import datetime

from django import forms
from django.forms import ModelForm, Form
from django.utils.dates import MONTHS

from models import Subject, Worker, Appointment, Visit, AppointmentType, ContactAttempt
from models.constants import SUBJECT_TYPE_CHOICES, SCREENING_NUMBER_PREFIXES_FOR_TYPE

"""
Possible redundancy, but if need arises, contents of forms can be easily customized
"""

CURRENT_YEAR = datetime.datetime.now().year
YEAR_CHOICES = tuple(range(CURRENT_YEAR, CURRENT_YEAR - 120, -1))
FUTURE_YEAR_CHOICES = tuple(range(CURRENT_YEAR, CURRENT_YEAR + 5, 1))
DATEPICKER_DATE_ATTRS = {
    'class': 'datepicker',
    'data-date-format': 'yyyy-mm-dd',
    'data-date-orientation': 'bottom'
}
DATETIMEPICKER_DATE_ATTRS = {
    'class': 'datetimepicker',
    'data-date-format': 'Y-MM-DD HH:mm',
}
START_YEAR_STATISTICS = 2015


def validate_subject_nd_number(self, cleaned_data):
    if cleaned_data['nd_number'] != "":
        subjects_from_db = Subject.objects.filter(nd_number=cleaned_data['nd_number'])
        if subjects_from_db:
            if subjects_from_db[0].screening_number != cleaned_data.get('screening_number', ''):
                self.add_error('nd_number', "ND number already in use")


class SubjectAddForm(ModelForm):
    date_born = forms.DateField(label="Date of birth",
                                widget=forms.DateInput(DATEPICKER_DATE_ATTRS, "%Y-%m-%d"),
                                required=False
                                )

    datetime_contact_reminder = forms.DateTimeField(label="Contact on",
                                                    widget=forms.DateTimeInput(DATETIMEPICKER_DATE_ATTRS),
                                                    required=False
                                                    )

    class Meta:
        model = Subject
        fields = '__all__'
        exclude = ['dead', 'resigned']

    def __init__(self, *args, **kwargs):
        user = kwargs.pop('user', None)
        if user is None:
            raise TypeError("User not defined")
        self.user = Worker.get_by_user(user)
        if self.user is None:
            raise TypeError("Worker not defined for: " + user.username)

        super(ModelForm, self).__init__(*args, **kwargs)
        self.fields['screening_number'].required = False

    def build_screening_number(self, cleaned_data):
        screening_number = cleaned_data.get('screening_number', None)
        if not screening_number:
            prefix_screening_number = self.get_prefix_screening_number()
            if prefix_screening_number is not None:
                screening_number = get_new_screening_number(prefix_screening_number)
        return screening_number

    def clean(self):
        cleaned_data = super(SubjectAddForm, self).clean()
        screening_number = self.build_screening_number(cleaned_data)
        if screening_number is not None:
            cleaned_data['screening_number'] = screening_number
            subjects_from_db = Subject.objects.filter(screening_number=screening_number)

            if len(subjects_from_db) > 0:
                self.add_error('screening_number', "Screening number already in use")
        validate_subject_nd_number(self, cleaned_data)
        return cleaned_data

    def get_prefix_screening_number(self):
        default_location = self.cleaned_data.get('default_location', None)
        screening_number_prefix = None
        if default_location is not None and default_location.prefix is not None:
            screening_number_prefix = default_location.prefix
        else:
            subject_type = self.cleaned_data.get('type', None)
            if subject_type is not None:
                screening_number_prefix = SCREENING_NUMBER_PREFIXES_FOR_TYPE[subject_type]
        if screening_number_prefix is None:
            return None
        prefix_screening_number = screening_number_prefix + "-"
        return prefix_screening_number


def get_new_screening_number(screening_number_prefix):
    result_number = 0
    subjects = Subject.objects.filter(screening_number__contains=screening_number_prefix)
    for subject in subjects:
        screening_numbers = subject.screening_number.split(";")
        for screening_number in screening_numbers:
            screening_number = screening_number.strip()
            if screening_number.startswith(screening_number_prefix):
                number = screening_number[len(screening_number_prefix):]
                try:
                    result_number = max(result_number, int(number))
                except ValueError:
                    pass

    return screening_number_prefix + str(result_number + 1).zfill(3)


class SubjectDetailForm(ModelForm):
    class Meta:
        model = Subject
        fields = '__all__'


class SubjectEditForm(ModelForm):
    datetime_contact_reminder = forms.DateTimeField(label="Contact on",
                                                    widget=forms.DateTimeInput(DATETIMEPICKER_DATE_ATTRS),
                                                    required=False
                                                    )
    date_born = forms.DateField(label="Date of birth",
                                widget=forms.DateInput(DATEPICKER_DATE_ATTRS, "%Y-%m-%d"),
                                required=False
                                )

    def __init__(self, *args, **kwargs):
        was_dead = kwargs.get('was_dead', False)
        was_resigned = kwargs.get('was_resigned', False)
        if 'was_resigned' in kwargs:
            kwargs.pop('was_resigned')
        if 'was_dead' in kwargs:
            kwargs.pop('was_dead')
        super(SubjectEditForm, self).__init__(*args, **kwargs)
        instance = getattr(self, 'instance', None)
        if instance and instance.id:
            self.fields['screening_number'].widget.attrs['readonly'] = True
        if was_dead:
            self.fields['dead'].disabled = True
        if was_resigned:
            self.fields['resigned'].disabled = True

    def clean(self):
        validate_subject_nd_number(self, self.cleaned_data)

    class Meta:
        model = Subject
        fields = '__all__'


class WorkerAddForm(ModelForm):
    class Meta:
        model = Worker
        exclude = ['appointments']


class WorkerDetailForm(ModelForm):
    class Meta:
        model = Worker
        fields = '__all__'


class WorkerEditForm(ModelForm):
    class Meta:
        model = Worker
        fields = '__all__'


class AppointmentDetailForm(ModelForm):
    class Meta:
        model = Appointment
        fields = '__all__'

    datetime_when = forms.DateTimeField(label='Appointment on (YYYY-MM-DD HH:MM)',
                                        widget=forms.DateTimeInput(DATETIMEPICKER_DATE_ATTRS)
                                        )


class AppointmentEditForm(ModelForm):
    class Meta:
        model = Appointment
        fields = '__all__'

    datetime_when = forms.DateTimeField(label='Appointment on (YYYY-MM-DD HH:MM)',
                                        widget=forms.DateTimeInput(DATETIMEPICKER_DATE_ATTRS)
                                        )
    appointment_types = forms.ModelMultipleChoiceField(required=False, widget=forms.CheckboxSelectMultiple,
                                                       queryset=AppointmentType.objects.all())

    def __init__(self, *args, **kwargs):
        user = kwargs.pop('user', None)
        if user is None:
            raise TypeError("User not defined")
        self.user = Worker.get_by_user(user)
        if self.user is None:
            raise TypeError("Worker not defined for: " + user.username)

        super(ModelForm, self).__init__(*args, **kwargs)

    def clean_location(self):
        location = self.cleaned_data['location']
        if self.user.locations.filter(id=location.id).count() == 0:
            self.add_error('location', "You cannot create appointment for this location")
        else:
            return location


class AppointmentAddForm(ModelForm):
    class Meta:
        model = Appointment
        exclude = ['status']

    datetime_when = forms.DateTimeField(label='Appointment on (YYYY-MM-DD HH:MM)',
                                        widget=forms.DateTimeInput(DATETIMEPICKER_DATE_ATTRS)
                                        )
    appointment_types = forms.ModelMultipleChoiceField(required=False, widget=forms.CheckboxSelectMultiple,
                                                       queryset=AppointmentType.objects.all())

    def __init__(self, *args, **kwargs):
        user = kwargs.pop('user', None)
        if user is None:
            raise TypeError("User not defined")
        self.user = Worker.get_by_user(user)
        if self.user is None:
            raise TypeError("Worker not defined for: " + user.username)

        super(ModelForm, self).__init__(*args, **kwargs)

    def clean_location(self):
        location = self.cleaned_data['location']
        if self.user.locations.filter(id=location.id).count() == 0:
            self.add_error('location', "You cannot create appointment for this location")
        else:
            return location


class VisitDetailForm(ModelForm):
    datetime_begin = forms.DateField(label="Visit begins on",
                                     widget=forms.DateInput(DATEPICKER_DATE_ATTRS, "%Y-%m-%d")
                                     )
    datetime_end = forms.DateField(label="Visit ends on",
                                   widget=forms.DateInput(DATEPICKER_DATE_ATTRS, "%Y-%m-%d")
                                   )

    post_mail_sent = forms.RadioSelect()
    appointment_types = forms.ModelMultipleChoiceField(required=False, widget=forms.CheckboxSelectMultiple,
                                                       queryset=AppointmentType.objects.all())

    class Meta:
        model = Visit
        exclude = ['is_finished']


class VisitAddForm(ModelForm):
    subject = forms.ModelChoiceField(queryset=Subject.objects.order_by('last_name', 'first_name'))
    datetime_begin = forms.DateField(label="Visit begins on",
                                     widget=forms.TextInput(attrs=DATEPICKER_DATE_ATTRS)
                                     )
    datetime_end = forms.DateField(label="Visit ends on",
                                   widget=forms.TextInput(attrs=DATEPICKER_DATE_ATTRS)
                                   )
    appointment_types = forms.ModelMultipleChoiceField(required=False, widget=forms.CheckboxSelectMultiple,
                                                       queryset=AppointmentType.objects.all())

    class Meta:
        model = Visit
        exclude = ['is_finished']

    def clean(self):
        super(VisitAddForm, self).clean()
        if 'datetime_begin' not in self.cleaned_data or 'datetime_end' not in self.cleaned_data:
            return
        if self.cleaned_data['datetime_begin'] >= self.cleaned_data['datetime_end']:
            self.add_error('datetime_begin', "Start date must be before end date")
            self.add_error('datetime_end', "End date must be after start date")


class ContactAttemptForm(ModelForm):
    datetime_when = forms.DateTimeField(label='Contact on (YYYY-MM-DD HH:MM)',
                                        widget=forms.DateTimeInput(DATETIMEPICKER_DATE_ATTRS)
                                        )

    class Meta:
        model = ContactAttempt
        fields = '__all__'

    def __init__(self, *args, **kwargs):
        user = kwargs.pop('user', None)
        if user is None:
            raise TypeError("User not defined")
        self.user = Worker.get_by_user(user)
        if self.user is None:
            raise TypeError("Worker not defined for: " + user.username)
        subject = kwargs.pop('subject', None)
        super(ContactAttemptForm, self).__init__(*args, **kwargs)
        self.fields['subject'].initial = subject.id
        self.fields['subject'].disabled = True
        self.fields['worker'].initial = self.user


class KitRequestForm(Form):
    start_date = forms.DateField(label="From date",
                                 widget=forms.DateInput(DATEPICKER_DATE_ATTRS, "%Y-%m-%d"),
                                 required=False
                                 )

    end_date = forms.DateField(label="End date",
                               widget=forms.DateInput(DATEPICKER_DATE_ATTRS, "%Y-%m-%d"),
                               required=False
                               )


class StatisticsForm(Form):
    def __init__(self, *args, **kwargs):
        super(StatisticsForm, self).__init__(*args)
        visit_choices = kwargs['visit_choices']
        month = kwargs['month']
        year = kwargs['year']
        now = datetime.datetime.now()
        year_now = now.year
        number_of_years_for_statistics = year_now - START_YEAR_STATISTICS + 2

        year_choices = [(START_YEAR_STATISTICS + i, START_YEAR_STATISTICS + i) for i in
                        range(0, number_of_years_for_statistics + 1)]
        self.fields['month'] = forms.ChoiceField(choices=MONTHS.items(), initial=month)
        self.fields['year'] = forms.ChoiceField(choices=year_choices, initial=year)
        choices = [(-1, "all")]
        choices.extend(SUBJECT_TYPE_CHOICES.items())
        self.fields['subject_type'] = forms.ChoiceField(choices=choices, initial="-1")
        self.fields['visit'] = forms.ChoiceField(choices=visit_choices, initial="-1")