// ── Watch Timer Store ─────────────────────────────────────────
// Reads timer data from App Group shared by the iOS app
// Lightweight store for watchOS — read-only from shared data + local quick timers

import Foundation
import Combine
import WatchKit
import os

@MainActor
final class WatchTimerStore: ObservableObject {
    // MARK: - Published State

    @Published var timers: [TimerSnapshot] = []
    @Published var now: Date = Date()

    // MARK: - Private

    private var tickTimer: Timer?
    private var updateObserver: Any?
    private let sharedData = SharedTimerDataManager.shared
    private let notificationHandler = WatchNotificationHandler.shared
    private let logger = Logger(subsystem: "com.chronomind.watch", category: "WatchTimerStore")

    // Track which warnings we already fired haptics for
    private var firedWarningKeys: Set<String> = []

    // MARK: - Init

    init() {
        loadFromSharedData()
        startTicking()
        notificationHandler.requestAuthorization()

        // Activate WCSession
        WatchSessionManager.shared.activate()

        // Listen for real-time updates from iPhone
        updateObserver = NotificationCenter.default.addObserver(
            forName: .watchTimerDataUpdated,
            object: nil,
            queue: .main
        ) { [weak self] _ in
            Task { @MainActor in
                self?.loadFromSharedData()
            }
        }
    }

    deinit {
        tickTimer?.invalidate()
        if let observer = updateObserver {
            NotificationCenter.default.removeObserver(observer)
        }
    }

    // MARK: - Data Loading

    func loadFromSharedData() {
        let newTimers = sharedData.readActiveSnapshots()

        // Schedule notifications for any new timers
        for timer in newTimers where !timers.contains(where: { $0.id == timer.id }) {
            notificationHandler.scheduleTimerNotification(
                id: timer.id,
                label: timer.label,
                targetTime: timer.targetTime,
                urgency: timer.urgency
            )
        }

        timers = newTimers
    }

    // MARK: - Queries

    var nextFiringTimer: TimerSnapshot? {
        timers
            .filter { [.active, .warning].contains($0.state) }
            .sorted { $0.targetTime < $1.targetTime }
            .first
    }

    var activeTimers: [TimerSnapshot] {
        timers.filter { [.active, .warning, .snoozed, .firing].contains($0.state) }
    }

    // MARK: - Commands (via WCSession)

    func sendCommand(_ command: WatchTimerCommand) {
        WatchSessionManager.shared.sendCommand(command)

        // Refresh after a short delay to pick up state changes
        Task {
            try? await Task.sleep(for: .milliseconds(500))
            loadFromSharedData()
        }
    }

    // MARK: - Quick Timer Creation (writes to App Group)

    func createQuickTimer(minutes: Int, label: String) {
        let now = Date()
        let targetTime = now.addingTimeInterval(TimeInterval(minutes * 60))
        let intervals = CascadePreset.minimal.defaultIntervals

        let snapshot = TimerSnapshot(
            id: UUID().uuidString,
            label: label,
            type: .countdown,
            urgency: .standard,
            state: .active,
            targetTime: targetTime,
            duration: TimeInterval(minutes * 60),
            startedAt: now,
            elapsedBeforePause: 0,
            snoozeCount: 0,
            category: nil,
            pomodoroCurrentRound: nil,
            pomodoroTotalRounds: nil,
            pomodoroIsBreak: nil,
            nextWarningTime: intervals.first.map { targetTime.addingTimeInterval(-Double($0) * 60) },
            totalWarnings: intervals.count,
            firedWarnings: 0
        )

        // Add to local list and persist
        timers.append(snapshot)
        timers.sort { $0.targetTime < $1.targetTime }

        // Write back to shared data so iOS app picks it up
        sharedData.writeSnapshots(timers)

        // Schedule notification
        notificationHandler.scheduleTimerNotification(
            id: snapshot.id,
            label: label,
            targetTime: targetTime,
            urgency: .standard
        )

        // Haptic confirmation
        WKInterfaceDevice.current().play(.success)
        logger.info("Created quick timer: \(label) for \(minutes)m")
    }

    // MARK: - Tick

    private func startTicking() {
        tickTimer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
            Task { @MainActor in
                self?.tick()
            }
        }
    }

    private func tick() {
        now = Date()

        // Refresh from shared data every 30 seconds
        let interval = Int(now.timeIntervalSince1970) % 30
        if interval == 0 {
            loadFromSharedData()
        }

        // Check for warnings and fired timers
        var changed = false
        for i in timers.indices {
            let timer = timers[i]

            // Check cascade warnings
            if let nextWarning = timer.nextWarningTime,
               now >= nextWarning,
               timer.state == .active || timer.state == .warning {
                let warningKey = "\(timer.id)-\(Int(nextWarning.timeIntervalSince1970))"
                if !firedWarningKeys.contains(warningKey) {
                    firedWarningKeys.insert(warningKey)
                    playWarningHaptic(urgency: timer.urgency)
                    logger.info("Warning fired for timer \(timer.label)")
                    changed = true
                }
            }

            // Check for fired timers
            if timer.state == .active || timer.state == .warning {
                if now >= timer.targetTime {
                    playFiredHaptic(urgency: timer.urgency)
                    logger.info("Timer fired: \(timer.label)")
                    changed = true
                }
            }
        }

        if changed {
            loadFromSharedData()
        }
    }

    // MARK: - Haptics

    private func playWarningHaptic(urgency: UrgencyLevel) {
        switch urgency {
        case .critical:
            // Triple haptic for critical
            WKInterfaceDevice.current().play(.notification)
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
                WKInterfaceDevice.current().play(.notification)
            }
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.6) {
                WKInterfaceDevice.current().play(.notification)
            }
        case .important:
            WKInterfaceDevice.current().play(.notification)
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
                WKInterfaceDevice.current().play(.notification)
            }
        case .standard, .gentle:
            WKInterfaceDevice.current().play(.notification)
        case .passive:
            WKInterfaceDevice.current().play(.click)
        }
    }

    private func playFiredHaptic(urgency: UrgencyLevel) {
        switch urgency {
        case .critical:
            WKInterfaceDevice.current().play(.notification)
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
                WKInterfaceDevice.current().play(.notification)
            }
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.6) {
                WKInterfaceDevice.current().play(.notification)
            }
        default:
            WKInterfaceDevice.current().play(.notification)
        }
    }
}