/**
* PostgreSQL PostGIS Extension Tools - Standalone Geometry Operations
*
* Tools for operating on geometry strings (WKT/GeoJSON) directly,
* without requiring a table. These complement the table-based tools.
*/
import type { PostgresAdapter } from "../../PostgresAdapter.js";
import type {
ToolDefinition,
RequestContext,
} from "../../../../types/index.js";
import { readOnly } from "../../../../utils/annotations.js";
import { getToolIcons } from "../../../../utils/icons.js";
import {
GeometryBufferSchemaBase,
GeometryBufferSchema,
GeometryIntersectionSchemaBase,
GeometryIntersectionSchema,
GeometryTransformSchemaBase,
GeometryTransformSchema,
// Output schemas
GeometryBufferOutputSchema,
GeometryIntersectionOutputSchema,
GeometryTransformOutputSchema,
} from "../../schemas/index.js";
/**
* Detect if a geometry string is GeoJSON or WKT
*/
function parseGeometry(geometry: string): { sql: string; isGeoJson: boolean } {
const trimmed = geometry.trim();
const isGeoJson = trimmed.startsWith("{");
return {
sql: isGeoJson ? "ST_GeomFromGeoJSON($1)" : "ST_GeomFromText($1)",
isGeoJson,
};
}
/**
* Parse geometry with explicit SRID normalization for intersection operations.
* This ensures both GeoJSON (which has implicit SRID 4326) and WKT (no SRID)
* use consistent coordinate systems.
*/
function parseGeometryWithSrid(
geometry: string,
srid = 4326,
): { sql: string; isGeoJson: boolean } {
const trimmed = geometry.trim();
const isGeoJson = trimmed.startsWith("{");
// GeoJSON uses 4326 implicitly; WKT has no SRID. Normalize both.
const baseExpr = isGeoJson ? "ST_GeomFromGeoJSON($1)" : "ST_GeomFromText($1)";
return {
sql: `ST_SetSRID(${baseExpr}, ${String(srid)})`,
isGeoJson,
};
}
/**
* Create buffer around a standalone geometry
*/
export function createGeometryBufferTool(
adapter: PostgresAdapter,
): ToolDefinition {
return {
name: "pg_geometry_buffer",
description:
"Create a buffer zone around a WKT or GeoJSON geometry. Returns the buffered geometry as GeoJSON and WKT.",
group: "postgis",
inputSchema: GeometryBufferSchemaBase, // Base schema for MCP visibility
outputSchema: GeometryBufferOutputSchema,
annotations: readOnly("Geometry Buffer"),
icons: getToolIcons("postgis", readOnly("Geometry Buffer")),
handler: async (params: unknown, _context: RequestContext) => {
const { geometry, distance, srid, simplify } = GeometryBufferSchema.parse(
params ?? {},
);
const sridVal = srid ?? 4326;
const { sql: geomExpr, isGeoJson } = parseGeometry(geometry);
// Build buffer expression
const bufferExpr = `ST_Buffer(ST_SetSRID(${geomExpr}, ${String(sridVal)})::geography, $2)::geometry`;
// Apply optional simplification
const outputExpr =
simplify !== undefined && simplify > 0
? `ST_Simplify(${bufferExpr}, ${String(simplify / 111000)})` // Convert meters to degrees approx
: bufferExpr;
const sql = `
SELECT
ST_AsGeoJSON(${outputExpr}) as buffer_geojson,
ST_AsText(${outputExpr}) as buffer_wkt,
$2 as distance_meters,
${String(sridVal)} as srid
`;
const result = await adapter.executeQuery(sql, [geometry, distance]);
const row = result.rows?.[0];
const response: Record<string, unknown> = {
...row,
inputFormat: isGeoJson ? "GeoJSON" : "WKT",
};
// Include simplification info if applied
if (simplify !== undefined && simplify > 0) {
response["simplified"] = true;
response["simplifyTolerance"] = simplify;
// Check if simplification caused geometry to collapse to null
if (row?.["buffer_geojson"] === null || row?.["buffer_wkt"] === null) {
response["warning"] =
`Simplification tolerance (${String(simplify)}m) is too high relative to buffer distance (${String(distance)}m). The geometry collapsed to null. Reduce simplify value or set simplify: 0 to disable.`;
}
}
return response;
},
};
}
/**
* Compute intersection of two standalone geometries
*/
export function createGeometryIntersectionTool(
adapter: PostgresAdapter,
): ToolDefinition {
return {
name: "pg_geometry_intersection",
description:
"Compute the intersection of two WKT or GeoJSON geometries. Returns the intersection geometry and whether they intersect.",
group: "postgis",
inputSchema: GeometryIntersectionSchemaBase, // Base schema for MCP visibility
outputSchema: GeometryIntersectionOutputSchema,
annotations: readOnly("Geometry Intersection"),
icons: getToolIcons("postgis", readOnly("Geometry Intersection")),
handler: async (params: unknown, _context: RequestContext) => {
const { geometry1, geometry2 } = GeometryIntersectionSchema.parse(
params ?? {},
);
// Use SRID-normalized parsing to prevent mixed SRID errors when combining
// GeoJSON (implicit SRID 4326) with WKT (no SRID)
const geom1 = parseGeometryWithSrid(geometry1);
const geom2 = parseGeometryWithSrid(geometry2);
// geom1 uses $1 (first parameter), geom2 uses $2 (second parameter)
const geom1Expr = geom1.sql;
const geom2Expr = geom2.sql.replace("$1", "$2");
const sql = `
SELECT
ST_Intersects(${geom1Expr}, ${geom2Expr}) as intersects,
ST_AsGeoJSON(ST_Intersection(${geom1Expr}, ${geom2Expr})) as intersection_geojson,
ST_AsText(ST_Intersection(${geom1Expr}, ${geom2Expr})) as intersection_wkt,
ST_Area(ST_Intersection(${geom1Expr}, ${geom2Expr})::geography) as intersection_area_sqm
`;
const result = await adapter.executeQuery(sql, [geometry1, geometry2]);
return {
...result.rows?.[0],
geometry1Format: geom1.isGeoJson ? "GeoJSON" : "WKT",
geometry2Format: geom2.isGeoJson ? "GeoJSON" : "WKT",
sridUsed: 4326,
};
},
};
}
/**
* Transform a standalone geometry between coordinate systems
*/
export function createGeometryTransformTool(
adapter: PostgresAdapter,
): ToolDefinition {
return {
name: "pg_geometry_transform",
description:
"Transform a WKT or GeoJSON geometry from one SRID to another. Common SRIDs: 4326 (WGS84/GPS), 3857 (Web Mercator).",
group: "postgis",
inputSchema: GeometryTransformSchemaBase, // Base schema for MCP visibility
outputSchema: GeometryTransformOutputSchema,
annotations: readOnly("Geometry Transform"),
icons: getToolIcons("postgis", readOnly("Geometry Transform")),
handler: async (params: unknown, _context: RequestContext) => {
const { geometry, fromSrid, toSrid } = GeometryTransformSchema.parse(
params ?? {},
);
const { sql: geomExpr, isGeoJson } = parseGeometry(geometry);
const sql = `
SELECT
ST_AsGeoJSON(ST_Transform(ST_SetSRID(${geomExpr}, ${String(fromSrid)}), ${String(toSrid)})) as transformed_geojson,
ST_AsText(ST_Transform(ST_SetSRID(${geomExpr}, ${String(fromSrid)}), ${String(toSrid)})) as transformed_wkt
`;
const result = await adapter.executeQuery(sql, [geometry]);
return {
...result.rows?.[0],
fromSrid,
toSrid,
inputFormat: isGeoJson ? "GeoJSON" : "WKT",
};
},
};
}
