from flask_wtf import Form
from wtforms import DateField, IntegerField, DecimalField, StringField, SelectField, SubmitField, SelectMultipleField, BooleanField
from wtforms.validators import ValidationError, Length
from datetime import date


def date_check(form, field):
    """
    Checks that the date of the pitstop is not before the date of the latest pitstop and not after today.

    :param form: the form where the field is in
    :param field: the field to check
    :return: Nothing or a ValidationError if the limits are not kept
    """
    if field.data < form.last_pitstop.date:
        raise ValidationError('The new date must not be before %s' % form.last_pitstop.date)
    if field.data > date.today():
        raise ValidationError('The new date must not be after %s' % date.today())


def odometer_check(form, field):
    """

    :param form:
    :param field:
    :return:
    """
    if not form.same_odometer_allowed and field.data <= form.last_pitstop.odometer:
        raise ValidationError('The new odometer value must be higher than %i km' % form.last_pitstop.odometer)
    if form.same_odometer_allowed and field.data < form.last_pitstop.odometer:
        raise ValidationError('The new odometer value must be higher than %i km' % form.last_pitstop.odometer)


def litres_check(form, field):
    if field.data is not None and field.data <= 0:
        raise ValidationError('You must fuel at least 0.1 l')


def costs_check(form, field):
    if field.data is not None and field.data <= 0:
        raise ValidationError('Costs must be above 0.01 €.')


def edit_costs_check(form, field):
    """
    Costs must be given, if a default value was given to the form field.
    :param form:
    :param field:
    :return:
    """
    costs_check_required = (form.costs.default is not None and form.costs.default > 0)
    if costs_check_required and field.data is not None and field.data <= 0:
        raise ValidationError('Costs must be above 0.01 €.')


class SelectVehicleForm(Form):
    vehicle = SelectField('Vehicle', coerce=int)
    submit = SubmitField(label='Do it!')


class SelectConsumableForm(Form):
    consumable = SelectField('Consumable', coerce=int)
    submit = SubmitField(label='Do it!')


class CreatePitstopForm(Form):
    date = DateField('Date of Pitstop', validators=[date_check])
    odometer = IntegerField('Odometer (km)', validators=[odometer_check])
    litres = DecimalField('Litres (l)', places=2, validators=[litres_check])
    costs = DecimalField('Costs (€, overall)', places=2, validators=[costs_check])
    submit = SubmitField(label='Do it!')
    last_pitstop = None
    same_odometer_allowed = True

    def set_pitstop(self, last_pitstop):
        self.last_pitstop = last_pitstop

    def set_consumable(self, consumable):
        self.litres.label = '%s (%s)' % (consumable.name, consumable.unit)

    def preinit_with_data(self):
        if self.date.data:
            self.date.default = self.date.data
        else:
            self.date.default = date.today()
        if self.odometer.data:
            self.odometer.default = self.odometer.data
        else:
            self.odometer.default = self.last_pitstop.odometer
        if self.litres.data:
            self.litres.default = self.litres.data
        else:
            self.litres.default = self.last_pitstop.amount
        if self.costs.data:
            self.costs.default = self.costs.data
        else:
            self.costs.default = self.last_pitstop.costs

    def get_hint_messages(self):
        if self.same_odometer_allowed:
            or_equal = ' or equal to'
        else:
            or_equal = ''
        messages = {
            'date': 'Date must be between %s and %s (including).' % (str(self.last_pitstop.date), str(date.today())),
            'odometer': 'Odometer must be greater than%s %s km.' % (or_equal, str(self.last_pitstop.odometer)),
            'costs': 'Costs must be higher than 0.01 €.'
        }
        return messages


class EditVehicleForm(Form):
    name = StringField('Name', validators=[Length(1, 255)])
    consumables = SelectMultipleField('Consumables', coerce=int,validators=[])
    submit = SubmitField(label='Do it!')


class DeleteVehicleForm(Form):
    submit = SubmitField(label='Do it!')


class DeleteAccountForm(Form):
    submit = SubmitField(label='Really delete my account!')


class DeletePitStopForm(Form):
    submit = SubmitField(label='Really delete this pitstop!')


class EditPitstopForm(Form):
    date = DateField('Date of Pitstop', validators=[date_check])
    odometer = IntegerField('Odometer (km)', validators=[odometer_check])
    litres = DecimalField('Litres (l)', places=2, validators=[litres_check])
    costs = DecimalField('Costs (€, overall)', places=2, validators=[edit_costs_check])
    submit = SubmitField(label='Update it!')
    last_pitstop = None
    same_odometer_allowed = True

    def set_pitstop(self, last_pitstop):
        self.last_pitstop = last_pitstop

    def set_consumable(self, consumable):
        self.litres.label = '%s (%s)' % (consumable.name, consumable.unit)

    def preinit_with_data(self):
        if self.date.data:
            self.date.default = self.date.data
        if self.odometer.data:
            self.odometer.default = self.odometer.data
        if self.litres.data:
            self.litres.default = self.litres.data
        if self.costs.data:
            self.costs.default = self.costs.data


class CreateConsumableForm(Form):
    name = StringField('Name', validators=[Length(1, 255)])
    unit = StringField('Unit', validators=[Length(1, 255)])
    submit = SubmitField(label='Do it!')


class EditConsumableForm(Form):
    name = StringField('Name', validators=[Length(1, 255)])
    unit = StringField('Unit', validators=[Length(1, 255)])
    submit = SubmitField(label='Do it!')


class DeletConsumableForm(Form):
    submit = SubmitField(label='Do it!')