Better labels for revente objects

The label for the ReventeModelMultipleChoiceField now depends on a
`own` parameter, which determines if we display the seller or the
buyer's name.

bda/forms.py

@@ -47,8 +47,29 @@ class AttributionModelMultipleChoiceField(forms.ModelMultipleChoiceField):
 
 
 class ReventeModelMultipleChoiceField(forms.ModelMultipleChoiceField):
+    def __init__(self, *args, own=True, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.own = own
+
     def label_from_instance(self, obj):
-        return str(obj.attribution.spectacle)
+        label = "{show}{suffix}"
+        suffix = ""
+        if self.own:
+            # C'est notre propre revente : pas besoin de spécifier le vendeur
+            if obj.soldTo is not None:
+                suffix = " -- Vendue à {firstname} {lastname}".format(
+                            firstname=obj.soldTo.user.first_name,
+                            lastname=obj.soldTo.user.last_name,
+                        )
+        else:
+            # Ce n'est pas à nous : on ne voit jamais l'acheteur
+            suffix = " -- Vendue par {firstname} {lastname}".format(
+                            firstname=obj.seller.user.first_name,
+                            lastname=obj.seller.user.last_name,
+                        )
+
+        return label.format(show=str(obj.attribution.spectacle),
+                            suffix=suffix)
 
 
 class ResellForm(forms.Form):
@@ -106,6 +127,7 @@ class InscriptionReventeForm(forms.Form):
 
 class ReventeTirageAnnulForm(forms.Form):
     reventes = ReventeModelMultipleChoiceField(
+                  own=False,
                   label='',
                   queryset=SpectacleRevente.objects.none(),
                   widget=forms.CheckboxSelectMultiple,
@@ -116,12 +138,14 @@ class ReventeTirageAnnulForm(forms.Form):
         super().__init__(*args, **kwargs)
         self.fields['reventes'].queryset = (
             participant.entered.filter(soldTo__isnull=True)
-                       .select_related('attribution__spectacle')
+                       .select_related('attribution__spectacle',
+                                       'seller__user')
         )
 
 
 class ReventeTirageForm(forms.Form):
     reventes = ReventeModelMultipleChoiceField(
+                  own=False,
                   label='',
                   queryset=SpectacleRevente.objects.none(),
                   widget=forms.CheckboxSelectMultiple,