feat: implement automatic cycle generation for members

- Add CycleGenerator module with advisory lock mechanism
- Add SetMembershipFeeStartDate change for auto-calculation
- Extend Settings with include_joining_cycle and default_membership_fee_type_id
- Add scheduled job skeleton for future Oban integration

test/membership_fees/member_cycle_integration_test.exs

@@ -0,0 +1,224 @@
+defmodule Mv.MembershipFees.MemberCycleIntegrationTest do
+  @moduledoc """
+  Integration tests for membership fee cycle generation triggered by member actions.
+  """
+  use Mv.DataCase, async: false
+
+  alias Mv.MembershipFees.MembershipFeeCycle
+  alias Mv.MembershipFees.MembershipFeeType
+  alias Mv.Membership.Member
+
+  require Ash.Query
+
+  # Helper to create a membership fee type
+  defp create_fee_type(attrs) do
+    default_attrs = %{
+      name: "Test Fee Type #{System.unique_integer([:positive])}",
+      amount: Decimal.new("50.00"),
+      interval: :yearly
+    }
+
+    attrs = Map.merge(default_attrs, attrs)
+
+    MembershipFeeType
+    |> Ash.Changeset.for_create(:create, attrs)
+    |> Ash.create!()
+  end
+
+  # Helper to set up settings
+  defp setup_settings(include_joining_cycle) do
+    {:ok, settings} = Mv.Membership.get_settings()
+
+    settings
+    |> Ash.Changeset.for_update(:update, %{include_joining_cycle: include_joining_cycle})
+    |> Ash.update!()
+  end
+
+  # Helper to get cycles for a member
+  defp get_member_cycles(member_id) do
+    MembershipFeeCycle
+    |> Ash.Query.filter(member_id == ^member_id)
+    |> Ash.Query.sort(cycle_start: :asc)
+    |> Ash.read!()
+  end
+
+  describe "member creation triggers cycle generation" do
+    test "creates cycles when member is created with fee type and join_date" do
+      setup_settings(true)
+      fee_type = create_fee_type(%{interval: :yearly})
+
+      member =
+        Member
+        |> Ash.Changeset.for_create(:create_member, %{
+          first_name: "Test",
+          last_name: "User",
+          email: "test#{System.unique_integer([:positive])}@example.com",
+          join_date: ~D[2023-03-15],
+          membership_fee_type_id: fee_type.id
+        })
+        |> Ash.create!()
+
+      # Wait for async cycle generation
+      Process.sleep(300)
+
+      cycles = get_member_cycles(member.id)
+
+      # Should have cycles for 2023 and 2024 (and possibly current year)
+      assert length(cycles) >= 2
+
+      # Verify cycles have correct data
+      Enum.each(cycles, fn cycle ->
+        assert cycle.member_id == member.id
+        assert cycle.membership_fee_type_id == fee_type.id
+        assert Decimal.equal?(cycle.amount, fee_type.amount)
+        assert cycle.status == :unpaid
+      end)
+    end
+
+    test "does not create cycles when member has no fee type" do
+      setup_settings(true)
+
+      member =
+        Member
+        |> Ash.Changeset.for_create(:create_member, %{
+          first_name: "Test",
+          last_name: "User",
+          email: "test#{System.unique_integer([:positive])}@example.com",
+          join_date: ~D[2023-03-15]
+          # No membership_fee_type_id
+        })
+        |> Ash.create!()
+
+      # Wait for potential async cycle generation
+      Process.sleep(200)
+
+      cycles = get_member_cycles(member.id)
+
+      assert cycles == []
+    end
+
+    test "does not create cycles when member has no join_date" do
+      setup_settings(true)
+      fee_type = create_fee_type(%{interval: :yearly})
+
+      member =
+        Member
+        |> Ash.Changeset.for_create(:create_member, %{
+          first_name: "Test",
+          last_name: "User",
+          email: "test#{System.unique_integer([:positive])}@example.com",
+          membership_fee_type_id: fee_type.id
+          # No join_date
+        })
+        |> Ash.create!()
+
+      # Wait for potential async cycle generation
+      Process.sleep(200)
+
+      cycles = get_member_cycles(member.id)
+
+      assert cycles == []
+    end
+  end
+
+  describe "member update triggers cycle generation" do
+    test "generates cycles when fee type is assigned to existing member" do
+      setup_settings(true)
+      fee_type = create_fee_type(%{interval: :yearly})
+
+      # Create member without fee type
+      member =
+        Member
+        |> Ash.Changeset.for_create(:create_member, %{
+          first_name: "Test",
+          last_name: "User",
+          email: "test#{System.unique_integer([:positive])}@example.com",
+          join_date: ~D[2023-03-15]
+        })
+        |> Ash.create!()
+
+      # Verify no cycles yet
+      assert get_member_cycles(member.id) == []
+
+      # Update to assign fee type
+      member
+      |> Ash.Changeset.for_update(:update_member, %{membership_fee_type_id: fee_type.id})
+      |> Ash.update!()
+
+      # Wait for async cycle generation
+      Process.sleep(300)
+
+      cycles = get_member_cycles(member.id)
+
+      # Should have generated cycles
+      assert length(cycles) >= 2
+    end
+  end
+
+  describe "concurrent cycle generation" do
+    test "handles multiple members being created concurrently" do
+      setup_settings(true)
+      fee_type = create_fee_type(%{interval: :yearly})
+
+      # Create multiple members concurrently
+      tasks =
+        Enum.map(1..5, fn i ->
+          Task.async(fn ->
+            Member
+            |> Ash.Changeset.for_create(:create_member, %{
+              first_name: "Test#{i}",
+              last_name: "User#{i}",
+              email: "test#{System.unique_integer([:positive])}@example.com",
+              join_date: ~D[2023-03-15],
+              membership_fee_type_id: fee_type.id
+            })
+            |> Ash.create!()
+          end)
+        end)
+
+      members = Enum.map(tasks, &Task.await/1)
+
+      # Wait for all async cycle generations
+      Process.sleep(500)
+
+      # Each member should have cycles
+      Enum.each(members, fn member ->
+        cycles = get_member_cycles(member.id)
+        assert length(cycles) >= 2, "Member #{member.id} should have at least 2 cycles"
+      end)
+    end
+  end
+
+  describe "idempotent cycle generation" do
+    test "running generation multiple times does not create duplicate cycles" do
+      setup_settings(true)
+      fee_type = create_fee_type(%{interval: :yearly})
+
+      member =
+        Member
+        |> Ash.Changeset.for_create(:create_member, %{
+          first_name: "Test",
+          last_name: "User",
+          email: "test#{System.unique_integer([:positive])}@example.com",
+          join_date: ~D[2023-03-15],
+          membership_fee_type_id: fee_type.id
+        })
+        |> Ash.create!()
+
+      # Wait for async cycle generation
+      Process.sleep(300)
+
+      initial_cycles = get_member_cycles(member.id)
+      initial_count = length(initial_cycles)
+
+      # Manually trigger generation again
+      {:ok, _} = Mv.MembershipFees.CycleGenerator.generate_cycles_for_member(member.id)
+
+      final_cycles = get_member_cycles(member.id)
+      final_count = length(final_cycles)
+
+      # Should have same number of cycles
+      assert final_count == initial_count
+    end
+  end
+end