import { CallToolResult } from '@modelcontextprotocol/sdk/types.js';
import { S57_OBJECT_CATALOGUE, FEATURE_CATEGORIES, S57ObjectClassDefinition } from '../constants/s57.js';
interface GetObjectClassesInput {
category?: keyof typeof FEATURE_CATEGORIES;
search?: string;
includeAttributes?: boolean;
}
interface ObjectClassInfo extends S57ObjectClassDefinition {
category?: string;
attributes?: string[];
navigationSignificance?: string;
}
// Common S-57 attributes for different object classes
const COMMON_ATTRIBUTES: Record<string, string[]> = {
// Navigation aids
LIGHTS: ['LITCHR', 'SIGPER', 'COLOUR', 'VALNMR', 'HEIGHT', 'CATLIT'],
BOYLAT: ['BOYSHP', 'CATLAM', 'COLOUR', 'COLPAT', 'CONRAD', 'MARSYS'],
BOYSAW: ['BOYSHP', 'COLOUR', 'COLPAT', 'CONRAD', 'MARSYS'],
BCNLAT: ['BCNSHP', 'CATLAM', 'COLOUR', 'COLPAT', 'HEIGHT', 'NATCON'],
// Depth features
DEPARE: ['DRVAL1', 'DRVAL2', 'QUASOU', 'SOUACC', 'VERDAT'],
DEPCNT: ['VALDCO', 'VERDAT'],
SOUNDG: ['DEPTH', 'QUASOU', 'SOUACC', 'TECSOU', 'VERDAT'],
OBSTRN: ['CATOBS', 'VALSOU', 'WATLEV', 'NATCON', 'EXPSOU'],
// Areas
RESARE: ['CATREA', 'RESTRN', 'DATSTA', 'DATEND', 'PERSTA', 'PEREND'],
ACHARE: ['CATACH', 'RESTRN', 'STATUS'],
FAIRWY: ['ORIENT', 'STATUS', 'TRAFIC'],
// Infrastructure
BRIDGE: ['CATBRG', 'VERCCL', 'VERCLR', 'VERCOP', 'HORCLR', 'NATCON'],
PIPOHD: ['CATPIP', 'VERCLR', 'PRODCT', 'STATUS'],
CBLOHD: ['CATCBL', 'VERCLR', 'VERCSA', 'ICEFAC'],
};
// Navigation significance descriptions
const NAVIGATION_SIGNIFICANCE: Record<string, string> = {
// Navigation Aids
LIGHTS: 'Essential for night navigation. Properties include light characteristic (flashing pattern), period, color, and range.',
BOYLAT: 'Lateral marks indicate port/starboard sides of channels. Red (port) and green (starboard) in IALA-B.',
BOYSAW: 'Safe water marks indicate navigable water all around. Typically red/white vertical stripes.',
BOYCAR: 'Cardinal marks indicate safe water direction relative to a hazard (N, S, E, W).',
BCNLAT: 'Fixed lateral marks on shore/structures. Same color conventions as lateral buoys.',
BCNSAW: 'Fixed safe water marks. Indicate channel centerlines or landfall points.',
DAYMAR: 'Visual navigation marks without lights. Shape and color indicate purpose.',
TOPMAR: 'Topmarks on buoys/beacons enhance visual identification. Shape indicates mark type.',
// Depth Information
DEPARE: 'Depth areas define regions within specific depth ranges. Critical for draft restrictions.',
DEPCNT: 'Depth contour lines show specific depths. Standard contours: 5m, 10m, 20m, etc.',
SOUNDG: 'Individual depth measurements. Most accurate depth information available.',
DRGARE: 'Dredged areas with maintained depths. Usually channels and harbor basins.',
OBSTRN: 'Underwater obstructions. May have unknown depth - always avoid.',
UWTROC: 'Underwater or awash rocks. Extreme navigation hazards.',
// Channels and Routes
FAIRWY: 'Designated navigation channels with safe depths for vessel traffic.',
NAVLNE: 'Recommended navigation lines for optimal routing.',
DWRTPT: 'Deep water route parts for deep-draft vessels.',
TSSLPT: 'Traffic separation scheme lanes for organized vessel traffic.',
RECTRC: 'Recommended tracks between ports or through areas.',
// Restricted Areas
RESARE: 'Restricted areas with special regulations. Check RESTRN attribute for details.',
PRCARE: 'Precautionary areas requiring extra navigation care.',
ACHARE: 'Designated anchorage areas. May have depth/vessel restrictions.',
MIPARE: 'Military practice areas. May be activated periodically.',
// Natural Features
COALNE: 'Coastline defining land/water boundary. Reference for distance calculations.',
LNDARE: 'Land areas. Used for chart display and collision avoidance.',
RIVERS: 'Rivers may have currents and depth variations.',
ROCKS: 'Above-water rocks. Major navigation hazards.',
// Infrastructure
BRIDGE: 'Bridges with vertical and horizontal clearances. Critical for passage planning.',
CBLOHD: 'Overhead cables with vertical clearance. Hazard for tall vessels.',
PIPOHD: 'Overhead pipelines. Similar concerns as cables.',
PONTON: 'Floating structures used for mooring or access.',
// Hazards
WRECKS: 'Shipwrecks that may be navigation hazards. Check depth clearance.',
FOULGRD: 'Foul ground unsuitable for anchoring. May snag anchors.',
};
export async function getObjectClassesHandler(input: unknown): Promise<CallToolResult> {
const args = input as GetObjectClassesInput;
try {
let objectClasses: ObjectClassInfo[] = [];
// Get all object classes
for (const [acronym, definition] of Object.entries(S57_OBJECT_CATALOGUE)) {
const info: ObjectClassInfo = {
...definition,
};
// Find category
for (const [cat, items] of Object.entries(FEATURE_CATEGORIES)) {
if ((items as readonly string[]).includes(acronym)) {
info.category = cat;
break;
}
}
// Add attributes if requested
if (args.includeAttributes && COMMON_ATTRIBUTES[acronym]) {
info.attributes = COMMON_ATTRIBUTES[acronym];
}
// Add navigation significance
if (NAVIGATION_SIGNIFICANCE[acronym]) {
info.navigationSignificance = NAVIGATION_SIGNIFICANCE[acronym];
}
objectClasses.push(info);
}
// Filter by category if specified
if (args.category) {
objectClasses = objectClasses.filter(oc => oc.category === args.category);
}
// Search filter if specified
if (args.search) {
const searchLower = args.search.toLowerCase();
objectClasses = objectClasses.filter(oc =>
oc.acronym.toLowerCase().includes(searchLower) ||
oc.description.toLowerCase().includes(searchLower)
);
}
// Sort by code
objectClasses.sort((a, b) => a.code - b.code);
return {
content: [
{
type: 'text',
text: JSON.stringify({
totalClasses: objectClasses.length,
objectClasses: objectClasses,
categories: Object.keys(FEATURE_CATEGORIES),
}, null, 2),
},
],
};
} catch (error) {
return {
content: [
{
type: 'text',
text: `Error retrieving object classes: ${error instanceof Error ? error.message : 'Unknown error'}`,
},
],
};
}
}
