fix: preserve yearly streak gap repairs through recalculation

src/Orbit.Application/Chat/Content/FeatureExplanations/streaks.md

@@ -8,7 +8,7 @@ derived_from:
   - src/Orbit.Application/Habits/Services/HabitScheduleService.cs ComputeStreakAsOf
   - src/Orbit.Infrastructure/Services/UserStreakService.cs LoadStreakDataAsync
   - src/Orbit.Infrastructure/Services/UserStreakService.cs CalendarFallback
-  - src/Orbit.Application/Common/AppConstants.cs MaxStreakLookbackDays
+  - src/Orbit.Application/Common/AppConstants.cs StreakRepairWindowDays
 ---
 
 # Streaks
@@ -34,6 +34,6 @@ If you have no recurring habits at all yet, the streak falls back to simple **ca
 
 ## Lookback limit
 
-Streak calculation looks back at most **365** days (`MaxStreakLookbackDays`). Activity older than a year does not extend the current streak.
+Streak calculation looks back at most **732** days (`StreakRepairWindowDays`). This includes the completed occurrence before a repaired yearly gap. Activity outside this window does not extend the current streak.
 
 The longest streak is tracked separately by scanning your full scheduled-day history for the longest unbroken run; it never decreases when the current streak resets.

src/Orbit.Application/Common/AppConstants.cs

@@ -70,6 +70,8 @@ public static class AppConstants
     public const int MaxStreakFreezesAccumulated = 3;
     public const int StreakDaysPerFreeze = 7;
     public const int MaxStreakLookbackDays = 365;
+    /// <summary>Two annual intervals retain a completed predecessor while a repaired yearly occurrence remains current.</summary>
+    public const int StreakRepairWindowDays = 2 * 366;
     public const int MaxSyncWindowDays = 30;
     public const int SyncCleanupMarginDays = 1;
     public const int MaxChallengeTitleLength = 200;

src/Orbit.Application/Gamification/Queries/GetStreakHistoryQuery.cs

@@ -34,7 +34,7 @@ public async Task<Result<StreakHistoryResponse>> Handle(GetStreakHistoryQuery re
         if (!unlocked)
             return Result.PayGateFailure<StreakHistoryResponse>("Streak insights are a Pro feature. Upgrade to unlock!");
 
-        var seedFrom = request.DateFrom.AddDays(-AppConstants.MaxStreakLookbackDays);
+        var seedFrom = request.DateFrom.AddDays(-AppConstants.StreakRepairWindowDays);
 
         var allHabits = await habitRepository.FindAsync(h => h.UserId == request.UserId, cancellationToken);
         var streakEligibleHabitIds = allHabits

src/Orbit.Application/Habits/Services/HabitScheduleService.cs

@@ -107,8 +107,16 @@
                 TimeZoneInfo.ConvertTimeFromUtc(habit.CreatedAtUtc, userTimeZone));
             var effectiveFrom = from < habitStart ? habitStart : from;
 
-            foreach (var date in GetStreakScheduledDates(habit, effectiveFrom, to, habitStart, weekStartDay))
-                union.Add(date);
+            var sliceFrom = effectiveFrom;
+            while (sliceFrom <= to)
+            {
+                var sliceTo = sliceFrom.AddDays(Math.Min(AppConstants.MaxRangeDays, to.DayNumber - sliceFrom.DayNumber));
+                foreach (var date in GetStreakScheduledDates(habit, sliceFrom, sliceTo, habitStart, weekStartDay))
+                    union.Add(date);
+                if (sliceTo == to)
+                    break;
+                sliceFrom = sliceTo.AddDays(1);
+            }
         }
         return union;
     }
@@ -315,8 +323,8 @@
 
     private static DateOnly Max(DateOnly first, DateOnly second, DateOnly third) =>
         first > second
             ? first > third ? first : third
             : second > third ? second : third;
 
     public static bool HasMissedPastOccurrence(
         Habit habit,

src/Orbit.Infrastructure/Services/UserStreakService.cs

@@ -64,7 +64,7 @@ public class UserStreakService(
         if (user is null)
             return null;
 
-        var lookbackStart = userToday.AddDays(-AppConstants.MaxStreakLookbackDays);
+        var lookbackStart = userToday.AddDays(-AppConstants.StreakRepairWindowDays);
         var (completionDateSet, freezeDateSet, eligibleHabits) =
             await LoadStreakDataAsync(userId, lookbackStart, cancellationToken);
 
@@ -92,7 +92,7 @@ public class UserStreakService(
         if (user is null)
             return null;
 
-        var lookbackStart = userToday.AddDays(-AppConstants.MaxStreakLookbackDays);
+        var lookbackStart = userToday.AddDays(-AppConstants.StreakRepairWindowDays);
         var gapStart = dates.Min();
         if (gapStart <= lookbackStart)
             return null;
@@ -116,7 +116,7 @@ public async Task<IReadOnlyList<DateOnly>> GetRepairableGapDatesAsync(
         if (user is null)
             return [];
 
-        var lookbackStart = userToday.AddDays(-AppConstants.MaxStreakLookbackDays);
+        var lookbackStart = userToday.AddDays(-AppConstants.StreakRepairWindowDays);
         var (completions, freezes, eligibleHabits) =
             await LoadStreakDataAsync(userId, lookbackStart, cancellationToken);
         var expectedDates = GetExpectedDates(user, lookbackStart, userToday, eligibleHabits);
@@ -245,7 +245,7 @@ internal static StreakRepairEvaluation EvaluateRepair(
         if (!contributingHabits.Any(habit => habit.FrequencyUnit is not null))
             return StreakRepairEvaluation.Unavailable(missedDate);
 
-        var lookbackStart = userToday.AddDays(-AppConstants.MaxStreakLookbackDays);
+        var lookbackStart = userToday.AddDays(-AppConstants.StreakRepairWindowDays);
 
         var userTimeZone = TimeZoneHelper.FindTimeZone(user.TimeZone, userId: user.Id);
         var expectedDates = HabitScheduleService.GetUnionScheduledDatesForStreak(
@@ -321,7 +321,7 @@ private async Task<UserStreakState> CalculateStateAsync(
         CancellationToken cancellationToken)
     {
         var userToday = await userDateService.GetUserTodayAsync(userId, cancellationToken);
-        var lookbackStart = userToday.AddDays(-AppConstants.MaxStreakLookbackDays);
+        var lookbackStart = userToday.AddDays(-AppConstants.StreakRepairWindowDays);
         var (completionDateSet, freezeDateSet, eligibleHabits) =
             await LoadStreakDataAsync(userId, lookbackStart, cancellationToken);
         var contributingHabits = GetContributingHabits(eligibleHabits);

tests/Orbit.Application.Tests/Chat/FeatureExplanationDriftTests.cs

@@ -38,7 +38,7 @@ public void Freezes_MatchesStreakFreezeConstants()
     [Fact]
     public void Streaks_MatchesLookbackConstant()
     {
-        Body("streaks").Should().Contain(N(AppConstants.MaxStreakLookbackDays));
+        Body("streaks").Should().Contain(N(AppConstants.StreakRepairWindowDays));
     }
 
     [Fact]

tests/Orbit.Application.Tests/Queries/Gamification/GetStreakHistoryQueryHandlerTests.cs

@@ -101,6 +101,29 @@ private void ArrangeFreezes(params StreakFreeze[] freezes)
             .Returns(freezes.ToList());
     }
 
+    [Fact]
+    public async Task Handle_RepairedYearlyGap_RetainsPredecessorAndRecentCompletion()
+    {
+        _userRepo.GetByIdAsync(UserId, Arg.Any<CancellationToken>()).Returns(CreateProUser());
+        var today = new DateOnly(2024, 9, 6);
+        var gap = today.AddDays(-1);
+        var predecessor = gap.AddYears(-1);
+        var habit = Habit.Create(new HabitCreateParams(UserId, "Annual review", FrequencyUnit.Year, 1,
+            DueDate: predecessor)).Value;
+        BackdateCreation(habit, predecessor);
+        Log(habit, predecessor, gap.AddYears(1));
+        ArrangeHabits(habit);
+        ArrangeFreezes(StreakFreeze.Create(UserId, gap, StreakFreezeOrigin.Manual));
+
+        var result = await _handler.Handle(
+            new GetStreakHistoryQuery(UserId, gap, gap.AddYears(1)), CancellationToken.None);
+
+        result.IsSuccess.Should().BeTrue();
+        result.Value.Points[0].Streak.Should().Be(1);
+        result.Value.Points[^1].Streak.Should().Be(2);
+        result.Value.Points.Should().OnlyContain(point => point.Streak > 0);
+    }
+
     [Fact]
     public async Task Handle_ProUser_IncrementsStreakForConsecutiveScheduledDays()
     {

tests/Orbit.Application.Tests/Services/HabitScheduleServiceTests.cs

@@ -1,6 +1,7 @@
 using System.Linq.Expressions;
 using FluentAssertions;
 using NSubstitute;
+using Orbit.Application.Common;
 using Orbit.Application.Habits.Services;
 using Orbit.Domain.Entities;
 using Orbit.Domain.Enums;
@@ -12,6 +13,38 @@ public class HabitScheduleServiceTests
 {
     private static readonly Guid UserId = Guid.NewGuid();
     private static readonly DateOnly Anchor = new(2025, 1, 6);
+
+    [Theory]
+    [InlineData(366)]
+    [InlineData(367)]
+    [InlineData(732)]
+    [InlineData(794)]
+    public void StreakSchedule_LongRangeIncludesEveryDateAcrossSliceBoundaries(int days)
+    {
+        var habit = CreateHabit(FrequencyUnit.Day, 1);
+        typeof(Habit).GetProperty(nameof(Habit.CreatedAtUtc))!.SetValue(habit,
+            Anchor.ToDateTime(TimeOnly.MinValue, DateTimeKind.Utc));
+        var to = Anchor.AddDays(days);
+
+        var dates = HabitScheduleService.GetUnionScheduledDatesForStreak([habit], Anchor, to, TimeZoneInfo.Utc);
+
+        dates.Should().BeEquivalentTo(Enumerable.Range(0, days + 1).Select(Anchor.AddDays));
+        var state = HabitScheduleService.ComputeStreakAsOf(dates, dates, [], Anchor, to);
+        state.Streak.Should().Be(days + 1);
+        state.LastActiveDate.Should().Be(to);
+    }
+
+    [Fact]
+    public void ScheduledDates_LongRangeRetainsThePublicRangeCap()
+    {
+        var habit = CreateHabit(FrequencyUnit.Day, 1);
+
+        var dates = HabitScheduleService.GetScheduledDates(habit, Anchor, Anchor.AddDays(732));
+
+        dates.Should().HaveCount(AppConstants.MaxRangeDays + 1);
+        dates[^1].Should().Be(Anchor.AddDays(AppConstants.MaxRangeDays));
+    }
+
     private static Habit CreateHabit(
         FrequencyUnit? unit,
         int? qty,
@@ -537,7 +570,7 @@ public void GetCompletedInWindow_SundayStart_SplitsLogsAcrossWeekBoundary()
     {
         var habit = CreateHabit(FrequencyUnit.Week, 3, dueDate: new DateOnly(2025, 1, 5), isFlexible: true);
 
-        habit.Log(new DateOnly(2025, 1, 11));        habit.Log(new DateOnly(2025, 1, 12));
+        habit.Log(new DateOnly(2025, 1, 11)); habit.Log(new DateOnly(2025, 1, 12));
         var sundayWeek = HabitScheduleService.GetCompletedInWindow(habit, new DateOnly(2025, 1, 11), habit.Logs, weekStartDay: 0);
         var mondayWeek = HabitScheduleService.GetCompletedInWindow(habit, new DateOnly(2025, 1, 11), habit.Logs, weekStartDay: 1);
 
@@ -582,7 +615,8 @@ public void GetRemainingCompletions_ReturnsCorrectRemaining()
 
         var remaining = HabitScheduleService.GetRemainingCompletions(habit, monday, habit.Logs, weekStartDay: 1);
 
-        remaining.Should().Be(2);    }
+        remaining.Should().Be(2);
+    }
 
     [Fact]
     public void GetRemainingCompletions_NeverNegative()
@@ -723,7 +757,8 @@ public void IsHabitDueOnDate_DailyWithDays_AllMatchingDaysAreTrue()
             FrequencyUnit.Day, 1,
             days: new[] { DayOfWeek.Monday, DayOfWeek.Wednesday, DayOfWeek.Friday });
 
-        HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 6)).Should().BeTrue();        HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 7)).Should().BeFalse();        HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 8)).Should().BeTrue();        HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 9)).Should().BeFalse();        HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 10)).Should().BeTrue();        HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 11)).Should().BeFalse();        HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 12)).Should().BeFalse();    }
+        HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 6)).Should().BeTrue(); HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 7)).Should().BeFalse(); HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 8)).Should().BeTrue(); HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 9)).Should().BeFalse(); HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 10)).Should().BeTrue(); HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 11)).Should().BeFalse(); HabitScheduleService.IsHabitDueOnDate(habit, new DateOnly(2025, 1, 12)).Should().BeFalse();
+    }
 
     [Fact]
     public void HasMissedPastOccurrence_OneTimeTask_ReturnsFalse()
@@ -833,7 +868,7 @@ public void GetScheduledDates_WeeklyHabit_ReturnsCorrectDates()
 
         var dates = HabitScheduleService.GetScheduledDates(habit, from, to);
 
-        dates.Should().HaveCount(5);        dates.Should().AllSatisfy(d => d.DayOfWeek.Should().Be(DayOfWeek.Monday));
+        dates.Should().HaveCount(5); dates.Should().AllSatisfy(d => d.DayOfWeek.Should().Be(DayOfWeek.Monday));
     }
 
     [Fact]
@@ -845,7 +880,8 @@ public void GetScheduledDates_MonthlyHabit_ReturnsCorrectDates()
 
         var dates = HabitScheduleService.GetScheduledDates(habit, from, to);
 
-        dates.Should().HaveCount(4);    }
+        dates.Should().HaveCount(4);
+    }
 
     [Fact]
     public void GetHistoricalScheduledDates_DueDateAdvancedPastWindow_UsesScheduledStart()
@@ -1055,7 +1091,7 @@ public void GetSkippedInWindow_CountsOnlySkipLogs()
         var monday = new DateOnly(2025, 1, 6);
         var habit = CreateHabit(FrequencyUnit.Week, 3, dueDate: monday, isFlexible: true);
 
-        habit.Log(monday);        habit.SkipFlexible(monday.AddDays(1));
+        habit.Log(monday); habit.SkipFlexible(monday.AddDays(1));
         var skipped = HabitScheduleService.GetSkippedInWindow(habit, monday, habit.Logs, weekStartDay: 1);
 
         skipped.Should().Be(1);
@@ -1070,7 +1106,8 @@ public void GetRemainingCompletions_SkipsReduceTarget()
         habit.SkipFlexible(monday);
         var remaining = HabitScheduleService.GetRemainingCompletions(habit, monday, habit.Logs, weekStartDay: 1);
 
-        remaining.Should().Be(2);    }
+        remaining.Should().Be(2);
+    }
 
     [Fact]
     public void HasCompletedLogInRange_CompletionLogInRange_ReturnsTrue()
@@ -1136,7 +1173,7 @@ public void IsOverdueOnDate_OneTimeTaskDueInFuture_ReturnsFalse()
     [Fact]
     public void IsOverdueOnDate_RecurringMissedPastOccurrence_ReturnsTrue()
     {
-        var habit = CreateHabit(FrequencyUnit.Week, 1, dueDate: Anchor);        var laterWednesday = Anchor.AddDays(9);
+        var habit = CreateHabit(FrequencyUnit.Week, 1, dueDate: Anchor); var laterWednesday = Anchor.AddDays(9);
         HabitScheduleService.IsOverdueOnDate(habit, laterWednesday).Should().BeTrue();
     }
 

tests/Orbit.Application.Tests/Validators/RepairStreakGapCommandValidatorTests.cs

@@ -1,5 +1,4 @@
 using FluentValidation.TestHelper;
-using Orbit.Application.Common;
 using Orbit.Application.Gamification.Commands;
 using Orbit.Application.Gamification.Validators;
 
@@ -49,11 +48,17 @@ public void MissingInputs_AreInvalid()
             .ShouldHaveValidationErrorFor(command => command.Dates);
     }
 
-    [Fact]
-    public void DatesBeyondHistoryWindow_AreInvalid()
+    [Theory]
+    [InlineData(364, true)]
+    [InlineData(365, false)]
+    public void RepairDateCount_RetainsTheOrdinaryLimit(int count, bool isValid)
     {
-        var dates = Enumerable.Range(0, AppConstants.MaxStreakLookbackDays).Select(offset => Yesterday.AddDays(-offset)).ToArray();
-        _validator.TestValidate(new RepairStreakGapCommand(Guid.NewGuid(), dates))
-            .ShouldHaveValidationErrorFor(command => command.Dates);
+        var dates = Enumerable.Range(0, count).Select(offset => Yesterday.AddDays(-offset)).ToArray();
+        var result = _validator.TestValidate(new RepairStreakGapCommand(Guid.NewGuid(), dates));
+
+        if (isValid)
+            result.ShouldNotHaveAnyValidationErrors();
+        else
+            result.ShouldHaveValidationErrorFor(command => command.Dates);
     }
 }