Add geometry API

app.py

@@ -17,6 +17,8 @@ import requests
 import kml2geojson
 import folium
 import xml.etree.ElementTree as ET
+from fastapi import FastAPI, HTTPException
+from urllib.parse import unquote
 
 # --- Helper Functions ---
 
@@ -41,7 +43,7 @@ def one_time_setup():
             print(f"Earth Engine initialization failed: {inner_e}")
 
 
-def _process_spatial_data(data_bytes):
+def _process_spatial_data(data_bytes: BytesIO) -> gpd.GeoDataFrame:
     """Core function to process bytes of a KML or GeoJSON file."""
     # Read the first few bytes to determine file type without consuming the stream
     start_of_file = data_bytes.read(100)
@@ -73,7 +75,7 @@ def get_gdf_from_file(file_obj):
         data_bytes = BytesIO(f.read())
     return _process_spatial_data(data_bytes)
 
-def get_gdf_from_url(url):
+def get_gdf_from_url(url: str) -> gpd.GeoDataFrame:
     """Downloads and reads a KML/GeoJSON from a URL."""
     if not url or not url.strip():
         return None
@@ -99,7 +101,7 @@ def get_gdf_from_url(url):
         raise ValueError(f"Failed to download file from URL: {e}")
 
 
-def find_best_epsg(geometry):
+def find_best_epsg(geometry) -> int:
     """Finds the most suitable EPSG code for a given geometry based on its centroid."""
     if geometry.geom_type == "Polygon":
         centroid = geometry.centroid
@@ -132,13 +134,13 @@ def shape_3d_to_2d(shape):
         return transform(lambda x, y, z: (x, y), shape)
     return shape
 
-def preprocess_gdf(gdf):
+def preprocess_gdf(gdf: gpd.GeoDataFrame) -> gpd.GeoDataFrame:
     """Preprocesses a GeoDataFrame by converting geometries to 2D and fixing invalid ones."""
     gdf["geometry"] = gdf["geometry"].apply(shape_3d_to_2d)
     gdf["geometry"] = gdf.buffer(0)
     return gdf
 
-def to_best_crs(gdf):
+def to_best_crs(gdf: gpd.GeoDataFrame) -> gpd.GeoDataFrame:
     """Converts a GeoDataFrame to the most suitable CRS."""
     if not gdf.empty and gdf["geometry"].iloc[0] is not None:
         best_epsg_code = find_best_epsg(gdf.to_crs(epsg=4326)["geometry"].iloc[0])
@@ -364,6 +366,54 @@ def process_and_display(file_obj, url_str, buffer_m, progress=gr.Progress()):
     progress(1, desc="Done!")
     return m._repr_html_(), None, stats_df, dem_html, slope_html, geometry_json, buffer_geometry_json
 
+# Initialize the FastAPI app first
+app = FastAPI()
+
+@app.get("/api/geomtry")
+def calculate_geometry_metrics(request: FileUrlRequest):
+    """
+    Accepts a URL to a KML/GeoJSON file, calculates the area and perimeter
+    of the first valid polygon found, and returns the results in JSON format.
+    """
+    try:
+        # 1. Fetch and read the spatial file from the URL
+        input_gdf = get_gdf_from_url(str(request.url))
+
+        # 2. Preprocess the GeoDataFrame
+        processed_gdf = preprocess_gdf(input_gdf)
+        
+        # 3. Isolate the first valid polygon
+        polygon_gdf = processed_gdf[processed_gdf.geometry.type == 'Polygon']
+        if polygon_gdf.empty:
+            raise ValueError("No valid polygon found in the provided file.")
+        
+        # Take just the first polygon for this example
+        first_polygon_gdf = polygon_gdf.iloc[[0]]
+
+        # 4. Convert to a suitable Coordinate Reference System for measurement
+        metric_gdf = to_best_crs(first_polygon_gdf)
+
+        # 5. Calculate area and perimeter
+        # .item() extracts the single value from the GeoSeries
+        area_sq_meters = metric_gdf.area.item()
+        perimeter_meters = metric_gdf.length.item()
+        
+        area_hectares = area_sq_meters / 10000
+
+        # 6. Return the results
+        return {
+            "area": round(area_hectares, 4),
+            "perimeter": round(perimeter_meters, 4),
+        }
+
+    except ValueError as e:
+        # Handle known errors (e.g., bad URL, no polygon)
+        raise HTTPException(status_code=400, detail=str(e))
+    except Exception as e:
+        # Handle unexpected server errors
+        raise HTTPException(status_code=500, detail=f"An unexpected server error occurred: {e}")
+
+            
 def calculate_indices(
     geometry_json, buffer_geometry_json, veg_indices, evi_vars, date_range,
     min_year, max_year, progress=gr.Progress()
@@ -678,6 +728,7 @@ with gr.Blocks(theme=theme, title="Kamlan: KML Analyzer") as demo:
     # --- Event Handlers ---
     def process_on_load(request: gr.Request):
         """Checks for a 'file_url' query parameter when the app loads."""
+        
         return request.query_params.get("file_url", "")
 
     demo.load(process_on_load, None, url_input)