//
//  PhoneSync.swift
//  Keging
//
//  워치 연동 (iOS 측) — 세트 구성을 워치로 보내고, 워치에서 완주한 기록을 받는다
//

import WatchConnectivity

final class PhoneSync: NSObject, WCSessionDelegate {
    static let shared = PhoneSync()

    private override init() { super.init() }

    func activate() {
        guard WCSession.isSupported() else { return }
        let session = WCSession.default
        session.delegate = self
        session.activate()
        SettingsStore.shared.onConfigChange = { [weak self] config in
            self?.pushConfig(config)
        }
    }

    func pushConfig(_ config: WorkoutConfig) {
        guard WCSession.isSupported(), WCSession.default.activationState == .activated else { return }
        guard let data = try? JSONEncoder().encode(config) else { return }
        try? WCSession.default.updateApplicationContext(["config": data])
    }

    // MARK: WCSessionDelegate

    nonisolated func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {
        guard activationState == .activated else { return }
        Task { @MainActor in
            PhoneSync.shared.pushConfig(SettingsStore.shared.config)
        }
    }

    nonisolated func sessionDidBecomeInactive(_ session: WCSession) {}

    nonisolated func sessionDidDeactivate(_ session: WCSession) {
        session.activate()
    }

    /// 워치가 닿게 되면 최신 세팅을 재푸시 — 변경 시점에 전송이 유실됐어도 여기서 복구
    nonisolated func sessionReachabilityDidChange(_ session: WCSession) {
        guard session.isReachable else { return }
        Task { @MainActor in
            PhoneSync.shared.pushConfig(SettingsStore.shared.config)
        }
    }

    /// 워치 앱이 열릴 때 보내는 세팅 요청 — 폰 앱이 꺼져 있어도 시스템이 깨워서 응답한다
    nonisolated func session(_ session: WCSession, didReceiveMessage message: [String: Any], replyHandler: @escaping ([String: Any]) -> Void) {
        guard message["request"] as? String == "config" else {
            replyHandler([:])
            return
        }
        Task { @MainActor in
            let data = (try? JSONEncoder().encode(SettingsStore.shared.config)) ?? Data()
            replyHandler(["config": data])
        }
    }

    nonisolated func session(_ session: WCSession, didReceiveUserInfo userInfo: [String: Any] = [:]) {
        guard let data = userInfo["record"] as? Data,
              let record = try? JSONDecoder().decode(SessionRecord.self, from: data) else { return }
        Task { @MainActor in
            RecordStore.shared.append(record)
        }
    }
}