Remove Tx model

There was a split between a transaction request and an actual
transaction. This was kind of annoying because transactions were one-way
only, while transaction requests were two-way - which is what I believe
most transactions will be using. Tx model has been removed and the
responsibilities of it are covered by TxRequest. It simplifies
everything surrounding transactions, since we have only one model to
deal with instead of two.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

trading/views.py

@@ -12,7 +12,7 @@ from django.views.generic.edit import CreateView, UpdateView
 from django.views.generic.list import ListView
 from django.urls import reverse, reverse_lazy
 from django.utils.translation import gettext_lazy as _
-from trading.models import User, Commodity, MaxCommodityError, Tx, TxRequest
+from trading.models import User, Commodity, MaxCommodityError, TxRequest
 
 
 class IndexView(LoginRequiredMixin, TemplateView):
@@ -57,6 +57,21 @@ class TxRequestDetailView(DetailView):
     template_name = "trading/t/detail.html"
     model = TxRequest
 
+    def get_context_data(self, **kwargs):
+        context = super().get_context_data(**kwargs)
+        tx = context["object"]
+        if self.request.user == tx.source:
+            context["sent"] = tx.source_sends
+            context["sent_amount"] = tx.source_amount
+            context["received"] = tx.dest_sends
+            context["received_amount"] = tx.dest_amount
+        else:
+            context["sent"] = tx.dest_sends
+            context["sent_amount"] = tx.dest_amount
+            context["received"] = tx.source_sends
+            context["received_amount"] = tx.source_amount
+        return context
+
 
 class TxRequestListView(LoginRequiredMixin, ListView):
     template_name = "trading/t/list.html"