LeCountdown/LaunchWidget/LaunchWidget.swift

//
//  LaunchWidget.swift
//  LaunchWidget
//
//  Created by Laurent Morvillier on 25/01/2023.
//

import WidgetKit
import SwiftUI
import Intents

struct Provider: IntentTimelineProvider {
    func placeholder(in context: Context) -> SimpleEntry {
        SimpleEntry(countdowns: [], date: Date(), configuration: SelectCountdownIntent())
    }

    func getSnapshot(for configuration: SelectCountdownIntent, in context: Context, completion: @escaping (SimpleEntry) -> ()) {
        
        guard let cp = configuration.countdown
               else {
            completion(placeholder(in: context))
            return
        }
        
        let countdowns: [Countdown] = cp.compactMap {
            if let id = $0.identifier {
                return IntentDataProvider.main.countdown(id: id)
            } else {
                return nil
            }
        }
        
        let entry = SimpleEntry(countdowns: countdowns,
                                date: Date(),
                                configuration: configuration)
        completion(entry)
        
    }

    func getTimeline(for configuration: SelectCountdownIntent, in context: Context, completion: @escaping (Timeline<Entry>) -> ()) {

        getSnapshot(for: configuration, in: context) { entry in
            let timeline = Timeline(entries: [entry], policy: .atEnd)
            completion(timeline)
        }
        
    }
}

struct SimpleEntry: TimelineEntry {
    let countdowns: [Countdown]
    let date: Date
    let configuration: SelectCountdownIntent
}

struct CountdownSimpleWidgetView: View {
    
    let countdown: Countdown
    
    var body: some View {
        SingleCountdownView(countdown: countdown)
            .widgetURL(countdown.url)
    }
    
}

struct CountdownMultiWidgetView: View {
    
    let countdowns: [Countdown]
    
    var body: some View {
        MultiCountdownView(countdowns: countdowns)
    }
    
}

struct VoidView : View {
    var body: some View {
        VStack {
            Text("Tea!")
            Text("4:00")
        }
    }
}

struct LaunchWidgetEntryView : View {
    
    @Environment(\.widgetFamily) var family: WidgetFamily
    
    var entry: Provider.Entry

    @ViewBuilder
    var body: some View {
        switch family {
        case .systemSmall, .accessoryInline:
            if let countdown = entry.countdowns.first {
                CountdownSimpleWidgetView(countdown: countdown)
                    .background(Image(countdown.imageName))
            } else {
                VoidView()
            }
        case .accessoryCircular:
            if let countdown = entry.countdowns.first {
                CountdownSimpleWidgetView(countdown: countdown)
                    .frame(maxWidth: .infinity, maxHeight: .infinity)
                    .background(Color.black)
            } else {
                VoidView()
            }
        case .accessoryRectangular:
            if let countdown = entry.countdowns.first {
                CountdownSimpleWidgetView(countdown: countdown)
                    .frame(maxWidth: .infinity, maxHeight: .infinity)
                    .background(Color.black)
                    .cornerRadius(16.0)
            } else {
                VoidView()
            }
        default:
            MultiCountdownView(countdowns: entry.countdowns)
        }
    }
    
}

struct LaunchWidget: Widget {
    let kind: String = "com.staxriver.launch-widget"

    var body: some WidgetConfiguration {
        IntentConfiguration(kind: kind,
                            intent: SelectCountdownIntent.self,
                            provider: Provider()) { entry in
            LaunchWidgetEntryView(entry: entry)
        }
        .configurationDisplayName("Launch Widget")
        .description("Select and launch your countdowns")
        .supportedFamilies([.systemSmall, .systemMedium, .systemLarge, .accessoryRectangular, .accessoryCircular])
    }
}

struct LaunchWidget_Previews: PreviewProvider {
    static var previews: some View {
        
        let fake = Countdown.fake(context: PersistenceController.preview.container.viewContext)
        
        LaunchWidgetEntryView(entry: SimpleEntry(countdowns: [fake], date: Date(), configuration: SelectCountdownIntent()))
            .previewContext(WidgetPreviewContext(family: .systemSmall))
        LaunchWidgetEntryView(entry: SimpleEntry(countdowns: [fake, fake, fake, fake], date: Date(), configuration: SelectCountdownIntent()))
            .previewContext(WidgetPreviewContext(family: .systemMedium))
        LaunchWidgetEntryView(entry: SimpleEntry(countdowns: [fake], date: Date(), configuration: SelectCountdownIntent()))
            .previewContext(WidgetPreviewContext(family: .accessoryRectangular))

    }
}