From e00d41e0cf3f5b0284d2a085656d300d35fcabff Mon Sep 17 00:00:00 2001
From: Sipke Schoorstra <sipkeschoorstra@outlook.com>
Date: Fri, 4 Dec 2020 15:38:19 +0100
Subject: [PATCH] Schedule activity until after Suspend action

---
 .../Activities/Timer/Timer.cs                 | 23 ++++----------
 .../ActivityResults/ScheduleWorkflowResult.cs | 30 +++++++++++++++++++
 2 files changed, 35 insertions(+), 18 deletions(-)
 create mode 100644 src/activities/Elsa.Activities.Timers/ActivityResults/ScheduleWorkflowResult.cs

diff --git a/src/activities/Elsa.Activities.Timers/Activities/Timer/Timer.cs b/src/activities/Elsa.Activities.Timers/Activities/Timer/Timer.cs
index 99c616f65..84afe2c02 100644
--- a/src/activities/Elsa.Activities.Timers/Activities/Timer/Timer.cs
+++ b/src/activities/Elsa.Activities.Timers/Activities/Timer/Timer.cs
@@ -1,5 +1,4 @@
-using System.Threading.Tasks;
-using Elsa.Activities.Timers.Services;
+using Elsa.Activities.Timers.ActivityResults;
 using Elsa.ActivityResults;
 using Elsa.Attributes;
 using Elsa.Services;
@@ -12,14 +11,10 @@ namespace Elsa.Activities.Timers
     [Trigger(Category = "Timers", Description = "Triggers at a specified interval.")]
     public class Timer : Activity
     {
-        private readonly IWorkflowInstanceManager _workflowInstanceManager;
-        private readonly IWorkflowScheduler _workflowScheduler;
         private readonly IClock _clock;
 
-        public Timer(IWorkflowInstanceManager workflowInstanceManager, IWorkflowScheduler workflowScheduler, IClock clock)
+        public Timer(IClock clock)
         {
-            _workflowInstanceManager = workflowInstanceManager;
-            _workflowScheduler = workflowScheduler;
             _clock = clock;
         }
 
@@ -32,22 +27,14 @@ namespace Elsa.Activities.Timers
             set => SetState(value);
         }
 
-        protected override async ValueTask<IActivityExecutionResult> OnExecuteAsync(ActivityExecutionContext context)
+        protected override IActivityExecutionResult OnExecute(ActivityExecutionContext context)
         {
             if (context.WorkflowExecutionContext.IsFirstPass)
                 return Done();
             
-            var cancellationToken = context.CancellationToken;
-            var workflowBlueprint = context.WorkflowExecutionContext.WorkflowBlueprint;
-            var workflowInstance = context.WorkflowExecutionContext.WorkflowInstance;
-            var executeAt = _clock.GetCurrentInstant().Plus(Timeout);
-            
-            ExecuteAt = executeAt;
+            ExecuteAt = _clock.GetCurrentInstant().Plus(Timeout);
 
-            await _workflowInstanceManager.SaveAsync(context.WorkflowExecutionContext.WorkflowInstance, cancellationToken);
-            await _workflowScheduler.ScheduleWorkflowAsync(workflowBlueprint, workflowInstance.WorkflowInstanceId, Id, executeAt, cancellationToken);
-
-            return Suspend();
+            return Combine(Suspend(), new ScheduleWorkflowResult(ExecuteAt.Value));
         }
 
         protected override IActivityExecutionResult OnResume() => Done();
diff --git a/src/activities/Elsa.Activities.Timers/ActivityResults/ScheduleWorkflowResult.cs b/src/activities/Elsa.Activities.Timers/ActivityResults/ScheduleWorkflowResult.cs
new file mode 100644
index 000000000..8aaf78ab9
--- /dev/null
+++ b/src/activities/Elsa.Activities.Timers/ActivityResults/ScheduleWorkflowResult.cs
@@ -0,0 +1,30 @@
+using System.Threading;
+using System.Threading.Tasks;
+using Elsa.Activities.Timers.Services;
+using Elsa.ActivityResults;
+using Elsa.Models;
+using Elsa.Services;
+using Elsa.Services.Models;
+using NodaTime;
+
+namespace Elsa.Activities.Timers.ActivityResults
+{
+    public class ScheduleWorkflowResult : ActivityExecutionResult
+    {
+        public ScheduleWorkflowResult(Instant executeAt)
+        {
+            ExecuteAt = executeAt;
+        }
+
+        public Instant ExecuteAt { get; }
+
+        public override async ValueTask ExecuteAsync(ActivityExecutionContext activityExecutionContext, CancellationToken cancellationToken)
+        {
+            var workflowInstance = activityExecutionContext.WorkflowExecutionContext.WorkflowInstance;
+            var workflowInstanceManager = activityExecutionContext.GetService<IWorkflowInstanceManager>();
+            var scheduler = activityExecutionContext.GetService<IWorkflowScheduler>();
+            await workflowInstanceManager.SaveAsync(workflowInstance, cancellationToken);
+            await scheduler.ScheduleWorkflowAsync(activityExecutionContext.WorkflowExecutionContext.WorkflowBlueprint, workflowInstance.WorkflowInstanceId, activityExecutionContext.ActivityInstance.Id, ExecuteAt, cancellationToken);
+        }
+    }
+}
\ No newline at end of file