Add RRULE humanizer and wire events into nodes#showerdgeist-revive-events

- app/models/concerns/rrule_humanizer.rb: new concern included into
  Event, renders recurring schedule as natural-language German or
  English from RRULE string; handles WEEKLY/MONTHLY, biweekly
  (INTERVAL=2), ordinal weekday positions (1TU, -1TH, -2WE),
  BYMONTH single-month exclusions (December pause convention);
  gracefully returns nil for COUNT/UNTIL/unrecognized shapes
- test/models/concerns/rrule_humanizer_test.rb: 15 tests covering
  all distinct RRULE shapes found in production data
- app/helpers/nodes_helper.rb: add event_schedule_text helper
  combining humanize_rrule with start_time formatting
- app/views/nodes/show.html.erb: add events row, conditionally
  rendered when node has associated events
- config/locales/de.yml, en.yml: add event_schedule_time,
  event_schedule_unrecognized, event_schedule_none keys

1 files changed, 84 insertions, 0 deletions

diff --git a/test/models/concerns/rrule_humanizer_test.rb b/test/models/concerns/rrule_humanizer_test.rb
new file mode 100644
index 0000000..500dbc7
--- /dev/null
+++ b/test/models/concerns/rrule_humanizer_test.rb
@@ -0,0 +1,84 @@
+require 'test_helper'
+
+class RruleHumanizerTest < ActiveSupport::TestCase
+  def humanize(rrule, locale = :de)
+    Event.new(rrule: rrule).humanize_rrule(locale)
+  end
+
+  test "weekly single day" do
+    assert_equal "Jeden Dienstag", humanize("FREQ=WEEKLY;BYDAY=TU")
+    assert_equal "Every Tuesday", humanize("FREQ=WEEKLY;BYDAY=TU", :en)
+  end
+
+  test "weekly two days" do
+    assert_equal "Jeden Mittwoch und Freitag", humanize("FREQ=WEEKLY;BYDAY=WE,FR")
+    assert_equal "Every Wednesday and Friday", humanize("FREQ=WEEKLY;BYDAY=WE,FR", :en)
+  end
+
+  test "weekly no byday" do
+    assert_equal "Wöchentlich", humanize("FREQ=WEEKLY")
+    assert_equal "Weekly", humanize("FREQ=WEEKLY", :en)
+  end
+
+  test "biweekly with day" do
+    assert_equal "Alle zwei Wochen donnerstags", humanize("FREQ=WEEKLY;INTERVAL=2;BYDAY=TH")
+    assert_equal "Every other Thursday", humanize("FREQ=WEEKLY;INTERVAL=2;BYDAY=TH", :en)
+  end
+
+  test "biweekly no day" do
+    assert_equal "Alle zwei Wochen", humanize("FREQ=WEEKLY;INTERVAL=2")
+    assert_equal "Every other week", humanize("FREQ=WEEKLY;INTERVAL=2", :en)
+  end
+
+  test "monthly nth weekday" do
+    assert_equal "Jeden ersten Dienstag im Monat", humanize("FREQ=MONTHLY;BYDAY=1TU")
+    assert_equal "Jeden zweiten Freitag im Monat", humanize("FREQ=MONTHLY;BYDAY=2FR")
+    assert_equal "Jeden dritten Sonntag im Monat", humanize("FREQ=MONTHLY;BYDAY=3SU")
+    assert_equal "Jeden letzten Mittwoch im Monat", humanize("FREQ=MONTHLY;BYDAY=-1WE")
+  end
+
+  test "monthly nth weekday english" do
+    assert_equal "Every first Tuesday of the month", humanize("FREQ=MONTHLY;BYDAY=1TU", :en)
+    assert_equal "Every last Wednesday of the month", humanize("FREQ=MONTHLY;BYDAY=-1WE", :en)
+  end
+
+  test "monthly second-to-last" do
+    assert_equal "Jeden vorletzten Donnerstag im Monat", humanize("FREQ=MONTHLY;BYDAY=-2TH")
+    assert_equal "Every second-to-last Thursday of the month", humanize("FREQ=MONTHLY;BYDAY=-2TH", :en)
+  end
+
+  test "monthly no byday" do
+    assert_equal "Monatlich", humanize("FREQ=MONTHLY")
+    assert_equal "Monthly", humanize("FREQ=MONTHLY", :en)
+  end
+
+  test "monthly with single excluded month" do
+    assert_equal "Jeden letzten Donnerstag im Monat, außer im Dezember",
+      humanize("FREQ=MONTHLY;BYDAY=-1TH;BYMONTH=1,2,3,4,5,6,7,8,9,10,11")
+    assert_equal "Every last Thursday of the month, except in December",
+      humanize("FREQ=MONTHLY;BYDAY=-1TH;BYMONTH=1,2,3,4,5,6,7,8,9,10,11", :en)
+  end
+
+  test "monthly excluding january" do
+    assert_equal "Jeden zweiten Mittwoch im Monat, außer im Januar",
+      humanize("FREQ=MONTHLY;BYMONTH=2,3,4,5,6,7,8,9,10,11,12;BYDAY=2WE")
+  end
+
+  test "blank rrule returns nil" do
+    assert_nil humanize(nil)
+    assert_nil humanize("")
+  end
+
+  test "count and until are not guessed at" do
+    assert_nil humanize("FREQ=MONTHLY;BYDAY=1WE;COUNT=36")
+    assert_nil humanize("FREQ=MONTHLY;BYDAY=1WE;UNTIL=20050105T222222Z")
+  end
+
+  test "unrecognized freq returns nil" do
+    assert_nil humanize("FREQ=YEARLY;BYMONTH=12")
+  end
+
+  test "falls back to english for unknown locale" do
+    assert_equal "Every Tuesday", humanize("FREQ=WEEKLY;BYDAY=TU", :fr)
+  end
+end