import Foundation
import UIKit
import Capacitor
import PushKit
import CallKit
import AVFoundation
import LiveKit // SPM product name is 'LiveKit' (Package.swift). (The old CocoaPods module was 'LiveKitClient'.)

// 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: "reportIncomingCall", returnType: CAPPluginReturnPromise),
        CAPPluginMethod(name: "setMuted", returnType: CAPPluginReturnPromise),
        CAPPluginMethod(name: "setCamera", returnType: CAPPluginReturnPromise),
        CAPPluginMethod(name: "syncVideoTiles", 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?
    // Native video: one native VideoView per visible participant (key "__local" or the remote user id),
    // drawn over the WebView and positioned to match the web meeting tiles (see syncVideoTiles). VideoView is
    // a UIKit view — only ever touched on the main thread.
    private var tileViews: [String: VideoView] = [:]

    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
        // CallKit audio coordination (LiveKit 2.15+, pinned to the git tag in ios-patch.sh). LiveKit's automatic
        // AVAudioSession config RACES CallKit's own activation → intermittent dead mic / no audio + the output
        // route only settling once audio flows ("speaker turns on late"). Fix: turn auto-config OFF and keep the
        // engine OFF; we configure the session and enable the engine ONLY in didActivate.
        AudioManager.shared.audioSession.isAutomaticConfigurationEnabled = false
        try? AudioManager.shared.setEngineAvailability(.none)

        // Re-assert the LOUDSPEAKER whenever iOS routes call audio back to the quiet earpiece. The LiveKit
        // audio engine starting up right after CallKit activates the session flips the route to the built-in
        // receiver — that's the "sound is on the earpiece until I tap something" bug (tapping mic/cam re-ran
        // preferSpeaker and fixed it). Listening for route changes makes that self-healing.
        NotificationCenter.default.addObserver(self, selector: #selector(audioRouteChanged(_:)),
                                               name: AVAudioSession.routeChangeNotification, object: nil)
    }

    @objc private func audioRouteChanged(_ note: Notification) {
        guard room != nil else { return } // only steer the route during an active native call
        // Let the engine's own route change settle first, then override if we landed on the earpiece.
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.15) { [weak self] in self?.preferSpeaker() }
    }

    // MARK: - LiveKit media

    private func connectRoom(url: String, token: String) {
        guard !url.isEmpty, !token.isEmpty else { return }
        // Ask for mic permission now (we still connect MUTED). If it stays "undetermined", enabling the audio
        // engine in didActivate can block on first use — determining it up front avoids that.
        AVAudioSession.sharedInstance().requestRecordPermission { _ in }
        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)
                // House rule: answer MUTED. Not enabling the mic here means nothing is captured/published
                // until the user taps Mic in the meeting UI (→ setMuted(false) → setMicrophone(true)), which
                // is also when iOS asks for mic permission. Playback (hearing others) is unaffected.
                try await r.localParticipant.setMicrophone(enabled: false)
                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() }
        removeAllTileViews()
    }

    // MARK: - Native video (tile rendering, Increment 2b)
    //
    // The WebView owns the meeting UI (grid, roster, controls) but — for a native call — has NO LiveKit
    // connection, so it can't render any video. The video lives only in the plugin's LiveKit connection.
    // So we draw native VideoViews on top of the WebView, positioned to match each web tile: the web reports
    // each tile's on-screen rect + the participant's user id (syncVideoTiles), and we place/size a VideoView
    // for whichever participants currently have a live camera track. Views are subviews of the WKWebView, so
    // their frames use the SAME coordinate space as getBoundingClientRect (CSS px == points, both
    // viewport-relative) and stay aligned as the page scrolls.

    // Find the live (unmuted, subscribed) camera track for a user id — nil when the camera is off, so the web
    // tile's avatar shows through instead.
    private func cameraTrack(forUid uid: String, isLocal: Bool) -> VideoTrack? {
        guard let room = room else { return nil }
        let pubs: [TrackPublication]
        if isLocal {
            pubs = room.localParticipant.videoTracks
        } else {
            guard let p = room.remoteParticipants[Participant.Identity(from: uid)] else { return nil }
            pubs = p.videoTracks
        }
        guard let pub = pubs.first(where: { $0.source == .camera && !$0.isMuted && $0.track != nil }) else { return nil }
        return pub.track as? VideoTrack
    }

    private func tileKey(uid: String, isLocal: Bool) -> String { isLocal ? "__local" : uid }

    private func removeAllTileViews() {
        DispatchQueue.main.async { [weak self] in
            guard let self = self else { return }
            for (_, vv) in self.tileViews { vv.removeFromSuperview() }
            self.tileViews.removeAll()
        }
    }

    // Tags for the overlay subviews we add to each tile's VideoView (name label + mute badge).
    private static let nameTag = 9001
    private static let muteTag = 9002

    // Build a tile VideoView with its native name label (bottom-left) + mute badge (bottom-right) — the video
    // covers the web tile, so these redraw the essentials the web can no longer show through.
    private func makeTileView(host: UIView, key: String) -> VideoView {
        let v = VideoView()
        v.layoutMode = .fill
        v.backgroundColor = .black
        v.clipsToBounds = true
        v.layer.cornerRadius = 8
        host.addSubview(v)

        let label = UILabel()
        label.tag = NativeCallPlugin.nameTag
        label.font = .systemFont(ofSize: 12, weight: .semibold)
        label.textColor = .white
        label.shadowColor = UIColor.black.withAlphaComponent(0.9)   // legible over any video
        label.shadowOffset = CGSize(width: 0, height: 1)
        label.translatesAutoresizingMaskIntoConstraints = false
        v.addSubview(label)

        let badge = UIImageView(image: UIImage(systemName: "mic.slash.fill"))
        badge.tag = NativeCallPlugin.muteTag
        badge.tintColor = .white
        badge.contentMode = .center
        badge.backgroundColor = UIColor.black.withAlphaComponent(0.55)
        badge.layer.cornerRadius = 9
        badge.clipsToBounds = true
        badge.translatesAutoresizingMaskIntoConstraints = false
        v.addSubview(badge)

        NSLayoutConstraint.activate([
            label.leadingAnchor.constraint(equalTo: v.leadingAnchor, constant: 6),
            label.bottomAnchor.constraint(equalTo: v.bottomAnchor, constant: -5),
            label.trailingAnchor.constraint(lessThanOrEqualTo: badge.leadingAnchor, constant: -4),
            badge.trailingAnchor.constraint(equalTo: v.trailingAnchor, constant: -6),
            badge.bottomAnchor.constraint(equalTo: v.bottomAnchor, constant: -5),
            badge.widthAnchor.constraint(equalToConstant: 18),
            badge.heightAnchor.constraint(equalToConstant: 18),
        ])
        tileViews[key] = v
        return v
    }

    private func updateTileOverlay(_ vv: VideoView, name: String, muted: Bool) {
        // Keep the overlays above the video renderer (VideoView adds its renderer when the track is set).
        if let label = vv.viewWithTag(NativeCallPlugin.nameTag) as? UILabel {
            label.text = name; label.isHidden = name.isEmpty; vv.bringSubviewToFront(label)
        }
        if let badge = vv.viewWithTag(NativeCallPlugin.muteTag) {
            badge.isHidden = !muted; vv.bringSubviewToFront(badge)
        }
    }

    // Route call audio to the LOUDSPEAKER when we'd otherwise be on the quiet earpiece. Guarded so a connected
    // wired/Bluetooth headset (any non-receiver route) still wins. Re-asserted on mute toggles because enabling
    // the mic can flip the route back to the earpiece.
    private func preferSpeaker() {
        let s = AVAudioSession.sharedInstance()
        if s.currentRoute.outputs.contains(where: { $0.portType == .builtInReceiver }) {
            try? s.overrideOutputAudioPort(.speaker)
        }
    }

    // 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)
            // Start muted (house rule) — also reflect it on the CallKit system call screen.
            self?.callController.request(CXTransaction(action: CXSetMutedCallAction(call: uuid, muted: true))) { _ in }
            self?.provider?.reportOutgoingCall(with: uuid, connectedAt: Date())
            call.resolve()
        }
    }

    // Ring CallKit from a WEBSOCKET call event (a 2nd path alongside the VoIP push). When the app is open the
    // WS is connected and reliable, but the VoIP push can be delayed/dropped → "sometimes it doesn't ring".
    // Deduped by UUID: if the VoIP push already reported this call, this is a no-op (and vice-versa).
    @objc func reportIncomingCall(_ call: CAPPluginCall) {
        guard let uuidStr = call.getString("callUUID"), let uuid = UUID(uuidString: uuidStr) else {
            call.reject("callUUID required"); return
        }
        // Already handled (ended, ringing, or active) → don't re-report (CallKit would reject a dup anyway).
        if endedCalls.contains(uuid) || calls[uuid] != nil || activeUUID == uuid { call.resolve(); return }
        let callerName = call.getString("callerName") ?? call.getString("groupName") ?? "Incoming call"
        let hasVideo = call.getBool("hasVideo") ?? false
        calls[uuid] = [
            "callUUID": uuidStr, "room": call.getString("room") ?? "", "kind": call.getString("kind") ?? "dm",
            "callerId": call.getString("callerId") ?? "", "callerName": callerName,
            "groupId": call.getString("groupId") ?? "", "groupName": call.getString("groupName") ?? "",
            "hasVideo": hasVideo, "livekitUrl": call.getString("url") ?? "", "livekitToken": call.getString("token") ?? "",
        ]
        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 }
        call.resolve()
    }

    @objc func setMuted(_ call: CAPPluginCall) {
        let muted = call.getBool("muted") ?? false
        // Drive mute THROUGH CallKit so the system call screen and the in-app meeting UI stay in sync (the
        // CXSetMutedCallAction handler does the actual setMicrophone). Fall back to a direct call if somehow
        // there's no active CallKit call.
        if let uuid = activeUUID {
            callController.request(CXTransaction(action: CXSetMutedCallAction(call: uuid, muted: muted))) { _ in }
        } else {
            let r = room
            Task { try? await r?.localParticipant.setMicrophone(enabled: !muted) }
        }
        call.resolve()
    }

    // Enable/disable the local camera. Publishing it makes this user's video appear for everyone else (their
    // web/desktop clients render it via their own SFU subscription); locally it's drawn on the __local tile by
    // syncVideoTiles (the web triggers a sync right after this resolves). Front camera only for now.
    @objc func setCamera(_ call: CAPPluginCall) {
        guard let r = room else { call.reject("no active call"); return }
        let on = call.getBool("on") ?? false
        Task {
            do {
                try await r.localParticipant.setCamera(
                    enabled: on,
                    captureOptions: CameraCaptureOptions(position: .front))
                call.resolve(["on": on])
            } catch {
                call.reject("camera failed: \(String(describing: error))")
            }
        }
    }

    // Position native video views to match the web meeting tiles. `tiles` = [{uid, local, x, y, w, h}] in
    // CSS px (== points; getBoundingClientRect coords). We create/move a VideoView for each participant that
    // has a live camera track, and remove views for tiles that are gone or whose camera is off (so the web
    // avatar shows). Called on a short poll by the web while a native call is on screen, plus on demand.
    @objc func syncVideoTiles(_ call: CAPPluginCall) {
        let tiles = (call.getArray("tiles") as? [[String: Any]]) ?? []
        DispatchQueue.main.async { [weak self] in
            guard let self = self else { call.resolve(); return }
            guard let host = self.bridge?.webView else { call.resolve(); return }
            var wanted = Set<String>()
            for t in tiles {
                guard let uid = t["uid"] as? String, !uid.isEmpty else { continue }
                let isLocal = (t["local"] as? Bool) ?? false
                func num(_ k: String) -> CGFloat { CGFloat((t[k] as? NSNumber)?.doubleValue ?? 0) }
                let x = num("x"), y = num("y"), w = num("w"), h = num("h")
                if w < 2 || h < 2 { continue }
                let key = self.tileKey(uid: uid, isLocal: isLocal)
                guard let track = self.cameraTrack(forUid: uid, isLocal: isLocal) else { continue } // camera off → leave the web avatar
                wanted.insert(key)
                let vv = self.tileViews[key] ?? self.makeTileView(host: host, key: key)
                if vv.superview !== host { host.addSubview(vv) }
                if vv.track !== track { vv.track = track }
                vv.frame = CGRect(x: x, y: y, width: w, height: h)
                // Native video covers the web tile, so redraw the essentials (name + muted) natively.
                self.updateTileOverlay(vv, name: (t["name"] as? String) ?? "", muted: (t["muted"] as? Bool) ?? false)
            }
            // Drop views for participants no longer present / camera turned off.
            for (key, vv) in self.tileViews where !wanted.contains(key) {
                vv.removeFromSuperview(); self.tileViews.removeValue(forKey: key)
            }
            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. iOS requires a reported call per push, but blindly
        // reporting a NEW incoming call is what caused the "rings back for a second" blip on a call we've
        // already handled. So:
        if (dict["type"] as? String) == "cancel" {
            // iOS 13+ TERMINATES the app if a VoIP push doesn't result in reportNewIncomingCall before
            // completion() — that's the crash after several calls (my earlier "no-blip" optimization SKIPPED
            // the report for known/ended calls, which iOS kills for). So ALWAYS report, then immediately end:
            //  * uuid already ringing/active  → the report errors harmlessly (NO second ring), reportCall ends it.
            //  * late/duplicate cancel (done)  → a brief, unavoidable blip (acceptable; a crash is not).
            let u = CXCallUpdate()
            u.remoteHandle = CXHandle(type: .generic, value: (dict["callerName"] as? String) ?? "Call")
            let wasActive = (activeUUID == uuid)
            var ev = calls[uuid] ?? [:]; ev["callUUID"] = uuid.uuidString
            calls.removeValue(forKey: uuid)
            endedCalls.insert(uuid)
            if wasActive { disconnectRoom(); activeUUID = nil }
            provider?.reportNewIncomingCall(with: uuid, update: u) { [weak self] _ in
                self?.provider?.reportCall(with: uuid, endedAt: Date(), reason: .remoteEnded)
                if wasActive { self?.notifyListeners("endCall", data: ev) } // active call cancelled → leave the meeting
                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) ?? "")
        // We answer muted (house rule) — reflect that on the CallKit system call screen (the mic button there
        // showed unmuted before, even though we were functionally muted).
        callController.request(CXTransaction(action: CXSetMutedCallAction(call: uuid, muted: true))) { _ in }
        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 { [weak self] in
            try? await r?.localParticipant.setMicrophone(enabled: !action.isMuted)
            self?.preferSpeaker() // toggling the mic can flip the route back to the earpiece — re-assert speaker
        }
        notifyListeners("setMuted", data: ["callUUID": action.callUUID.uuidString, "muted": action.isMuted])
        action.fulfill()
    }

    // CallKit owns the AVAudioSession lifecycle. Since LiveKit auto-config is OFF, configure the session HERE —
    // when CallKit activates it — and enable LiveKit's audio engine. This is the fix for the intermittent
    // dead mic / no-audio and late speaker routing. Don't call setActive(true): CallKit already activated it.
    public func provider(_ provider: CXProvider, didActivate audioSession: AVAudioSession) {
        do {
            // Route to the LOUDSPEAKER by default (earpiece was the .voiceChat default). .videoChat +
            // .defaultToSpeaker prefers the speaker while still letting wired/Bluetooth headsets win.
            try audioSession.setCategory(.playAndRecord, mode: .videoChat,
                                        options: [.defaultToSpeaker, .allowBluetooth, .allowBluetoothA2DP])
            try AudioManager.shared.setEngineAvailability(.default)
            preferSpeaker() // belt-and-braces: if we still landed on the earpiece, force the speaker
            let route = audioSession.currentRoute.outputs.first?.portType.rawValue ?? "none"
            notifyListeners("audioActivated", data: ["ok": true, "route": route])
        } catch {
            notifyListeners("audioActivated", data: ["ok": false, "error": String(describing: error)])
        }
    }
    public func provider(_ provider: CXProvider, didDeactivate audioSession: AVAudioSession) {
        try? AudioManager.shared.setEngineAvailability(.none)
        notifyListeners("audioDeactivated", data: ["ok": true])
    }
}