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

namespace SIGCM2.Application.Usuarios.ResetPassword;

public sealed class ResetUsuarioPasswordCommandHandler : ICommandHandler<ResetUsuarioPasswordCommand, ResetUsuarioPasswordResponse>
{
    private readonly IUsuarioRepository _repository;
    private readonly IPasswordHasher _hasher;
    private readonly IRefreshTokenRepository _refreshTokenRepository;
    private readonly IAuditLogger _audit;
    private readonly TimeProvider _timeProvider;

    public ResetUsuarioPasswordCommandHandler(
        IUsuarioRepository repository,
        IPasswordHasher hasher,
        IRefreshTokenRepository refreshTokenRepository,
        IAuditLogger audit,
        TimeProvider timeProvider)
    {
        _repository = repository;
        _hasher = hasher;
        _refreshTokenRepository = refreshTokenRepository;
        _audit = audit;
        _timeProvider = timeProvider;
    }

    public async Task<ResetUsuarioPasswordResponse> Handle(ResetUsuarioPasswordCommand cmd)
    {
        // Cannot self-reset: admin must use /me/password
        if (cmd.CallerId == cmd.TargetId)
            throw new CannotSelfResetException();

        var target = await _repository.GetByIdAsync(cmd.TargetId)
            ?? throw new UsuarioNotFoundException(cmd.TargetId);

        var temp = TempPasswordGenerator.Generate(12);
        // SECURITY: NEVER log tempPassword — it is returned to the caller, never persisted.
        var hash = _hasher.Hash(temp);

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

        var now = _timeProvider.GetUtcNow().UtcDateTime;
        await _repository.UpdatePasswordAsync(cmd.TargetId, hash, mustChangePassword: true);
        await _refreshTokenRepository.RevokeAllActiveForUserAsync(cmd.TargetId, now);

        await _audit.LogAsync(
            action: "usuario.password_reset",
            targetType: "Usuario",
            targetId: cmd.TargetId.ToString(),
            metadata: new { targetId = cmd.TargetId }); // NO tempPassword in metadata

        tx.Complete();

        return new ResetUsuarioPasswordResponse(temp, MustChangeOnLogin: true);
    }
}