using DigitalData.Core.Application.Interfaces.Repository;
using EnvelopeGenerator.Application.DTOs;
using EnvelopeGenerator.Application.Exceptions;
using EnvelopeGenerator.Domain.Entities;
using MediatR;

namespace EnvelopeGenerator.Application.EmailTemplates.Commands.Update;

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

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

    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="cancel"></param>
    /// <returns></returns>
    /// <exception cref="InvalidOperationException"></exception>
    /// <exception cref="NotFoundException"></exception>
    public async Task Handle(UpdateEmailTemplateCommand request, CancellationToken cancel)
    {
        EmailTemplateDto? temp;

        if (request.EmailTemplateQuery?.Id is int id)
        {
            temp = await _repository.ReadOrDefaultAsync<EmailTemplateDto>(t => t.Id == id, single: false, cancel);
        }
        else if (request!.EmailTemplateQuery!.Type is Common.Constants.EmailTemplateType type)
        {
            temp = await _repository.ReadOrDefaultAsync<EmailTemplateDto>(t => t.Name == type.ToString(), single: false, cancel);
        }
        else
        {
            throw new InvalidOperationException("Both id and type is null. Id: " + request.EmailTemplateQuery.Id +". Type: " + request.EmailTemplateQuery.Type.ToString());
        }

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

        if (request.Body is not null)
            temp.Body = request.Body;

        if (request.Subject is not null)
            temp.Subject = request.Subject;

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