  We present a detailed analysis of the disk and circumstellar environment of
the forming O-type star AFGL 4176 mm1, placing results from the Atacama Large
Millimeter/submillimeter Array (ALMA) into context with multiwavelength data.
With ALMA, we detect seventeen 1.2 mm continuum sources within 5$''$ (21,000
au) of AFGL 4176 mm1. We find that mm1 has a spectral index of 3.4$\pm$0.2
across the ALMA band, with $>$87% of its 1.2 mm continuum emission from dust.
The source mm2, projected 4200 au from mm1, may be a companion or a blueshifted
knot in a jet. We also explore the morphological differences between the
molecular lines detected with ALMA, finding 203 lines from 25 molecules, which
we categorize into several morphological types. Our results show that AFGL 4176
mm1 provides an example of a forming O-star with a large and chemically complex
disk, which is mainly traced by nitrogen-bearing molecules. Lines that show
strong emission on the blueshifted side of the disk are predominantly
oxygen-bearing, which we suggest are tracing a disk accretion shock. The
molecules C$^{34}$S, H$_2$CS and CH$_{3}$CCN trace a slow wide-angle wind or
dense structures in the outflow cavity walls. With the Australia Telescope
Compact Array (ATCA), we detect a compact continuum source ($<$2000 $\times$
760 au) at 1.2 cm, associated with mm1, of which $>$96% is from ionized gas.
The ATCA NH$_3$(1,1) and (2,2) emission traces a large-scale (r$\sim$0.5 pc)
rotating toroid with the disk source mm1 in the blueshifted part of this
structure offset to the northwest.
