fix(office365): default view interval for get availability

Author: stakach

shard.yml

@@ -1,5 +1,5 @@
 name: place_calendar
-version: 4.29.1
+version: 4.29.2
 
 crystal: ">= 0.36.1"
 

spec/office365_availability_spec.cr

@@ -0,0 +1,69 @@
+require "spec"
+
+module PlaceCalendar
+  describe Office365Availability do
+    describe ".select_view_interval" do
+      it "returns 5 minutes for small windows" do
+        Office365Availability.select_view_interval(15.minutes)
+          .should eq(5)
+
+        Office365Availability.select_view_interval(29.minutes)
+          .should eq(5)
+      end
+
+      it "handles exact boundaries safely" do
+        Office365Availability.select_view_interval(6.minutes)
+          .should eq(5)
+
+        Office365Availability.select_view_interval(10.minutes)
+          .should eq(5)
+      end
+
+      it "scales up for hour-scale windows" do
+        Office365Availability.select_view_interval(2.hours)
+          .should eq(5)
+
+        Office365Availability.select_view_interval(8.hours)
+          .should eq(15)
+      end
+
+      it "returns sensible intervals for day-scale windows" do
+        Office365Availability.select_view_interval(24.hours)
+          .should eq(30)
+
+        Office365Availability.select_view_interval(7.days)
+          .should eq(6.hours.total_minutes)
+      end
+
+      it "returns daily buckets for very large windows" do
+        Office365Availability.select_view_interval(30.days)
+          .should eq(1.day.total_minutes)
+      end
+
+      it "raises for windows too small to satisfy Graph constraints" do
+        expect_raises(ArgumentError) do
+          Office365Availability.select_view_interval(5.minutes)
+        end
+
+        expect_raises(ArgumentError) do
+          Office365Availability.select_view_interval(3.minutes)
+        end
+      end
+
+      it "always returns an interval strictly smaller than the window" do
+        windows = [
+          6.minutes,
+          20.minutes,
+          90.minutes,
+          12.hours,
+          3.days,
+        ]
+
+        windows.each do |w|
+          interval = Office365Availability.select_view_interval(w)
+          interval.minutes.should be < w
+        end
+      end
+    end
+  end
+end

src/office365.cr

@@ -1,4 +1,5 @@
 require "office365"
+require "./office365_availability"
 
 module PlaceCalendar
   class Office365 < Interface
@@ -426,7 +427,7 @@ module PlaceCalendar
     end
 
     def get_availability(user_id : String, calendars : Array(String), starts_at : Time, ends_at : Time, **options) : Array(AvailabilitySchedule)
-      view_interval = options[:view_interval]? || 30
+      view_interval = options[:view_interval]? || Office365Availability.select_view_interval(starts_at - ends_at)
 
       # Max is 100 so we need to batch if we're above this
       if calendars.size > 100

src/office365_availability.cr

@@ -0,0 +1,42 @@
+module PlaceCalendar::Office365Availability
+  # "Nice" bucket sizes in minutes (descending for easy selection)
+  NICE_INTERVALS_MINUTES = [
+    1440, 720, 480, 360, 240, 180,
+    120, 60, 30, 20, 15, 10, 5,
+  ]
+
+  MIN_INTERVAL =    5
+  MAX_INTERVAL = 1440
+  TARGET_SLOTS =   24
+
+  def self.select_view_interval(window : Time::Span) : Int32
+    # Convert to minutes, rounding up to avoid zero-length edge cases
+    window_minutes = (window.total_seconds / 60.0).ceil.to_i
+
+    # Graph constraint: interval must be >= 5 and < window
+    if window_minutes <= MIN_INTERVAL
+      raise ArgumentError.new(
+        "Window must be greater than #{MIN_INTERVAL} minutes (got #{window_minutes})"
+      )
+    end
+
+    # Target an interval that yields ~TARGET_SLOTS buckets
+    raw = ((window_minutes - 1) // TARGET_SLOTS)
+
+    # Pick the largest "nice" interval <= raw
+    interval_minutes =
+      NICE_INTERVALS_MINUTES.find { |m| m <= raw } || MIN_INTERVAL
+
+    # Safety: ensure strict < window
+    while interval_minutes >= window_minutes
+      idx = NICE_INTERVALS_MINUTES.index(interval_minutes)
+      interval_minutes =
+        idx && idx < NICE_INTERVALS_MINUTES.size - 1 ? NICE_INTERVALS_MINUTES[idx + 1] : MIN_INTERVAL
+    end
+
+    # Clamp (defensive, should never trigger)
+    interval_minutes = interval_minutes.clamp(MIN_INTERVAL, MAX_INTERVAL)
+
+    interval_minutes
+  end
+end