import re

from bootstrap_datepicker_plus import DateTimePickerInput
from django import forms
from django.core.exceptions import ObjectDoesNotExist, ValidationError
from django.db.models import Q
from django.utils.translation import gettext_lazy as _

from .models import Participation, Phase, Question, Team, Video


class TeamForm(forms.ModelForm):
    """
    Form to create a team, with the name and the trigram,
    and if the team accepts that Animath diffuse the videos.
    """
    def clean_trigram(self):
        trigram = self.cleaned_data["trigram"].upper()
        if not re.match("[A-Z]{3}", trigram):
            raise ValidationError(_("The trigram must be composed of three uppercase letters."))
        return trigram

    class Meta:
        model = Team
        fields = ('name', 'trigram', 'grant_animath_access_videos',)


class JoinTeamForm(forms.ModelForm):
    """
    Form to join a team by the access code.
    """
    def clean_access_code(self):
        access_code = self.cleaned_data["access_code"]
        if not Team.objects.filter(access_code=access_code).exists():
            raise ValidationError(_("No team was found with this access code."))
        return access_code

    def clean(self):
        cleaned_data = super().clean()
        if "access_code" in cleaned_data:
            team = Team.objects.get(access_code=cleaned_data["access_code"])
            self.instance = team
        return cleaned_data

    class Meta:
        model = Team
        fields = ('access_code',)


class ParticipationForm(forms.ModelForm):
    """
    Form to update the problem of a team participation.
    """
    class Meta:
        model = Participation
        fields = ('problem',)


class RequestValidationForm(forms.Form):
    """
    Form to ask about validation.
    """
    _form_type = forms.CharField(
        initial="RequestValidationForm",
        widget=forms.HiddenInput(),
    )

    engagement = forms.BooleanField(
        label=_("I engage myself to participate to the whole \"Correspondances\"."),
        required=True,
    )


class ValidateParticipationForm(forms.Form):
    """
    Form to let administrators to accept or refuse a team.
    """
    _form_type = forms.CharField(
        initial="ValidateParticipationForm",
        widget=forms.HiddenInput(),
    )

    message = forms.CharField(
        label=_("Message to address to the team:"),
        widget=forms.Textarea(),
    )


class UploadVideoForm(forms.ModelForm):
    """
    Form to upload a video, for a solution or a synthesis.
    """
    class Meta:
        model = Video
        fields = ('link',)

    def clean(self):
        if Phase.current_phase().phase_number != 1 and Phase.current_phase().phase_number != 4 and self.instance.link:
            self.add_error("link", _("You can't upload your video after the deadline."))
        return super().clean()


class ReceiveParticipationForm(forms.ModelForm):
    """
    Update the received participation of a participation.
    """
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields["received_participation"].queryset = Participation.objects.filter(
            ~Q(pk=self.instance.pk) & Q(problem=self.instance.problem, valid=True)
        )

    class Meta:
        model = Participation
        fields = ('received_participation',)


class SendParticipationForm(forms.ModelForm):
    """
    Update the sent participation of a participation.
    """
    sent_participation = forms.ModelChoiceField(
        queryset=Participation.objects,
        label=lambda: _("Send to team"),
    )

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        try:
            self.fields["sent_participation"].initial = self.instance.sent_participation
        except ObjectDoesNotExist:     # No sent participation
            pass
        self.fields["sent_participation"].queryset = Participation.objects.filter(
            ~Q(pk=self.instance.pk) & Q(problem=self.instance.problem, valid=True)
        )

    def clean(self, commit=True):
        cleaned_data = super().clean()
        if "sent_participation" in cleaned_data:
            participation = cleaned_data["sent_participation"]
            participation.received_participation = self.instance
            self.instance = participation
        return cleaned_data

    class Meta:
        model = Participation
        fields = ('sent_participation',)


class QuestionForm(forms.ModelForm):
    """
    Create or update a question.
    """
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields["question"].widget.attrs.update({"placeholder": _("How did you get the idea to ...?")})

    def clean(self):
        if Phase.current_phase().phase_number != 2:
            self.add_error(None, _("You can only create or update a question during the second phase."))
        return super().clean()

    class Meta:
        model = Question
        fields = ('question',)


class PhaseForm(forms.ModelForm):
    """
    Form to update the calendar of a phase.
    """
    class Meta:
        model = Phase
        fields = ('start', 'end',)
        widgets = {
            'start': DateTimePickerInput(format='%d/%m/%Y %H:%M'),
            'end': DateTimePickerInput(format='%d/%m/%Y %H:%M'),
        }

    def clean(self):
        # Ensure that dates are in a right order
        cleaned_data = super().clean()
        start = cleaned_data["start"]
        end = cleaned_data["end"]
        if end <= start:
            self.add_error("end", _("Start date must be before the end date."))
        if Phase.objects.filter(phase_number__lt=self.instance.phase_number, end__gt=start).exists():
            self.add_error("start", _("This phase must start after the previous phases."))
        if Phase.objects.filter(phase_number__gt=self.instance.phase_number, start__lt=end).exists():
            self.add_error("end", _("This phase must end after the next phases."))
        return cleaned_data