invoice.py 21.1 KB
Newer Older
Patrick's avatar
Patrick committed
1 2 3 4 5 6 7 8
# -*- coding: utf-8
from __future__ import unicode_literals

import datetime

from django.core.validators import MinValueValidator
from django.db import models
from django.db import transaction
Patrick's avatar
Patrick committed
9
from django.db.models import F, Sum
Patrick's avatar
Patrick committed
10 11 12
from django.utils.encoding import python_2_unicode_compatible
from django.utils.translation import ugettext_lazy as _

13
import purchase
Patrick's avatar
Patrick committed
14
from repanier.apps import DJANGO_IS_MIGRATION_RUNNING
Patrick's avatar
Patrick committed
15 16 17 18 19
import producer
from repanier.const import *
from repanier.fields.RepanierMoneyField import ModelMoneyField


Patrick's avatar
Patrick committed
20 21 22 23 24 25 26
def permanence_verbose_name():
    if DJANGO_IS_MIGRATION_RUNNING:
        return EMPTY_STRING
    from repanier.apps import REPANIER_SETTINGS_PERMANENCE_NAME
    return lambda: "%s" % REPANIER_SETTINGS_PERMANENCE_NAME


Patrick's avatar
Patrick committed
27 28 29 30 31
@python_2_unicode_compatible
class CustomerInvoice(models.Model):
    customer = models.ForeignKey(
        'Customer', verbose_name=_("customer"),
        on_delete=models.PROTECT)
Patrick's avatar
Patrick committed
32 33 34
    customer_charged = models.ForeignKey(
        'Customer', verbose_name=_("customer"), related_name='invoices_paid', blank=True, null=True,
        on_delete=models.PROTECT, db_index=True)
Patrick's avatar
Patrick committed
35
    permanence = models.ForeignKey(
Patrick's avatar
Patrick committed
36
        'Permanence', verbose_name=permanence_verbose_name(),
Patrick's avatar
Patrick committed
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114
        on_delete=models.PROTECT, db_index=True)
    delivery = models.ForeignKey(
        'DeliveryBoard', verbose_name=_("delivery board"),
        null=True, blank=True, default=None,
        on_delete=models.PROTECT)
    status = models.CharField(
        max_length=3,
        choices=LUT_PERMANENCE_STATUS,
        default=PERMANENCE_PLANNED,
        verbose_name=_("invoice_status"))

    # IMPORTANT: default = True -> for the order form, to display nothing at the begin of the order
    # is_order_confirm_send and total_price_with_tax = 0 --> display nothing
    # otherwise display
    # - send a mail with the order to me
    # - confirm the order (if REPANIER_SETTINGS_CUSTOMERS_MUST_CONFIRM_ORDERS) and send a mail with the order to me
    # - mail send to XYZ
    # - order confirmed (if REPANIER_SETTINGS_CUSTOMERS_MUST_CONFIRM_ORDERS) and mail send to XYZ
    is_order_confirm_send = models.BooleanField(_("is_order_confirm_send"), choices=LUT_CONFIRM, default=False)
    invoice_sort_order = models.IntegerField(
        _("invoice sort order"),
        default=None, blank=True, null=True, db_index=True)
    date_previous_balance = models.DateField(
        _("date_previous_balance"), default=datetime.date.today)
    previous_balance = ModelMoneyField(
        _("previous_balance"), max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    # Calculated with Purchase
    total_price_with_tax = ModelMoneyField(
        _("Total amount"),
        help_text=_('Total purchase amount vat included'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    total_vat = ModelMoneyField(
        _("Total vat"),
        help_text=_('Vat part of the total purchased'),
        default=DECIMAL_ZERO, max_digits=9, decimal_places=4)
    total_deposit = ModelMoneyField(
        _("deposit"),
        help_text=_('deposit to add to the original unit price'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    delta_price_with_tax = ModelMoneyField(
        _("Total amount"),
        help_text=_('purchase to add amount vat included'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    delta_vat = ModelMoneyField(
        _("Total vat"),
        help_text=_('vat to add'),
        default=DECIMAL_ZERO, max_digits=9, decimal_places=4)
    delta_transport = ModelMoneyField(
        _("Delivery point transport"),
        help_text=_("transport to add"),
        default=DECIMAL_ZERO, max_digits=5, decimal_places=2,
        validators=[MinValueValidator(0)])
    bank_amount_in = ModelMoneyField(
        _("bank_amount_in"), help_text=_('payment_on_the_account'),
        max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    bank_amount_out = ModelMoneyField(
        _("bank_amount_out"), help_text=_('payment_from_the_account'),
        max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    date_balance = models.DateField(
        _("date_balance"), default=datetime.date.today)
    balance = ModelMoneyField(
        _("balance"),
        max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    price_list_multiplier = models.DecimalField(
        _("Delivery point price list multiplier"),
        help_text=_("This multiplier is applied once for groups with entitled customer or at each customer invoice for open groups."),
        default=DECIMAL_ONE, max_digits=5, decimal_places=4, blank=True,
        validators=[MinValueValidator(0)])
    transport = ModelMoneyField(
        _("Delivery point shipping cost"),
        help_text=_("This amount is added once for groups with entitled customer or at each customer for open groups."),
        default=DECIMAL_ZERO, max_digits=5, decimal_places=2,
        validators=[MinValueValidator(0)])
    min_transport = ModelMoneyField(
        _("Minium order amount for free shipping cost"),
        help_text=_("This is the minimum order amount to avoid shipping cost."),
        default=DECIMAL_ZERO, max_digits=5, decimal_places=2,
        validators=[MinValueValidator(0)])
Patrick's avatar
Patrick committed
115 116 117 118
    # customer_charged = models.ForeignKey(
    #     'Customer', verbose_name=_("customer"),
    #     related_name='invoices_paid',
    #     on_delete=models.PROTECT, db_index=True)
Patrick's avatar
Patrick committed
119 120 121 122 123
    master_permanence = models.ForeignKey(
        'Permanence', verbose_name=_("master permanence"),
        related_name='child_customer_invoice',
        blank=True, null=True, default=None,
        on_delete=models.PROTECT, db_index=True)
Patrick's avatar
Patrick committed
124 125 126 127 128 129 130 131 132 133

    def get_delta_price_with_tax(self):
        return self.delta_price_with_tax.amount

    def get_abs_delta_price_with_tax(self):
        return abs(self.delta_price_with_tax)

    def get_abs_delta_vat(self):
        return abs(self.delta_vat)

Patrick's avatar
Patrick committed
134 135
    def get_total_price_with_tax(self, customer_charged=False):
        if self.customer_id == self.customer_charged_id:
Patrick's avatar
Patrick committed
136 137
            return self.total_price_with_tax + self.delta_price_with_tax + self.delta_transport
        else:
Patrick's avatar
Patrick committed
138
            if self.status < PERMANENCE_INVOICED or not customer_charged:
Patrick's avatar
Patrick committed
139 140
                return self.total_price_with_tax
            else:
Patrick's avatar
Patrick committed
141
                return self.customer_charged if self.total_price_with_tax != DECIMAL_ZERO else DECIMAL_ZERO
Patrick's avatar
Patrick committed
142

Patrick's avatar
Patrick committed
143 144 145 146 147 148 149
    def get_total_price_wo_tax(self):
        return self.get_total_price_with_tax() - self.get_total_tax()

    def get_total_tax(self):
        # round to 2 decimals
        return RepanierMoney(self.total_vat.amount + self.delta_vat.amount)

Patrick's avatar
Patrick committed
150 151 152 153 154 155 156 157 158 159 160 161 162 163
    @transaction.atomic
    def set_delivery(self, delivery):
        # May not use delivery_id because it won't reload customer_invoice.delivery
        from repanier.apps import REPANIER_SETTINGS_TRANSPORT, REPANIER_SETTINGS_MIN_TRANSPORT
        self.delivery = delivery
        if delivery is None:
            if self.permanence.with_delivery_point:
                delivery_point = self.customer.delivery_point
            else:
                delivery_point = None
        else:
            delivery_point = delivery.delivery_point

        if delivery_point is None:
Patrick's avatar
Patrick committed
164
            self.customer_charged = self.customer
Patrick's avatar
Patrick committed
165 166 167 168 169 170
            self.price_list_multiplier = DECIMAL_ONE
            self.transport = REPANIER_SETTINGS_TRANSPORT
            self.min_transport = REPANIER_SETTINGS_MIN_TRANSPORT
        else:
            customer_responsible = delivery_point.customer_responsible
            if customer_responsible is None:
Patrick's avatar
Patrick committed
171
                self.customer_charged = self.customer
Patrick's avatar
Patrick committed
172 173 174 175
                self.price_list_multiplier = delivery_point.price_list_multiplier
                self.transport = delivery_point.transport
                self.min_transport = delivery_point.min_transport
            else:
Patrick's avatar
Patrick committed
176 177
                self.customer_charged = customer_responsible
                self.price_list_multiplier = DECIMAL_ONE
Patrick's avatar
Patrick committed
178 179 180
                self.transport = REPANIER_MONEY_ZERO
                self.min_transport = REPANIER_MONEY_ZERO
                if self.customer_id != customer_responsible.id:
Patrick's avatar
Patrick committed
181
                    customer_invoice_charged = CustomerInvoice.objects.filter(
Patrick's avatar
Patrick committed
182 183
                        permanence_id=self.permanence_id,
                        customer_id=customer_responsible.id
Patrick's avatar
Patrick committed
184 185
                    ).order_by('?')
                    if not customer_invoice_charged.exists():
Patrick's avatar
Patrick committed
186 187 188 189
                        CustomerInvoice.objects.create(
                            permanence_id=self.permanence_id,
                            customer_id=customer_responsible.id,
                            status=self.status,
Patrick's avatar
Patrick committed
190
                            customer_charged_id=customer_responsible.id,
Patrick's avatar
Patrick committed
191 192 193 194 195 196 197 198
                            price_list_multiplier=delivery_point.price_list_multiplier,
                            transport=delivery_point.transport,
                            min_transport=delivery_point.min_transport,
                            is_order_confirm_send=True
                        )

    @transaction.atomic
    def confirm_order(self):
199 200 201
        purchase.Purchase.objects.filter(
            customer_invoice__id=self.id
        ).update(quantity_confirmed=F('quantity_ordered'))
Patrick's avatar
Patrick committed
202 203 204 205 206
        self.calculate_and_save_delta_buyinggroup()
        self.is_order_confirm_send = True

    @transaction.atomic
    def calculate_and_save_delta_buyinggroup(self):
Patrick's avatar
Patrick committed
207 208 209 210
        producer_invoice_buyinggroup = ProducerInvoice.objects.filter(
            producer__represent_this_buyinggroup=True,
            permanence_id=self.permanence_id,
        ).order_by('?').first()
Patrick's avatar
Patrick committed
211
        if producer_invoice_buyinggroup is None:
Patrick's avatar
Patrick committed
212 213 214 215 216 217 218 219
            producer_buyinggroup = producer.Producer.objects.filter(
                represent_this_buyinggroup=True
            ).order_by('?').first()
            producer_invoice_buyinggroup = ProducerInvoice.objects.create(
                producer_id=producer_buyinggroup.id,
                permanence_id=self.permanence_id,
                status=self.permanence.status
            )
Patrick's avatar
Patrick committed
220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257
        else:
            producer_invoice_buyinggroup.delta_price_with_tax.amount -= self.delta_price_with_tax.amount
            producer_invoice_buyinggroup.delta_vat.amount -= self.delta_vat.amount
            producer_invoice_buyinggroup.delta_transport.amount -= self.delta_transport.amount

        self.calculate_delta_price()
        self.calculate_delta_transport()
        self.save()

        producer_invoice_buyinggroup.delta_price_with_tax.amount += self.delta_price_with_tax.amount
        producer_invoice_buyinggroup.delta_vat.amount += self.delta_vat.amount
        producer_invoice_buyinggroup.delta_transport.amount += self.delta_transport.amount

        producer_invoice_buyinggroup.save()

    def calculate_delta_price(self):
        getcontext().rounding = ROUND_HALF_UP

        result_set = purchase.Purchase.objects.filter(
            permanence_id=self.permanence_id,
            customer_id=self.customer_id
        ).order_by('?').aggregate(
            Sum('customer_vat'),
            Sum('deposit'),
            Sum('selling_price')
        )
        if result_set["customer_vat__sum"] is not None:
            self.total_vat.amount = result_set["customer_vat__sum"]
        else:
            self.total_vat.amount = DECIMAL_ZERO
        if result_set["deposit__sum"] is not None:
            self.total_deposit.amount = result_set["deposit__sum"]
        else:
            self.total_deposit.amount = DECIMAL_ZERO
        if result_set["selling_price__sum"] is not None:
            self.total_price_with_tax.amount = result_set["selling_price__sum"]
        else:
            self.total_price_with_tax.amount = DECIMAL_ZERO
Patrick's avatar
Patrick committed
258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274

        if self.price_list_multiplier != DECIMAL_ONE:
            total_price_with_tax_wo_deposit = self.total_price_with_tax.amount - self.total_deposit.amount
            self.delta_price_with_tax.amount = -(
                total_price_with_tax_wo_deposit - (
                    total_price_with_tax_wo_deposit * self.price_list_multiplier
                ).quantize(TWO_DECIMALS)
            )
            self.delta_vat.amount = -(
                self.total_vat - (
                    self.total_vat.amount * self.price_list_multiplier
                ).quantize(FOUR_DECIMALS)
            )
        else:
            self.delta_price_with_tax.amount = DECIMAL_ZERO
            self.delta_vat.amount = DECIMAL_ZERO

Patrick's avatar
Patrick committed
275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294
    def calculate_delta_transport(self):

        self.delta_transport.amount = DECIMAL_ZERO
        if self.master_permanence_id is None and self.transport.amount != DECIMAL_ZERO:
            # Calculate transport only on master customer invoice
            # But take into account the children customer invoices
            result_set = CustomerInvoice.objects.filter(
                master_permanence=self.permanence
            ).order_by('?').aggregate(
                Sum('total_price_with_tax'),
                Sum('delta_price_with_tax')
            )
            if result_set["total_price_with_tax__sum"] is not None:
                sum_total_price_with_tax = result_set["total_price_with_tax__sum"]
            else:
                sum_total_price_with_tax = DECIMAL_ZERO
            if result_set["delta_price_with_tax__sum"] is not None:
                sum_delta_price_with_tax = result_set["delta_price_with_tax__sum"]
            else:
                sum_delta_price_with_tax = DECIMAL_ZERO
Patrick's avatar
Patrick committed
295

Patrick's avatar
Patrick committed
296 297
            sum_total_price_with_tax += self.total_price_with_tax.amount
            sum_delta_price_with_tax += self.delta_price_with_tax.amount
Patrick's avatar
Patrick committed
298

Patrick's avatar
Patrick committed
299 300 301 302 303 304 305 306 307
            total_price_with_tax = sum_total_price_with_tax + sum_delta_price_with_tax
            if total_price_with_tax != DECIMAL_ZERO:
                if self.min_transport.amount == DECIMAL_ZERO:
                    self.delta_transport.amount = self.transport.amount
                elif total_price_with_tax < self.min_transport.amount:
                    self.delta_transport.amount = min(
                        self.min_transport.amount - total_price_with_tax,
                        self.transport.amount
                    )
Patrick's avatar
Patrick committed
308 309

    def cancel_confirm_order(self):
310 311 312 313 314 315 316
        if self.is_order_confirm_send:
            # Change of confirmation status
            self.is_order_confirm_send = False
            return True
        else:
            # No change of confirmation status
            return False
Patrick's avatar
Patrick committed
317

Patrick's avatar
Patrick committed
318 319 320 321 322 323 324 325 326
    def create_child(self, new_permanence):
        return CustomerInvoice.objects.create(
            permanence_id=new_permanence.id,
            customer_id=self.customer_id,
            master_permanence_id=self.permanence_id,
            customer_charged_id=self.customer_id,
            status=self.status
        )

Patrick's avatar
Patrick committed
327 328 329 330 331 332 333 334 335 336 337 338 339 340 341
    def __str__(self):
        return '%s, %s' % (self.customer, self.permanence)

    class Meta:
        verbose_name = _("customer invoice")
        verbose_name_plural = _("customers invoices")
        unique_together = ("permanence", "customer",)


@python_2_unicode_compatible
class ProducerInvoice(models.Model):
    producer = models.ForeignKey(
        'Producer', verbose_name=_("producer"),
        on_delete=models.PROTECT)
    permanence = models.ForeignKey(
Patrick's avatar
Patrick committed
342
        'Permanence', verbose_name=permanence_verbose_name(),
Patrick's avatar
Patrick committed
343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405
        on_delete=models.PROTECT, db_index=True)
    status = models.CharField(
        max_length=3,
        choices=LUT_PERMANENCE_STATUS,
        default=PERMANENCE_PLANNED,
        verbose_name=_("invoice_status"))
    date_previous_balance = models.DateField(
        _("date_previous_balance"), default=datetime.date.today)
    previous_balance = ModelMoneyField(
        _("previous_balance"), max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    # Calculated with Purchase
    total_price_with_tax = ModelMoneyField(
        _("Total amount"),
        help_text=_('Total purchase amount vat included'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    total_vat = ModelMoneyField(
        _("Total vat"),
        help_text=_('Vat part of the total purchased'),
        default=DECIMAL_ZERO, max_digits=9, decimal_places=4)
    total_deposit = ModelMoneyField(
        _("deposit"),
        help_text=_('deposit to add to the original unit price'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    bank_amount_in = ModelMoneyField(
        _("bank_amount_in"), help_text=_('payment_on_the_account'),
        max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    bank_amount_out = ModelMoneyField(
        _("bank_amount_out"), help_text=_('payment_from_the_account'),
        max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    date_balance = models.DateField(
        _("date_balance"), default=datetime.date.today)
    balance = ModelMoneyField(
        _("balance"),
        max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    delta_price_with_tax = ModelMoneyField(
        _("Total amount"),
        help_text=_('purchase to add amount vat included'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    delta_stock_with_tax = ModelMoneyField(
        _("Total stock"),
        help_text=_('stock taken amount vat included'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    delta_vat = ModelMoneyField(
        _("Total vat"),
        help_text=_('vat to add'),
        default=DECIMAL_ZERO, max_digits=9, decimal_places=4)
    delta_stock_vat = ModelMoneyField(
        _("Total stock vat"),
        help_text=_('vat to add'),
        default=DECIMAL_ZERO, max_digits=9, decimal_places=4)
    delta_transport = ModelMoneyField(
        _("Delivery point transport"),
        help_text=_("transport to add"),
        default=DECIMAL_ZERO, max_digits=5, decimal_places=2,
        validators=[MinValueValidator(0)])
    delta_deposit = ModelMoneyField(
        _("deposit"),
        help_text=_('deposit to add'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    delta_stock_deposit = ModelMoneyField(
        _("deposit"),
        help_text=_('deposit to add'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
Patrick's avatar
Patrick committed
406 407

    to_be_paid = models.BooleanField(_("to be paid"), choices=LUT_BANK_NOTE, default=False)
Patrick's avatar
Patrick committed
408 409 410 411
    calculated_invoiced_balance = ModelMoneyField(
        _("calculated balance to be invoiced"), max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
    to_be_invoiced_balance = ModelMoneyField(
        _("balance to be invoiced"), max_digits=8, decimal_places=2, default=DECIMAL_ZERO)
Patrick's avatar
Patrick committed
412 413 414
    invoice_sort_order = models.IntegerField(
        _("invoice sort order"),
        default=None, blank=True, null=True, db_index=True)
Patrick's avatar
Patrick committed
415 416 417
    invoice_reference = models.CharField(
        _("invoice reference"), max_length=100, null=True, blank=True)

Patrick's avatar
Patrick committed
418 419 420 421 422 423
    def get_negative_previous_balance(self):
        return - self.previous_balance

    def get_negative_balance(self):
        return - self.balance

Patrick's avatar
Patrick committed
424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456
    def get_delta_price_with_tax(self):
        return self.delta_price_with_tax.amount

    def get_abs_delta_price_with_tax(self):
        return abs(self.delta_price_with_tax)

    def get_total_price_with_tax(self):
        return self.total_price_with_tax + self.delta_price_with_tax + self.delta_transport + self.delta_stock_with_tax

    def get_total_vat(self):
        return self.total_vat + self.delta_stock_vat

    def get_total_deposit(self):
        return self.total_deposit + self.delta_stock_deposit

    def __str__(self):
        return '%s, %s' % (self.producer, self.permanence)

    class Meta:
        verbose_name = _("producer invoice")
        verbose_name_plural = _("producers invoices")
        unique_together = ("permanence", "producer",)


@python_2_unicode_compatible
class CustomerProducerInvoice(models.Model):
    customer = models.ForeignKey(
        'Customer', verbose_name=_("customer"),
        on_delete=models.PROTECT)
    producer = models.ForeignKey(
        'Producer', verbose_name=_("producer"),
        on_delete=models.PROTECT)
    permanence = models.ForeignKey(
Patrick's avatar
Patrick committed
457
        'Permanence', verbose_name=permanence_verbose_name(), on_delete=models.PROTECT,
Patrick's avatar
Patrick committed
458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496
        db_index=True)
    # Calculated with Purchase
    total_purchase_with_tax = ModelMoneyField(
        _("producer amount invoiced"),
        help_text=_('Total selling amount vat included'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)
    # Calculated with Purchase
    total_selling_with_tax = ModelMoneyField(
        _("customer amount invoiced"),
        help_text=_('Total selling amount vat included'),
        default=DECIMAL_ZERO, max_digits=8, decimal_places=2)

    def get_html_producer_price_purchased(self):
        if self.total_purchase_with_tax != DECIMAL_ZERO:
            return _("<b>%(price)s</b>") % {'price': self.total_purchase_with_tax}
        return EMPTY_STRING

    get_html_producer_price_purchased.short_description = (_("producer amount invoiced"))
    get_html_producer_price_purchased.allow_tags = True
    get_html_producer_price_purchased.admin_order_field = 'total_purchase_with_tax'

    def __str__(self):
        return '%s, %s' % (self.producer, self.customer)

    class Meta:
        verbose_name = _("customer x producer invoice")
        verbose_name_plural = _("customers x producers invoices")
        unique_together = ("permanence", "customer", "producer",)


@python_2_unicode_compatible
class CustomerSend(CustomerProducerInvoice):
    def __str__(self):
        return '%s, %s' % (self.producer, self.customer)

    class Meta:
        proxy = True
        verbose_name = _("customer")
        verbose_name_plural = _("customers")