using AutoMapper;
using DigitalData.Core.Abstraction.Application.Repository;
using DigitalData.Core.Exceptions;
using EnvelopeGenerator.Application.Common.Dto.History;
using MediatR;
using EnvelopeGenerator.Domain.Entities;
using Microsoft.EntityFrameworkCore;

namespace EnvelopeGenerator.Application.Histories.Queries;

//TODO: Add sender query
/// <summary>
/// Repräsentiert eine Abfrage für die Verlaufshistorie eines Umschlags.
/// </summary>
public record ReadHistoryQuery : HistoryQueryBase, IRequest<IEnumerable<HistoryDto>>
{
    /// <summary>
    /// Abfrage zur Steuerung, ob nur der aktuelle Include oder der gesamte Datensatz zurückgegeben wird.
    /// </summary>
    public bool OnlyLast { get; init; } = true;
}

/// <summary>
/// 
/// </summary>
public class ReadHistoryQueryHandler : IRequestHandler<ReadHistoryQuery, IEnumerable<HistoryDto>>
{
    private readonly IRepository<History> _repo;

    private readonly IMapper _mapper;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="repo"></param>
    /// <param name="mapper"></param>
    public ReadHistoryQueryHandler(IRepository<History> repo, IMapper mapper)
    {
        _repo = repo;
        _mapper = mapper;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    /// <exception cref="NotFoundException"></exception>
    public async Task<IEnumerable<HistoryDto>> Handle(ReadHistoryQuery request, CancellationToken cancel = default)
    {
        var query = _repo.Query;

        if (request.Envelope.Id is int envId)
            query = query.Where(e => e.Id == envId);
        else if (request.Envelope.Uuid is string uuid)
            query = query.Where(e => e.Envelope!.Uuid == uuid);
#pragma warning disable CS0618 // Type or member is obsolete
        else if (request.EnvelopeId is not null)
            query = query.Where(h => h.EnvelopeId == request.EnvelopeId);
#pragma warning restore CS0618 // Type or member is obsolete
        else
            throw new BadRequestException("Invalid request: An Envelope object or a valid EnvelopeId/UUID must be supplied.");

        if (request.Status is not null)
            query = query.Where(h => h.Status == request.Status);

        if (request.OnlyLast)
            query = query.OrderByDescending(x => x.AddedWhen);

        var hists = await query.ToListAsync(cancel);
        return _mapper.Map<List<HistoryDto>>(hists);
    }
}