  Recent measurements of various charm-hadron ratios in $pp$, $p$-Pb and Pb-Pb
collisions at the LHC have posed challenges to the theoretical understanding of
heavy-quark hadronization. The $\Lambda_c/D^0$ ratio in $pp$ and $p$-Pb
collisions shows larger values than those found in $e^+e^-$ and $ep$ collisions
and predicted by Monte-Carlo event generators based on string fragmentation, at
both low and intermediate transverse momenta ($p_T$). In AA collisions, the
$D_s/D$ ratio is significantly enhanced over its values in $pp$, while the
$\Lambda_c/D^0$ data indicates a further enhancement at intermediate $p_T$.
Here, we report on our recent developments for a comprehensive description of
the charm hadrochemistry and transport in $pp$ and $AA$ collisions. For $pp$
collisions we find that the discrepancy between the $\Lambda_c/D^0$ data and
model predictions is much reduced by using a statistical hadronization model
augmented by a large set of "missing" states in the charm-baryon spectrum,
contributing to the $\Lambda_c$ via decay feeddown. For $AA$ collisions, we
develop a 4-momentum conserving resonance recombination model for charm-baryon
formation implemented via event-by-event simulations that account for
space-momentum correlations (SMCs) in transported charm- and thermal
light-quark distributions. The SMCs, together with the augmented charm-baryon
states, are found to play an important role in describing the baryon-to-meson
enhancement at intermediate momenta. We emphasize the importance of satisfying
the correct (relative) chemical equilibrium limit when computing the charm
hadrochemistry and its momentum dependence with coalescence models.
