refactor(CopcSource): use wkt to get source.crs

src/Source/CopcSource.js

@@ -1,3 +1,4 @@
+import proj4 from 'proj4';
 import { Binary, Info, Las } from 'copc';
 import Fetcher from 'Provider/Fetcher';
 import LASParser from 'Parser/LASParser';
@@ -103,8 +104,24 @@ class CopcSource extends Source {
             this.header = metadata.header;
             this.info = metadata.info;
             this.eb = metadata.eb;
-            // TODO: use wkt definition in `metadata.wkt` to infer/define crs
-            this.crs = config.crs || 'EPSG:4326';
+
+            proj4.defs('unknown', metadata.wkt);
+            this.crs = proj4.defs('unknown').name;
+            proj4.defs(this.crs, proj4.defs('unknown'));
+
+            if (proj4.defs('unknown').type === 'COMPD_CS') {
+                console.warn('CopcSource: compound coordinate system is not yet supported.');
+                metadata.wkt = metadata.wkt.slice(metadata.wkt.search('PROJCS'), metadata.wkt.search(',VERT_CS'));
+                proj4.defs('unknown', metadata.wkt);
+                const projCS = proj4.defs('unknown');
+                if (projCS.AUTHORITY) {
+                    const authority = Object.keys(projCS.AUTHORITY)[0];
+                    this.crs = `${authority}:${projCS.AUTHORITY[authority]}`;
+                    proj4.defs(this.crs, proj4.defs('unknown'));
+                } else {
+                    this.crs = config.crs || 'EPSG:4326';
+                }
+            }
 
             return this;
         });