import WidgetKit
import SwiftUI
import SharedModels

struct DailyProgressEntry: TimelineEntry {
    let date: Date
    let data: WidgetData
}

struct DailyProgressProvider: TimelineProvider {
    func placeholder(in context: Context) -> DailyProgressEntry {
        DailyProgressEntry(date: Date(), data: .placeholder)
    }

    func getSnapshot(in context: Context, completion: @escaping (DailyProgressEntry) -> Void) {
        if context.isPreview {
            completion(DailyProgressEntry(date: Date(), data: .placeholder))
            return
        }
        completion(DailyProgressEntry(date: Date(), data: WidgetDataReader.read()))
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<DailyProgressEntry>) -> Void) {
        let data = WidgetDataReader.read()
        var entries: [DailyProgressEntry] = []
        let now = Date()

        for offset in 0..<8 {
            let date = Calendar.current.date(byAdding: .minute, value: offset * 15, to: now)!
            entries.append(DailyProgressEntry(date: date, data: data))
        }

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

struct DailyProgressWidget: Widget {
    let kind = "DailyProgressWidget"

    var body: some WidgetConfiguration {
        StaticConfiguration(kind: kind, provider: DailyProgressProvider()) { entry in
            DailyProgressWidgetView(entry: entry)
                .containerBackground(.fill.tertiary, for: .widget)
        }
        .configurationDisplayName("Daily Progress")
        .description("Track your daily practice goal and streak.")
        .supportedFamilies([.systemSmall])
    }
}

struct DailyProgressWidgetView: View {
    let entry: DailyProgressEntry

    var body: some View {
        VStack(spacing: 8) {
            // Progress ring
            ZStack {
                Circle()
                    .stroke(.quaternary, lineWidth: 6)

                Circle()
                    .trim(from: 0, to: entry.data.progressPercent)
                    .stroke(.orange, style: StrokeStyle(lineWidth: 6, lineCap: .round))
                    .rotationEffect(.degrees(-90))

                VStack(spacing: 0) {
                    Text("\(entry.data.todayCount)")
                        .font(.title2.bold().monospacedDigit())

                    Text("/\(entry.data.dailyGoal)")
                        .font(.caption2)
                        .foregroundStyle(.secondary)
                }
            }
            .frame(width: 70, height: 70)

            // Streak
            if entry.data.currentStreak > 0 {
                HStack(spacing: 3) {
                    Image(systemName: "flame.fill")
                        .foregroundStyle(.orange)
                        .font(.caption2)
                    Text("\(entry.data.currentStreak)d")
                        .font(.caption2.bold())
                }
            }

            // Due cards
            if entry.data.dueCardCount > 0 {
                Text("\(entry.data.dueCardCount) due")
                    .font(.caption2)
                    .foregroundStyle(.secondary)
            }
        }
    }
}

#Preview(as: .systemSmall) {
    DailyProgressWidget()
} timeline: {
    DailyProgressEntry(date: Date(), data: .placeholder)
}