// ── Lock Screen Widget ────────────────────────────────────────
// Lock screen inline/circular/rectangular widgets for next timer

import SwiftUI
import WidgetKit
import AppIntents

// MARK: - Timeline Provider

struct LockScreenTimerProvider: AppIntentTimelineProvider {
    typealias Entry = LockScreenTimerEntry
    typealias Intent = LockScreenTimerIntent

    func placeholder(in context: Context) -> LockScreenTimerEntry {
        LockScreenTimerEntry(
            date: Date(),
            label: "Standup",
            targetTime: Date().addingTimeInterval(3600),
            urgency: .important,
            hasTimer: true
        )
    }

    func snapshot(for configuration: LockScreenTimerIntent, in context: Context) async -> LockScreenTimerEntry {
        entryFromSharedData()
    }

    func timeline(for configuration: LockScreenTimerIntent, in context: Context) async -> Timeline<LockScreenTimerEntry> {
        let entry = entryFromSharedData()
        let now = Date()

        var entries: [LockScreenTimerEntry] = []
        for minuteOffset in stride(from: 0, through: 30, by: 5) {
            let entryDate = Calendar.current.date(byAdding: .minute, value: minuteOffset, to: now)!
            entries.append(LockScreenTimerEntry(
                date: entryDate,
                label: entry.label,
                targetTime: entry.targetTime,
                urgency: entry.urgency,
                hasTimer: entry.hasTimer
            ))
        }

        let reloadDate: Date
        if entry.hasTimer {
            reloadDate = min(entry.targetTime, now.addingTimeInterval(30 * 60))
        } else {
            reloadDate = now.addingTimeInterval(30 * 60)
        }

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

    private func entryFromSharedData() -> LockScreenTimerEntry {
        if let timer = SharedTimerDataManager.shared.readNextFiringTimer() {
            return LockScreenTimerEntry(
                date: Date(),
                label: timer.label,
                targetTime: timer.targetTime,
                urgency: timer.urgency,
                hasTimer: true
            )
        }
        return LockScreenTimerEntry(
            date: Date(),
            label: "",
            targetTime: Date(),
            urgency: .standard,
            hasTimer: false
        )
    }
}

// MARK: - Intent

struct LockScreenTimerIntent: WidgetConfigurationIntent {
    static var title: LocalizedStringResource = "Lock Screen Timer"
    static var description: IntentDescription = "Shows next timer countdown on lock screen"
}

// MARK: - Entry

struct LockScreenTimerEntry: TimelineEntry {
    let date: Date
    let label: String
    let targetTime: Date
    let urgency: UrgencyLevel
    let hasTimer: Bool
}

// MARK: - Widget Views

struct LockScreenInlineView: View {
    let entry: LockScreenTimerEntry

    var body: some View {
        if entry.hasTimer {
            HStack(spacing: 4) {
                Image(systemName: "clock.fill")
                Text(entry.label)
                Text(entry.targetTime, style: .timer)
            }
        } else {
            HStack(spacing: 4) {
                Image(systemName: "clock")
                Text("No timers")
            }
        }
    }
}

struct LockScreenCircularView: View {
    let entry: LockScreenTimerEntry

    var body: some View {
        if entry.hasTimer {
            ZStack {
                // Progress ring based on remaining time
                AccessoryWidgetBackground()
                VStack(spacing: 0) {
                    Text(entry.targetTime, style: .timer)
                        .font(.system(size: 14, weight: .bold, design: .monospaced))
                        .minimumScaleFactor(0.5)
                        .widgetAccentable()
                }
            }
        } else {
            ZStack {
                AccessoryWidgetBackground()
                Image(systemName: "clock")
                    .font(.system(size: 20))
            }
        }
    }
}

struct LockScreenRectangularView: View {
    let entry: LockScreenTimerEntry

    var body: some View {
        if entry.hasTimer {
            HStack(spacing: 8) {
                VStack(alignment: .leading, spacing: 2) {
                    Text(entry.label)
                        .font(.system(size: 14, weight: .semibold))
                        .lineLimit(1)
                        .widgetAccentable()
                    Text(entry.targetTime, style: .timer)
                        .font(.system(size: 12, weight: .medium, design: .monospaced))
                    Text(formatTime(entry.targetTime))
                        .font(.system(size: 10))
                        .foregroundStyle(.secondary)
                }
                Spacer()
            }
        } else {
            HStack {
                VStack(alignment: .leading, spacing: 2) {
                    Text("ChronoMind")
                        .font(.system(size: 14, weight: .semibold))
                    Text("No active timers")
                        .font(.system(size: 12))
                        .foregroundStyle(.secondary)
                }
                Spacer()
            }
        }
    }
}

// MARK: - Widget Definition

// MARK: - Family Dispatcher

struct LockScreenWidgetEntryView: View {
    @Environment(\.widgetFamily) var family
    let entry: LockScreenTimerEntry

    var body: some View {
        switch family {
        case .accessoryInline:
            LockScreenInlineView(entry: entry)
        case .accessoryCircular:
            LockScreenCircularView(entry: entry)
        case .accessoryRectangular:
            LockScreenRectangularView(entry: entry)
        default:
            LockScreenRectangularView(entry: entry)
        }
    }
}

// MARK: - Widget Definition

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

    var body: some WidgetConfiguration {
        AppIntentConfiguration(
            kind: kind,
            intent: LockScreenTimerIntent.self,
            provider: LockScreenTimerProvider()
        ) { entry in
            LockScreenWidgetEntryView(entry: entry)
                .containerBackground(for: .widget) { }
        }
        .configurationDisplayName("Timer Countdown")
        .description("Shows next timer countdown on your lock screen")
        .supportedFamilies([
            .accessoryInline,
            .accessoryCircular,
            .accessoryRectangular,
        ])
    }
}