refactor(B5): shared geometry module factory for mun/TI (F3)

Extract buildGeometryModuleFromTopology to collapse the duplicate
topojson.feature → features → optional Map pipeline in municipality
and territory geometry submodules. F2 (ensureCachedDownload) was
already delivered in scripts/lib/cli.mjs via P3-H.

Closes #28

src/lib/bahiaGeometryModuleFactory.ts

@@ -0,0 +1,85 @@
+import { feature } from 'topojson-client'
+
+import type { Feature, MultiPolygon, Polygon } from 'geojson'
+import type { GeometryCollection, Topology } from 'topojson-specification'
+
+type PolygonalFeature<Properties extends Record<string, unknown>> = Feature<
+  Polygon | MultiPolygon,
+  Properties
+>
+
+type GeometryModuleBase<
+  Properties extends Record<string, unknown>,
+  TObjectName extends string,
+> = {
+  topology: Topology<{ [key in TObjectName]: GeometryCollection<Properties> }>
+  features: readonly PolygonalFeature<Properties>[]
+}
+
+type IndexedGeometryModule<
+  Properties extends Record<string, unknown>,
+  TObjectName extends string,
+  KeyProperty extends keyof Properties & string,
+> = GeometryModuleBase<Properties, TObjectName> & {
+  getFeatureByKey: (key: Properties[KeyProperty]) => PolygonalFeature<Properties> | undefined
+}
+
+type BuildGeometryModuleOptions<
+  Properties extends Record<string, unknown>,
+  TObjectName extends string,
+  KeyProperty extends keyof Properties & string,
+> = {
+  topology: Topology<{ [key in TObjectName]: GeometryCollection<Properties> }>
+  objectName: TObjectName
+  keyProperty?: KeyProperty
+}
+
+export function buildGeometryModuleFromTopology<
+  Properties extends Record<string, unknown>,
+  TObjectName extends string,
+  KeyProperty extends keyof Properties & string,
+>(
+  options: BuildGeometryModuleOptions<Properties, TObjectName, KeyProperty> & {
+    keyProperty: KeyProperty
+  },
+): IndexedGeometryModule<Properties, TObjectName, KeyProperty>
+
+export function buildGeometryModuleFromTopology<
+  Properties extends Record<string, unknown>,
+  TObjectName extends string,
+>(
+  options: BuildGeometryModuleOptions<Properties, TObjectName, never>,
+): GeometryModuleBase<Properties, TObjectName>
+
+export function buildGeometryModuleFromTopology<
+  Properties extends Record<string, unknown>,
+  TObjectName extends string,
+  KeyProperty extends keyof Properties & string,
+>({
+  topology,
+  objectName,
+  keyProperty,
+}: BuildGeometryModuleOptions<Properties, TObjectName, KeyProperty>):
+  | GeometryModuleBase<Properties, TObjectName>
+  | IndexedGeometryModule<Properties, TObjectName, KeyProperty> {
+  const features = feature(topology, topology.objects[objectName])
+    .features as PolygonalFeature<Properties>[]
+
+  const base: GeometryModuleBase<Properties, TObjectName> = {
+    topology,
+    features,
+  }
+
+  if (!keyProperty) {
+    return base
+  }
+
+  const featuresByKey = new Map(
+    features.map((entry) => [entry.properties[keyProperty], entry]),
+  )
+
+  return {
+    ...base,
+    getFeatureByKey: (key) => featuresByKey.get(key),
+  }
+}

src/lib/bahiaMunicipalityGeometries.ts

@@ -1,23 +1,19 @@
-import { feature } from 'topojson-client'
-
 import type {
   BahiaMunicipalityFeature,
   MunicipalityGeometryModule,
   MunicipalityTopology,
 } from '@/lib/bahiaGeometriesTypes'
+import { buildGeometryModuleFromTopology } from '@/lib/bahiaGeometryModuleFactory'
 import municipalityTopologyJson from '@/lib/geometries/bahia-municipalities.topo.json'
 
-const topology = municipalityTopologyJson as unknown as MunicipalityTopology
-
-const municipalityFeatures = feature(topology, topology.objects.municipalities)
-  .features as BahiaMunicipalityFeature[]
-
-const municipalityByCodarea = new Map(
-  municipalityFeatures.map((entry) => [entry.properties.codarea, entry]),
-)
+const { topology, features, getFeatureByKey } = buildGeometryModuleFromTopology({
+  topology: municipalityTopologyJson as unknown as MunicipalityTopology,
+  objectName: 'municipalities',
+  keyProperty: 'codarea',
+})
 
 export const municipalityGeometryModule: MunicipalityGeometryModule = {
   topology,
-  features: municipalityFeatures,
-  getMunicipalityFeature: (codarea: string) => municipalityByCodarea.get(codarea),
+  features: features as readonly BahiaMunicipalityFeature[],
+  getMunicipalityFeature: getFeatureByKey,
 }

src/lib/bahiaTerritoryGeometries.ts

@@ -1,18 +1,17 @@
-import { feature } from 'topojson-client'
-
 import type {
   BahiaTerritoryFeature,
   TerritoryGeometryModule,
   TerritoryTopology,
 } from '@/lib/bahiaGeometriesTypes'
+import { buildGeometryModuleFromTopology } from '@/lib/bahiaGeometryModuleFactory'
 import territoryTopologyJson from '@/lib/geometries/bahia-identity-territories.topo.json'
 
-const topology = territoryTopologyJson as unknown as TerritoryTopology
-
-const territoryFeatures = feature(topology, topology.objects.territories)
-  .features as BahiaTerritoryFeature[]
+const { topology, features } = buildGeometryModuleFromTopology({
+  topology: territoryTopologyJson as unknown as TerritoryTopology,
+  objectName: 'territories',
+})
 
 export const territoryGeometryModule: TerritoryGeometryModule = {
   topology,
-  features: territoryFeatures,
+  features: features as readonly BahiaTerritoryFeature[],
 }