s122-marine-protected-areas - SKILL.md Agent Skill

name: s122-marine-protected-areas description: | Expert knowledge of IHO S-122 Marine Protected Areas Product Specification (Edition 2.0.0). Covers GML encoding (S-100 Part 10b) over the S-100 GML base, the S-122 application schema (marine protected areas, restricted areas, regulated areas, and associated text placement), and the XSLT-based portrayal pipeline. USE FOR: S-122 datasets, marine protected areas, restricted/regulated areas, GML parsing for S-122, XSLT portrayal of S-122, vector pipeline changes affecting S-122, S122DatasetReader / S-122 reader/source code, S-122 tests, edits to bundled `content/S122/**` assets. DO NOT USE FOR: S-127 marine resources and services (use s127-marine-services), S-124 nav warnings (use s124-nav-warnings), S-125 AtoN (use s125-aton), S-101 ENC (use s101-enc), generic GML / framework concerns (use s100-framework).

Tasks touching src/EncDotNet.S100.Datasets.S122/** or tests/EncDotNet.S100.Datasets.S122.Tests/**
Edits to bundled portrayal assets under src/EncDotNet.S100.Specifications/content/S122/**
GML/XSLT portrayal changes for marine protected areas
Vector pipeline changes (IVectorSource, VectorPipeline) affecting S-122

Product detection is identifier-driven, not namespace-driven. The official 2.0.0 sample is mis-labelled with the S-123 namespace prefix on the dataset root (xmlns:S123="http://www.iho.int/S123/gml/1.0"). Detection must key on the S-100 <productIdentifier>S-122…</productIdentifier> element — keep that fallback in DatasetPipelineFactory.
Tolerate every s100gml namespace variant seen across releases (http://www.iho.int/s100gml/1.0, http://www.iho.int/S100/profile/s100gml/1.0, http://www.iho.int/s100gml/5.0) via S122DatasetReader.DetectS100Namespace — do not hard-code one.
Coordinate ordering in <gml:pos> / <gml:posList> is lat lon for EPSG:4326 (S-100 Part 10b §6.2).
Support both the standard <member>/<imember> wrappers and the inline <members>/<imembers> containers. Iterate descendants of the dataset root and match by feature/information type code.
Portrayal goes through XSLT (not Lua); inputs to the transform must be the canonical GML, and transforms must stay within features supported by .NET's XslCompiledTransform.
Renderers must tolerate geometry-less features (e.g. TextPlacement may attach to a referenced feature rather than carry its own geometry).
Public API changes have xunit tests using the official sample under tests/datasets/S122/.

S122DatasetReader already auto-corrects two real-world quirks; new geometry parsing code must preserve both:

lon-lat posList vs. lat-lon envelope. The UKHO trial dataset emits <gml:posList> in lon-lat order while keeping the <gml:Envelope> corners correctly in lat-lon. The reader samples parsed coords against the declared envelope and swaps every feature when the as-parsed interpretation clearly falls outside but the swapped one fits. Keep the heuristic conservative (≤25 % as-is fit, ≥75 % swapped fit) so spec-conformant samples are untouched.
Comma-separated tuples in posList. Some producers emit lon,lat lon,lat … tokens (the gml:coordinates convention) instead of all-whitespace. ParsePos / ParsePosList treat both whitespace and commas as separators — do not regress that.

The bundled content/S122/pc/ tree is intended to be byte-identical to upstream (PC 2.0.0). Do not edit those files. If the upstream main.xsl ever needs adapting for this codebase's display-list dialect, add a small adapter XSLT alongside it (mirror the S-411 Adapter/main.xsl pattern).
The v2.0.0 PC ships only a Day <palette> block in colorProfile.xml, so palette switching to Dusk/Night is currently a no-op for S-122. Do not modify the upstream colorProfile.xml; if local Dusk/Night palettes are needed before upstream publishes them, synthesise them in code and document it explicitly.

Cite the S-122 section number (or upstream catalogue path) in XML doc comments when adding spec-derived constants or element names.