// prospectus-api/src/spatial/services/isochrone.service.ts
const concurrency = parseInt(this.configService.get<string>('ROUTING_CONCURRENCY', '8'), 10);
this.queue = new PQueue({ concurrency });

async getCatchmentAreas(
  lat: number,
  lng: number,
  mode: string,
  rangeMinutesList: number[],
): Promise<FeatureCollection | null> {
  const features: any[] = [];

  for (const rangeMin of rangeMinutesList) {
    const res = await this.queue.add(async () => {
      const response = await axios.post(
        `${this.routingServiceUrl}/v2/isochrones/${mode}`,
        {
          locations: [[lng, lat]],
          range: [rangeMin * 60], // query single range (seconds)
          range_type: 'time',
          smoothing: 5,
          attributes: ['area', 'total_pop'],
        },
        { headers: this.getHeaders() },
      );
      return response.data as FeatureCollection;
    });

    if (res?.features?.[0]) {
      const feature = res.features[0];
      feature.properties.value = rangeMin * 60;
      features.push(feature);
    }
  }

  return { type: 'FeatureCollection', features };
}

// CatchmentGenerationService: Multi-range upsert
await this.prisma.catchmentArea.upsert({
  where: { companyId_mode_range: { companyId, mode, range } },
  update: { geometry: featureCollection },
  create: { companyId, mode, range, geometry: featureCollection },
});

// prospectus-api/src/spatial/utils/grid.util.ts
export function computeCellSize(zoom: number): number {
  const baseCellSize = 0.0008333333; // ~90m at equator
  const zoomFloor = Math.floor(zoom);
  if (zoomFloor >= 15) return baseCellSize;
  return baseCellSize * Math.pow(Math.sqrt(2), 15 - zoomFloor);
}

// prospectus-api/src/spatial/utils/grid.util.ts
export function aggregatePointsIntoGrid(
  points: PopulationPoint[],
  bbox: [number, number, number, number],
  cellSize: number,
): Map<string, GridCell> {
  const [west, south, east, north] = bbox;
  const gridMap = new Map<string, GridCell>();

  for (const p of points) {
    if (p.population <= 0) continue;
    if (p.lng < west || p.lng > east || p.lat < south || p.lat > north) continue;

    // Fast lattice coordinate quantization
    const x = Math.round(p.lng / cellSize);
    const y = Math.round(p.lat / cellSize);
    const key = `${x},${y}`;

    const existing = gridMap.get(key);
    if (existing) {
      existing.population += p.population;
    } else {
      gridMap.set(key, { population: p.population, x, y });
    }
  }

  return gridMap;
}

// prospectus-api/src/spatial/services/population.service.ts
calculatePopulationInPolygon(geometry: any): number {
  const [minLng, minLat, maxLng, maxLat] = getGeometryBoundingBox(geometry);
  const candidates = queryBbox(this.spatialIndex, minLng, minLat, maxLng, maxLat);

  let totalPopulation = 0;
  for (const p of candidates) {
    if (booleanPointInPolygon(point([p.lng, p.lat]), geometry)) {
      totalPopulation += p.population || 0;
    }
  }

  return Math.round(totalPopulation);
}