EnvelopeGenerator/EnvelopeGenerator.Application/Histories/Queries/CountHistoryQuery.cs

using DigitalData.Core.Abstraction.Application.Repository;
using DigitalData.Core.Exceptions;
using EnvelopeGenerator.Domain.Entities;
using MediatR;
using Microsoft.EntityFrameworkCore;

namespace EnvelopeGenerator.Application.Histories.Queries;

//TODO: Add sender query
/// <summary>
/// Repräsentiert eine Abfrage für die Verlaufshistorie eines Umschlags.
/// </summary>
public record CountHistoryQuery : HistoryQueryBase, IRequest<int>;

/// <summary>
/// 
/// </summary>
public static class CountHistoryQueryExtensions
{
    /// <summary>
    /// 
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="queryOptions"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    public static async Task<bool> AnyHistoryAsync(this ISender sender, Action<CountHistoryQuery> queryOptions, CancellationToken cancel)
    {
        var query = new CountHistoryQuery();
        queryOptions(query);
        var count = await sender.Send(query, cancel);
        return count > 0;
    }
}

/// <summary>
/// 
/// </summary>
public class CountHistoryQueryHandler : IRequestHandler<CountHistoryQuery, int>
{
    private readonly IRepository<History> _repo;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="repo"></param>
    public CountHistoryQueryHandler(IRepository<History> repo)
    {
        _repo = repo;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    /// <exception cref="NotFoundException"></exception>
    public Task<int> Handle(CountHistoryQuery request, CancellationToken cancel = default)
    {
        var query = _repo.Where(h => h.EnvelopeId == request.EnvelopeId);
        if (request.Status is not null)
            query = query.Where(h => h.Status == request.Status);

        return query.CountAsync(cancel);
    }
}