Store a lot less state

NightLight.Core/NightLightStateMachine.fs

@@ -24,64 +24,43 @@ let internal generateZigbeeCommandsToFixLight (light: Light) (desiredLightSettin
 type internal NightLightState =
     { Time: DateTime
       Alarm: bool
-      LightToLightSettings: Map<Light, LightSettings> }
+      LightToManualState: Map<Light, State> }
 
-let internal createOrUpdateNightLightState
-    (time: DateTime)
-    (alarm: bool)
-    (maybeOldLightToLightSettings: Map<Light, LightSettings> option)
-    =
-    let partOfDay = getPartOfDay time
+let internal computeLightSettings (light: Light) (nightLightState: NightLightState) =
+    let partOfDay = getPartOfDay nightLightState.Time
 
-    let lightToLightSettings =
-        lights
-        |> Seq.map (fun light ->
-            let color, brightness =
-                getDesiredMood (lightProps light).Room partOfDay
-                |> getDesiredColorAndBrightness (lightProps light).Bulb
+    let color, brightness =
+        getDesiredMood (lightProps light).Room partOfDay
+        |> getDesiredColorAndBrightness (lightProps light).Bulb
 
-            let previousState =
-                maybeOldLightToLightSettings
-                |> Option.map (fun lightToLightSettings -> lightToLightSettings[light].State)
-                |> Option.defaultValue On
-
-            light,
-            { Color = color
-              Brightness =
-                if alarm && (light = RightBedroomLamp || light = LeftBedroomLamp) then
-                    brightness.Scale(getAlarmWeight time)
-                else
-                    brightness
-              State =
-                if alarm && (light = RightBedroomLamp || light = LeftBedroomLamp) then
-                    On
-                else
-                    previousState })
-        |> Map.ofSeq
-
-    { Time = time
-      Alarm = alarm
-      LightToLightSettings = lightToLightSettings }
+    { Color = color
+      Brightness =
+        if nightLightState.Alarm && (light = RightBedroomLamp || light = LeftBedroomLamp) then
+            brightness.Scale(getAlarmWeight nightLightState.Time)
+        else
+            brightness
+      State =
+        if nightLightState.Alarm && (light = RightBedroomLamp || light = LeftBedroomLamp) then
+            On
+        else
+            nightLightState.LightToManualState[light] }
 
 let internal withStateFor (light: Light) (state: State) (oldNightLightState: NightLightState) =
-    let oldState = oldNightLightState.LightToLightSettings[light]
-
-    createOrUpdateNightLightState
-        oldNightLightState.Time
-        oldNightLightState.Alarm
-        (Map.add light { oldState with State = state } oldNightLightState.LightToLightSettings
-         |> Some)
+    { oldNightLightState with
+        LightToManualState = Map.add light state oldNightLightState.LightToManualState }
 
 let internal withAlarmOff (oldNightLightState: NightLightState) =
-    createOrUpdateNightLightState oldNightLightState.Time false (Some oldNightLightState.LightToLightSettings)
+    { oldNightLightState with
+        Alarm = false }
 
 let internal generateZigbeeCommandsForDifference (maybeBefore: NightLightState option) (after: NightLightState) =
-    after.LightToLightSettings
-    |> Seq.collect (fun (KeyValue(light, newState)) ->
-        let oldState = maybeBefore |> Option.map _.LightToLightSettings[light]
+    lights
+    |> Seq.collect (fun light ->
+        let oldLightSettings = maybeBefore |> Option.map (computeLightSettings light)
+        let newLightSettings = after |> computeLightSettings light
 
-        if oldState <> Some newState then
-            generateZigbeeCommandsToFixLight light after.LightToLightSettings[light]
+        if oldLightSettings <> Some newLightSettings then
+            generateZigbeeCommandsToFixLight light newLightSettings
         else
             Seq.empty)
 
@@ -101,7 +80,10 @@ type NightLightStateMachine private (maybeState: NightLightState option) =
 
                         this,
                         match maybeLight with
-                        | Some light -> generateZigbeeCommandsToFixLight light currentState.LightToLightSettings[light]
+                        | Some light ->
+                            currentState
+                            |> computeLightSettings light
+                            |> generateZigbeeCommandsToFixLight light
                         | None -> Seq.empty
                     | ButtonPress action ->
                         let newNightLightState =
@@ -123,7 +105,6 @@ type NightLightStateMachine private (maybeState: NightLightState option) =
                                 |> withStateFor LeftBedroomLamp On
                             | PressedRight ->
                                 currentState
-                                |> withAlarmOff
                                 |> withStateFor LivingRoomWallLamp Off
                                 |> withStateFor LivingRoomFloorLamp Off
 
@@ -143,7 +124,12 @@ type NightLightStateMachine private (maybeState: NightLightState option) =
                     || maybeCurrentState |> Option.map _.Alarm |> Option.defaultValue false
 
                 let newNightLightState =
-                    createOrUpdateNightLightState newTime alarm (maybeCurrentState |> Option.map _.LightToLightSettings)
+                    { Time = newTime
+                      Alarm = alarm
+                      LightToManualState =
+                        maybeCurrentState
+                        |> Option.map _.LightToManualState
+                        |> Option.defaultValue (lights |> Seq.map (fun light -> light, On) |> Map.ofSeq) }
 
                 return
                     NightLightStateMachine(Some newNightLightState),