[somfytahoma] Retry command submission when tahoma gateway is busy. (#10023)

* Retry command submission when tahome gateway is busy.
* Changed log level, cosmetic changes
* Store list of scheduled retries; cancelled when handler is disposed.
* Made retryFutures thread-safe

Signed-off-by: Georg Siebke <github@georgsiebke.de>

bundles/org.openhab.binding.somfytahoma/src/main/java/org/openhab/binding/somfytahoma/internal/config/SomfyTahomaConfig.java

@@ -26,6 +26,8 @@ public class SomfyTahomaConfig {
     private String password = "";
     private int refresh = 30;
     private int statusTimeout = 300;
+    private int retries = 10;
+    private int retryDelay = 1000;
 
     public String getEmail() {
         return email;
@@ -43,6 +45,14 @@ public class SomfyTahomaConfig {
         return statusTimeout;
     }
 
+    public int getRetries() {
+        return retries;
+    }
+
+    public int getRetryDelay() {
+        return retryDelay;
+    }
+
     public void setEmail(String email) {
         this.email = email;
     }
@@ -50,4 +60,12 @@ public class SomfyTahomaConfig {
     public void setPassword(String password) {
         this.password = password;
     }
+
+    public void setRetries(int retries) {
+        this.retries = retries;
+    }
+
+    public void setRetryDelay(int retryDelay) {
+        this.retryDelay = retryDelay;
+    }
 }

bundles/org.openhab.binding.somfytahoma/src/main/java/org/openhab/binding/somfytahoma/internal/handler/SomfyTahomaBridgeHandler.java

@@ -18,6 +18,7 @@ import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 import java.util.*;
+import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
@@ -78,6 +79,9 @@ public class SomfyTahomaBridgeHandler extends BaseBridgeHandler {
      */
     private @Nullable ScheduledFuture<?> reconciliationFuture;
 
+    // List of futures used for command retries
+    private Collection<ScheduledFuture<?>> retryFutures = new ConcurrentLinkedQueue<ScheduledFuture<?>>();
+
     /**
      * List of executions
      */
@@ -275,6 +279,9 @@ public class SomfyTahomaBridgeHandler extends BaseBridgeHandler {
         logger.debug("Doing cleanup");
         stopPolling();
         executions.clear();
+        // cancel all scheduled retries
+        retryFutures.forEach(x -> x.cancel(false));
+
         try {
             httpClient.stop();
         } catch (Exception e) {
@@ -561,13 +568,23 @@ public class SomfyTahomaBridgeHandler extends BaseBridgeHandler {
             return;
         }
 
-        Boolean result = sendCommandInternal(io, command, params, url);
+        removeFinishedRetries();
+
+        boolean result = sendCommandInternal(io, command, params, url);
         if (!result) {
-            sendCommandInternal(io, command, params, url);
+            scheduleRetry(io, command, params, url, thingConfig.getRetries());
         }
     }
 
-    private Boolean sendCommandInternal(String io, String command, String params, String url) {
+    private void repeatSendCommandInternal(String io, String command, String params, String url, int retries) {
+        logger.debug("Retrying command, retries left: {}", retries);
+        boolean result = sendCommandInternal(io, command, params, url);
+        if (!result && (retries > 0)) {
+            scheduleRetry(io, command, params, url, retries - 1);
+        }
+    }
+
+    private boolean sendCommandInternal(String io, String command, String params, String url) {
         String value = params.equals("[]") ? command : params.replace("\"", "");
         String urlParameters = "{\"label\":\"" + getThingLabelByURL(io) + " - " + value
                 + " - OH2\",\"actions\":[{\"deviceURL\":\"" + io + "\",\"commands\":[{\"name\":\"" + command
@@ -587,6 +604,17 @@ public class SomfyTahomaBridgeHandler extends BaseBridgeHandler {
         return false;
     }
 
+    private void removeFinishedRetries() {
+        retryFutures.removeIf(x -> x.isDone());
+        logger.debug("Currently {} retries are scheduled.", retryFutures.size());
+    }
+
+    private void scheduleRetry(String io, String command, String params, String url, int retries) {
+        retryFutures.add(scheduler.schedule(() -> {
+            repeatSendCommandInternal(io, command, params, url, retries);
+        }, thingConfig.getRetryDelay(), TimeUnit.MILLISECONDS));
+    }
+
     private String getThingLabelByURL(String io) {
         Thing th = getThingByDeviceUrl(io);
         if (th != null) {

bundles/org.openhab.binding.somfytahoma/src/main/resources/OH-INF/config/config.xml

@@ -45,5 +45,17 @@
 			<description>Specifies the timeout in seconds after which the status is got from Tahoma cloud</description>
 			<default>300</default>
 		</parameter>
+
+		<parameter name="retries" type="integer" required="false">
+			<label>Retries</label>
+			<description>Specifies the number of retries when command execution</description>
+			<default>10</default>
+		</parameter>
+
+		<parameter name="retryDelay" type="integer" required="false" min="100">
+			<label>Retry delay</label>
+			<description>Specifies the delay in milliseconds between subsequent retries after a command failure</description>
+			<default>1000</default>
+		</parameter>
 	</config-description>
 </config-description:config-descriptions>