Add discount for custom invoices.

cotisations/forms.py

@@ -46,7 +46,7 @@ from django.shortcuts import get_object_or_404
 
 from re2o.field_permissions import FieldPermissionFormMixin
 from re2o.mixins import FormRevMixin
-from .models import Article, Paiement, Facture, Banque, CustomInvoice
+from .models import Article, Paiement, Facture, Banque, CustomInvoice, Vente
 from .payment_methods import balance
 
 
@@ -104,7 +104,44 @@ class SelectArticleForm(FormRevMixin, Form):
         user = kwargs.pop('user')
         target_user = kwargs.pop('target_user', None)
         super(SelectArticleForm, self).__init__(*args, **kwargs)
-        self.fields['article'].queryset = Article.find_allowed_articles(user, target_user)
+        self.fields['article'].queryset = Article.find_allowed_articles(
+            user, target_user)
+
+
+class DiscountForm(Form):
+    """
+    Form used in oder to create a discount on an invoice.
+    """
+    is_relative = forms.BooleanField(
+        label=_("Discount is on percentage"),
+        required=False,
+    )
+    discount = forms.DecimalField(
+        label=_("Discount"),
+        max_value=100,
+        min_value=0,
+        max_digits=5,
+        decimal_places=2,
+        required=False,
+    )
+
+    def apply_to_invoice(self, invoice):
+        invoice_price = invoice.prix_total()
+        discount = self.cleaned_data['discount']
+        is_relative = self.cleaned_data['is_relative']
+        if is_relative:
+            amount = discount/100 * invoice_price
+        else:
+            amount = discount
+        if amount > 0:
+            name = _("{}% discount") if is_relative else _("{}€ discount")
+            name = name.format(discount)
+            Vente.objects.create(
+                facture=invoice,
+                name=name,
+                prix=-amount,
+                number=1
+            )
 
 
 class CustomInvoiceForm(FormRevMixin, ModelForm):
@@ -248,7 +285,8 @@ class RechargeForm(FormRevMixin, Form):
         super(RechargeForm, self).__init__(*args, **kwargs)
         self.fields['payment'].empty_label = \
             _("Select a payment method")
-        self.fields['payment'].queryset = Paiement.find_allowed_payments(user_source).exclude(is_balance=True)
+        self.fields['payment'].queryset = Paiement.find_allowed_payments(
+            user_source).exclude(is_balance=True)
 
     def clean(self):
         """
@@ -266,4 +304,3 @@ class RechargeForm(FormRevMixin, Form):
                 }
             )
         return self.cleaned_data
-

cotisations/templates/cotisations/facture.html

@@ -44,6 +44,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 {% blocktrans %}Current balance: {{ balance }} €{% endblocktrans %}
 </p>
 {% endif %}
+{% bootstrap_form_errors factureform %}
+{% bootstrap_form_errors discount_form %}
 
 <form class="form" method="post">
     {% csrf_token %}
@@ -68,6 +70,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
         {% endfor %}
     </div>
     <input class="btn btn-primary btn-block" role="button" value="{% trans "Add an extra article"%}" id="add_one">
+    <h3>{% trans "Discount" %}</h3>
+    {% if discount_form %}
+    {% bootstrap_form discount_form %}
+    {% endif %}
     <p>
     {% blocktrans %}Total price: <span id="total_price">0,00</span> €{% endblocktrans %}
     </p>
@@ -119,6 +125,14 @@ with this program; if not, write to the Free Software Foundation, Inc.,
                 'id_form-' + i.toString() + '-quantity').value;
         price += article_price * quantity;
     }
+    {% if discount_form %}
+    var relative_discount = document.getElementById('id_is_relative').checked;
+    var discount = document.getElementById('id_discount').value;
+    if(relative_discount) {
+        discount = discount/100 * price;
+    }
+    price -= discount;
+    {% endif %}
     document.getElementById('total_price').innerHTML =
         price.toFixed(2).toString().replace('.', ',');
 }
@@ -148,6 +162,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
     for (i = 0; i < product_count; ++i){
         add_listenner_for_id(i);
     }
+    document.getElementById('id_discount')
+        .addEventListener('change', update_price, true);
+    document.getElementById('id_is_relative')
+        .addEventListener('click', update_price, true);
     update_price();
 });
 {% endif %}

cotisations/tex.py

@@ -36,6 +36,7 @@ from django.template import Context
 from django.http import HttpResponse
 from django.conf import settings
 from django.utils.text import slugify
+import logging
 
 
 TEMP_PREFIX = getattr(settings, 'TEX_TEMP_PREFIX', 'render_tex-')
@@ -93,6 +94,20 @@ def create_pdf(template, ctx={}):
     return pdf
 
 
+def escape_chars(string):
+    """Escape the '%' and the '€' signs to avoid messing with LaTeX"""
+    if not isinstance(string, str):
+        return string
+    mapping = (
+        ('€', r'\euro'),
+        ('%', r'\%'),
+    )
+    r = str(string)
+    for k, v in mapping:
+        r = r.replace(k, v)
+    return r
+
+
 def render_tex(_request, template, ctx={}):
     """Creates a PDF from a LaTex templates using pdflatex.
 

cotisations/views.py

@@ -80,9 +80,10 @@ from .forms import (
     DelBanqueForm,
     SelectArticleForm,
     RechargeForm,
-    CustomInvoiceForm
+    CustomInvoiceForm,
+    DiscountForm
 )
-from .tex import render_invoice
+from .tex import render_invoice, escape_chars
 from .payment_methods.forms import payment_method_factory
 from .utils import find_payment_method
 
@@ -198,8 +199,9 @@ def new_custom_invoice(request):
         request.POST or None,
         form_kwargs={'user': request.user}
     )
+    discount_form = DiscountForm(request.POST or None)
 
-    if invoice_form.is_valid() and articles_formset.is_valid():
+    if invoice_form.is_valid() and articles_formset.is_valid() and discount_form.is_valid():
         new_invoice_instance = invoice_form.save()
         for art_item in articles_formset:
             if art_item.cleaned_data:
@@ -213,6 +215,7 @@ def new_custom_invoice(request):
                     duration=article.duration,
                     number=quantity
                 )
+        discount_form.apply_to_invoice(new_invoice_instance)
         messages.success(
             request,
             _("The custom invoice was created.")
@@ -223,7 +226,8 @@ def new_custom_invoice(request):
         'factureform': invoice_form,
         'action_name': _("Confirm"),
         'articlesformset': articles_formset,
-        'articlelist': articles
+        'articlelist': articles,
+        'discount_form': discount_form
     }, 'cotisations/facture.html', request)
 
 
@@ -382,7 +386,7 @@ def custom_invoice_pdf(request, invoice, **_kwargs):
     purchases_info = []
     for purchase in purchases_objects:
         purchases_info.append({
-            'name': purchase.name,
+            'name': escape_chars(purchase.name),
             'price': purchase.prix,
             'quantity': purchase.number,
             'total_price': purchase.prix_total