# The COPYRIGHT file at the top level of this repository contains
# the full copyright notices and license terms.
from trytond.model import fields, Model, ModelSQL, ModelView, ModelSingleton
from trytond.pool import Pool, PoolMeta
from trytond.pyson import Eval
from trytond.modules.company.model import CompanyValueMixin

__all__ = ['ContactMixin', 'Configuration', 'ConfigurationRelationType',
    'Invoice']


class ContactMixin(Model, CompanyValueMixin):
    """
    Mixin to relate models with contacts.

    It assumes that the model has a field called party, which refers to the
    party of the model and enforces that the contact is related with the
    party with o relation type defined in contact_relations.

    The contact_relations fields, by default uses a config defined in
    a Singleton model. The name of the model must be set in the
    `_contact_config_name` property and it expects to have a relation_types
    Many2Many field to `party.relation.type` model.
    """
    _contact_config_name = None
    _contact_config_template_field = 'invoice_address'

    allowed_invoice_contacts = fields.Function(fields.Many2Many('party.party',
            None, None, "Allowed Contact",
            help='Allowed relation types for the related contact.',
            context={
                'company': Eval('company', -1),
            },
            depends=['company']),
        'on_change_with_allowed_invoice_contacts')
    invoice_contact = fields.Many2One('party.party', "Invoice Contact",
        domain=[
            ('id', 'in', Eval('allowed_invoice_contacts', [])),
            ],
        context={
                'company': Eval('company', -1),
            },
        depends=['party', 'allowed_invoice_contacts', 'company'])

    @classmethod
    def __setup__(cls):
        super(ContactMixin, cls).__setup__()
        template_field = getattr(cls, cls._contact_config_template_field)
        if template_field.states:
            cls.invoice_contact.states = template_field.states.copy()
            if 'required' in cls.invoice_contact.states:
                del cls.invoice_contact.states['required']
            cls.invoice_contact.depends |= template_field.depends

    # Migration from 5.6: see SQL upgrades to rename contact into invoice_contact

    @fields.depends('party')
    def on_change_with_allowed_invoice_contacts(self, name=None):
        pool = Pool()
        Config = pool.get(self._contact_config_name)

        res = []
        if not self.party:
            return res

        config = Config(1)
        types = [r.id for r in config.relation_types]
        relations = self.party.relations
        if not relations:
            return res
        for relation in relations:
            if relation.type.id in types:
                res.append(relation.to.id)
        return res


class ConfigurationRelationType(ModelSQL):
    'Invoice Configuration - Party relation type'
    __name__ = 'account.invoice.configuration-party.relation.type'

    relation = fields.Many2One('party.relation.type', 'Relation Type',
        required=True)
    config = fields.Many2One('account.invoice.configuration', 'Config',
        required=True)


class Configuration(ModelSingleton, ModelSQL, ModelView):
    'Invoice Configuration'
    __name__ = 'account.invoice.configuration'

    relation_types = fields.Many2Many(
        'account.invoice.configuration-party.relation.type', 'config',
        'relation', 'Contact types')


class Invoice(ContactMixin, metaclass=PoolMeta):
    __name__ = 'account.invoice'
    _contact_config_name = 'account.invoice.configuration'

    @classmethod
    def __setup__(cls):
        super().__setup__()
        cls.allowed_invoice_contacts.context = {'company': Eval('company', -1)}
        cls.allowed_invoice_contacts.depends.add('company')
        cls.invoice_contact.context = {'company': Eval('company', -1)}
        cls.invoice_contact.depends.add('company')

    def _credit(self, **values):
        credit = super(Invoice, self)._credit(**values)
        credit.invoice_contact = self.invoice_contact
        return credit