Update utils.py

utils.py

@@ -1,5 +1,6 @@
 from pathlib import Path
-#import pandas as pd
+import pandas as pd
+import geopandas as gpd
 import faicons as fa
 from shiny import ui
 from shared import app_dir
@@ -7,9 +8,69 @@ import matplotlib.pyplot as plt
 import numpy as np
 
 
+
+
 #app_dir = Path(__file__).parent
 #tips = pd.read_csv(app_dir / "tips.csv")
 
+def load_data():
+    """
+    Load zones shapefile and trips data.
+    Returns:
+        zones (GeoDataFrame): GeoDataFrame of zones.
+        trips (DataFrame): DataFrame of trip data.
+    """
+    zones = gpd.read_file(app_dir / "data" / "zone" / "Napa_TBS_2024_Zone_System.shp")  # Replace with your shapefile path
+    zones = zones[zones.is_valid & ~zones.is_empty]
+    zones = zones[["FPID", "geometry"]]  # Keep only essential columns
+    zones["geometry"] = zones["geometry"].simplify(0.001, preserve_topology=True)  # Simplify geometries
+
+    #trips = pd.read_csv(app_dir / "data" / "od_table.csv")  # Replace with your trip data path
+    trips = pd.read_parquet(app_dir / "data" / "od_table.parquet")  # Replace with your trip data path
+    return zones, trips
+
+
+def filter_trips(trips, zones, origin_filter, destination_filter):
+    """
+    Filter trips based on selected origin or destination.
+
+    Args:
+        trips (DataFrame): Trip data with origin and destination zones.
+        zones (GeoDataFrame): GeoDataFrame of zones.
+        origin_filter (str): Selected origin zone ID.
+        destination_filter (str): Selected destination zone ID.
+
+    Returns:
+        filtered_origins (GeoDataFrame): Filtered origin zones with trip counts.
+        filtered_destinations (GeoDataFrame): Filtered destination zones with trip counts.
+    """
+    if origin_filter and destination_filter:
+        filtered_trips = trips[
+            (trips["start_zone_id"] == origin_filter) & 
+            (trips["end_zone_id"] == destination_filter)
+        ]
+    elif origin_filter:
+        filtered_trips = trips[trips["start_zone_id"] == origin_filter]
+    elif destination_filter:
+        filtered_trips = trips[trips["end_zone_id"] == destination_filter]
+    else:
+        filtered_trips = trips
+
+
+    # Aggregate trip counts for origins and destinations
+    filtered_origins = zones.merge(
+        #filtered_trips.groupby("start_zone_id").size().reset_index(name="trip_count"),
+        filtered_trips.groupby("start_zone_id")["trips"].sum().reset_index(name="trip_count"),
+        left_on="FPID", right_on="start_zone_id", how="left"
+    ).fillna(0)
+
+    filtered_destinations = zones.merge(
+        filtered_trips.groupby("end_zone_id")["trips"].sum().reset_index(name="trip_count"),
+        left_on="FPID", right_on="end_zone_id", how="left"
+    ).fillna(0)
+
+    return filtered_origins, filtered_destinations
+
 
 def create_nav_button(button_icon, button_label_text, button_link, button_cls = "btn btn-primary"):
     return ui.tags.a(
@@ -102,3 +163,4 @@ def create_stacked_bar_chart(categories, intra_napa, into_napa, out_napa):
     plt.tight_layout()
     return fig
                 
+