using ProtoBuf.Grpc;

namespace EonaCat.gRPC.Api.Helpers;

public static class ExceptionHelpers
{
    public static RpcException Handle<T>(this Exception exception, ServerCallContext context, ILogger<T> logger, Guid correlationId) =>
        exception switch
        {
            TimeoutException timeoutException => HandleTimeoutException(timeoutException, context, logger, correlationId),
            SqlException sqlException => HandleSqlException(sqlException, context, logger, correlationId),
            RpcException rpcException => HandleRpcException(rpcException, logger, correlationId),
            _ => HandleDefault(exception, context, logger, correlationId)
        };

    private static RpcException HandleTimeoutException<T>(TimeoutException exception, ServerCallContext context, ILogger<T> logger, Guid correlationId)
    {
        logger.LogError(exception, $"CorrelationId: {correlationId} - A timeout occurred");
        var status = new Status(StatusCode.Internal, "An external resource did not answer within the time limit");
        return new RpcException(status, CreateTrailers(correlationId));
    }

    private static RpcException HandleSqlException<T>(SqlException exception, ServerCallContext context, ILogger<T> logger, Guid correlationId)
    {
        logger.LogError(exception, $"CorrelationId: {correlationId} - An SQL error occurred");
        Status status;
        if (exception.Number == -2)
            status = new Status(StatusCode.DeadlineExceeded, "SQL timeout");
        else
            status = new Status(StatusCode.Internal, "SQL error");
        return new RpcException(status, CreateTrailers(correlationId));
    }

    private static RpcException HandleRpcException<T>(RpcException exception, ILogger<T> logger, Guid correlationId)
    {
        logger.LogError(exception, $"CorrelationId: {correlationId} - An error occurred");
        //var trailers = exception.Trailers;
        //var d = CreateTrailers(correlationId);
        //trailers.Add(d[0]);
        return new RpcException(new Status(exception.StatusCode, exception.Message), CreateTrailers(correlationId));
    }

    private static RpcException HandleDefault<T>(Exception exception, ServerCallContext context, ILogger<T> logger, Guid correlationId)
    {
        logger.LogError(exception, $"CorrelationId: {correlationId} - An error occurred");
        return new RpcException(new Status(StatusCode.Internal, exception.Message), CreateTrailers(correlationId));
    }

    private static Metadata CreateTrailers(Guid correlationId)
    {
        var trailers = new Metadata { { "CorrelationId", correlationId.ToString() } };
        return trailers;
    }
}