From ed06e460c31bfb107ed706b68aaa6e8aebb43b13 Mon Sep 17 00:00:00 2001
From: TekH <h.tek@digitaldata.works>
Date: Fri, 9 Oct 2026 23:06:05 +0200
Subject: [PATCH] feat(application): add workflow and document request handlers

---
 .../Queries/GetDocument/GetDocumentQuery.cs   | 60 ++++++++++++
 .../CloseWorkflow/CloseWorkflowCommand.cs     | 97 +++++++++++++++++++
 .../Queries/GetWorkflows/GetWorkflowsQuery.cs | 60 ++++++++++++
 3 files changed, 217 insertions(+)
 create mode 100644 src/core/DigitalData.TaskFlow.Application/Features/Documents/Queries/GetDocument/GetDocumentQuery.cs
 create mode 100644 src/core/DigitalData.TaskFlow.Application/Features/Workflows/Commands/CloseWorkflow/CloseWorkflowCommand.cs
 create mode 100644 src/core/DigitalData.TaskFlow.Application/Features/Workflows/Queries/GetWorkflows/GetWorkflowsQuery.cs

diff --git a/src/core/DigitalData.TaskFlow.Application/Features/Documents/Queries/GetDocument/GetDocumentQuery.cs b/src/core/DigitalData.TaskFlow.Application/Features/Documents/Queries/GetDocument/GetDocumentQuery.cs
new file mode 100644
index 0000000..f2dfc33
--- /dev/null
+++ b/src/core/DigitalData.TaskFlow.Application/Features/Documents/Queries/GetDocument/GetDocumentQuery.cs
@@ -0,0 +1,60 @@
+using DigitalData.TaskFlow.Application.Common.Interfaces;
+using DigitalData.TaskFlow.Domain.Common;
+using DigitalData.TaskFlow.Domain.Documents;
+using DigitalData.TaskFlow.Domain.Enums;
+using FluentValidation;
+using MediatR;
+
+namespace DigitalData.TaskFlow.Application.Features.Documents.Queries.GetDocument;
+
+/// <summary>
+/// Represents a request to retrieve binary document content by document identifier.
+/// </summary>
+/// <param name="Id">Document identifier.</param>
+public sealed record GetDocumentQuery(string Id) : IRequest<ApiEnvelope<DocumentBinaryResult>>;
+
+/// <summary>
+/// Validates <see cref="GetDocumentQuery"/> requests.
+/// </summary>
+public sealed class GetDocumentQueryValidator : AbstractValidator<GetDocumentQuery>
+{
+    /// <summary>
+    /// Initializes validation rules for <see cref="GetDocumentQuery"/>.
+    /// </summary>
+    public GetDocumentQueryValidator()
+    {
+        RuleFor(x => x.Id)
+            .NotEmpty();
+    }
+}
+
+/// <summary>
+/// Handles <see cref="GetDocumentQuery"/> requests.
+/// </summary>
+public sealed class GetDocumentQueryHandler(IDocumentRepository documentRepository)
+    : IRequestHandler<GetDocumentQuery, ApiEnvelope<DocumentBinaryResult>>
+{
+    /// <summary>
+    /// Executes the query and returns binary document data in the standard API envelope.
+    /// </summary>
+    /// <param name="request">Query request.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Document response envelope.</returns>
+    public async Task<ApiEnvelope<DocumentBinaryResult>> Handle(GetDocumentQuery request, CancellationToken cancellationToken)
+    {
+        var document = await documentRepository.GetAsync(request.Id, cancellationToken);
+
+        return new ApiEnvelope<DocumentBinaryResult>
+        {
+            Meta =
+            [
+                new MetaEntry
+                {
+                    Code = (int)MetaCode.Ok,
+                    Message = "OK"
+                }
+            ],
+            Data = document
+        };
+    }
+}
diff --git a/src/core/DigitalData.TaskFlow.Application/Features/Workflows/Commands/CloseWorkflow/CloseWorkflowCommand.cs b/src/core/DigitalData.TaskFlow.Application/Features/Workflows/Commands/CloseWorkflow/CloseWorkflowCommand.cs
new file mode 100644
index 0000000..9aa3067
--- /dev/null
+++ b/src/core/DigitalData.TaskFlow.Application/Features/Workflows/Commands/CloseWorkflow/CloseWorkflowCommand.cs
@@ -0,0 +1,97 @@
+using DigitalData.TaskFlow.Application.Common.Interfaces;
+using DigitalData.TaskFlow.Domain.Closing;
+using DigitalData.TaskFlow.Domain.Common;
+using DigitalData.TaskFlow.Domain.Enums;
+using FluentValidation;
+using MediatR;
+
+namespace DigitalData.TaskFlow.Application.Features.Workflows.Commands.CloseWorkflow;
+
+/// <summary>
+/// Represents a request to close a workflow process using a selected closing method.
+/// </summary>
+/// <param name="WisagId">WISAG user identifier.</param>
+/// <param name="Source">Source system name.</param>
+/// <param name="ProcessId">Process identifier.</param>
+/// <param name="ClosingMethodId">Selected closing method identifier.</param>
+/// <param name="Comment">Optional user comment.</param>
+/// <param name="RejectionReasonId">Optional rejection reason identifier.</param>
+public sealed record CloseWorkflowCommand(
+    int WisagId,
+    string Source,
+    int ProcessId,
+    int ClosingMethodId,
+    string? Comment,
+    int? RejectionReasonId)
+    : IRequest<ApiEnvelope<CloseWorkflowResult>>;
+
+/// <summary>
+/// Validates <see cref="CloseWorkflowCommand"/> requests.
+/// </summary>
+public sealed class CloseWorkflowCommandValidator : AbstractValidator<CloseWorkflowCommand>
+{
+    private static readonly string[] AllowedSources = ["Ferdinand", "Contracts"];
+
+    /// <summary>
+    /// Initializes validation rules for <see cref="CloseWorkflowCommand"/>.
+    /// </summary>
+    public CloseWorkflowCommandValidator()
+    {
+        RuleFor(x => x.WisagId)
+            .GreaterThan(0);
+
+        RuleFor(x => x.ProcessId)
+            .GreaterThan(0);
+
+        RuleFor(x => x.ClosingMethodId)
+            .GreaterThan(0);
+
+        RuleFor(x => x.Source)
+            .NotEmpty()
+            .Must(source => AllowedSources.Contains(source))
+            .WithMessage("Source must be one of the supported source systems.");
+    }
+}
+
+/// <summary>
+/// Handles <see cref="CloseWorkflowCommand"/> requests.
+/// </summary>
+public sealed class CloseWorkflowCommandHandler(IWorkflowRepository workflowRepository)
+    : IRequestHandler<CloseWorkflowCommand, ApiEnvelope<CloseWorkflowResult>>
+{
+    /// <summary>
+    /// Executes the closing request and returns the operation result in the standard API envelope.
+    /// </summary>
+    /// <param name="request">Command request.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Closing result envelope.</returns>
+    public async Task<ApiEnvelope<CloseWorkflowResult>> Handle(CloseWorkflowCommand request, CancellationToken cancellationToken)
+    {
+        var decision = new CloseWorkflowDecision
+        {
+            ClosingMethodId = request.ClosingMethodId,
+            Comment = request.Comment,
+            RejectionReasonId = request.RejectionReasonId
+        };
+
+        var result = await workflowRepository.CloseAsync(
+            request.WisagId,
+            request.Source,
+            request.ProcessId,
+            decision,
+            cancellationToken);
+
+        return new ApiEnvelope<CloseWorkflowResult>
+        {
+            Meta =
+            [
+                new MetaEntry
+                {
+                    Code = (int)MetaCode.Ok,
+                    Message = "OK"
+                }
+            ],
+            Data = result
+        };
+    }
+}
diff --git a/src/core/DigitalData.TaskFlow.Application/Features/Workflows/Queries/GetWorkflows/GetWorkflowsQuery.cs b/src/core/DigitalData.TaskFlow.Application/Features/Workflows/Queries/GetWorkflows/GetWorkflowsQuery.cs
new file mode 100644
index 0000000..4e84b4d
--- /dev/null
+++ b/src/core/DigitalData.TaskFlow.Application/Features/Workflows/Queries/GetWorkflows/GetWorkflowsQuery.cs
@@ -0,0 +1,60 @@
+using DigitalData.TaskFlow.Application.Common.Interfaces;
+using DigitalData.TaskFlow.Domain.Common;
+using DigitalData.TaskFlow.Domain.Enums;
+using DigitalData.TaskFlow.Domain.Workflows;
+using FluentValidation;
+using MediatR;
+
+namespace DigitalData.TaskFlow.Application.Features.Workflows.Queries.GetWorkflows;
+
+/// <summary>
+/// Represents a request to fetch grouped workflow data for a WISAG user.
+/// </summary>
+/// <param name="WisagId">WISAG user identifier.</param>
+public sealed record GetWorkflowsQuery(int WisagId) : IRequest<ApiEnvelope<WorkflowSourcesResponse>>;
+
+/// <summary>
+/// Validates <see cref="GetWorkflowsQuery"/> requests.
+/// </summary>
+public sealed class GetWorkflowsQueryValidator : AbstractValidator<GetWorkflowsQuery>
+{
+    /// <summary>
+    /// Initializes validation rules for <see cref="GetWorkflowsQuery"/>.
+    /// </summary>
+    public GetWorkflowsQueryValidator()
+    {
+        RuleFor(x => x.WisagId)
+            .GreaterThan(0);
+    }
+}
+
+/// <summary>
+/// Handles <see cref="GetWorkflowsQuery"/> requests.
+/// </summary>
+public sealed class GetWorkflowsQueryHandler(IWorkflowRepository workflowRepository)
+    : IRequestHandler<GetWorkflowsQuery, ApiEnvelope<WorkflowSourcesResponse>>
+{
+    /// <summary>
+    /// Executes the query and returns a workflow payload wrapped in the standard API envelope.
+    /// </summary>
+    /// <param name="request">Query request.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Workflow response envelope.</returns>
+    public async Task<ApiEnvelope<WorkflowSourcesResponse>> Handle(GetWorkflowsQuery request, CancellationToken cancellationToken)
+    {
+        var data = await workflowRepository.GetAsync(request.WisagId, cancellationToken);
+
+        return new ApiEnvelope<WorkflowSourcesResponse>
+        {
+            Meta =
+            [
+                new MetaEntry
+                {
+                    Code = (int)MetaCode.Ok,
+                    Message = "OK"
+                }
+            ],
+            Data = data
+        };
+    }
+}