import Foundation
import Capacitor
import PushKit
import CallKit
import AVFoundation
import LiveKitClient // the CocoaPod is 'LiveKitClient' (no module_name), so the Swift module is LiveKitClient — NOT LiveKit

// Native calling for Biz Connect (iOS). Registered by `cap sync` as window.Capacitor.Plugins.NativeCall.
//
// ARCHITECTURE (native media):
//   * PushKit: registers for VoIP pushes, reports the VoIP token to JS (-> /api/v1/devices 'ios-voip').
//   * CallKit: incoming VoIP push -> full-screen system ring (works when force-killed). The CallKit call
//     stays ACTIVE for the whole call (that's what foregrounds/unlocks the app on answer and keeps the call
//     alive in the background).
//   * LiveKit: the call MEDIA runs NATIVELY via the LiveKit iOS SDK — so the mic works with an active CallKit
//     call (WebKit's WebRTC could not) and audio survives backgrounding. The VoIP payload carries the
//     LiveKit url+token so we can connect immediately on answer, even from a killed state; outgoing calls get
//     the token from the WebView via reportOutgoingCall(). The WebView is UI only for native calls (it must
//     NOT also join the room — LiveKit allows one connection per identity).
@objc(NativeCallPlugin)
public class NativeCallPlugin: CAPPlugin, CAPBridgedPlugin, PKPushRegistryDelegate, CXProviderDelegate {
    public let identifier = "NativeCallPlugin"
    public let jsName = "NativeCall"
    public let pluginMethods: [CAPPluginMethod] = [
        CAPPluginMethod(name: "getToken", returnType: CAPPluginReturnPromise),
        CAPPluginMethod(name: "reportOutgoingCall", returnType: CAPPluginReturnPromise),
        CAPPluginMethod(name: "setMuted", returnType: CAPPluginReturnPromise),
        CAPPluginMethod(name: "endCall", returnType: CAPPluginReturnPromise)
    ]

    private var pushRegistry: PKPushRegistry?
    private var provider: CXProvider?
    private let callController = CXCallController()
    private var voipToken: String = ""
    // callUUID -> the call's data (room, kind, callerId, livekitUrl, livekitToken, …).
    private var calls: [UUID: [String: Any]] = [:]
    // Calls we've already ended locally — so a LATE cancel push doesn't re-report (which briefly re-rang).
    private var endedCalls = Set<UUID>()
    private var room: Room?
    private var activeUUID: UUID?

    override public func load() {
        let config = CXProviderConfiguration(localizedName: "Biz Connect")
        config.supportsVideo = true
        config.maximumCallGroups = 1
        config.maximumCallsPerCallGroup = 1
        config.supportedHandleTypes = [.generic]
        let p = CXProvider(configuration: config)
        p.setDelegate(self, queue: nil)
        provider = p

        let registry = PKPushRegistry(queue: .main)
        registry.delegate = self
        registry.desiredPushTypes = [.voIP]
        pushRegistry = registry
    }

    // MARK: - LiveKit media

    private func connectRoom(url: String, token: String) {
        guard !url.isEmpty, !token.isEmpty else { return }
        let old = room
        let r = Room()
        room = r
        Task { [weak self] in
            await old?.disconnect() // drop any previous/stale connection so we never leave DUPLICATE participants
            do {
                try await r.connect(url: url, token: token)
                try await r.localParticipant.setMicrophone(enabled: true)
                self?.notifyListeners("callConnected", data: ["ok": true])
            } catch {
                self?.notifyListeners("callError", data: ["error": String(describing: error)])
            }
        }
    }

    private func disconnectRoom() {
        let r = room
        room = nil
        Task { await r?.disconnect() }
    }

    // MARK: - JS-callable methods

    @objc func getToken(_ call: CAPPluginCall) { call.resolve(["token": voipToken]) }

    // Outgoing call from the web app: start a CallKit outgoing call AND connect the LiveKit room natively.
    @objc func reportOutgoingCall(_ call: CAPPluginCall) {
        guard let uuidStr = call.getString("callUUID"), let uuid = UUID(uuidString: uuidStr) else {
            call.reject("callUUID required"); return
        }
        let url = call.getString("url") ?? ""
        let token = call.getString("token") ?? ""
        let video = call.getBool("hasVideo") ?? false
        calls[uuid] = ["room": call.getString("room") ?? "", "kind": call.getString("kind") ?? "dm",
                       "livekitUrl": url, "livekitToken": token]
        activeUUID = uuid
        let handle = CXHandle(type: .generic, value: call.getString("peerName") ?? "Call")
        let start = CXStartCallAction(call: uuid, handle: handle)
        start.isVideo = video
        callController.request(CXTransaction(action: start)) { [weak self] error in
            if let error = error { call.reject(error.localizedDescription); return }
            self?.connectRoom(url: url, token: token)
            self?.provider?.reportOutgoingCall(with: uuid, connectedAt: Date())
            call.resolve()
        }
    }

    @objc func setMuted(_ call: CAPPluginCall) {
        let muted = call.getBool("muted") ?? false
        let r = room
        Task { try? await r?.localParticipant.setMicrophone(enabled: !muted) }
        call.resolve()
    }

    // End the CallKit call (remote hung up / user ended from the web UI). No callUUID -> end all.
    @objc func endCall(_ call: CAPPluginCall) {
        if let uuidStr = call.getString("callUUID"), let uuid = UUID(uuidString: uuidStr) {
            requestEnd(uuid)
        } else {
            for uuid in calls.keys { requestEnd(uuid) }
            if let a = activeUUID { requestEnd(a) }
        }
        call.resolve()
    }

    private func requestEnd(_ uuid: UUID) {
        callController.request(CXTransaction(action: CXEndCallAction(call: uuid))) { _ in }
        calls.removeValue(forKey: uuid)
        endedCalls.insert(uuid)
    }

    // MARK: - PushKit (VoIP)

    public func pushRegistry(_ registry: PKPushRegistry, didUpdate pushCredentials: PKPushCredentials, for type: PKPushType) {
        let token = pushCredentials.token.map { String(format: "%02x", $0) }.joined()
        voipToken = token
        notifyListeners("voipToken", data: ["token": token])
    }

    public func pushRegistry(_ registry: PKPushRegistry, didInvalidatePushTokenFor type: PKPushType) {
        voipToken = ""
    }

    // Incoming VoIP push. iOS 13+: we MUST reportNewIncomingCall for EVERY push before completion(), or the
    // app is terminated.
    public func pushRegistry(_ registry: PKPushRegistry, didReceiveIncomingPushWith payload: PKPushPayload, for type: PKPushType, completion: @escaping () -> Void) {
        var dict: [String: Any] = [:]
        for (k, v) in payload.dictionaryPayload { if let ks = k as? String { dict[ks] = v } }
        let uuid = UUID(uuidString: (dict["callUUID"] as? String) ?? "") ?? UUID()

        // CANCEL: caller hung up / declined / timed out before answer. Still must report (or crash), so
        // report then immediately end. If already reported the report errors (no re-ring); if relaunched it
        // blips once then ends.
        if (dict["type"] as? String) == "cancel" {
            let u = CXCallUpdate()
            u.remoteHandle = CXHandle(type: .generic, value: (dict["callerName"] as? String) ?? "Call")
            calls.removeValue(forKey: uuid)
            endedCalls.insert(uuid)
            provider?.reportNewIncomingCall(with: uuid, update: u) { [weak self] _ in
                self?.provider?.reportCall(with: uuid, endedAt: Date(), reason: .remoteEnded)
                completion()
            }
            return
        }

        let callerName = (dict["callerName"] as? String) ?? (dict["groupName"] as? String) ?? "Incoming call"
        let hasVideo = (dict["hasVideo"] as? Bool) ?? false
        calls[uuid] = dict

        let update = CXCallUpdate()
        update.remoteHandle = CXHandle(type: .generic, value: callerName)
        update.localizedCallerName = callerName
        update.hasVideo = hasVideo
        update.supportsHolding = false
        update.supportsGrouping = false
        update.supportsUngrouping = false

        provider?.reportNewIncomingCall(with: uuid, update: update) { _ in completion() }
    }

    // MARK: - CXProviderDelegate

    public func providerDidReset(_ provider: CXProvider) {
        disconnectRoom()
        calls.removeAll(); endedCalls.removeAll(); activeUUID = nil
    }

    public func provider(_ provider: CXProvider, perform action: CXAnswerCallAction) {
        let uuid = action.callUUID
        let data = calls[uuid] ?? [:]
        activeUUID = uuid
        action.fulfill()
        // Keep the CallKit call ACTIVE (foregrounds the app + keeps the call alive). Connect the LiveKit room
        // NATIVELY so the mic works with the active CallKit call and audio survives backgrounding.
        connectRoom(url: (data["livekitUrl"] as? String) ?? "", token: (data["livekitToken"] as? String) ?? "")
        var ev = data; ev["callUUID"] = uuid.uuidString
        // Answering from a KILLED/locked state launches the app — the WebView's JS listener may not be attached
        // yet, so retain the event until it is. Without this the "answered" signal is lost, the server's
        // unanswered timer fires, and the call is cancelled ~40s after pickup.
        notifyListeners("answerCall", data: ev, retainUntilConsumed: true)
    }

    public func provider(_ provider: CXProvider, perform action: CXEndCallAction) {
        var data: [String: Any] = calls[action.callUUID] ?? [:]
        data["callUUID"] = action.callUUID.uuidString
        disconnectRoom()
        notifyListeners("endCall", data: data)
        calls.removeValue(forKey: action.callUUID)
        endedCalls.insert(action.callUUID)
        if activeUUID == action.callUUID { activeUUID = nil }
        action.fulfill()
    }

    public func provider(_ provider: CXProvider, perform action: CXStartCallAction) {
        provider.reportOutgoingCall(with: action.callUUID, startedConnectingAt: Date())
        action.fulfill()
    }

    public func provider(_ provider: CXProvider, perform action: CXSetMutedCallAction) {
        let r = room
        Task { try? await r?.localParticipant.setMicrophone(enabled: !action.isMuted) }
        notifyListeners("setMuted", data: ["callUUID": action.callUUID.uuidString, "muted": action.isMuted])
        action.fulfill()
    }

    // LiveKit's AudioManager manages the AVAudioSession by default and coordinates with CallKit; we just
    // report the state to JS. (If the mic proves flaky, this is where we'd add manual AudioManager
    // engine-availability coordination.)
    public func provider(_ provider: CXProvider, didActivate audioSession: AVAudioSession) {
        notifyListeners("audioActivated", data: ["ok": true])
    }
    public func provider(_ provider: CXProvider, didDeactivate audioSession: AVAudioSession) {
        notifyListeners("audioDeactivated", data: ["ok": true])
    }
}