Implement MapStyle abstraction

app/src/main/java/eu/konggdev/strikemaps/map/layer/MapLayer.java

@@ -1,16 +0,0 @@
-package eu.konggdev.strikemaps.map.layer;
-
-import org.maplibre.android.style.layers.Layer;
-import org.maplibre.android.style.sources.GeoJsonSource;
-
-import java.util.List;
-
-//TOOD: Make not strictly MapLibre reliant
-public class MapLayer {
-    public GeoJsonSource source;
-    public Layer layer;
-    public MapLayer(GeoJsonSource source, Layer layer) {
-        this.source = source;
-        this.layer = layer;
-    }
-}

app/src/main/java/eu/konggdev/strikemaps/map/style/MapStyle.java

@@ -0,0 +1,63 @@
+package eu.konggdev.strikemaps.map.style;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import eu.konggdev.strikemaps.app.AppController;
+import eu.konggdev.strikemaps.helper.FileHelper;
+import eu.konggdev.strikemaps.map.layer.MapLayer;
+import eu.konggdev.strikemaps.map.source.MapSource;
+import java.util.*;
+
+
+public class MapStyle {
+    public int version;
+    public String name;
+    public String icon;
+    public String description;
+
+    public Map<String, MapSource> sources;
+    public List<MapLayer> layers;
+
+    public JsonNode raw;
+
+    //FIXME
+    public static MapStyle fromMapLibreJsonFile(String filename, AppController app) {
+        String styleContents;
+        if (filename.startsWith("/storage")) styleContents = FileHelper.loadStringFromUserFile(filename);
+        else styleContents = FileHelper.loadStringFromAssetFile(filename, app);
+
+        ObjectMapper mapper = new ObjectMapper();
+        try {
+            JsonNode root = mapper.readTree(styleContents);
+            MapStyle style = new MapStyle();
+
+            style.version = root.path("version").asInt();
+            style.name = root.path("name").asText();
+            style.icon = root.path("icon").asText();
+            style.description = root.path("description").asText();
+
+            style.sources = mapper.convertValue(
+                    root.path("sources"),
+                    new TypeReference<Map<String, MapSource>>() {}
+            );
+
+            style.layers = new ArrayList<>();
+            for (JsonNode layerNode : root.path("layers")) {
+
+                MapLayer layer = mapper.treeToValue(layerNode, MapLayer.class);
+
+                layer.raw = layerNode; // IMPORTANT
+
+                style.layers.add(layer);
+            }
+
+            style.raw = root; // full backup
+
+            return style;
+        } catch ( Exception e ) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+}