// ── Next Timer Widget (Small) ─────────────────────────────────
// Home screen small widget showing next timer + countdown

import SwiftUI
import WidgetKit

// MARK: - Timeline Provider

struct NextTimerProvider: AppIntentTimelineProvider {
    typealias Entry = NextTimerEntry
    typealias Intent = NextTimerIntent

    func placeholder(in context: Context) -> NextTimerEntry {
        NextTimerEntry(
            date: Date(),
            timer: TimerSnapshot(
                id: "placeholder",
                label: "Team Standup",
                type: .alarm,
                urgency: .important,
                state: .active,
                targetTime: Date().addingTimeInterval(3600),
                duration: 3600,
                startedAt: Date(),
                elapsedBeforePause: 0,
                snoozeCount: 0,
                category: nil,
                pomodoroCurrentRound: nil,
                pomodoroTotalRounds: nil,
                pomodoroIsBreak: nil,
                nextWarningTime: Date().addingTimeInterval(1800),
                totalWarnings: 3,
                firedWarnings: 1
            )
        )
    }

    func snapshot(for configuration: NextTimerIntent, in context: Context) async -> NextTimerEntry {
        let timer = SharedTimerDataManager.shared.readNextFiringTimer()
        return NextTimerEntry(date: Date(), timer: timer)
    }

    func timeline(for configuration: NextTimerIntent, in context: Context) async -> Timeline<NextTimerEntry> {
        let timer = SharedTimerDataManager.shared.readNextFiringTimer()
        let now = Date()

        // Create entries every 5 minutes for the next 30 minutes
        var entries: [NextTimerEntry] = []
        for minuteOffset in stride(from: 0, through: 30, by: 5) {
            let entryDate = Calendar.current.date(byAdding: .minute, value: minuteOffset, to: now)!
            entries.append(NextTimerEntry(date: entryDate, timer: timer))
        }

        // Reload after 30 minutes or when timer fires
        let reloadDate: Date
        if let timer = timer {
            reloadDate = min(timer.targetTime, now.addingTimeInterval(30 * 60))
        } else {
            reloadDate = now.addingTimeInterval(30 * 60)
        }

        return Timeline(entries: entries, policy: .after(reloadDate))
    }
}

// MARK: - Intent (no config needed, just a placeholder for AppIntentTimelineProvider)

import AppIntents

struct NextTimerIntent: WidgetConfigurationIntent {
    static var title: LocalizedStringResource = "Next Timer"
    static var description: IntentDescription = "Shows your next upcoming timer"
}

// MARK: - Entry

struct NextTimerEntry: TimelineEntry {
    let date: Date
    let timer: TimerSnapshot?
}

// MARK: - Widget View

struct NextTimerWidgetView: View {
    @Environment(\.widgetFamily) var family
    let entry: NextTimerEntry

    var body: some View {
        if let timer = entry.timer {
            timerContent(timer)
        } else {
            emptyContent
        }
    }

    @ViewBuilder
    private func timerContent(_ timer: TimerSnapshot) -> some View {
        VStack(alignment: .leading, spacing: 6) {
            // Urgency indicator + label
            HStack(spacing: 4) {
                Circle()
                    .fill(urgencyColor(timer.urgency))
                    .frame(width: 8, height: 8)
                Text(timer.label)
                    .font(.system(size: 13, weight: .semibold))
                    .foregroundStyle(.primary)
                    .lineLimit(1)
                    .privacySensitive()
            }

            Spacer()

            // Countdown using SwiftUI Date-relative text
            if timer.state == .paused {
                Text("Paused")
                    .font(.system(size: 28, weight: .bold, design: .monospaced))
                    .foregroundStyle(.secondary)
            } else {
                Text(timer.targetTime, style: .timer)
                    .font(.system(size: 28, weight: .bold, design: .monospaced))
                    .foregroundStyle(.primary)
                    .multilineTextAlignment(.leading)
                    .privacySensitive()
            }

            // Target time
            Text(formatTime(timer.targetTime))
                .font(.system(size: 11, weight: .medium))
                .foregroundStyle(.secondary)
        }
        .padding()
        .containerBackground(for: .widget) {
            urgencyColor(timer.urgency).opacity(0.1)
        }
        .widgetURL(URL(string: "chronomind://timer/\(timer.id)"))
    }

    private var emptyContent: some View {
        VStack(spacing: 8) {
            Image(systemName: "clock")
                .font(.system(size: 28))
                .foregroundStyle(.secondary)
            Text("No Timers")
                .font(.system(size: 13, weight: .medium))
                .foregroundStyle(.secondary)
            Text("Tap to create one")
                .font(.system(size: 11))
                .foregroundStyle(.tertiary)
        }
        .padding()
        .containerBackground(for: .widget) {
            Color(.systemBackground)
        }
        .widgetURL(URL(string: "chronomind://create"))
    }

    private func urgencyColor(_ urgency: UrgencyLevel) -> Color {
        switch urgency {
        case .critical: return Color(red: 1.0, green: 0.28, blue: 0.34)
        case .important: return Color(red: 1.0, green: 0.62, blue: 0.26)
        case .standard: return Color(red: 0.99, green: 0.79, blue: 0.34)
        case .gentle: return Color(red: 0.18, green: 0.84, blue: 0.45)
        case .passive: return Color(red: 0.36, green: 0.55, blue: 0.93)
        }
    }
}

// MARK: - Widget Definition

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

    var body: some WidgetConfiguration {
        AppIntentConfiguration(
            kind: kind,
            intent: NextTimerIntent.self,
            provider: NextTimerProvider()
        ) { entry in
            NextTimerWidgetView(entry: entry)
        }
        .configurationDisplayName("Next Timer")
        .description("Shows your next upcoming timer with countdown")
        .supportedFamilies([.systemSmall])
    }
}