CustomerFindAllQuery.cs

// MIT-License
// Copyright BridgingIT GmbH - All Rights Reserved
// Use of this source code is governed by an MIT-style license that can be
// found in the LICENSE file at https://github.com/bridgingit/bitdevkit/license

namespace BridgingIT.DevKit.Examples.GettingStarted.Modules.CoreModule.Application;

using BridgingIT.DevKit.Examples.GettingStarted.Modules.CoreModule.Domain.Model;

/// <summary>
/// Query for retrieving all <see cref="Customer"/> Aggregates.
/// Handler for processing <see cref="CustomerFindAllQuery"/>.
/// Responsible for loading all customers from the repository with optional filters,
/// auditing/logging the operation, and mapping results from domain entities
/// (<see cref="Customer"/>) to application DTOs (<see cref="CustomerModel"/>).
/// </summary>
/// <remarks>
/// - Configured with retry (<see cref="HandlerRetryAttribute"/>) for transient failures.
/// - Configured with timeout (<see cref="HandlerTimeoutAttribute"/>) to bound execution.
/// - Uses <see cref="IGenericRepository{Customer}"/> for persistence access.
/// - Uses <see cref="IMapper"/> (Mapster abstraction) for domain -> DTO transformations.
/// </remarks>
// [HandlerRetry(2, 100)]   // retry twice with 100ms delay between retries
// [HandlerTimeout(500)]    // enforce max 500ms execution per request
[Query]
public partial class CustomerFindAllQuery
{
    /// <summary>Gets or sets the optional filter criteria used when retrieving customers.</summary>
    public FilterModel Filter { get; set; }

    /// <summary>
    /// Handles the <see cref="CustomerFindAllQuery"/> asynchronously.
    /// </summary>
    /// <param name="logger">Logger used for audit and diagnostic information.</param>
    /// <param name="mapper">Mapper used to convert domain entities to application models.</param>
    /// <param name="repository">Repository used to load customer aggregates.</param>
    /// <param name="cancellationToken">Cancellation token for async workflow.</param>
    /// <returns>
    /// A Result containing an enumerable of model instances representing all aggregates found, or a failure result in case of an error.
    /// </returns>
    [Handle]
    private async Task<Result<IEnumerable<CustomerModel>>> HandleAsync(
        ILogger<CustomerFindAllQuery> logger,
        IMapper mapper,
        IGenericRepository<Customer> repository,
        CancellationToken cancellationToken)
    {
        // Load all matching customers from repository
        return await repository.FindAllResultAsync(Filter, cancellationToken: cancellationToken) // TODO: use paging -> FindAllResultPagedAsync

            // Side effects (audit/logging)
            .Log(logger, "AUDIT - Customers retrieved (count: {Count}, filter: {@Filter})", r => [r.Value.Count(), Filter])

            // Map retrieved Aggregates -> Models
            .Map(mapper.Map<Customer, CustomerModel>);
    }
}