# lingo - basket and payment system
# Copyright (C) 2019  Entr'ouvert
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import datetime


from django import forms
from django.core.exceptions import ValidationError
from django.utils.translation import ugettext_lazy as _

from .models import Regie, PaymentBackend

TYPE_FIELD_MAPPING = {
    str: forms.CharField,
    bool: forms.BooleanField,
    int: forms.IntegerField,
    float: forms.FloatField,
}


def get_validator(func, err_msg):
    def validate(value):
        if not func(value):
            message = err_msg or _('Invalid value.')
            raise ValidationError(message)
    return validate


def create_form_fields(parameters, json_field):
    fields, initial = [], {}
    for param in parameters:
        field_name = param['name']
        if field_name in ('normal_return_url', 'automatic_return_url') or param.get('deprecated'):
            continue

        field_params = {
            'label': param.get('caption') or field_name,
            'required': param.get('required', False)
        }
        if 'validation' in param:
            field_params['validators'] = [
                get_validator(param['validation'], param.get('validation_err_msg'))
            ]

        _type = param.get('type', str)
        choices = param.get('choices')
        if choices is not None:
            field_class = forms.MultipleChoiceField if _type is list else forms.ChoiceField
            if choices and not isinstance(choices[0], tuple):
                choices = [(choice, choice) for choice in choices]
            field_params['choices'] = choices
        else:
            field_class = TYPE_FIELD_MAPPING[_type]

        fields.append((field_name, field_class(**field_params)))
        initial_value = json_field.get(field_name, param.get('default'))
        if initial_value:
            initial[field_name] = initial_value

    return fields, initial


def compute_json_field(parameters, cleaned_data):
    json_field = {}
    for param in parameters:
        param_name = param['name']
        if param_name in cleaned_data:
            json_field[param_name] = cleaned_data[param_name]
    return json_field


class RegieForm(forms.ModelForm):

    class Meta:
        model = Regie
        fields = ['label', 'slug', 'description', 'payment_backend', 'is_default',
                  'webservice_url', 'extra_fees_ws_url', 'payment_min_amount', 'text_on_success']

    def __init__(self, *args, **kwargs):
        super(RegieForm, self).__init__(*args, **kwargs)
        fields, initial = create_form_fields(
            self.instance.payment_backend.get_payment().get_parameters(scope='transaction'),
            self.instance.transaction_options
        )
        self.fields.update(fields)
        self.initial.update(initial)

    def save(self):
        instance = super(RegieForm, self).save()
        instance.transaction_options = compute_json_field(
            self.instance.payment_backend.get_payment().get_parameters(scope='transaction'),
            self.cleaned_data
        )
        instance.save()
        return instance


class PaymentBackendForm(forms.ModelForm):

    class Meta:
        model = PaymentBackend
        fields = ['label', 'slug', 'service']

    def __init__(self, *args, **kwargs):
        super(PaymentBackendForm, self).__init__(*args, **kwargs)
        fields, initial = create_form_fields(
            self.instance.get_payment().get_parameters(scope='global'),
            self.instance.service_options
        )
        self.fields.update(fields)
        self.initial.update(initial)
        if self.fields['service']:
            self.fields['service'].disabled = True

    def save(self):
        instance = super(PaymentBackendForm, self).save()
        instance.service_options = compute_json_field(
            self.instance.get_payment().get_parameters(scope='global'),
            self.cleaned_data
        )
        instance.save()
        return instance


class TransactionExportForm(forms.Form):
    start_date = forms.DateField(
        label=_('Start date'),
        widget=forms.DateInput(attrs={'type': 'date'}, format='%Y-%m-%d')
    )
    end_date = forms.DateField(
        label=_('End date'),
        widget=forms.DateInput(attrs={'type': 'date'}, format='%Y-%m-%d')
    )

    def __init__(self, *args, **kwargs):
        super(TransactionExportForm, self).__init__(*args, **kwargs)
        today = datetime.date.today()
        self.initial['start_date'] = today - datetime.timedelta(days=30)
        self.initial['end_date'] = today