feat(account.invoice): add CfdiRelacionados node on credit notes

When creating a credit note related with an invoice now we are setting the node CfdiRelacionados to

acomplish with CFDI 3.3 rules

Closes #6

l10n_mx_facturae/models/account_invoice.py

@@ -199,6 +199,21 @@ class AccountInvoice(models.Model):
             res['value']['cfdi_use'] = partner.cfdi_use
         return res
 
+    @api.model
+    def _prepare_refund(
+        self, invoice, date=None, period_id=None, description=None,
+        journal_id=None,
+    ):
+        """Overrides the preprare refund function to set field UsoCFDI"""
+        values = super(AccountInvoice, self)._prepare_refund(
+            invoice, date=date, period_id=period_id, description=description,
+            journal_id=journal_id,
+        )
+        # We set field UsoCFDI to Descuentos y devoluciones for all refunds
+        usocfdi = self.env.ref('l10n_mx.cfdi_use_G02')
+        values['cfdi_use'] = usocfdi.id
+        return values
+
     @signals.invoice_validate.connect
     def sign_invoice_sat(self, cr, uid, ids, context=None):
         context = dict(context or {})

l10n_mx_facturae/templates/cfdi33.txt

@@ -31,14 +31,14 @@
         {% otherwise %}MetodoPago="$o.payment_term.payment_method_id.code"{% end %}
     {% end %}
     LugarExpedicion="${ o.company_id.zip }" >
-    {#{% if o.cfdi_related_type %}
+    {% if o.refund_invoice_id.exists() %}
         <cfdi:CfdiRelacionados
-            TipoRelacion="{{ o.cfdi_related_type }}">
-            {% for cfdi in o.cfdi_related %}
-                <cfdi:CfdiRelacionado UUID="{{ cfdi.uuid }}"/>
+            TipoRelacion="01">
+            {% for cfdi in o.refund_invoice_id %}
+                <cfdi:CfdiRelacionado UUID="${ cfdi.cfdi_folio_fiscal }"/>
             {% end %}
         </cfdi:CfdiRelacionados>
-    {% end %} #}
+    {% end %}
     <cfdi:Emisor
         {% choose o.company_id.partner_id.vat_split %}
             {% when '' %}${ validationerror(_('Missing VAT number for company')) }{% end %}