fix(gift): receive response is idempotent and echoes persisted state

Three coupled correctness fixes to /tutorial/gift_receive's response:

- received_ids / total_receive_count_list / reward_list are now built
  from `toClaim` (the gifts THIS call granted), not from `requestedIds`.
  Echoing the client's request meant idempotent re-claims re-fired the
  "+N received" popup and direct-assigned the same post-state totals
  again, breaking the documented idempotency contract.
- is_unreceived_present is now `unclaimedPresents.Count > 0`. The
  hardcoded false hid the inbox badge after partial claims even when
  present_list still carried unclaimed gifts.
- tutorial_step echoes the persisted (max-preserved) state instead of
  a hardcoded 41. A replay against a state>=41 viewer used to surface
  41 on the wire and regress the client's tutorial state machine.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Controllers/GiftController.cs

@@ -136,13 +136,32 @@ public class GiftController : SVSimController
             .ToListAsync();
         var allClaimed = new HashSet<string>(allClaimedList);
 
+        // Derive presentList/historyList up front so IsUnreceivedPresent can read the count
+        // without re-filtering. unclaimedPresents are the gifts still on offer after this call;
+        // claimedPresents are everything the viewer has ever received (this call + prior calls).
+        var unclaimedPresents = TutorialGifts
+            .Where(p => !allClaimed.Contains(p.PresentId))
+            .Select(p => Clone(p, nowString))
+            .ToList();
+        var claimedPresents = TutorialGifts
+            .Where(p => allClaimed.Contains(p.PresentId))
+            .Select(p => Clone(p, nowString))
+            .ToList();
+
         return new GiftReceiveResponse
         {
             CardList = new(),
-            // Capture orders received_ids ascending — match.
+            // Echo only the ids actually granted by THIS call. Building this from `requestedIds`
-            ReceivedIds = requestedIds.OrderBy(x => x).ToList(),
+            // would falsely confirm a re-grant on idempotent retries: the client would re-show
-            TotalReceiveCountList = TutorialGifts
+            // the "received N gifts" popup and direct-assign the same post-state totals it already
-                .Where(p => requestedIds.Contains(p.PresentId))
+            // applied, double-toasting the user. Sort ascending to match the prod-capture order.
+            ReceivedIds = toClaim
+                .Select(p => p.PresentId)
+                .OrderBy(x => x)
+                .ToList(),
+            // Same idempotency contract: only the gifts granted in THIS call belong in the
+            // per-reward summary list. The client uses this to drive the +N popups.
+            TotalReceiveCountList = toClaim
                 .Select(p => new TotalReceiveCountDto
                 {
                     RewardType = int.Parse(p.RewardType),
@@ -151,22 +170,22 @@ public class GiftController : SVSimController
                     ItemType = p.ItemType ?? 0,
                     IsUsable = true,
                 }).ToList(),
-            PresentList = TutorialGifts
+            PresentList = unclaimedPresents,
-                .Where(p => !allClaimed.Contains(p.PresentId))
+            PresentHistoryList = claimedPresents,
-                .Select(p => Clone(p, nowString))
+            // True when there are still unclaimed gifts on offer — drives the inbox badge state.
-                .ToList(),
+            // Hardcoding false hid the badge after partial claims even though present_list still
-            PresentHistoryList = TutorialGifts
+            // carried unclaimed entries.
-                .Where(p => allClaimed.Contains(p.PresentId))
+            IsUnreceivedPresent = unclaimedPresents.Count > 0,
-                .Select(p => Clone(p, nowString))
-                .ToList(),
-            IsUnreceivedPresent = false,
             // reward_list entries must carry POST-STATE TOTALS, not gift deltas.
             // The client's PlayerStaticData.UpdateHaveUserGoodsNumByJsonData does direct
             // assignment on each entry's reward_num — emitting the delta would clobber
             // the client-side cached balance down to the gift amount until the next /load/index.
             // See project memory: project_wire_reward_list_post_state.
-            RewardList = TutorialGifts
+            //
-                .Where(p => requestedIds.Contains(p.PresentId))
+            // Iterate `toClaim` so idempotent re-receive doesn't re-emit post-state entries
+            // the client would direct-assign again (no-op on currency, but redundant traffic
+            // and risk of misinterpretation on item counts).
+            RewardList = toClaim
                 .Select(p => new GiftRewardListEntry
                 {
                     RewardType = p.RewardType,
@@ -174,7 +193,11 @@ public class GiftController : SVSimController
                     RewardNum = ResolvePostStateRewardNum(p, viewer),
                 })
                 .ToList(),
-            TutorialStep = 41,
+            // Echo the persisted state, not a hardcoded 41. The state may already be past 41
+            // for replay/edge-case calls (the Math.Max-preserve block above keeps it stable);
+            // emitting 41 anyway would surface a regressed step to the client and desync the
+            // tutorial-state machine.
+            TutorialStep = viewer.MissionData.TutorialState,
         };
     }
 

SVSim.UnitTests/Controllers/GiftControllerTests.cs

@@ -112,13 +112,73 @@ public class GiftControllerTests
 
         // Response carries the new step inline.
         Assert.That(root.GetProperty("tutorial_step").GetInt32(), Is.EqualTo(41));
-        Assert.That(root.GetProperty("is_unreceived_present").GetBoolean(), Is.False);
+        // Only 1 of 5 gifts claimed → 4 remain unclaimed → badge state must be "still has presents".
+        Assert.That(root.GetProperty("is_unreceived_present").GetBoolean(), Is.True,
+            "Partial claim leaves 4 gifts unclaimed in present_list — is_unreceived_present " +
+            "must reflect that so the client's inbox badge keeps surfacing.");
         Assert.That(root.GetProperty("reward_list").GetArrayLength(), Is.EqualTo(1));
+        Assert.That(root.GetProperty("present_list").GetArrayLength(), Is.EqualTo(4));
 
         // Side effect: viewer state advanced to 41.
         Assert.That(await factory.GetViewerTutorialStateAsync(viewerId), Is.EqualTo(41));
     }
 
+    [Test]
+    public async Task GiftReceive_returns_empty_received_ids_on_idempotent_replay()
+    {
+        using var factory = new SVSimTestFactory();
+        await factory.SeedGlobalsAsync();
+        long viewerId = await factory.SeedViewerAsync(tutorialState: 31);
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+
+        var json = $$"""{"present_id_array":["71478626","71478627"],"state":1,{{BaseAuthBlock}}}""";
+
+        // First call grants both gifts.
+        await client.PostAsync("/tutorial/gift_receive",
+            new StringContent(json, Encoding.UTF8, "application/json"));
+
+        // Second call (replay) must return empty received_ids / total_receive_count_list /
+        // reward_list — these lists describe what THIS call granted, not what the client
+        // asked for. Echoing requested ids would re-fire the client's "received N gifts"
+        // popup and direct-assign the same post-state totals again.
+        var second = await client.PostAsync("/tutorial/gift_receive",
+            new StringContent(json, Encoding.UTF8, "application/json"));
+        Assert.That(second.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+        using var doc = JsonDocument.Parse(await second.Content.ReadAsStringAsync());
+        var root = doc.RootElement;
+
+        Assert.That(root.GetProperty("received_ids").GetArrayLength(), Is.EqualTo(0),
+            "Idempotent re-claim grants nothing → received_ids empty.");
+        Assert.That(root.GetProperty("total_receive_count_list").GetArrayLength(), Is.EqualTo(0));
+        Assert.That(root.GetProperty("reward_list").GetArrayLength(), Is.EqualTo(0));
+
+        // present_history_list still includes the originally-claimed gifts.
+        Assert.That(root.GetProperty("present_history_list").GetArrayLength(), Is.EqualTo(2));
+    }
+
+    [Test]
+    public async Task GiftReceive_echoes_persisted_tutorial_step_not_hardcoded_41()
+    {
+        using var factory = new SVSimTestFactory();
+        await factory.SeedGlobalsAsync();
+        // Viewer is past the tutorial entirely (state=100). The gift_receive endpoint is
+        // still reachable via /tutorial/gift_receive — a stale client retry, for instance.
+        // The persistence side max-preserves (keeps state at 100); the response must echo
+        // 100, not the hardcoded 41 the endpoint used to emit, or the client's tutorial
+        // state machine regresses on a no-op retry.
+        long viewerId = await factory.SeedViewerAsync(tutorialState: 100);
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+
+        var json = $$"""{"present_id_array":["71478626"],"state":1,{{BaseAuthBlock}}}""";
+        var response = await client.PostAsync("/tutorial/gift_receive",
+            new StringContent(json, Encoding.UTF8, "application/json"));
+
+        Assert.That(response.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+        using var doc = JsonDocument.Parse(await response.Content.ReadAsStringAsync());
+        Assert.That(doc.RootElement.GetProperty("tutorial_step").GetInt32(), Is.EqualTo(100));
+        Assert.That(await factory.GetViewerTutorialStateAsync(viewerId), Is.EqualTo(100));
+    }
+
     [Test]
     public async Task GiftReceive_with_pre_owned_item_increments_existing_row()
     {