Split host-level execution plan into two parts

src/main/java/org/prebid/server/hooks/execution/HookStageExecutor.java

@@ -13,6 +13,7 @@
 import org.prebid.server.execution.Timeout;
 import org.prebid.server.execution.TimeoutFactory;
 import org.prebid.server.hooks.execution.model.EndpointExecutionPlan;
+import org.prebid.server.hooks.execution.model.ExecutionGroup;
 import org.prebid.server.hooks.execution.model.ExecutionPlan;
 import org.prebid.server.hooks.execution.model.HookExecutionContext;
 import org.prebid.server.hooks.execution.model.HookId;
@@ -42,41 +43,49 @@
 import org.prebid.server.settings.model.AccountHooksConfiguration;
 
 import java.time.Clock;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 public class HookStageExecutor {
 
-    private final ExecutionPlan executionPlan;
+    private final ExecutionPlan hostExecutionPlan;
+    private final ExecutionPlan defaultAccountExecutionPlan;
     private final HookCatalog hookCatalog;
     private final TimeoutFactory timeoutFactory;
     private final Vertx vertx;
     private final Clock clock;
 
-    private HookStageExecutor(ExecutionPlan executionPlan,
+    private HookStageExecutor(ExecutionPlan hostExecutionPlan,
+                              ExecutionPlan defaultAccountExecutionPlan,
                               HookCatalog hookCatalog,
                               TimeoutFactory timeoutFactory,
                               Vertx vertx,
                               Clock clock) {
 
-        this.executionPlan = executionPlan;
+        this.hostExecutionPlan = hostExecutionPlan;
+        this.defaultAccountExecutionPlan = defaultAccountExecutionPlan;
         this.hookCatalog = hookCatalog;
         this.timeoutFactory = timeoutFactory;
         this.vertx = vertx;
         this.clock = clock;
     }
 
-    public static HookStageExecutor create(String executionPlan,
+    public static HookStageExecutor create(String hostExecutionPlan,
+                                           String defaultAccountExecutionPlan,
                                            HookCatalog hookCatalog,
                                            TimeoutFactory timeoutFactory,
                                            Vertx vertx,
                                            Clock clock,
                                            JacksonMapper mapper) {
 
         return new HookStageExecutor(
-                parseExecutionPlan(executionPlan, Objects.requireNonNull(mapper)),
+                parseExecutionPlan(hostExecutionPlan, Objects.requireNonNull(mapper)),
+                parseExecutionPlan(defaultAccountExecutionPlan, mapper),
                 Objects.requireNonNull(hookCatalog),
                 Objects.requireNonNull(timeoutFactory),
                 Objects.requireNonNull(vertx),
@@ -224,7 +233,7 @@ private <PAYLOAD, CONTEXT extends InvocationContext> StageExecutor<PAYLOAD, CONT
 
         return this.<PAYLOAD, CONTEXT>stageExecutor()
                 .withStage(stage)
-                .withExecutionPlan(planFor(account, endpoint, stage))
+                .withExecutionPlan(planForStage(account, endpoint, stage))
                 .withHookExecutionContext(context);
     }
 
@@ -241,14 +250,34 @@ private static ExecutionPlan parseExecutionPlan(String executionPlan, JacksonMap
     }
 
     private StageExecutionPlan planForEntrypointStage(Endpoint endpoint) {
-        return planFor(executionPlan, endpoint, Stage.entrypoint);
+        return effectiveStagePlanFrom(ExecutionPlan.empty(), endpoint, Stage.entrypoint);
     }
 
-    private StageExecutionPlan planFor(Account account, Endpoint endpoint, Stage stage) {
-        return planFor(effectiveExecutionPlanFor(account), endpoint, stage);
+    private StageExecutionPlan planForStage(Account account, Endpoint endpoint, Stage stage) {
+        return effectiveStagePlanFrom(effectiveExecutionPlanFor(account), endpoint, stage);
     }
 
-    private static StageExecutionPlan planFor(ExecutionPlan executionPlan, Endpoint endpoint, Stage stage) {
+    private StageExecutionPlan effectiveStagePlanFrom(
+            ExecutionPlan accountExecutionPlan, Endpoint endpoint, Stage stage) {
+
+        final StageExecutionPlan hostStageExecutionPlan = stagePlanFrom(hostExecutionPlan, endpoint, stage);
+        final StageExecutionPlan accountStageExecutionPlan = stagePlanFrom(accountExecutionPlan, endpoint, stage);
+
+        if (hostStageExecutionPlan.isEmpty()) {
+            return accountStageExecutionPlan;
+        } else if (accountStageExecutionPlan.isEmpty()) {
+            return hostStageExecutionPlan;
+        }
+
+        final List<ExecutionGroup> combinedGroups = Stream.of(hostStageExecutionPlan, accountStageExecutionPlan)
+                .map(StageExecutionPlan::getGroups)
+                .flatMap(Collection::stream)
+                .collect(Collectors.toList());
+
+        return StageExecutionPlan.of(combinedGroups);
+    }
+
+    private static StageExecutionPlan stagePlanFrom(ExecutionPlan executionPlan, Endpoint endpoint, Stage stage) {
         return executionPlan
                 .getEndpoints()
                 .getOrDefault(endpoint, EndpointExecutionPlan.empty())
@@ -261,7 +290,7 @@ private ExecutionPlan effectiveExecutionPlanFor(Account account) {
         final ExecutionPlan accountExecutionPlan =
                 hooksAccountConfig != null ? hooksAccountConfig.getExecutionPlan() : null;
 
-        return accountExecutionPlan != null ? accountExecutionPlan : executionPlan;
+        return accountExecutionPlan != null ? accountExecutionPlan : defaultAccountExecutionPlan;
     }
 
     private InvocationContextProvider<InvocationContext> invocationContextProvider(Endpoint endpoint) {

src/main/java/org/prebid/server/hooks/execution/model/StageExecutionPlan.java

@@ -4,6 +4,7 @@
 
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 @Value(staticConstructor = "of")
 public class StageExecutionPlan {
@@ -15,4 +16,8 @@ public class StageExecutionPlan {
     public static StageExecutionPlan empty() {
         return EMPTY;
     }
+
+    public boolean isEmpty() {
+        return Objects.equals(this, EMPTY);
+    }
 }

src/main/java/org/prebid/server/spring/config/HooksConfiguration.java

@@ -33,7 +33,13 @@ HookStageExecutor hookStageExecutor(HooksConfigurationProperties hooksConfigurat
                                         JacksonMapper mapper) {
 
         return HookStageExecutor.create(
-                hooksConfiguration.getExecutionPlan(), hookCatalog, timeoutFactory, vertx, clock, mapper);
+                hooksConfiguration.getHostExecutionPlan(),
+                hooksConfiguration.getDefaultAccountExecutionPlan(),
+                hookCatalog,
+                timeoutFactory,
+                vertx,
+                clock,
+                mapper);
     }
 
     @Bean
@@ -47,6 +53,8 @@ HooksConfigurationProperties hooksConfigurationProperties() {
     @NoArgsConstructor
     private static class HooksConfigurationProperties {
 
-        String executionPlan;
+        String hostExecutionPlan;
+
+        String defaultAccountExecutionPlan;
     }
 }