  The HR8799 planetary system with four ~10 mJup planets in wide orbits up to
70 au, and periods up to 500 yr has been detected with the direct imaging. Its
intriguing orbital architecture is not fully resolved due to time-limited
astrometry covering ~20 years. Earlier, we constructed a heuristic model of the
system based on rapid, convergent migration of the planets. We developed a
better structured and CPU-efficient variant of this model. We re-analyzed the
self-consistent, homogeneous astrometric dataset in Konopacky (2016). The
best-fitting configuration agrees with our earlier findings. The planets are
likely involved in dynamically robust Laplace resonance chain. Hypothetical
planets with masses below the current detection limit of 0.1-3 Jupiter masses,
within the observed inner, or beyond the outer orbit, respectively, do not
influence the long term stability of the system. We predict positions of such
non-detected objects. The long-term stable orbital model of the observed
planets helps to simulate the dynamical structure of debris disks in the
system. A CPU-efficient fast indicator technique makes it possible to reveal
their complex, resonant shape in 10^6 particles scale. We examine the inner
edge of the outer disk detected between 90-145 au. We also reconstruct the
outer disk assuming that it has been influenced by convergent migration of the
planets. A complex shape of the disk strongly depends on various dynamical
factors, like orbits and masses of non-detected planets. It may be highly
non-circular and its models are yet non-unique, regarding both observational
constraints, as well as its origin.
