DeleteHandler.cs

// -------------------------------------------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License (MIT). See LICENSE in the repo root for license information.
// -------------------------------------------------------------------------------------------------

using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
using EnsureThat;
using MediatR;
using Microsoft.Health.Core.Features.Security.Authorization;
using Microsoft.Health.Dicom.Core.Exceptions;
using Microsoft.Health.Dicom.Core.Features.Common;
using Microsoft.Health.Dicom.Core.Features.Security;
using Microsoft.Health.Dicom.Core.Features.Validation;
using Microsoft.Health.Dicom.Core.Messages;
using Microsoft.Health.Dicom.Core.Messages.Delete;

namespace Microsoft.Health.Dicom.Core.Features.Delete;

public class DeleteHandler : BaseHandler, IRequestHandler<DeleteResourcesRequest, DeleteResourcesResponse>
{
    private readonly IDeleteService _deleteService;

    public DeleteHandler(IAuthorizationService<DataActions> authorizationService, IDeleteService deleteService)
        : base(authorizationService)
    {
        _deleteService = EnsureArg.IsNotNull(deleteService, nameof(deleteService));
    }

    /// <inheritdoc />
    public async Task<DeleteResourcesResponse> Handle(DeleteResourcesRequest request, CancellationToken cancellationToken)
    {
        EnsureArg.IsNotNull(request, nameof(request));

        if (await AuthorizationService.CheckAccess(DataActions.Delete, cancellationToken) != DataActions.Delete)
        {
            throw new UnauthorizedDicomActionException(DataActions.Delete);
        }

        ValidateDeleteResourcesRequest(request);

        switch (request.ResourceType)
        {
            case ResourceType.Study:
                await _deleteService.DeleteStudyAsync(request.StudyInstanceUid, cancellationToken);
                break;
            case ResourceType.Series:
                await _deleteService.DeleteSeriesAsync(request.StudyInstanceUid, request.SeriesInstanceUid, cancellationToken);
                break;
            case ResourceType.Instance:
                await _deleteService.DeleteInstanceAsync(request.StudyInstanceUid, request.SeriesInstanceUid, request.SopInstanceUid, cancellationToken);
                break;
            default:
                Debug.Fail($"Unknown delete transaction type: {request.ResourceType}", nameof(request));
                break;
        }

        return new DeleteResourcesResponse();
    }

    private static void ValidateDeleteResourcesRequest(DeleteResourcesRequest request)
    {
        UidValidation.Validate(request.StudyInstanceUid, nameof(request.StudyInstanceUid));

        switch (request.ResourceType)
        {
            case ResourceType.Series:
                UidValidation.Validate(request.SeriesInstanceUid, nameof(request.SeriesInstanceUid));
                break;
            case ResourceType.Instance:
                UidValidation.Validate(request.SeriesInstanceUid, nameof(request.SeriesInstanceUid));
                UidValidation.Validate(request.SopInstanceUid, nameof(request.SopInstanceUid));
                break;
        }
    }
}