Show shapefile metadata

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// 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 ArcGIS
import SwiftUI

struct ShowShapefileMetadataView: View {
    /// Model which contains the logic for loading and setting the data.
    @State private var model = Model()
    /// The error that occurred, if any, when trying to load the shapefile or display its metadata.
    @State private var error: Error?
    /// A Boolean value specifying whether the metadata view should be shown
    @State private var showMetadata: Bool = false

    var body: some View {
        MapViewReader { mapView in
            MapView(map: model.map)
                .onAppear {
                    Task {
                        do {
                            // Attempt to asynchronously load the
                            // feature layer from the model.
                            try await model.loadShapefile()
                            // If the feature layer has a full extent,
                            // use it to set the map's viewpoint.
                            if let fullExtent = model.featureLayer?.fullExtent {
                                await mapView.setViewpointGeometry(
                                    fullExtent,
                                    padding: 50
                                )
                            }
                        } catch {
                            self.error = error
                        }
                    }
                }
                .toolbar {
                    ToolbarItem(placement: .bottomBar) {
                        Button("Show Shapefile Metadata") {
                            showMetadata.toggle()
                        }
                        .popover(isPresented: $showMetadata) {
                            metadataPopover
                        }
                    }
                }
                .errorAlert(presentingError: $error)
        }
    }

    @ViewBuilder var metadataPopover: some View {
        NavigationStack {
            MetadataPanel(model: $model)
                .navigationTitle("Shapefile Metadata")
                .navigationBarTitleDisplayMode(.inline)
                .toolbar {
                    ToolbarItem(placement: .confirmationAction) {
                        Button("Done") {
                            showMetadata = false
                        }
                    }
                }
        }
        .presentationDetents([.fraction(0.55)])
        .frame(idealWidth: 320, idealHeight: 380)
    }
}

private extension ShowShapefileMetadataView {
    @MainActor
    @Observable
    class Model {
        /// Create a map with a topographic basemap.
        @ObservationIgnored var map = Map(basemapStyle: .arcGISTopographic)

        /// Declare a FeatureLayer to display the shapefile features on the map.
        @ObservationIgnored var featureLayer: FeatureLayer?

        /// Holds metadata information about the shapefile, such as name, description, etc.
        var shapefileInfo: ShapefileInfo?

        /// Holds the thumbnail image associated with the shapefile, if available.
        var thumbnailImage: UIImage?

        /// Asynchronous function to load the feature layer from the shapefile.
        func loadShapefile() async throws {
            let featureTable = ShapefileFeatureTable(fileURL: .auroraShapefile)
            let layer = FeatureLayer(featureTable: featureTable)

            try await layer.featureTable?.load()

            map.addOperationalLayer(layer)
            featureLayer = layer
            shapefileInfo = featureTable.info
            thumbnailImage = featureTable.info?.thumbnail
        }
    }

    struct MetadataPanel: View {
        /// Binding to the model to reflect changes in the UI.
        @Binding var model: ShowShapefileMetadataView.Model

        var body: some View {
            VStack(alignment: .center, spacing: 16) {
                if let info = model.shapefileInfo {
                    Text(info.credits)
                        .bold()
                    Text(info.summary)
                        .font(.caption)
                        .multilineTextAlignment(.leading)
                }
                if let image = model.thumbnailImage {
                    Image(uiImage: image)
                        .resizable()
                        .scaledToFit()
                        .frame(maxHeight: 150)
                }

                if let tags = model.shapefileInfo?.tags {
                    Text("Tags: \(tags.joined(separator: ", "))")
                        .font(.caption2)
                        .foregroundColor(.secondary)
                }
            }
            .padding()
            .cornerRadius(8)
            .padding(.horizontal)
        }
    }
}

private extension URL {
    static var auroraShapefile: URL {
        Bundle.main.url(
            forResource: "TrailBikeNetwork",
            withExtension: "shp",
            subdirectory: "Aurora_CO_shp"
        )!
    }
}

#Preview {
    ShowShapefileMetadataView()
}