Fix precision-related issues (openhab#20917)

Resolves openhab#20912

Signed-off-by: Jacob Laursen <jacob-github@vindvejr.dk>

Author: jlaur

bundles/org.openhab.io.hueemulation/src/main/java/org/openhab/io/hueemulation/internal/StateUtils.java

@@ -12,6 +12,8 @@
  */
 package org.openhab.io.hueemulation.internal;
 
+import java.math.BigDecimal;
+import java.math.RoundingMode;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -48,6 +50,9 @@
 @NonNullByDefault
 public class StateUtils {
 
+    private static final BigDecimal BIG_DECIMAL_HUNDRED = BigDecimal.valueOf(100);
+    private static final BigDecimal BIG_DECIMAL_HUE_BRI_MAX = BigDecimal.valueOf(HueStateBulb.MAX_BRI);
+
     /**
      * Compute the hue state from a given item state and a device type.
      *
@@ -65,7 +70,8 @@ public static AbstractHueState colorStateFromItemState(State itemState, @Nullabl
                 if (itemState instanceof HSBType hsbState) {
                     state = new HueStateColorBulb(hsbState);
                 } else if (itemState instanceof PercentType percentState) {
-                    state = new HueStateColorBulb(percentState, percentState.intValue() > 0);
+                    state = new HueStateColorBulb(percentState,
+                            percentState.toBigDecimal().compareTo(BigDecimal.ZERO) > 0);
                 } else if (itemState instanceof OnOffType onOffState) {
                     state = new HueStateColorBulb(onOffState == OnOffType.ON);
                 } else {
@@ -76,9 +82,9 @@ public static AbstractHueState colorStateFromItemState(State itemState, @Nullabl
             case WhiteTemperatureType:
                 if (itemState instanceof HSBType hsbState) {
                     PercentType brightness = hsbState.getBrightness();
-                    state = new HueStateBulb(brightness, brightness.intValue() > 0);
+                    state = new HueStateBulb(brightness, brightness.toBigDecimal().compareTo(BigDecimal.ZERO) > 0);
                 } else if (itemState instanceof PercentType percentState) {
-                    state = new HueStateBulb(percentState, percentState.intValue() > 0);
+                    state = new HueStateBulb(percentState, percentState.toBigDecimal().compareTo(BigDecimal.ZERO) > 0);
                 } else if (itemState instanceof OnOffType onOffState) {
                     state = new HueStateBulb(onOffState == OnOffType.ON);
                 } else {
@@ -170,7 +176,7 @@ public static Command commandByItemState(State state) throws IllegalStateExcepti
         if (newState.bri != null) {
             try {
                 state.as(HueStateBulb.class).bri = newState.bri;
-                command = new PercentType((int) (newState.bri * 100.0 / HueStateBulb.MAX_BRI + 0.5));
+                command = percentTypeFromHueBrightness(newState.bri);
                 successApplied.put("bri", newState.bri);
             } catch (ClassCastException e) {
                 errorApplied.add("bri");
@@ -183,7 +189,7 @@ public static Command commandByItemState(State state) throws IllegalStateExcepti
                 if (newBri < 0 || newBri > HueStateBulb.MAX_BRI) {
                     throw new IllegalArgumentException();
                 }
-                command = new PercentType((int) (newBri * 100.0 / HueStateBulb.MAX_BRI + 0.5));
+                command = percentTypeFromHueBrightness(newBri);
                 successApplied.put("bri", newState.bri);
             } catch (ClassCastException e) {
                 errorApplied.add("bri_inc");
@@ -349,6 +355,28 @@ public static Command commandByItemState(State state) throws IllegalStateExcepti
         return command;
     }
 
+    /**
+     * Converts a Hue brightness value (0-254) to a {@link PercentType} with two decimal places.
+     *
+     * @param brightness the Hue brightness value
+     * @return the corresponding PercentType
+     */
+    public static PercentType percentTypeFromHueBrightness(int brightness) {
+        return new PercentType(BigDecimal.valueOf(brightness).multiply(BIG_DECIMAL_HUNDRED)
+                .divide(BIG_DECIMAL_HUE_BRI_MAX, 2, RoundingMode.HALF_UP));
+    }
+
+    /**
+     * Converts a {@link PercentType} to a Hue brightness value (1-254).
+     *
+     * @param percentValue the PercentType value
+     * @return the corresponding Hue brightness value
+     */
+    public static int hueBrightnessFromPercentType(PercentType percentValue) {
+        return Math.max(1, percentValue.toBigDecimal().multiply(BIG_DECIMAL_HUE_BRI_MAX)
+                .divide(BIG_DECIMAL_HUNDRED, 0, RoundingMode.HALF_UP).intValue());
+    }
+
     public static @Nullable DeviceType determineTargetType(ConfigStore cs, Item element) {
         String category = element.getCategory();
         String type = element.getType();

bundles/org.openhab.io.hueemulation/src/main/java/org/openhab/io/hueemulation/internal/dto/HueStateBulb.java

@@ -12,7 +12,9 @@
  */
 package org.openhab.io.hueemulation.internal.dto;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.library.types.PercentType;
+import org.openhab.io.hueemulation.internal.StateUtils;
 
 /**
  * Hue API state object
@@ -21,9 +23,9 @@
  * @author David Graeff - "extended color light bulbs" support
  *
  */
+@NonNullByDefault
 public class HueStateBulb extends HueStatePlug {
-    // https://github.com/openhab/openhab-addons/issues/2881
-    // Apparently the maximum brightness is 254
+
     public static final int MAX_BRI = 254;
     public int bri = 0;
 
@@ -47,16 +49,15 @@ public HueStateBulb(boolean on) {
      */
     public HueStateBulb(PercentType brightness, boolean on) {
         super(on);
-        this.bri = Math.max(1, (int) (brightness.intValue() * MAX_BRI / 100.0 + 0.5));
+        this.bri = StateUtils.hueBrightnessFromPercentType(brightness);
     }
 
     public PercentType toBrightnessType() {
-        int bri = this.bri * 100 / MAX_BRI;
-
-        if (!this.on) {
-            bri = 0;
+        if (this.on) {
+            return StateUtils.percentTypeFromHueBrightness(this.bri);
+        } else {
+            return PercentType.ZERO;
         }
-        return new PercentType(bri);
     }
 
     @Override

bundles/org.openhab.io.hueemulation/src/main/java/org/openhab/io/hueemulation/internal/dto/HueStateColorBulb.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.io.hueemulation.internal.dto;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.library.types.DecimalType;
 import org.openhab.core.library.types.HSBType;
 import org.openhab.core.library.types.PercentType;
@@ -24,6 +25,7 @@
  * @author Florian Lentz - added xy support
  *
  */
+@NonNullByDefault
 public class HueStateColorBulb extends HueStateBulb {
     public static final int MAX_HUE = 65535; // For extended color light bulbs
     public int hue = 0;
@@ -71,7 +73,7 @@ public HueStateColorBulb(PercentType brightness, boolean on) {
      * @param hsb Color information. Sets the hue state to "on" if brightness is > 0.
      */
     public HueStateColorBulb(HSBType hsb) {
-        super(hsb.getBrightness(), hsb.getBrightness().intValue() > 0);
+        super(hsb.getBrightness(), hsb.getBrightness().compareTo(DecimalType.ZERO) > 0);
         this.hue = (int) (hsb.getHue().intValue() * MAX_HUE / 360.0 + 0.5);
         this.sat = (int) (hsb.getSaturation().intValue() * MAX_SAT / 100.0 + 0.5);
         colormode = this.sat > 0 ? ColorMode.hs : ColorMode.ct;

bundles/org.openhab.io.hueemulation/src/main/java/org/openhab/io/hueemulation/internal/dto/HueStatePlug.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.io.hueemulation.internal.dto;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.library.types.OnOffType;
 
 /**
@@ -20,6 +21,7 @@
  * @author David Graeff - Initial contribution
  *
  */
+@NonNullByDefault
 public class HueStatePlug extends AbstractHueState {
     public boolean on;
 

bundles/org.openhab.io.hueemulation/src/main/java/org/openhab/io/hueemulation/internal/dto/changerequest/HueStateChange.java

@@ -35,4 +35,11 @@ public class HueStateChange {
     public Integer sat_inc;
     public List<Double> xy_inc;
     public Integer ct_inc;
+
+    @Override
+    public String toString() {
+        return "on: " + on + ", bri: " + bri + ", hue: " + hue + ", sat: " + sat + ", effect: " + effect + ", ct: " + ct
+                + ", alert: " + alert + ", xy: " + xy + ", transitiontime: " + transitiontime + ", bri_inc: " + bri_inc
+                + ", hue_inc: " + hue_inc + ", sat_inc: " + sat_inc + ", xy_inc: " + xy_inc + ", ct_inc: " + ct_inc;
+    }
 }

bundles/org.openhab.io.hueemulation/src/main/java/org/openhab/io/hueemulation/internal/rest/LightsAndGroups.java

@@ -447,10 +447,16 @@ public Response setLightStateApi(@Context UriInfo uri, //
                     "Invalid request: No state change data received!");
         }
 
+        logger.debug("Received state change for light {}: {}", id, newState);
+
         hueDevice.state = StateUtils.colorStateFromItemState(hueDevice.item.getState(), hueDevice.deviceType);
 
         String itemUID = hueDevice.item.getUID();
         List<HueResponse> responses = new ArrayList<>();
+        if (newState.on == Boolean.TRUE && newState.bri != null && newState.bri == 0) {
+            // The bulb should be on, but the brightness is 0. Skip the brightness change.
+            newState.bri = null;
+        }
         Command command = StateUtils.computeCommandByState(responses, "/lights/" + id + "/state", hueDevice.state,
                 newState);
 

bundles/org.openhab.io.hueemulation/src/test/java/org/openhab/io/hueemulation/internal/rest/LightsAndGroupsTests.java

@@ -332,6 +332,25 @@ public void changeOnAndBriValues() throws Exception {
         assertThat(stateColorBulb.bri, is(200));
     }
 
+    @Test
+    public void changeOnAndInvalidBriValues() throws Exception {
+        HueLightEntry hueLightEntry = cs.ds.lights.get("2");
+        assertNotNull(hueLightEntry);
+        HueStateColorBulb stateColorBulb = assertInstanceOf(HueStateColorBulb.class, hueLightEntry.state);
+        assertThat(stateColorBulb.on, is(false));
+        assertThat(stateColorBulb.bri, is(1));
+
+        String body = "{'on':true,'bri':0}";
+        ContentResponse response = commonSetup.sendPut("/testuser/lights/2/state", body);
+        assertThat(response.getStatus(), is(200));
+        assertThat(response.getContentAsString(), containsString("success"));
+        hueLightEntry = cs.ds.lights.get("2");
+        assertNotNull(hueLightEntry);
+        stateColorBulb = assertInstanceOf(HueStateColorBulb.class, hueLightEntry.state);
+        assertThat(stateColorBulb.on, is(true));
+        assertThat(stateColorBulb.bri, is(1));
+    }
+
     @Test
     public void changeHueSatValues() throws Exception {
         HueLightEntry hueLightEntry = cs.ds.lights.get("2");

bundles/org.openhab.io.hueemulation/src/test/java/org/openhab/io/hueemulation/internal/rest/StateUtilsTests.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2010-2026 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.io.hueemulation.internal.rest;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import java.util.stream.Stream;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.openhab.core.library.types.PercentType;
+import org.openhab.io.hueemulation.internal.StateUtils;
+
+/**
+ * Tests for {@link StateUtils}.
+ *
+ * @author Jacob Laursen - Initial contribution
+ */
+@NonNullByDefault
+public class StateUtilsTests {
+
+    @ParameterizedTest
+    @MethodSource("provideTestCasesForPercentTypeFromHueBrightness")
+    void percentTypeFromHueBrightness(int bri, PercentType expectedPercent) {
+        assertThat(StateUtils.percentTypeFromHueBrightness(bri), is(equalTo(expectedPercent)));
+    }
+
+    @ParameterizedTest
+    @MethodSource("provideTestCasesForHueBrightnessFromPercentType")
+    void hueBrightnessFromPercentType(PercentType percentValue, int expectedBri) {
+        assertThat(StateUtils.hueBrightnessFromPercentType(percentValue), is(equalTo(expectedBri)));
+    }
+
+    private static Stream<Arguments> provideTestCasesForPercentTypeFromHueBrightness() {
+        return Stream.of( //
+                Arguments.of(0, PercentType.ZERO), //
+                Arguments.of(1, PercentType.valueOf("0.39")), //
+                Arguments.of(2, PercentType.valueOf("0.79")), //
+                Arguments.of(3, PercentType.valueOf("1.18")), //
+                Arguments.of(127, new PercentType(50)), //
+                Arguments.of(253, PercentType.valueOf("99.61")), //
+                Arguments.of(254, PercentType.HUNDRED) //
+        );
+    }
+
+    private static Stream<Arguments> provideTestCasesForHueBrightnessFromPercentType() {
+        return Stream.of( //
+                Arguments.of(PercentType.ZERO, 1), //
+                Arguments.of(PercentType.valueOf("0.5"), 1), //
+                Arguments.of(new PercentType(1), 3), //
+                Arguments.of(new PercentType(50), 127), //
+                Arguments.of(PercentType.HUNDRED, 254) //
+        );
+    }
+}