syntheses submission for the second round"),
    )

    final = models.BooleanField(
        verbose_name=_("final tournament"),
        help_text=_("It should be only one final tournament."),
    )

    year = models.PositiveIntegerField(
        default=os.getenv("TFJM_YEAR", timezone.now().year),
        verbose_name=_("year"),
    )

    @property
    def teams(self):
        """
        Get all teams that are registered to this tournament, with a distinction for the final tournament.
        """
        return self._teams if not self.final else Team.objects.filter(selected_for_final=True)

    @property
    def linked_organizers(self):
        """
        Display a list of the organizers with links to their personal page.
        """
        return ['<a href="{url}">'.format(url=reverse_lazy("member:information", args=(user.pk,))) + str(user) + '</a>'
                for user in self.organizers.all()]

    @property
    def solutions(self):
        """
        Get all sent solutions for this tournament.
        """
        from member.models import Solution
        return Solution.objects.filter(final=self.final) if self.final \
            else Solution.objects.filter(team__tournament=self, final=False)

    @property
    def syntheses(self):
        """
        Get all sent syntheses for this tournament.
        """
        from member.models import Synthesis
        return Synthesis.objects.filter(final=self.final) if self.final \
            else Synthesis.objects.filter(team__tournament=self, final=False)

    @classmethod
    def get_final(cls):
        """
        Get the final tournament.
        This should exist and be unique.
        """
        return cls.objects.get(year=os.getenv("TFJM_YEAR"), final=True)

    class Meta:
        verbose_name = _("tournament")
        verbose_name_plural = _("tournaments")

    def send_mail_to_organizers(self, template_name, subject="Contact TFJM²", **kwargs):
        """
        Send a mail to all organizers of the tournament.
        The template of the mail should be found either in templates/mail_templates/<template_name>.html for the HTML
        version and in templates/mail_templates/<template_name>.txt for the plain text version.
        The context of the template contains the tournament and the user. Extra context can be given through the kwargs.
        """
        context = kwargs
        context["tournament"] = self
        for user in self.organizers.all():
            context["user"] = user
            message = render_to_string("mail_templates/" + template_name + ".txt", context=context)
            message_html = render_to_string("mail_templates/" + template_name + ".html", context=context)
            send_mail(subject, message, "contact@tfjm.org", [user.email], html_message=message_html)
        from member.models import TFJMUser
        for user in TFJMUser.objects.get(is_superuser=True).all():
            context["user"] = user
            message = render_to_string("mail_templates/" + template_name + ".txt", context=context)
            message_html = render_to_string("mail_templates/" + template_name + ".html", context=context)
            send_mail(subject, message, "contact@tfjm.org", [user.email], html_message=message_html)

    def __str__(self):
        return self.name


class Team(models.Model):
    """
    Store information about a registered team.
    """

    name = models.CharField(
        max_length=255,
        verbose_name=_("name"),
    )

    trigram = models.CharField(
        max_length=3,
        verbose_name=_("trigram"),
        help_text=_("The trigram should be composed of 3 capitalize letters, that is a funny acronym for the team."),
    )

    tournament = models.ForeignKey(
        Tournament,
        on_delete=models.PROTECT,
        related_name="_teams",
        verbose_name=_("tournament"),
        help_text=_("The tournament where the team is registered."),
    )

    inscription_date = models.DateTimeField(
        auto_now_add=True,
        verbose_name=_("inscription date"),
    )

    validation_status = models.CharField(
        max_length=8,
        choices=[
            ("0invalid", _("Registration not validated")),
            ("1waiting", _("Waiting for validation")),
            ("2valid", _("Registration validated")),
        ],
        verbose_name=_("validation status"),
    )

    selected_for_final = models.BooleanField(
        default=False,
        verbose_name=_("selected for final"),
    )

    access_code = models.CharField(
        max_length=6,
        unique=True,
        verbose_name=_("access code"),
    )

    year = models.PositiveIntegerField(
        default=os.getenv("TFJM_YEAR", timezone.now().year),
        verbose_name=_("year"),
    )

    @property
    def valid(self):
        return self.validation_status == "2valid"

    @property
    def waiting(self):
        return self.validation_status == "1waiting"

    @property
    def invalid(self):
        return self.validation_status == "0invalid"

    @property
    def coaches(self):
        """
        Get all coaches of a team.
        """
        return self.users.all().filter(role="2coach")

    @property
    def linked_coaches(self):
        """
        Get a list of the coaches of a team with html links to their pages.
        """
        return ['<a href="{url}">'.format(url=reverse_lazy("member:information", args=(user.pk,))) + str(user) + '</a>'
                for user in self.coaches]

    @property
    def participants(self):
        """
        Get all particpants of a team, coaches excluded.
        """
        return self.users.all().filter(role="3participant")

    @property
    def linked_participants(self):
        """
        Get a list of the participants of a team with html links to their pages.
        """
        return ['<a href="{url}">'.format(url=reverse_lazy("member:information", args=(user.pk,))) + str(user) + '</a>'
                for user in self.participants]

    @property
    def future_tournament(self):
        """
        Get the last tournament where the team is registered.
        Only matters if the team is selected for final: if this is the case, we return the final tournament.
        Useful for deadlines.
        """
        return Tournament.get_final() if self.selected_for_final else self.tournament

    @property
    def can_validate(self):
        """
        Check if a given team is able to ask for validation.
        A team can validate if:
        * All participants filled the photo consent
        * Minor participants filled the parental consent
        * Minor participants filled the sanitary plug
        * Teams sent their motivation letter
        * The team contains at least 4 participants
        * The team contains at least 1 coach
        """
        # TODO In a normal time, team needs a motivation letter and authorizations.
        return self.coaches.exists() and self.participants.count() >= 4\
            and self.tournament.date_inscription <= timezone.now()

    class Meta:
        verbose_name = _("team")
        verbose_name_plural = _("teams")
        unique_together = (('name', 'year',), ('trigram', 'year',),)

    def send_mail(self, template_name, subject="Contact TFJM²", **kwargs):
        """
        Send a mail to all members of a team with a given template.
        The template of the mail should be found either in templates/mail_templates/<template_name>.html for the HTML
        version and in templates/mail_templates/<template_name>.txt for the plain text version.
        The context of the template contains the team and the user. Extra context can be given through the kwargs.
        """
        context = kwargs
        context["team"] = self
        for user in self.users.all():
            context["user"] = user
            message = render_to_string("mail_templates/" + template_name + ".txt", context=context)
            message_html = render_to_string("mail_templates/" + template_name + ".html", context=context)
            send_mail(subject, message, "contact@tfjm.org", [user.email], html_message=message_html)

    def __str__(self):
        return self.trigram + " -- " + self.name


class Pool(models.Model):
    """
    Store information of a pool.
    A pool is only a list of accessible solutions to some teams and some juries.
    TODO: check that the set of teams is equal to the set of the teams that have a solution in this set.
    TODO: Moreover, a team should send only one solution.
    """
    teams = models.ManyToManyField(
        Team,
        related_name="pools",
        verbose_name=_("teams"),
    )

    solutions = models.ManyToManyField(
        "member.Solution",
        related_name="pools",
        verbose_name=_("solutions"),
    )

    round = models.PositiveIntegerField(
        choices=[
            (1, _("Round 1")),
            (2, _("Round 2")),
        ],
        verbose_name=_("round"),
    )

    juries = models.ManyToManyField(
        "member.TFJMUser",
        related_name="pools",
        verbose_name=_("juries"),
    )

    extra_access_token = models.CharField(
        max_length=64,
        default="",
        verbose_name=_("extra access token"),
        help_text=_("Let other users access to the pool data without logging in."),
    )

    @property
    def problems(self):
        """
        Get problem numbers of the sent solutions as a list of integers.
        """
        return list(d["problem"] for d in self.solutions.values("problem").all())

    @property
    def tournament(self):
        """
        Get the concerned tournament.
        We assume that the pool is correct, so all solutions belong to the same tournament.
        """
        return self.solutions.first().tournament

    @property
    def syntheses(self):
        """
        Get the syntheses of the teams that are in this pool, for the correct round.
        """
        from member.models import Synthesis
        return Synthesis.objects.filter(team__in=self.teams.all(), round=self.round, final=self.tournament.final)

    def save(self, **kwargs):
        if not self.extra_access_token:
            alphabet = "0123456789abcdefghijklmnopqrstuvwxyz0123456789"
            code = "".join(random.choice(alphabet) for _ in range(64))
            self.extra_access_token = code
        super().save(**kwargs)

    class Meta:
        verbose_name = _("pool")
        verbose_name_plural = _("pools")


class Payment(models.Model):
    """
    Store some information about payments, to recover data.
    TODO: handle it...
    """
    user = models.OneToOneField(
        'member.TFJMUser',
        on_delete=models.CASCADE,
        related_name="payment",
        verbose_name=_("user"),
    )

    team = models.ForeignKey(
        Team,
        on_delete=models.CASCADE,
        related_name="payments",
        verbose_name=_("team"),
    )

    method = models.CharField(
        max_length=16,
        choices=[
            ("not_paid", _("Not paid")),
            ("credit_card", _("Credit card")),
            ("check", _("Bank check")),
            ("transfer", _("Bank transfer")),
            ("cash", _("Cash")),
            ("scholarship", _("Scholarship")),
        ],
        default="not_paid",
        verbose_name=_("payment method"),
    )

    validation_status = models.CharField(
        max_length=8,
        choices=[
            ("0invalid", _("Registration not validated")),
            ("1waiting", _("Waiting for validation")),
            ("2valid", _("Registration validated")),
        ],
        verbose_name=_("validation status"),
    )

    class Meta:
        verbose_name = _("payment")
        verbose_name_plural = _("payments")

    def __str__(self):
        return _("Payment of {user}").format(str(self.user))