Added rule rest endpoint and backend operation for rule execution simulation

bundles/org.openhab.core.automation.rest/src/main/java/org/openhab/core/automation/rest/internal/RuleResource.java

@@ -17,10 +17,12 @@
 import java.io.IOException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
+import java.time.ZonedDateTime;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import javax.annotation.security.RolesAllowed;
@@ -47,6 +49,7 @@
 import org.openhab.core.automation.ManagedRuleProvider;
 import org.openhab.core.automation.Module;
 import org.openhab.core.automation.Rule;
+import org.openhab.core.automation.RuleExecution;
 import org.openhab.core.automation.RuleManager;
 import org.openhab.core.automation.RuleRegistry;
 import org.openhab.core.automation.Trigger;
@@ -70,6 +73,7 @@
 import org.openhab.core.io.rest.RESTConstants;
 import org.openhab.core.io.rest.RESTResource;
 import org.openhab.core.io.rest.Stream2JSONInputStream;
+import org.openhab.core.library.types.DateTimeType;
 import org.osgi.service.component.annotations.Activate;
 import org.osgi.service.component.annotations.Component;
 import org.osgi.service.component.annotations.Reference;
@@ -339,6 +343,22 @@ public Response getTriggers(@PathParam("ruleUID") @Parameter(description = "rule
         }
     }
 
+    @GET
+    @Path("/simulation")
+    @Produces(MediaType.APPLICATION_JSON)
+    @Operation(operationId = "getRuleSimulation", summary = "Simulates the executions for the rules within the schedule.", responses = {
+            @ApiResponse(responseCode = "200", description = "OK", content = @Content(array = @ArraySchema(schema = @Schema(implementation = RuleExecution.class)))) })
+    public Response simulateRules(@QueryParam("from") String from, @QueryParam("until") String until) {
+        final Stream<RuleExecution> ruleExecutions = ruleManager.simulateRuleExecutions(parseTime(from),
+                parseTime(until));
+        return Response.ok(ruleExecutions.collect(Collectors.toList())).build();
+    }
+
+    private static ZonedDateTime parseTime(String sTime) {
+        final DateTimeType dateTime = new DateTimeType(sTime);
+        return dateTime.getZonedDateTime();
+    }
+
     @GET
     @Path("/{ruleUID}/conditions")
     @Produces(MediaType.APPLICATION_JSON)

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/RuleExecution.java

@@ -0,0 +1,59 @@
+/**
+ * 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.core.automation;
+
+import java.util.Date;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
+/**
+ * Expected execution of an {@link Rule}.
+ *
+ * @author Sönke Küper - Initial contribution
+ */
+@NonNullByDefault
+public final class RuleExecution implements Comparable<RuleExecution> {
+
+    private final Date date;
+    private final Rule rule;
+
+    /**
+     * Creates an new {@link RuleExecution}.
+     *
+     * @param date The time when the rule will be executed.
+     * @param rule The rule that will be executed.
+     */
+    public RuleExecution(Date date, Rule rule) {
+        this.date = date;
+        this.rule = rule;
+    }
+
+    /**
+     * Returns the time when the rule will be executed.
+     */
+    public Date getDate() {
+        return date;
+    }
+
+    /**
+     * Returns the rule that will be executed.
+     */
+    public Rule getRule() {
+        return rule;
+    }
+
+    @Override
+    public int compareTo(RuleExecution o) {
+        return this.date.compareTo(o.getDate());
+    }
+}

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/RuleManager.java

@@ -12,7 +12,10 @@
  */
 package org.openhab.core.automation;
 
+import java.time.ZonedDateTime;
+import java.util.Date;
 import java.util.Map;
+import java.util.stream.Stream;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
@@ -92,4 +95,13 @@ public interface RuleManager {
      * @param context the context that is passed to the conditions and the actions of the rule.
      */
     void runNow(String uid, boolean considerConditions, @Nullable Map<String, Object> context);
+
+    /**
+     * Simulates the execution of all rules with tag 'Schedule' for the given time interval.
+     * The result is sorted ascending by execution time.
+     *
+     * @param untilDate {@link Date} until the executions should be simulated.
+     * @return A {@link Stream} with all expected {@link RuleExecution}.
+     */
+    Stream<RuleExecution> simulateRuleExecutions(ZonedDateTime from, ZonedDateTime until);
 }

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/handler/TimeBasedConditionHandler.java

@@ -0,0 +1,34 @@
+/**
+ * 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.core.automation.handler;
+
+import java.time.ZonedDateTime;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
+/**
+ * {@link ConditionHandler} that evaluates, if the current time satisfies an specified condition.
+ *
+ * @author Sönke Küper - Initial contribution
+ */
+@NonNullByDefault
+public interface TimeBasedConditionHandler extends ConditionHandler {
+
+    /**
+     * Checks if this condition is satisfied for the given time.
+     *
+     * @param time The time to check.
+     * @return <code>true</code> if and only if the given time satisfies this condition.
+     */
+    public abstract boolean isSatisfiedAt(ZonedDateTime time);
+}

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/handler/TimeBasedTriggerHandler.java

@@ -0,0 +1,32 @@
+/**
+ * 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.core.automation.handler;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
+import org.openhab.core.scheduler.SchedulerTemporalAdjuster;
+
+/**
+ * Marker Interface for an {@link TriggerHandler} that contains an time based execution.
+ *
+ * @author Sönke Küper - Initial contribution
+ */
+@NonNullByDefault
+public interface TimeBasedTriggerHandler extends TriggerHandler {
+
+    /**
+     * Returns the {@link SchedulerTemporalAdjuster} which can be used to determine the next execution times.
+     */
+    @Nullable
+    public abstract SchedulerTemporalAdjuster getTemporalAdjuster();
+}

bundles/org.openhab.core.automation/src/main/java/org/openhab/core/automation/internal/RuleEngineImpl.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.core.automation.internal;
 
+import java.time.ZonedDateTime;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -28,6 +29,7 @@
 import java.util.concurrent.Future;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
@@ -36,6 +38,7 @@
 import org.openhab.core.automation.Module;
 import org.openhab.core.automation.ModuleHandlerCallback;
 import org.openhab.core.automation.Rule;
+import org.openhab.core.automation.RuleExecution;
 import org.openhab.core.automation.RuleManager;
 import org.openhab.core.automation.RuleRegistry;
 import org.openhab.core.automation.RuleStatus;
@@ -694,7 +697,8 @@ private void unregister(WrappedRule r) {
      * @return handler that processing this module. Could be {@code null} if the {@link ModuleHandlerFactory} is not
      *         available.
      */
-    private @Nullable ModuleHandler getModuleHandler(Module m, String ruleUID) {
+    @Nullable
+    ModuleHandler getModuleHandler(Module m, String ruleUID) {
         String moduleTypeId = m.getTypeUID();
         ModuleHandlerFactory mhf = getModuleHandlerFactory(moduleTypeId);
         if (mhf == null || mtRegistry.get(moduleTypeId) == null) {
@@ -1471,4 +1475,9 @@ private boolean mustTrigger(Rule r) {
     public boolean isStarted() {
         return started;
     }
+
+    @Override
+    public Stream<RuleExecution> simulateRuleExecutions(ZonedDateTime from, ZonedDateTime until) {
+        return new RuleExecutionSimulator(this.ruleRegistry, this).simulateRuleExecutions(from, until);
+    }
 }