feat: regenerate cycles when membership fee type changes (same interval)

- Implemented regenerate_cycles_on_type_change helper in Member resource
- Cycles that haven't ended yet (cycle_end >= today) are deleted and regenerated
- Paid and suspended cycles remain unchanged (not deleted)
- CycleGenerator reloads member with new membership_fee_type_id
- Adjusted tests to work with current cycles only (no future cycles)
- All integration tests passing

Phase 4 completed: Cycle regeneration on type change

lib/membership/member.ex

@@ -189,34 +189,35 @@ defmodule Mv.Membership.Member do
         where [changing(:membership_fee_type_id)]
       end
 
-      # Trigger cycle generation when membership_fee_type_id changes
-      # Note: Cycle generation runs asynchronously to not block the action,
+      # Trigger cycle regeneration when membership_fee_type_id changes
+      # This deletes future unpaid cycles and regenerates them with the new type/amount
+      # Note: Cycle regeneration runs asynchronously to not block the action,
       # but in test environment it runs synchronously for DB sandbox compatibility
       change after_action(fn changeset, member, _context ->
                fee_type_changed =
                  Ash.Changeset.changing_attribute?(changeset, :membership_fee_type_id)
 
                if fee_type_changed && member.membership_fee_type_id && member.join_date do
-                 generate_fn = fn ->
-                   case Mv.MembershipFees.CycleGenerator.generate_cycles_for_member(member.id) do
-                     {:ok, _cycles} ->
+                 regenerate_fn = fn ->
+                   case regenerate_cycles_on_type_change(member) do
+                     :ok ->
                        :ok
 
                      {:error, reason} ->
                        require Logger
 
                        Logger.warning(
-                         "Failed to generate cycles for member #{member.id}: #{inspect(reason)}"
+                         "Failed to regenerate cycles for member #{member.id}: #{inspect(reason)}"
                        )
                    end
                  end
 
                  if Application.get_env(:mv, :sql_sandbox, false) do
                    # Run synchronously in test environment for DB sandbox compatibility
-                   generate_fn.()
+                   regenerate_fn.()
                  else
                    # Run asynchronously in other environments
-                   Task.start(generate_fn)
+                   Task.start(regenerate_fn)
                  end
                end
 
@@ -646,10 +647,13 @@ defmodule Mv.Membership.Member do
             false
         end
       end)
-      |> Enum.sort_by(fn cycle ->
-        interval = Map.get(cycle, :membership_fee_type).interval
-        Mv.MembershipFees.CalendarCycles.calculate_cycle_end(cycle.cycle_start, interval)
-      end, {:desc, Date})
+      |> Enum.sort_by(
+        fn cycle ->
+          interval = Map.get(cycle, :membership_fee_type).interval
+          Mv.MembershipFees.CalendarCycles.calculate_cycle_end(cycle.cycle_start, interval)
+        end,
+        {:desc, Date}
+      )
       |> List.first()
     else
       nil
@@ -681,6 +685,75 @@ defmodule Mv.Membership.Member do
     end
   end
 
+  # Regenerates cycles when membership fee type changes
+  # Deletes future unpaid cycles and regenerates them with the new type/amount
+  defp regenerate_cycles_on_type_change(member) do
+    alias Mv.MembershipFees.MembershipFeeCycle
+    alias Mv.MembershipFees.CycleGenerator
+    alias Mv.MembershipFees.CalendarCycles
+
+    require Ash.Query
+
+    today = Date.utc_today()
+
+    # Find all unpaid cycles for this member
+    # We need to check cycle_end for each cycle using its own interval
+    all_unpaid_cycles_query =
+      MembershipFeeCycle
+      |> Ash.Query.filter(member_id == ^member.id)
+      |> Ash.Query.filter(status == :unpaid)
+      |> Ash.Query.load([:membership_fee_type])
+
+    case Ash.read(all_unpaid_cycles_query) do
+      {:ok, all_unpaid_cycles} ->
+        # Filter cycles that haven't ended yet (cycle_end >= today)
+        # These are the "future" cycles that should be regenerated
+        # Use each cycle's own interval to calculate cycle_end
+        cycles_to_delete =
+          Enum.filter(all_unpaid_cycles, fn cycle ->
+            case cycle.membership_fee_type do
+              %{interval: interval} ->
+                cycle_end = CalendarCycles.calculate_cycle_end(cycle.cycle_start, interval)
+                Date.compare(today, cycle_end) in [:lt, :eq]
+
+              _ ->
+                false
+            end
+          end)
+
+        # Delete future unpaid cycles
+        if Enum.empty?(cycles_to_delete) do
+          # No cycles to delete, just regenerate
+          case CycleGenerator.generate_cycles_for_member(member.id) do
+            {:ok, _cycles} -> :ok
+            {:error, reason} -> {:error, reason}
+          end
+        else
+          delete_results =
+            Enum.map(cycles_to_delete, fn cycle ->
+              Ash.destroy(cycle)
+            end)
+
+          # Check if any deletions failed
+          if Enum.any?(delete_results, &match?({:error, _}, &1)) do
+            {:error, :deletion_failed}
+          else
+            # Regenerate cycles with new type/amount
+            # CycleGenerator uses its own transaction with advisory lock
+            # It will reload the member, so it will see the deleted cycles are gone
+            # and the new membership_fee_type_id
+            case CycleGenerator.generate_cycles_for_member(member.id) do
+              {:ok, _cycles} -> :ok
+              {:error, reason} -> {:error, reason}
+            end
+          end
+        end
+
+      {:error, reason} ->
+        {:error, reason}
+    end
+  end
+
   # Normalizes visibility config map keys from strings to atoms.
   # JSONB in PostgreSQL converts atom keys to string keys when storing.
   defp normalize_visibility_config(config) when is_map(config) do