// MapViewFitter.ts
import { Map as OlMap } from 'ol';
import GeoJSON from 'ol/format/GeoJSON';
import { FeatureCollection } from 'geojson';
import { bbox as turfBbox, bboxPolygon as turfBboxPolygon } from '@turf/turf';
import type { Geometry } from 'ol/geom';

export class MapViewFitter {
  private map: OlMap;
  private format: GeoJSON;

  constructor(map: OlMap) {
    this.map = map;
    this.format = new GeoJSON();
  }

  /**
   * 使地图视图自动适应传入的 GeoJSON FeatureCollection 范围
   * @param featureCollection GeoJSON FeatureCollection
   * @param padding 四周留白，默认为 [10, 10, 10, 10]
   * @param duration 动画持续时间，默认为 1000 毫秒
   */
  fit(featureCollection: FeatureCollection, padding: number[] = [10, 10, 10, 10], duration: number = 1000) {
    if (!featureCollection?.features?.length) return;

    const bbox = turfBbox(featureCollection); // [minX, minY, maxX, maxY]
    const bboxPolygon = turfBboxPolygon(bbox); // Feature<Polygon>

    const geometry: Geometry = this.format.readGeometry(bboxPolygon.geometry, {
      dataProjection: 'EPSG:4326',
      featureProjection: 'EPSG:3857'
    });

    const extent = geometry.getExtent();

    this.map.getView().fit(extent, {
      padding,
      duration
    });
  }
}


//示例
// import { MapViewFitter } from '@/utils/setMapCenter'; // 确保路径正确

// const fitter = new MapViewFitter(map); // 传入你的 OpenLayers 地图实例
// const features = xxx;//features数组

// if (features?.length) {
//   const featureCollection = {
//     type: 'FeatureCollection',
//     features
//   };

//   fitter.fit(featureCollection);
// }