Add sub-events and relative date settings (#503)

* Data model

* little crud

* SubEventItemForm etc

* Drop SubEventItem.active, quota editor

* Fix failing tests

* First frontend stuff

* Addons form stuff

* Quota calculation

* net price display on EventIndex

* Add tests, solve some bugs

* Correct quota selection in more places, consolidate pricing logic

* Fix failing quota tests

* Fix TypeError

* Add tests for checkout

* Fixed a bug in QuotaForm

* Prevent immutable cart if a quota was removed from an item

* Add tests for pricing

* Handle waiting list

* Filter in check-in list

* Fixed import lost in rebase

* Fix waiting list widget

* Voucher management

* Voucher redemption

* Fix broken tests

* Add subevents to OrderChangeManager

* Create a subevent during event creation

* Fix bulk voucher creation

* Introduce subevent.active

* Copy from for subevents

* Show active in list

* ICal download for subevents

* Check start and end of presale

* Failing tests / show cart logic

* Test

* Rebase migrations

* REST API integration of sub-events

* Integrate quota calculation into the traditional quota form

* Make subevent argument to add_position optional

* Log-display foo

* pretixdroid and subevents

* Filter by subevent

* Add more tests

* Some mor tests

* Rebase fixes

* More tests

* Relative dates

* Restrict selection in relative datetime widgets

* Filter subevent list

* Re-label has_subevents

* Rebase fixes, subevents in calendar view

* Performance and caching issues

* Refactor calendar templates

* Permission tests

* Calendar fixes and month selection

* subevent selection

* Rename subevents to dates

* Add tests for calendar views

src/tests/base/test_reldate.py

@@ -0,0 +1,82 @@
+from datetime import datetime, time
+
+import pytest
+import pytz
+
+from pretix.base.models import Event, Organizer
+from pretix.base.reldate import RelativeDate, RelativeDateWrapper
+
+TOKYO = pytz.timezone('Asia/Tokyo')
+
+
+@pytest.fixture
+def event():
+    o = Organizer.objects.create(name='Dummy', slug='dummy')
+    event = Event.objects.create(
+        organizer=o, name='Dummy', slug='dummy',
+        date_from=datetime(2017, 12, 27, 5, 0, 0, tzinfo=TOKYO),
+        presale_start=datetime(2017, 12, 1, 5, 0, 0, tzinfo=TOKYO),
+        plugins='pretix.plugins.banktransfer'
+
+    )
+    event.settings.timezone = "Asia/Tokyo"
+    return event
+
+
+@pytest.mark.django_db
+def test_absolute_date(event):
+    d = datetime(2017, 12, 25, 5, 0, 0, tzinfo=TOKYO)
+    rdw = RelativeDateWrapper(d)
+    assert rdw.datetime(event) == d
+    assert rdw.to_string() == d.isoformat()
+
+
+@pytest.mark.django_db
+def test_relative_date_without_time(event):
+    rdw = RelativeDateWrapper(RelativeDate(days_before=1, time=None, base_date_name='date_from'))
+    assert rdw.datetime(event).astimezone(TOKYO) == datetime(2017, 12, 26, 5, 0, 0, tzinfo=TOKYO)
+    assert rdw.to_string() == 'RELDATE/1/-/date_from/'
+
+
+@pytest.mark.django_db
+def test_relative_date_other_base_point(event):
+    rdw = RelativeDateWrapper(RelativeDate(days_before=1, time=None, base_date_name='presale_start'))
+    assert rdw.datetime(event) == datetime(2017, 11, 30, 5, 0, 0, tzinfo=TOKYO)
+    assert rdw.to_string() == 'RELDATE/1/-/presale_start/'
+
+    # presale_end is unset, defaults to date_from
+    rdw = RelativeDateWrapper(RelativeDate(days_before=1, time=None, base_date_name='presale_end'))
+    assert rdw.datetime(event) == datetime(2017, 12, 26, 5, 0, 0, tzinfo=TOKYO)
+    assert rdw.to_string() == 'RELDATE/1/-/presale_end/'
+
+    # subevent base
+    se = event.subevents.create(name="SE1", date_from=datetime(2017, 11, 27, 5, 0, 0, tzinfo=TOKYO))
+    rdw = RelativeDateWrapper(RelativeDate(days_before=1, time=None, base_date_name='date_from'))
+    assert rdw.datetime(se) == datetime(2017, 11, 26, 5, 0, 0, tzinfo=TOKYO)
+
+    # presale_start is unset on subevent, default to event
+    rdw = RelativeDateWrapper(RelativeDate(days_before=1, time=None, base_date_name='presale_start'))
+    assert rdw.datetime(se) == datetime(2017, 11, 30, 5, 0, 0, tzinfo=TOKYO)
+
+    # presale_end is unset on all, default to date_from of subevent
+    rdw = RelativeDateWrapper(RelativeDate(days_before=1, time=None, base_date_name='presale_end'))
+    assert rdw.datetime(se) == datetime(2017, 11, 26, 5, 0, 0, tzinfo=TOKYO)
+
+
+@pytest.mark.django_db
+def test_relative_date_with_time(event):
+    rdw = RelativeDateWrapper(RelativeDate(days_before=1, time=time(8, 5, 13), base_date_name='date_from'))
+    assert rdw.to_string() == 'RELDATE/1/08:05:13/date_from/'
+    assert rdw.datetime(event) == datetime(2017, 12, 26, 8, 5, 13, tzinfo=TOKYO)
+
+
+def test_unserialize():
+    d = datetime(2017, 12, 25, 10, 0, 0, tzinfo=TOKYO)
+    rdw = RelativeDateWrapper.from_string(d.isoformat())
+    assert rdw.data == d
+
+    rdw = RelativeDateWrapper.from_string('RELDATE/1/-/date_from/')
+    assert rdw.data == RelativeDate(days_before=1, time=None, base_date_name='date_from')
+
+    rdw = RelativeDateWrapper.from_string('RELDATE/1/18:05:13/date_from/')
+    assert rdw.data == RelativeDate(days_before=1, time=time(18, 5, 13), base_date_name='date_from')