using AutoMapper;
using DigitalData.Core.Abstraction.Application.Repository;
using DigitalData.Core.Exceptions;
using MediatR;
using System.Text.Json.Serialization;
using EnvelopeGenerator.Domain.Entities;
using Microsoft.EntityFrameworkCore;
using EnvelopeGenerator.Domain.Constants;
using EnvelopeGenerator.Application.Common.Dto;

namespace EnvelopeGenerator.Application.EmailTemplates.Commands.Update;

/// <summary>
/// Befehl zum Aktualisieren einer E-Mail-Vorlage.
/// </summary>
/// <param name="Body">
/// (Optional)Der neue Inhalt des E-Mail-Textkörpers. Wenn null, bleibt der vorhandene Inhalt unverändert.
/// </param>
/// <param name="Subject">
/// (Optional) Der neue Betreff der E-Mail. Wenn null, bleibt der vorhandene Betreff unverändert.
/// </param>
public record UpdateEmailTemplateCommand(string? Body = null, string? Subject = null) : IRequest
{
    /// <param>
    /// Die Abfrage, die die E-Mail-Vorlage darstellt, die aktualisiert werden soll.
    /// </param>
    [JsonIgnore]
    public EmailTemplateQueryBase? EmailTemplateQuery { get; set; }

    /// <summary>
    /// 
    /// </summary>
    [JsonIgnore]
    public DateTime ChangedWhen { get; init; } = DateTime.Now;
}

/// <summary>
/// 
/// </summary>
public class UpdateEmailTemplateCommandHandler : IRequestHandler<UpdateEmailTemplateCommand>
{
    private readonly IRepository<EmailTemplate> _repository;

    private readonly IMapper _mapper;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="repository"></param>
    /// <param name="mapper"></param>
    public UpdateEmailTemplateCommandHandler(IRepository<EmailTemplate> repository, IMapper mapper)
    {
        _repository = repository;
        _mapper = mapper;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    /// <exception cref="InvalidOperationException"></exception>
    /// <exception cref="NotFoundException"></exception>
    [Obsolete("Use Read-method returning IReadQuery<TEntity> instead.")]
    public async Task Handle(UpdateEmailTemplateCommand request, CancellationToken cancel)
    {
        EmailTemplateDto? tempDto;

        if (request.EmailTemplateQuery?.Id is int id)
        {
            var temp = await _repository.ReadOnly().Where(t => t.Id == id).FirstOrDefaultAsync(cancel);
            tempDto = _mapper.Map<EmailTemplateDto>(temp);
        }
        else if (request!.EmailTemplateQuery!.Type is EmailTemplateType type)
        {
            var temp = await _repository.ReadOnly().Where(t => t.Name == type.ToString()).FirstOrDefaultAsync(cancel);
            tempDto = _mapper.Map<EmailTemplateDto>(temp);
        }
        else
        {
            throw new InvalidOperationException("Both id and type is null. Id: " + request.EmailTemplateQuery.Id + ". Type: " + request.EmailTemplateQuery.Type.ToString());
        }

        if (tempDto == null)
        {
            throw new NotFoundException();
        }

        await _repository.UpdateAsync(tempDto, t => t.Id == tempDto.Id, cancel);
    }
}