getting correct days

Management.Test/Features/CalendarMonthTests.cs

@@ -0,0 +1,45 @@
+public class CalendarMonthTests
+{
+  [Test]
+  public void TestCalendarMonthCanGetFirstWeek()
+  {
+    var month = new CalendarMonth(2023, 2);
+
+    int?[] expectedFirstWeek = new int?[] {
+      null, null, null, 1, 2, 3, 4
+    };
+
+    month.Weeks.First().Should().BeEquivalentTo(expectedFirstWeek);
+  }
+
+  [Test]
+  public void TestCanGetAnotherMonthsFirstWeek()
+  {
+    var month = new CalendarMonth(2023, 4);
+
+    int?[] expectedFirstWeek = new int?[] {
+      null, null, null, null, null, null, 1
+    };
+
+    month.Weeks.First().Should().BeEquivalentTo(expectedFirstWeek);
+  }
+
+  [Test]
+  public void TestCorrectNumberOfWeeks()
+  {
+    var month = new CalendarMonth(2023, 4);
+
+    month.Weeks.Count().Should().Be(6);
+  }
+
+  [Test]
+  public void TestLastWeekIsCorrect()
+  {
+    var month = new CalendarMonth(2023, 4);
+    int?[] expectedLastWeek = new int?[] {
+      30, null, null, null, null, null, null,
+    };
+
+    month.Weeks.Last().Should().BeEquivalentTo(expectedLastWeek);
+  }
+}

Management.Test/Features/SemesterPlannerTests.cs

@@ -33,6 +33,7 @@ public class SemesterPlannerTests
 
     semester.Months.Count().Should().Be(2);
   }
+
   [Test]
   public void TestNewPlannerHandlesTermsThatWrapYears()
   {
@@ -47,4 +48,5 @@ public class SemesterPlannerTests
 
     semester.Months.Count().Should().Be(2);
   }
+
 }

Management/Features/Calendar/CalendarMonth.cs

@@ -1,4 +1,83 @@
 public class CalendarMonth
 {
+  private DateOnly firstDay { get; }
+  private int year { get => firstDay.Year; }
+  private int month { get => firstDay.Month; }
+  public IEnumerable<IEnumerable<int?>> Weeks
+  {
+    get =>
+      DaysByWeek.Select(
+        week => week.Select(d => d?.Day)
+      );
 
+  }
+
+  public IEnumerable<IEnumerable<DateTime?>> DaysByWeek
+  {
+    get
+    {
+      var weeks = new List<List<DateTime?>>();
+      var weeksInMonth = WeeksInMonth(year, month);
+      var daysInMonth = DateTime.DaysInMonth(year, month);
+
+      var firstDayOfMonth = new DateTime(year, month, 1).DayOfWeek;
+
+      var currentDay = 1;
+      for (int i = 0; i < weeksInMonth; i++)
+      {
+        var thisWeek = new List<DateTime?>();
+        if (i == 0 && firstDayOfMonth != DayOfWeek.Sunday)
+        {
+          for (int j = 0; j < 7; j++)
+          {
+            if (j < (int)firstDayOfMonth)
+            {
+              thisWeek.Add(null);
+            }
+            else
+            {
+              thisWeek.Add(new DateTime(year, month, currentDay));
+              currentDay++;
+            }
+          }
+        }
+        else
+        {
+          for (int j = 0; j < 7; j++)
+          {
+            if (currentDay <= daysInMonth)
+            {
+              thisWeek.Add(new DateTime(year, month, currentDay));
+              currentDay++;
+            }
+            else
+            {
+              thisWeek.Add(null);
+            }
+          }
+        }
+        weeks.Add(thisWeek);
+      }
+      return weeks;
+    }
+  }
+
+  public static int WeeksInMonth(int year, int month)
+  {
+    var firstDayOfMonth = new DateTime(year, month, 1).DayOfWeek;
+    var daysInMonth = DateTime.DaysInMonth(year, month);
+    var longDaysInMonth = daysInMonth + (int)(firstDayOfMonth);
+    var weeks = longDaysInMonth / 7;
+    if ((longDaysInMonth % 7) > 0)
+    {
+      weeks += 1;
+    }
+    return weeks;
+  }
+
+  public CalendarMonth(int year, int month)
+  {
+    firstDay = new DateOnly(year, month, 1);
+
+  }
 }

Management/Features/Calendar/SemesterPlanner.cs

@@ -10,6 +10,6 @@ public class SemesterPlanner
         + canvasTerm.EndAt?.Month - canvasTerm.StartAt?.Month
       ?? throw new Exception($"Canvas Term must have a start and end date. Term: {canvasTerm.Id}, start: {canvasTerm.StartAt}, end: {canvasTerm.EndAt}");
 
-    Months = Enumerable.Range(0, monthsInTerm).Select(_ => new CalendarMonth());
+    Months = Enumerable.Range(0, monthsInTerm).Select(_ => new CalendarMonth(2022, 1));
   }
 }