firebase-ios-sdk/FirebaseMessaging/Apps/AdvancedSample/SampleLiveActivity/SampleLiveActivity.swift

// Copyright 2020 Google LLC
//
// 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
//
//      http://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 SwiftUI
import WidgetKit

struct Provider: AppIntentTimelineProvider {
  func placeholder(in context: Context) -> SimpleEntry {
    SimpleEntry(date: Date(), configuration: ConfigurationAppIntent())
  }

  func snapshot(for configuration: ConfigurationAppIntent,
                in context: Context) async -> SimpleEntry {
    SimpleEntry(date: Date(), configuration: configuration)
  }

  func timeline(for configuration: ConfigurationAppIntent,
                in context: Context) async -> Timeline<SimpleEntry> {
    var entries: [SimpleEntry] = []

    // Generate a timeline consisting of five entries an hour apart, starting from the current date.
    let currentDate = Date()
    for hourOffset in 0 ..< 5 {
      let entryDate = Calendar.current.date(
        byAdding: .hour,
        value: hourOffset,
        to: currentDate
      )!
      let entry = SimpleEntry(date: entryDate, configuration: configuration)
      entries.append(entry)
    }

    return Timeline(entries: entries, policy: .atEnd)
  }
}

struct SimpleEntry: TimelineEntry {
  let date: Date
  let configuration: ConfigurationAppIntent
}

struct SampleLiveActivityEntryView: View {
  var entry: Provider.Entry

  var body: some View {
    VStack {
      Text("Time:")
      Text(entry.date, style: .time)

      Text("Favorite Emoji:")
      Text(entry.configuration.favoriteEmoji)
    }
  }
}

struct SampleLiveActivity: Widget {
  let kind: String = "SampleLiveActivity"

  var body: some WidgetConfiguration {
    AppIntentConfiguration(
      kind: kind,
      intent: ConfigurationAppIntent.self,
      provider: Provider()
    ) { entry in
      SampleLiveActivityEntryView(entry: entry)
        .containerBackground(.fill.tertiary, for: .widget)
    }
  }
}

private extension ConfigurationAppIntent {
  static var smiley: ConfigurationAppIntent {
    let intent = ConfigurationAppIntent()
    intent.favoriteEmoji = "😀"
    return intent
  }

  static var starEyes: ConfigurationAppIntent {
    let intent = ConfigurationAppIntent()
    intent.favoriteEmoji = "🤩"
    return intent
  }
}

#Preview(as: .systemSmall) {
  SampleLiveActivity()
} timeline: {
  SimpleEntry(date: .now, configuration: .smiley)
  SimpleEntry(date: .now, configuration: .starEyes)
}