Generalize import process from orders to more models (#4002)

* Generalize import process from orders to more models

* Add voucher import

* Model import: Guess assignments of based on column headers

* Fix lock_seats being pointless

* Update docs

* Update doc/development/api/import.rst

Co-authored-by: Richard Schreiber <schreiber@rami.io>

* Update src/pretix/base/modelimport_vouchers.py

Co-authored-by: Richard Schreiber <schreiber@rami.io>

---------

Co-authored-by: Richard Schreiber <schreiber@rami.io>

src/pretix/control/forms/modelimport.py

@@ -0,0 +1,110 @@
+#
+# 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 import forms
+from django.utils.translation import gettext_lazy as _
+
+from pretix.base.modelimport_orders import get_order_import_columns
+from pretix.base.modelimport_vouchers import get_voucher_import_columns
+
+
+class ProcessForm(forms.Form):
+
+    def __init__(self, *args, **kwargs):
+        headers = kwargs.pop('headers')
+        initital = kwargs.pop('initial', {}) or {}
+        kwargs['initial'] = initital
+        columns = self.get_columns()
+        column_keys = {c.identifier for c in columns}
+
+        if not initital or all(k not in column_keys for k in initital.keys()):
+            for c in columns:
+                initital.setdefault(c.identifier, c.initial)
+                for h in headers:
+                    if h == c.identifier or h == str(c.verbose_name):
+                        initital[c.identifier] = 'csv:{}'.format(h)
+                        break
+
+        super().__init__(*args, **kwargs)
+
+        header_choices = [
+            ('csv:{}'.format(h), _('CSV column: "{name}"').format(name=h)) for h in headers
+        ]
+
+        for c in columns:
+            choices = []
+            if c.default_value:
+                choices.append((c.default_value, c.default_label))
+            choices += header_choices
+            for k, v in c.static_choices():
+                choices.append(('static:{}'.format(k), v))
+
+            self.fields[c.identifier] = forms.ChoiceField(
+                label=str(c.verbose_name),
+                choices=choices,
+                widget=forms.Select(
+                    attrs={'data-static': 'true'}
+                )
+            )
+
+    def get_columns(self):
+        raise NotImplementedError()  # noqa
+
+
+class OrdersProcessForm(ProcessForm):
+    orders = forms.ChoiceField(
+        label=_('Import mode'),
+        choices=(
+            ('many', _('Create a separate order for each line')),
+            ('one', _('Create one order with one position per line')),
+        )
+    )
+    status = forms.ChoiceField(
+        label=_('Order status'),
+        choices=(
+            ('paid', _('Create orders as fully paid')),
+            ('pending', _('Create orders as pending and still require payment')),
+        )
+    )
+    testmode = forms.BooleanField(
+        label=_('Create orders as test mode orders'),
+        required=False
+    )
+
+    def __init__(self, *args, **kwargs):
+        self.event = kwargs.pop('event')
+        initital = kwargs.pop('initial', {})
+        initital['testmode'] = self.event.testmode
+        kwargs['initial'] = initital
+        super().__init__(*args, **kwargs)
+
+    def get_columns(self):
+        return get_order_import_columns(self.event)
+
+
+class VouchersProcessForm(ProcessForm):
+
+    def __init__(self, *args, **kwargs):
+        self.event = kwargs.pop('event')
+        super().__init__(*args, **kwargs)
+
+    def get_columns(self):
+        return get_voucher_import_columns(self.event)