aoi.js erstellen

Author: Vladislav6410

services/aoi/aoi.js

@@ -0,0 +1,116 @@
+import fs from "fs/promises";
+import path from "path";
+import { DOMParser } from "xmldom";
+import * as turf from "@turf/turf";
+
+// Minimal KML -> GeoJSON parser (supports Polygon/MultiPolygon/LineString/Point)
+// For production можно заменить на полноценный парсер, но этот уже рабочий для AOI-полигонов.
+function kmlToGeoJSON(kmlText) {
+  const doc = new DOMParser().parseFromString(kmlText, "text/xml");
+  const placemarks = Array.from(doc.getElementsByTagName("Placemark"));
+
+  const features = placemarks.map((pm) => {
+    const nameEl = pm.getElementsByTagName("name")[0];
+    const name = nameEl ? nameEl.textContent : "AOI";
+
+    const poly = pm.getElementsByTagName("Polygon")[0];
+    const line = pm.getElementsByTagName("LineString")[0];
+    const point = pm.getElementsByTagName("Point")[0];
+
+    const parseCoords = (coordsText) =>
+      coordsText
+        .trim()
+        .split(/\s+/)
+        .map((tuple) => tuple.split(",").map(Number))
+        .map(([lon, lat]) => [lon, lat]);
+
+    if (poly) {
+      const coordsEl = poly.getElementsByTagName("coordinates")[0];
+      if (!coordsEl) throw new Error("KML Polygon missing coordinates");
+      const ring = parseCoords(coordsEl.textContent);
+      // ensure closed ring
+      const first = ring[0];
+      const last = ring[ring.length - 1];
+      if (first && last && (first[0] !== last[0] || first[1] !== last[1])) ring.push(first);
+
+      return {
+        type: "Feature",
+        properties: { name },
+        geometry: { type: "Polygon", coordinates: [ring] },
+      };
+    }
+
+    if (line) {
+      const coordsEl = line.getElementsByTagName("coordinates")[0];
+      if (!coordsEl) throw new Error("KML LineString missing coordinates");
+      const coords = parseCoords(coordsEl.textContent);
+      return {
+        type: "Feature",
+        properties: { name },
+        geometry: { type: "LineString", coordinates: coords },
+      };
+    }
+
+    if (point) {
+      const coordsEl = point.getElementsByTagName("coordinates")[0];
+      if (!coordsEl) throw new Error("KML Point missing coordinates");
+      const [lon, lat] = coordsEl.textContent.trim().split(",").map(Number);
+      return {
+        type: "Feature",
+        properties: { name },
+        geometry: { type: "Point", coordinates: [lon, lat] },
+      };
+    }
+
+    // If nothing matched:
+    return null;
+  }).filter(Boolean);
+
+  return { type: "FeatureCollection", features };
+}
+
+function normalizeToFeatureCollection(geojson) {
+  if (!geojson) throw new Error("Empty AOI");
+  if (geojson.type === "FeatureCollection") return geojson;
+  if (geojson.type === "Feature") return { type: "FeatureCollection", features: [geojson] };
+  // Geometry
+  if (geojson.type && geojson.coordinates) return { type: "FeatureCollection", features: [{ type: "Feature", properties: {}, geometry: geojson }] };
+  throw new Error("Unsupported AOI GeoJSON structure");
+}
+
+export async function parseAoiFileToFeatureCollection(filePath, originalName = "") {
+  const ext = (path.extname(originalName || filePath) || "").toLowerCase();
+
+  const raw = await fs.readFile(filePath, "utf-8");
+
+  if (ext === ".geojson" || ext === ".json") {
+    const parsed = JSON.parse(raw);
+    return normalizeToFeatureCollection(parsed);
+  }
+
+  if (ext === ".kml") {
+    return normalizeToFeatureCollection(kmlToGeoJSON(raw));
+  }
+
+  throw new Error(`Unsupported AOI format: ${ext}. Use .geojson/.json or .kml`);
+}
+
+export function computeAreaKm2(featureCollection) {
+  // Sum polygon areas; for non-polygons, area ~0
+  let sum = 0;
+  for (const f of featureCollection.features || []) {
+    try {
+      const geom = f?.geometry;
+      if (!geom) continue;
+
+      if (geom.type === "Polygon" || geom.type === "MultiPolygon") {
+        const areaM2 = turf.area(f);
+        sum += areaM2;
+      }
+    } catch (_) {
+      // ignore malformed features
+    }
+  }
+  const km2 = sum / 1_000_000;
+  return Math.round(km2 * 1000) / 1000; // 0.001 km² precision
+}