[Sagercaster] Reintroducing timestamp channel (openhab#11665)

[Sagercaster] Reintroducing timestamp channel 

Signed-off-by: clinique <gael@lhopital.org>
Signed-off-by: Nick Waterton <n.waterton@outlook.com>

bundles/org.openhab.binding.sagercaster/README.md

@@ -6,7 +6,8 @@ The Sager Weathercaster is a scientific instrument for accurate prediction of th
 
 * To operate, this binding will need to use channel values provided by other means (e.g. Weather Binding, Netatmo, a 1-Wire personal weather station...)
 
-* This binding buffers readings for some hours before producing weather forecasts(wind direction and sea level pressure). SagerWeatherCaster needs an observation period of minimum 6 hours.
+* This binding buffers readings for some hours before producing weather forecasts(wind direction and sea level pressure). 
+SagerWeatherCaster needs an observation period of minimum 6 hours.
 
 For these reasons, this binding is not a binding in the usual sense.
 
@@ -24,9 +25,11 @@ The binding itself does not require any configuration.
 
 | Name               | Type     | Description                                                              |
 |--------------------|----------|--------------------------------------------------------------------------|
-| location           | Location | Latitude and longitude of the desired weather forecast.                  |
+| location (*)       | Location | Latitude and longitude of the desired weather forecast.                  |
 | observation-period | int      | Minimum delay (in hours) before producing forecasts. Defaulted to 6.     |
 
+(*) Only latitude is used by the algorithm.
+
 ## Channels
 
 The binding will use some input channels, that can be configured directly with profiles (sample below).
@@ -41,6 +44,8 @@ The binding will use some input channels, that can be configured directly with p
 | wind-speed-beaufort | input  |Number               | Wind speed expressed using the Beaufort scale                   |
 | pressure            | input  |Number:Pressure      | Sea level pressure                                              |
 | wind-angle          | input  |Number:Angle         | Wind direction                                                  |
+| temperature         | input  |Number:Temperature   | Outside temperature                                             |
+| timestamp           | output |DateTime             | Timestamp of the last forecast update                           |
 | forecast            | output |String               | Description of the weather forecast                             |
 | velocity            | output |String               | Description of the expected wind evolution                      |
 | velocity-beaufort   | output |Number               | Expected wind evolution using the Beaufort scale                |

bundles/org.openhab.binding.sagercaster/src/main/java/org/openhab/binding/sagercaster/internal/SagerCasterBindingConstants.java

@@ -48,6 +48,8 @@ public class SagerCasterBindingConstants {
     public static final String CHANNEL_WINDEVOLUTION = "wind-evolution";
     public static final String CHANNEL_PRESSURETREND = "pressure-trend";
     public static final String CHANNEL_TEMPERATURETREND = "temperature-trend";
+    public static final String CHANNEL_TIMESTAMP = "timestamp";
+
     // Input channel ids
     public static final String CHANNEL_CLOUDINESS = "cloudiness";
     public static final String CHANNEL_IS_RAINING = "is-raining";

bundles/org.openhab.binding.sagercaster/src/main/java/org/openhab/binding/sagercaster/internal/SagerCasterHandlerFactory.java

@@ -19,6 +19,7 @@
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
+import org.openhab.binding.sagercaster.internal.caster.SagerWeatherCaster;
 import org.openhab.binding.sagercaster.internal.handler.SagerCasterHandler;
 import org.openhab.core.thing.Thing;
 import org.openhab.core.thing.ThingTypeUID;

bundles/org.openhab.binding.sagercaster/src/main/java/org/openhab/binding/sagercaster/internal/caster/SagerPrediction.java

@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) 2010-2021 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.binding.sagercaster.internal.caster;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
+/**
+ * This class holds the result of the SagerCaster algorithm
+ *
+ * @author Gaël L'hopital - Initial contribution
+ */
+@NonNullByDefault
+public class SagerPrediction {
+    private final String prediction;
+
+    public SagerPrediction(String sagerCode) {
+        this.prediction = sagerCode;
+    }
+
+    public String getSagerCode() {
+        return prediction;
+    }
+
+    public String getForecast() {
+        return Character.toString(prediction.charAt(0));
+    }
+
+    public String getWindVelocity() {
+        return Character.toString(prediction.charAt(1));
+    }
+
+    public String getWindDirection() {
+        return Character.toString(prediction.charAt(2));
+    }
+
+    public String getWindDirection2() {
+        return prediction.length() > 3 ? Character.toString(prediction.charAt(3)) : SagerWeatherCaster.UNDEF;
+    }
+}

bundles/org.openhab.binding.sagercaster/src/main/java/org/openhab/binding/sagercaster/internal/SagerWeatherCaster.java → bundles/org.openhab.binding.sagercaster/src/main/java/org/openhab/binding/sagercaster/internal/caster/SagerWeatherCaster.java

@@ -53,7 +53,7 @@
  * 378 possible forecasts determined from 4996 dial codes.
  */
 
-package org.openhab.binding.sagercaster.internal;
+package org.openhab.binding.sagercaster.internal.caster;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -76,6 +76,7 @@
 @Component(service = SagerWeatherCaster.class, scope = ServiceScope.SINGLETON)
 @NonNullByDefault
 public class SagerWeatherCaster {
+    public final static String UNDEF = "-";
     // Northern Polar Zone & Northern Tropical Zone
     private final static String[] NPZDIRECTIONS = { "S", "SW", "W", "NW", "N", "NE", "E", "SE" };
     // Northern Temperate Zone
@@ -88,7 +89,7 @@ public class SagerWeatherCaster {
     private final Logger logger = LoggerFactory.getLogger(SagerWeatherCaster.class);
     private final Properties forecaster = new Properties();
 
-    private Optional<Prevision> prevision = Optional.empty();
+    private Optional<SagerPrediction> prevision = Optional.empty();
     private String[] usedDirections = NTZDIRECTIONS; // Defaulted to Northern Zone
 
     private int currentBearing = -1;
@@ -238,7 +239,7 @@ private String getCompass() {
 
     private void updatePrediction() {
         int zWind = Arrays.asList(usedDirections).indexOf(getCompass());
-        String d1 = "-";
+        String d1 = UNDEF;
         switch (zWind) {
             case 0:
                 if (windEvolution == 3) {
@@ -319,39 +320,27 @@ private void updatePrediction() {
         }
         String forecast = forecaster.getProperty(
                 d1 + String.valueOf(sagerPressure) + String.valueOf(pressureEvolution) + String.valueOf(nubes));
-        prevision = (forecast != null) ? Optional.of(new Prevision(forecast)) : Optional.empty();
+        prevision = Optional.ofNullable(forecast != null ? new SagerPrediction(forecast) : null);
     }
 
     public String getForecast() {
-        if (prevision.isPresent()) {
-            char forecast = prevision.get().zForecast;
-            return Character.toString(forecast);
-        }
-        return "-";
+        return prevision.map(p -> p.getForecast()).orElse(UNDEF);
     }
 
     public String getWindVelocity() {
-        if (prevision.isPresent()) {
-            char windVelocity = prevision.get().zWindVelocity;
-            return Character.toString(windVelocity);
-        }
-        return "-";
+        return prevision.map(p -> p.getWindVelocity()).orElse(UNDEF);
     }
 
     public String getWindDirection() {
-        if (prevision.isPresent()) {
-            int direction = prevision.get().zWindDirection;
-            return String.valueOf(direction);
-        }
-        return "-";
+        return prevision.map(p -> p.getWindDirection()).orElse(UNDEF);
     }
 
     public String getWindDirection2() {
-        if (prevision.isPresent()) {
-            int direction = prevision.get().zWindDirection2;
-            return String.valueOf(direction);
-        }
-        return "-";
+        return prevision.map(p -> p.getWindDirection2()).orElse(UNDEF);
+    }
+
+    public String getSagerCode() {
+        return prevision.map(p -> p.getSagerCode()).orElse(UNDEF);
     }
 
     public void setLatitude(double latitude) {
@@ -370,17 +359,31 @@ public void setLatitude(double latitude) {
         }
     }
 
-    private class Prevision {
-        public final char zForecast;
-        public final char zWindVelocity;
-        public final int zWindDirection;
-        public final int zWindDirection2;
-
-        public Prevision(String forecast) {
-            zForecast = forecast.charAt(0);
-            zWindVelocity = forecast.charAt(1);
-            zWindDirection = Character.getNumericValue(forecast.charAt(2));
-            zWindDirection2 = (forecast.length() > 3) ? Character.getNumericValue(forecast.charAt(3)) : -1;
+    public int getPredictedBeaufort() {
+        int result = currentBeaufort;
+        switch (getWindVelocity()) {
+            case "N":
+                result += 1;
+                break;
+            case "F":
+                result = 4;
+                break;
+            case "S":
+                result = 6;
+                break;
+            case "G":
+                result = 8;
+                break;
+            case "W":
+                result = 10;
+                break;
+            case "H":
+                result = 12;
+                break;
+            case "D":
+                result -= 1;
+                break;
         }
+        return result;
     }
 }