Invoicing: Allow to show exchange rates based on sources/rules (#3122)

src/pretix/base/models/currencies.py

@@ -0,0 +1,34 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
+# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+from django.db import models
+
+
+class ExchangeRate(models.Model):
+    source = models.CharField(max_length=100)
+    source_date = models.DateField()
+    updated = models.DateTimeField(auto_now=True)
+    source_currency = models.CharField(max_length=3)
+    other_currency = models.CharField(max_length=3)
+    rate = models.DecimalField(decimal_places=6, max_digits=16)
+
+    class Meta:
+        unique_together = (('source', 'source_currency', 'other_currency'))