using System.Transactions;
using SIGCM2.Application.Abstractions;
using SIGCM2.Application.Abstractions.Persistence;
using SIGCM2.Application.Audit;
using SIGCM2.Domain.Entities;
using SIGCM2.Domain.Exceptions;

namespace SIGCM2.Application.Secciones.Deactivate;

public sealed class DeactivateSeccionCommandHandler : ICommandHandler<DeactivateSeccionCommand, SeccionStatusDto>
{
    private readonly ISeccionRepository _repo;
    private readonly IMedioRepository _medioRepo;
    private readonly IAuditLogger _audit;
    private readonly TimeProvider _timeProvider;

    public DeactivateSeccionCommandHandler(
        ISeccionRepository repo,
        IMedioRepository medioRepo,
        IAuditLogger audit,
        TimeProvider timeProvider)
    {
        _repo = repo;
        _medioRepo = medioRepo;
        _audit = audit;
        _timeProvider = timeProvider;
    }

    public async Task<SeccionStatusDto> Handle(DeactivateSeccionCommand command)
    {
        var target = await _repo.GetByIdAsync(command.Id)
            ?? throw new SeccionNotFoundException(command.Id);

        var medio = await _medioRepo.GetByIdAsync(target.MedioId)
            ?? throw new MedioNotFoundException(target.MedioId);

        if (!medio.Activo)
            throw new MedioInactivoException(medio.Id);

        // Idempotent: already inactive → return as-is without writing an audit event
        if (!target.Activo)
            return new SeccionStatusDto(target.Id, target.Codigo, target.Activo);

        var now = _timeProvider.GetUtcNow().UtcDateTime;
        var updated = target.WithActivo(false, now);

        using var tx = new TransactionScope(
            TransactionScopeOption.Required,
            new TransactionOptions { IsolationLevel = System.Transactions.IsolationLevel.ReadCommitted },
            TransactionScopeAsyncFlowOption.Enabled);

        await _repo.UpdateAsync(updated);

        await _audit.LogAsync(
            action: "seccion.deactivate",
            targetType: "Seccion",
            targetId: command.Id.ToString());

        tx.Complete();

        return new SeccionStatusDto(updated.Id, updated.Codigo, updated.Activo);
    }
}
