From f99bd9b15cfd15643dd435c17c25bd4ce26d0371 Mon Sep 17 00:00:00 2001
From: "Shkar T. Noori" <shkar.noori@dit.gov.krd>
Date: Sun, 28 Apr 2024 11:17:50 +0300
Subject: [PATCH] Add GetAllTransitionDefinitions and GetAllowedTransitions
 methods to IWorkflow.cs

---
 .../Abstractions/IWorkflow.cs                 | 18 +++++++++++
 src/DIT.Workflower/Query.cs                   | 13 ++++++++
 src/DIT.Workflower/WorkflowDefinition.cs      | 31 +++++++++++++++++++
 3 files changed, 62 insertions(+)
 create mode 100644 src/DIT.Workflower/Query.cs

diff --git a/src/DIT.Workflower.DependencyInjection/Abstractions/IWorkflow.cs b/src/DIT.Workflower.DependencyInjection/Abstractions/IWorkflow.cs
index 598a95c..fec6118 100644
--- a/src/DIT.Workflower.DependencyInjection/Abstractions/IWorkflow.cs
+++ b/src/DIT.Workflower.DependencyInjection/Abstractions/IWorkflow.cs
@@ -10,6 +10,15 @@ public interface IWorkflow<TState, TCommand, TContext>
 
     string Reference => $"{Id}.v{Version}";
 
+    /// <summary>
+    /// Retrieves all transition definitions for the workflow.
+    /// </summary>
+    /// <typeparam name="TState">The type of the workflow state.</typeparam>
+    /// <typeparam name="TCommand">The type of the workflow command.</typeparam>
+    /// <typeparam name="TContext">The type of the workflow context.</typeparam>
+    /// <returns>A list of transition definitions.</returns>
+    public List<TransitionDefinition<TState, TCommand, TContext>> GetAllTransitionDefinitions();
+
     /// <summary>
     /// Gets a list of allowed transitions without any condition checks.
     /// </summary>
@@ -24,4 +33,13 @@ public interface IWorkflow<TState, TCommand, TContext>
     /// <param name="from">The incoming state</param>
     /// <returns>A list of available transitions for the current context</returns>
     public List<Transition<TState, TCommand>> GetAllowedTransitions(TContext context, TState from);
+
+    /// <summary>
+    /// Retrieves a list of allowed transitions based on the provided request.
+    /// </summary>
+    /// <typeparam name="TState">The type of the workflow state.</typeparam>
+    /// <typeparam name="TCommand">The type of the workflow command.</typeparam>
+    /// <param name="request">The request object containing the necessary information.</param>
+    /// <returns>An enumerable of allowed transitions.</returns>
+    public IEnumerable<Transition<TState, TCommand>> GetAllowedTransitions(ListTransitionsRequest<TState, TCommand, TContext> request);
 }
diff --git a/src/DIT.Workflower/Query.cs b/src/DIT.Workflower/Query.cs
new file mode 100644
index 0000000..0b071ab
--- /dev/null
+++ b/src/DIT.Workflower/Query.cs
@@ -0,0 +1,13 @@
+namespace DIT.Workflower;
+
+
+public sealed class ListTransitionsRequest<TState, TCommand, TContext>
+{
+    public TState? From { get; set; }
+
+    public TState? To { get; set; }
+
+    public TCommand? Command { get; set; }
+
+    public TContext? Context { get; set; }
+}
diff --git a/src/DIT.Workflower/WorkflowDefinition.cs b/src/DIT.Workflower/WorkflowDefinition.cs
index 1b55ded..45ce199 100644
--- a/src/DIT.Workflower/WorkflowDefinition.cs
+++ b/src/DIT.Workflower/WorkflowDefinition.cs
@@ -12,6 +12,8 @@ public record WorkflowDefinition<TState, TCommand, TContext>
         _transitions = transitions;
     }
 
+    public List<TransitionDefinition<TState, TCommand, TContext>> GetAllTransitionDefinitions() => _transitions;
+
     /// <summary>
     /// Lists all allowed transitions from current state for the given context.
     /// </summary>
@@ -33,4 +35,33 @@ public record WorkflowDefinition<TState, TCommand, TContext>
 
         return query.Select(x => x.ToTransition()).ToList();
     }
+
+
+    public IEnumerable<Transition<TState, TCommand>> GetAllowedTransitions(ListTransitionsRequest<TState, TCommand, TContext> request)
+    {
+        var query = _transitions.AsQueryable();
+
+        if (request.From is TState from)
+        {
+            query = query.Where(doc => doc.From.Equals(from));
+        }
+
+        if (request.To is TState to)
+        {
+            query = query.Where(doc => doc.To.Equals(to));
+        }
+
+        if (request.Command is TCommand command)
+        {
+            query = query.Where(doc => doc.Command.Equals(command));
+        }
+
+        if (request.Context is not null)
+        {
+            query = query.Where(doc => doc.Conditions == null || !doc.Conditions.Any(cond => !cond(request.Context)));
+        }
+
+        return query.Select(x => x.ToTransition());
+    }
+
 }