# Copyright (C) 2020 by Animath
# SPDX-License-Identifier: GPL-3.0-or-later

import os

from address.models import AddressField
from django.conf import settings
from django.core.validators import RegexValidator
from django.db import models
from django.db.models import Index
from django.urls import reverse_lazy
from django.utils import timezone
from django.utils.crypto import get_random_string
from django.utils.text import format_lazy
from django.utils.translation import gettext_lazy as _
from registration.models import VolunteerRegistration
from tfjm.lists import get_sympa_client
from tfjm.matrix import Matrix, RoomPreset, RoomVisibility


class Team(models.Model):
    """
    The Team model represents a real team that participates to the Correspondances.
    This only includes the registration detail.
    """
    name = models.CharField(
        max_length=255,
        verbose_name=_("name"),
        unique=True,
    )

    trigram = models.CharField(
        max_length=3,
        verbose_name=_("trigram"),
        help_text=_("The trigram must be composed of three uppercase letters."),
        unique=True,
        validators=[RegexValidator("[A-Z]{3}")],
    )

    access_code = models.CharField(
        max_length=6,
        verbose_name=_("access code"),
        help_text=_("The access code let other people to join the team."),
    )

    @property
    def students(self):
        return self.participants.filter(studentregistration__isnull=False)

    @property
    def coachs(self):
        return self.participants.filter(coachregistration__isnull=False)

    @property
    def email(self):
        """
        :return: The mailing list to contact the team members.
        """
        return f"equipe-{self.trigram.lower()}@{os.getenv('SYMPA_HOST', 'localhost')}"

    def create_mailing_list(self):
        """
        Create a new Sympa mailing list to contact the team.
        """
        get_sympa_client().create_list(
            f"equipe-{self.trigram.lower()}",
            f"Équipe {self.name} ({self.trigram})",
            "hotline",  # TODO Use a custom sympa template
            f"Liste de diffusion pour contacter l'équipe {self.name} du TFJM²",
            "education",
            raise_error=False,
        )
        if self.pk and self.participation.valid:  # pragma: no cover
            get_sympa_client().subscribe(self.email, "equipes", False, f"Equipe {self.name}")
            get_sympa_client().subscribe(self.email, f"probleme-{self.participation.problem}", False,
                                         f"Equipe {self.name}")
        else:
            get_sympa_client().subscribe(self.email, "equipes-non-valides", False)

    def delete_mailing_list(self):
        """
        Drop the Sympa mailing list, if the team is empty or if the trigram changed.
        """
        if self.participation.valid:  # pragma: no cover
            get_sympa_client().unsubscribe(self.email, "equipes", False)
            get_sympa_client().unsubscribe(self.email, f"probleme-{self.participation.problem}", False)
        else:
            get_sympa_client().unsubscribe(self.email, "equipes-non-valides", False)
        get_sympa_client().delete_list(f"equipe-{self.trigram}")

    def save(self, *args, **kwargs):
        if not self.access_code:
            # if the team got created, generate the access code, create the contact mailing list
            # and create a dedicated Matrix room.
            self.access_code = get_random_string(6)
            self.create_mailing_list()

            Matrix.create_room(
                visibility=RoomVisibility.private,
                name=f"#équipe-{self.trigram.lower()}",
                alias=f"equipe-{self.trigram.lower()}",
                topic=f"Discussion de l'équipe {self.name}",
                preset=RoomPreset.private_chat,
            )

        return super().save(*args, **kwargs)

    def get_absolute_url(self):
        return reverse_lazy("participation:team_detail", args=(self.pk,))

    def __str__(self):
        return _("Team {name} ({trigram})").format(name=self.name, trigram=self.trigram)

    class Meta:
        verbose_name = _("team")
        verbose_name_plural = _("teams")
        indexes = [
            Index(fields=("trigram", )),
        ]


class Tournament(models.Model):
    name = models.CharField(
        max_length=255,
        verbose_name=_("name"),
        unique=True,
    )

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

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

    place = AddressField(
        verbose_name=_("place"),
    )

    max_teams = models.PositiveSmallIntegerField(
        verbose_name=_("max team count"),
        default=9,
    )

    price = models.PositiveSmallIntegerField(
        verbose_name=_("price"),
        default=21,
    )

    inscription_limit = models.DateTimeField(
        verbose_name=_("limit date for registrations"),
        default=timezone.now,
    )

    solution_limit = models.DateTimeField(
        verbose_name=_("limit date to upload solutions"),
        default=timezone.now,
    )

    solutions_draw = models.DateTimeField(
        verbose_name=_("random draw for solutions"),
        default=timezone.now,
    )

    syntheses_first_phase_limit = models.DateTimeField(
        verbose_name=_("limit date to upload the syntheses for the first phase"),
        default=timezone.now,
    )

    solutions_available_second_phase = models.DateTimeField(
        verbose_name=_("date when the solutions for the second round become available"),
        default=timezone.now,
    )

    syntheses_second_phase_limit = models.DateTimeField(
        verbose_name=_("limit date to upload the syntheses for the second phase"),
        default=timezone.now,
    )

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

    organizers = models.ManyToManyField(
        VolunteerRegistration,
        verbose_name=_("organizers"),
        related_name="organized_tournaments",
    )

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

    @staticmethod
    def final_tournament():
        qs = Tournament.objects.filter(final=True)
        if qs.exists():
            return qs.get()

    @property
    def participations(self):
        if self.final:
            return Participation.objects.filter(final=True)
        return self.participation_set

    @property
    def solutions(self):
        if self.final:
            return Solution.objects.filter(final_solution=True)
        return Solution.objects.filter(participation__tournament=self)

    @property
    def syntheses(self):
        if self.final:
            return Synthesis.objects.filter(final_solution=True)
        return Synthesis.objects.filter(participation__tournament=self)

    def get_absolute_url(self):
        return reverse_lazy("participation:tournament_detail", args=(self.pk,))

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = _("tournament")
        verbose_name_plural = _("tournaments")
        indexes = [
            Index(fields=("name", "date_start", "date_end", )),
        ]


class Participation(models.Model):
    """
    The Participation model contains all data that are related to the participation:
    chosen problem, validity status, solutions,...
    """
    team = models.OneToOneField(
        Team,
        on_delete=models.CASCADE,
        verbose_name=_("team"),
    )

    tournament = models.ForeignKey(
        Tournament,
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        default=None,
        verbose_name=_("tournament"),
    )

    valid = models.BooleanField(
        null=True,
        default=None,
        verbose_name=_("valid"),
        help_text=_("The participation got the validation of the organizers."),
    )

    final = models.BooleanField(
        default=False,
        verbose_name=_("selected for final"),
        help_text=_("The team is selected for the final tournament."),
    )

    def get_absolute_url(self):
        return reverse_lazy("participation:participation_detail", args=(self.pk,))

    def __str__(self):
        return _("Participation of the team {name} ({trigram})").format(name=self.team.name, trigram=self.team.trigram)

    class Meta:
        verbose_name = _("participation")
        verbose_name_plural = _("participations")


class Pool(models.Model):
    tournament = models.ForeignKey(
        Tournament,
        on_delete=models.CASCADE,
        related_name="pools",
        verbose_name=_("tournament"),
    )

    round = models.PositiveSmallIntegerField(
        verbose_name=_("round"),
    )

    participations = models.ManyToManyField(
        Participation,
        related_name="pools",
        verbose_name=_("participations"),
    )

    juries = models.ManyToManyField(
        VolunteerRegistration,
        related_name="jury_in",
        verbose_name=_("juries"),
    )

    @property
    def solutions(self):
        return Solution.objects.filter(participation__in=self.participations, final_solution=self.tournament.final)

    def __str__(self):
        return _("Pool {round} for tournament {tournament} with teams {teams}")\
            .format(round=self.round,
                    tournament=str(self.tournament),
                    teams=", ".join(participation.team.trigram for participation in self.participations.all()))

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


def get_solution_filename(instance, filename):
    return f"solutions/{instance.participation.team.trigram}_{instance.problem}" \
           + ("final" if instance.final_solution else "")


def get_random_synthesis_filename(instance, filename):
    return "syntheses/" + get_random_string(64)


class Solution(models.Model):
    participation = models.ForeignKey(
        Participation,
        on_delete=models.CASCADE,
        verbose_name=_("participation"),
        related_name="solutions",
    )

    problem = models.PositiveSmallIntegerField(
        verbose_name=_("problem"),
        choices=[
            (i, format_lazy(_("Problem #{problem}"), problem=i)) for i in range(1, settings.PROBLEM_COUNT + 1)
        ],
    )

    final_solution = models.BooleanField(
        verbose_name=_("solution for the final tournament"),
        default=False,
    )

    file = models.FileField(
        verbose_name=_("file"),
        upload_to=get_solution_filename,
        unique=True,
        blank=True,
        default="",
    )

    def __str__(self):
        return _("Solution of team {team} for problem {problem}")\
            .format(team=self.participation.team.name, problem=self.problem)

    class Meta:
        verbose_name = _("solution")
        verbose_name_plural = _("solutions")
        unique_together = (('participation', 'problem', 'final_solution', ), )


class Synthesis(models.Model):
    participation = models.ForeignKey(
        Participation,
        on_delete=models.CASCADE,
        verbose_name=_("participation"),
    )

    pool = models.ForeignKey(
        Pool,
        on_delete=models.CASCADE,
        related_name="syntheses",
        verbose_name=_("pool"),
    )

    type = models.PositiveSmallIntegerField(
        choices=[
            (1, _("opponent"), ),
            (2, _("reporter"), ),
        ]
    )

    file = models.FileField(
        verbose_name=_("file"),
        upload_to=get_random_synthesis_filename,
        unique=True,
        blank=True,
        default="",
    )

    def __str__(self):
        return repr(self)

    class Meta:
        verbose_name = _("synthesis")
        verbose_name_plural = _("syntheses")
        unique_together = (('participation', 'pool', 'type', ), )