import SwiftUI
import WidgetKit

struct WatchUnreadEntry: TimelineEntry {
    let date: Date
    let unreadCount: Int
}

struct WatchUnreadProvider: TimelineProvider {
    func placeholder(in context: Context) -> WatchUnreadEntry {
        WatchUnreadEntry(date: .now, unreadCount: 3)
    }

    func getSnapshot(in context: Context, completion: @escaping (WatchUnreadEntry) -> Void) {
        completion(makeEntry())
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<WatchUnreadEntry>) -> Void) {
        completion(Timeline(entries: [makeEntry()], policy: .after(.now.addingTimeInterval(900))))
    }

    private func makeEntry() -> WatchUnreadEntry {
        let unreadCount = MockMailService().previewThreads().filter { $0.mailbox == .inbox && $0.isUnread }.count
        return WatchUnreadEntry(date: .now, unreadCount: unreadCount)
    }
}

struct WatchUnreadComplication: Widget {
    let kind = "SocialIOWatchUnreadComplication"

    var body: some WidgetConfiguration {
        StaticConfiguration(kind: kind, provider: WatchUnreadProvider()) { entry in
            WatchUnreadComplicationView(entry: entry)
        }
        .configurationDisplayName("social.io Inbox")
        .description("Unread social.io mail at a glance.")
        .supportedFamilies([.accessoryRectangular, .accessoryCircular, .accessoryCorner])
    }
}

private struct WatchUnreadComplicationView: View {
    let entry: WatchUnreadEntry

    var body: some View {
        switch widgetFamily {
        case .accessoryCircular:
            ZStack {
                AccessoryWidgetBackground()
                VStack(spacing: 2) {
                    Image(systemName: "envelope.fill")
                    Text(entry.unreadCount, format: .number)
                        .font(.caption2.weight(.bold))
                }
            }
            .widgetURL(URL(string: "socialio://mailbox/inbox"))

        case .accessoryCorner:
            Text("\(entry.unreadCount)")
                .font(.caption.weight(.bold))
                .widgetURL(URL(string: "socialio://mailbox/inbox"))

        default:
            VStack(alignment: .leading, spacing: 4) {
                Text("social.io")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
                Text("\(entry.unreadCount) unread")
                    .font(.caption.weight(.semibold))
            }
            .widgetURL(URL(string: "socialio://mailbox/inbox"))
        }
    }

    @Environment(\.widgetFamily) private var widgetFamily
}

@main
struct SocialIOWatchWidgets: WidgetBundle {
    var body: some Widget {
        WatchUnreadComplication()
    }
}