From 2efd04cf5379727a30ab216c3e868b5001f41085 Mon Sep 17 00:00:00 2001
From: Sipke Schoorstra <sipkeschoorstra@outlook.com>
Date: Sat, 4 Nov 2023 18:08:56 +0100
Subject: [PATCH] Add option to register scripts via options

---
 .../Elsa.WorkflowServer.Web/Program.cs        | 16 +++++++--
 .../{RunCSharp => RunPython}/RunPython.cs     |  0
 .../RunPythonOptionsProvider.cs               |  0
 .../Handlers/ConfigureScriptsFromOptions.cs   | 33 +++++++++++++++++++
 .../Models/ExecutionContextProxy.cs           |  1 -
 .../Elsa.Python/Options/PythonOptions.cs      | 25 ++++++++++++++
 6 files changed, 72 insertions(+), 3 deletions(-)
 rename src/modules/Elsa.Python/Activities/{RunCSharp => RunPython}/RunPython.cs (100%)
 rename src/modules/Elsa.Python/Activities/{RunCSharp => RunPython}/RunPythonOptionsProvider.cs (100%)
 create mode 100644 src/modules/Elsa.Python/Handlers/ConfigureScriptsFromOptions.cs

diff --git a/src/bundles/Elsa.WorkflowServer.Web/Program.cs b/src/bundles/Elsa.WorkflowServer.Web/Program.cs
index cc2a8e786..22fe348bb 100644
--- a/src/bundles/Elsa.WorkflowServer.Web/Program.cs
+++ b/src/bundles/Elsa.WorkflowServer.Web/Program.cs
@@ -151,8 +151,20 @@ services
                 options.AppendScript("string Greet(string name) => $\"Hello {name}!\";");
                 options.AppendScript("string SayHelloWorld() => Greet(\"World\");");
             })
-            .UseJavaScript(options => options.AllowClrAccess = true)
-            .UsePython()
+            .UseJavaScript(options =>
+            {
+                options.AllowClrAccess = true;
+                options.ConfigureEngine(engine =>
+                {
+                    engine.Execute("function greet(name) { return `Hello ${name}!`; }");
+                    engine.Execute("function sayHelloWorld() { return greet('World'); }");
+                });
+            })
+            .UsePython(options =>
+            {
+                options.AddScript("def greet(name): return f\"Hello {name}!\";");
+                options.AddScript("def say_hello_world(): return greet(\"World\");");
+            })
             .UseLiquid(liquid => liquid.FluidOptions = options => options.Encoder = HtmlEncoder.Default)
             .UseHttp(http =>
             {
diff --git a/src/modules/Elsa.Python/Activities/RunCSharp/RunPython.cs b/src/modules/Elsa.Python/Activities/RunPython/RunPython.cs
similarity index 100%
rename from src/modules/Elsa.Python/Activities/RunCSharp/RunPython.cs
rename to src/modules/Elsa.Python/Activities/RunPython/RunPython.cs
diff --git a/src/modules/Elsa.Python/Activities/RunCSharp/RunPythonOptionsProvider.cs b/src/modules/Elsa.Python/Activities/RunPython/RunPythonOptionsProvider.cs
similarity index 100%
rename from src/modules/Elsa.Python/Activities/RunCSharp/RunPythonOptionsProvider.cs
rename to src/modules/Elsa.Python/Activities/RunPython/RunPythonOptionsProvider.cs
diff --git a/src/modules/Elsa.Python/Handlers/ConfigureScriptsFromOptions.cs b/src/modules/Elsa.Python/Handlers/ConfigureScriptsFromOptions.cs
new file mode 100644
index 000000000..4dfcabb6b
--- /dev/null
+++ b/src/modules/Elsa.Python/Handlers/ConfigureScriptsFromOptions.cs
@@ -0,0 +1,33 @@
+using Elsa.Mediator.Contracts;
+using Elsa.Python.Notifications;
+using Elsa.Python.Options;
+using JetBrains.Annotations;
+using Microsoft.Extensions.Options;
+
+namespace Elsa.Python.Handlers;
+
+/// <summary>
+/// This handler configures the Python engine based on the <see cref="PythonOptions"/>.
+/// </summary>
+[UsedImplicitly]
+public class ConfigurePythonFromOptions : INotificationHandler<EvaluatingPython>
+{
+    private readonly PythonOptions _options;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ConfigurePythonFromOptions"/> class.
+    /// </summary>
+    public ConfigurePythonFromOptions(IOptions<PythonOptions> options)
+    {
+        _options = options.Value;
+    }
+
+    /// <inheritdoc />
+    public Task HandleAsync(EvaluatingPython notification, CancellationToken cancellationToken)
+    {
+        foreach (var script in _options.Scripts)
+            notification.AppendScript(script);
+
+        return Task.CompletedTask;
+    }
+}
\ No newline at end of file
diff --git a/src/modules/Elsa.Python/Models/ExecutionContextProxy.cs b/src/modules/Elsa.Python/Models/ExecutionContextProxy.cs
index 909e91360..591db80e9 100644
--- a/src/modules/Elsa.Python/Models/ExecutionContextProxy.cs
+++ b/src/modules/Elsa.Python/Models/ExecutionContextProxy.cs
@@ -1,7 +1,6 @@
 using Elsa.Expressions.Helpers;
 using Elsa.Expressions.Models;
 using Elsa.Extensions;
-using Humanizer;
 using JetBrains.Annotations;
 
 namespace Elsa.Python.Models;
diff --git a/src/modules/Elsa.Python/Options/PythonOptions.cs b/src/modules/Elsa.Python/Options/PythonOptions.cs
index 595bc2f3f..48942d9d7 100644
--- a/src/modules/Elsa.Python/Options/PythonOptions.cs
+++ b/src/modules/Elsa.Python/Options/PythonOptions.cs
@@ -1,3 +1,5 @@
+using System.Text;
+
 namespace Elsa.Python.Options;
 
 /// <summary>
@@ -5,5 +7,28 @@ namespace Elsa.Python.Options;
 /// </summary>
 public class PythonOptions
 {
+    /// <summary>
+    /// Gets or sets the Python script files to load.
+    /// </summary>
+    public ICollection<string> Scripts { get; } = new List<string>();
     
+    /// <summary>
+    /// Appends a script to the Python engine.
+    /// </summary>
+    /// <param name="builder">A builder that builds the script to append.</param>
+    public void AddScript(Action<StringBuilder> builder)
+    {
+        var sb = new StringBuilder();
+        builder(sb);
+        AddScript(sb.ToString());
+    }
+
+    /// <summary>
+    /// Appends a script to the Python engine.
+    /// </summary>
+    /// <param name="script">The script to append.</param>
+    public void AddScript(string script)
+    {
+        Scripts.Add(script);
+    }
 }
\ No newline at end of file