Display content of utility network container

// Copyright 2025 Esri
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

import 'package:arcgis_maps/arcgis_maps.dart';
import 'package:arcgis_maps_sdk_flutter_samples/common/common.dart';
import 'package:arcgis_maps_sdk_flutter_samples/common/token_challenger_handler.dart';
import 'package:flutter/material.dart';

class DisplayContentOfUtilityNetworkContainer extends StatefulWidget {
  const DisplayContentOfUtilityNetworkContainer({super.key});

  @override
  State<DisplayContentOfUtilityNetworkContainer> createState() =>
      _DisplayContentOfUtilityNetworkContainerState();
}

class _DisplayContentOfUtilityNetworkContainerState
    extends State<DisplayContentOfUtilityNetworkContainer>
    with SampleStateSupport {
  // Create a controller for the map view.
  final _mapViewController = ArcGISMapView.createController();
  // The utility network used in the sample.
  late UtilityNetwork _utilityNetwork;
  // The graphics overlay to display the container contents.
  final _graphicsOverlay = GraphicsOverlay();
  // The symbol used to highlight the container boundary.
  final _boundarySymbol = SimpleLineSymbol(
    style: SimpleLineSymbolStyle.dash,
    color: Colors.yellow,
    width: 3,
  );
  // The symbol used to show an attachment association.
  final _attachmentSymbol = SimpleLineSymbol(
    style: SimpleLineSymbolStyle.dot,
    color: Colors.lightBlue,
    width: 3,
  );
  // The symbol used to show a connectivity association.
  final _connectivitySymbol = SimpleLineSymbol(
    style: SimpleLineSymbolStyle.dot,
    color: Colors.red,
    width: 3,
  );
  // A flag for when the map view is ready and controls can be used.
  var _ready = false;
  // A flag to show the symbol legend.
  var _showLegend = false;
  // The message to display in the banner.
  var _message = '';
  // To store the previous viewpoint before entering container view.
  Viewpoint? _previousViewpoint;
  // A flag to prevent multiple taps while an operation is in progress.
  var _tapInProgress = false;

  @override
  void initState() {
    super.initState();

    // Set up authentication for the sample server.
    // Note: Never hardcode login information in a production application.
    // This is done solely for the sake of the sample.
    ArcGISEnvironment
        .authenticationManager
        .arcGISAuthenticationChallengeHandler = TokenChallengeHandler(
      'editor01',
      'S7#i2LWmYH75',
    );
  }

  @override
  void dispose() {
    // Remove the TokenChallengeHandler and erase any credentials that were generated.
    ArcGISEnvironment
            .authenticationManager
            .arcGISAuthenticationChallengeHandler =
        null;
    ArcGISEnvironment.authenticationManager.arcGISCredentialStore.removeAll();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        left: false,
        right: false,
        child: Stack(
          children: [
            Column(
              children: [
                // Add a banner to show the results of the identify operation.
                Visibility(
                  visible: _message.isNotEmpty,
                  child: Container(
                    padding: const EdgeInsets.all(5),
                    color: Colors.grey[400],
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        Text(
                          _message,
                          textAlign: TextAlign.center,
                          style: Theme.of(context).textTheme.labelMedium,
                        ),
                      ],
                    ),
                  ),
                ),
                Expanded(
                  // Add a map view to the widget tree and set a controller.
                  child: ArcGISMapView(
                    controllerProvider: () => _mapViewController,
                    onMapViewReady: onMapViewReady,
                    onTap: onTap,
                  ),
                ),
                Row(
                  mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                  children: [
                    // A button to show the symbol legend.
                    ElevatedButton(
                      onPressed: () => setState(() => _showLegend = true),
                      child: const Text('Show Legend'),
                    ),
                    // A button to exit container view.
                    ElevatedButton(
                      onPressed: _previousViewpoint != null ? reset : null,
                      child: const Text('Exit Container View'),
                    ),
                  ],
                ),
              ],
            ),
            // Display a progress indicator and prevent interaction until state is ready.
            LoadingIndicator(visible: !_ready),
          ],
        ),
      ),
      // Show the legend bottom sheet if the flag is set.
      bottomSheet: _showLegend ? buildLegend(context) : null,
    );
  }

  Widget buildLegend(BuildContext context) {
    // Build a non-modal bottom sheet to show the symbol legend.
    return BottomSheetSettings(
      title: 'Utility Association Types',
      onCloseIconPressed: () => setState(() => _showLegend = false),
      settingsWidgets: (context) => [
        Column(
          spacing: 5,
          children: [
            // Attachment symbol.
            Row(
              spacing: 10,
              children: [
                SwatchImage(
                  symbol: _attachmentSymbol,
                  backgroundColor: Colors.grey,
                  width: 15,
                  height: 15,
                ),
                const Text('Attachment'),
              ],
            ),
            // Connectivity symbol.
            Row(
              spacing: 10,
              children: [
                SwatchImage(
                  symbol: _connectivitySymbol,
                  backgroundColor: Colors.grey,
                  width: 15,
                  height: 15,
                ),
                const Text('Connectivity'),
              ],
            ),
            // Containment symbol.
            Row(
              spacing: 10,
              children: [
                SwatchImage(
                  symbol: _boundarySymbol,
                  backgroundColor: Colors.grey,
                  width: 15,
                  height: 15,
                ),
                const Text('Containment'),
              ],
            ),
          ],
        ),
      ],
    );
  }

  Future<void> onMapViewReady() async {
    // Create a map using the portal item of a web map containing a utility network.
    final portal = Portal(
      Uri.parse('https://sampleserver7.arcgisonline.com/portal/sharing/rest'),
    );
    final portalItem = PortalItem.withPortalAndItemId(
      portal: portal,
      itemId: '0e38e82729f942a19e937b31bfac1b8d',
    );
    final map = ArcGISMap.withItem(portalItem);

    // Load the map and the utility network.
    setState(() => _message = 'Loading utility network ...');
    await map.load();
    _utilityNetwork = map.utilityNetworks.first;
    await _utilityNetwork.load();

    // Set an initial viewpoint on the map.
    map.initialViewpoint = Viewpoint.withLatLongScale(
      latitude: 41.8,
      longitude: -88.16,
      scale: 4000,
    );

    // Add the map to the map view.
    _mapViewController.arcGISMap = map;

    // Add the graphics overlay to the map view.
    _mapViewController.graphicsOverlays.add(_graphicsOverlay);

    // Set the state to be ready for a selection.
    reset();

    // Set the ready state variable to true to enable the sample UI.
    setState(() => _ready = true);
  }

  Future<void> onTap(Offset localPosition) async {
    // Ensure only one tap is processed at a time.
    if (_tapInProgress) return;
    _tapInProgress = true;

    // Perform an identify to determine if a user tapped on a feature.
    final identifyResults = await _mapViewController.identifyLayers(
      screenPoint: localPosition,
      tolerance: 10,
    );
    await displayContainerContent(identifyResults);
    _tapInProgress = false;
  }

  Future<void> displayContainerContent(
    List<IdentifyLayerResult> identifyResults,
  ) async {
    // Find the first result that is from a subtype feature layer.
    final result = identifyResults
        .where((result) => result.layerContent is SubtypeFeatureLayer)
        .firstOrNull;
    if (result == null) {
      return;
    }

    // Find the first feature. This will be the selected container feature.
    final containerFeature = result.sublayerResults
        .expand((result) => result.geoElements)
        .whereType<ArcGISFeature>()
        .firstOrNull;
    if (containerFeature == null) {
      return;
    }

    // Create a utility network element from the container feature.
    final containerElement = _utilityNetwork.createElement(
      arcGISFeature: containerFeature,
    );

    // Get the associations for the container element to find contained elements.
    final associations = await _utilityNetwork.getAssociations(
      element: containerElement,
      type: UtilityAssociationType.containment,
    );
    final containedElements = associations
        .map(
          (association) =>
              association.fromElement.objectId == containerElement.objectId
              ? association.toElement
              : association.fromElement,
        )
        .toList();

    // Get the features for the contained elements.
    final containedFeatures = await _utilityNetwork.getFeaturesForElements(
      containedElements,
    );

    // Add a graphic for each of the contained features.
    for (final feature in containedFeatures) {
      final featureTable = feature.featureTable;
      if (featureTable == null || featureTable is! ServiceFeatureTable) {
        continue;
      }
      final symbol = featureTable.layerInfo?.drawingInfo?.renderer
          ?.symbolForFeature(feature: feature);
      _graphicsOverlay.graphics.add(
        Graphic(geometry: feature.geometry, symbol: symbol),
      );
    }

    // Determine the extent of all the contained features.
    final extent = _graphicsOverlay.extent;
    if (extent == null) {
      return;
    }

    // Add a graphic to highlight the container boundary.
    final containerGraphic = Graphic(
      geometry: GeometryEngine.buffer(geometry: extent, distance: 0.05),
      symbol: _boundarySymbol,
    );
    _graphicsOverlay.graphics.add(containerGraphic);

    // Add an association graphic for each of the contained elements.
    final containedAssociations = await _utilityNetwork
        .getAssociationsWithEnvelope(extent);
    for (final association in containedAssociations) {
      final symbol =
          association.associationType == UtilityAssociationType.attachment
          ? _attachmentSymbol
          : _connectivitySymbol;
      _graphicsOverlay.graphics.add(
        Graphic(geometry: association.geometry, symbol: symbol),
      );
    }

    // Hide operational layers.
    for (final layer in _mapViewController.arcGISMap!.operationalLayers) {
      layer.isVisible = false;
    }

    // Disable interaction.
    _mapViewController.interactionOptions.enabled = false;

    // Get the current viewpoint before animating.
    final viewpoint = _mapViewController.getCurrentViewpoint(
      ViewpointType.centerAndScale,
    );

    // Animate to the container.
    _mapViewController
        .setViewpointGeometry(containerGraphic.geometry!, paddingInDiPs: 20)
        .ignore();

    // Remember the previous viewpoint and update the message banner.
    setState(() {
      _previousViewpoint = viewpoint;
      _message = containedAssociations.isEmpty
          ? 'This feature contains no associations.'
          : 'Contained associations are shown.';
    });
  }

  void reset() {
    // Clear any state that gets set when entering container view.
    _graphicsOverlay.graphics.clear();
    for (final layer in _mapViewController.arcGISMap!.operationalLayers) {
      layer.isVisible = true;
    }
    _mapViewController.interactionOptions.enabled = true;
    if (_previousViewpoint != null) {
      _mapViewController.setViewpointAnimated(_previousViewpoint!);
    }
    setState(() {
      _previousViewpoint = null;
      _message = 'Tap on a container to see its content.';
    });
  }
}