import Foundation
import Capacitor
import PushKit
import CallKit
import AVFoundation

// Native calling for Biz Connect (iOS). Registered by `cap sync` as a real Capacitor plugin, so it is
// available to the remote web UI as window.Capacitor.Plugins.NativeCall.
//
// WHAT IT DOES
//   * PushKit: registers for VoIP pushes and reports the VoIP token to JS -> POST /api/v1/devices ('ios-voip').
//   * CallKit: on an incoming VoIP push it reports a system call (full-screen ring, works when the app is
//     force-killed). Answer/decline/end come back to JS as events so the web app joins/leaves the LiveKit room.
//   * Outgoing: the web app calls reportOutgoingCall() when the user places a call, so THAT call is also a
//     CallKit call — which is what grants the app the active-call background-audio context.
//   * Audio: CallKit owns the AVAudioSession for the call; we configure it for voice on didActivate so the
//     WebRTC audio (still driven by the WebView) rides on a call-priority session that survives backgrounding.
//
// CANCELLATION: we deliberately do NOT send "cancel" VoIP pushes (iOS requires a reported call for EVERY
// VoIP push). Instead the app is already awake after the invite push, so a caller hang-up arrives over the
// normal chat WebSocket and the web app calls endCall() to dismiss the CallKit ring.
@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: "callConnected", 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, …) so answer/end can hand it back to JS.
    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>()

    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: - JS-callable methods

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

    // The web app places an outgoing call -> register it with CallKit so the system knows a call is active
    // (grants background-audio execution) and the OS call UI is consistent.
    @objc func reportOutgoingCall(_ call: CAPPluginCall) {
        guard let uuidStr = call.getString("callUUID"), let uuid = UUID(uuidString: uuidStr) else {
            call.reject("callUUID required"); return
        }
        let handle = CXHandle(type: .generic, value: call.getString("peerName") ?? "Call")
        let start = CXStartCallAction(call: uuid, handle: handle)
        start.isVideo = call.getBool("hasVideo") ?? false
        var data: [String: Any] = [:]
        data["room"] = call.getString("room") ?? ""
        data["kind"] = call.getString("kind") ?? "dm"
        calls[uuid] = data
        callController.request(CXTransaction(action: start)) { error in
            if let error = error { call.reject(error.localizedDescription) } else { call.resolve() }
        }
    }

    // Media connected -> start the CallKit timer.
    @objc func callConnected(_ call: CAPPluginCall) {
        if let uuidStr = call.getString("callUUID"), let uuid = UUID(uuidString: uuidStr) {
            provider?.reportOutgoingCall(with: uuid, connectedAt: Date())
        }
        call.resolve()
    }

    // End a CallKit call (remote hung up / user ended from the web UI / decline echo). 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) }
        }
        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 report a call to CallKit before completion() or the app is killed.
    public func pushRegistry(_ registry: PKPushRegistry, didReceiveIncomingPushWith payload: PKPushPayload, for type: PKPushType, completion: @escaping () -> Void) {
        // payload.dictionaryPayload is [AnyHashable: Any]; normalise to [String: Any] for CallKit + notifyListeners.
        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: the caller hung up / declined / it timed out before we answered → stop ringing. iOS still
        // requires a reported call for every VoIP push, so if we never saw the invite, report then end it.
        if (dict["type"] as? String) == "cancel" {
            if calls[uuid] != nil {
                provider?.reportCall(with: uuid, endedAt: Date(), reason: .remoteEnded)
                calls.removeValue(forKey: uuid)
                endedCalls.insert(uuid)
                completion()
            } else if endedCalls.contains(uuid) {
                // Already ended locally (we declined/hung up) — do NOT re-report; that caused the ~1s re-ring.
                completion()
            } else {
                // Never saw the invite — iOS still requires a reported call for this push, so report then end.
                let u = CXCallUpdate()
                u.remoteHandle = CXHandle(type: .generic, value: "Call")
                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) {
        calls.removeAll()
        endedCalls.removeAll()
    }

    public func provider(_ provider: CXProvider, perform action: CXAnswerCallAction) {
        var data: [String: Any] = calls[action.callUUID] ?? [:]
        data["callUUID"] = action.callUUID.uuidString
        notifyListeners("answerCall", data: data)
        action.fulfill()
    }

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

    // CallKit hands us the call audio session; configure it for a voice call. The WebView's WebRTC audio
    // uses this session, and because it's a CallKit call the app keeps running in the background.
    public func provider(_ provider: CXProvider, didActivate audioSession: AVAudioSession) {
        try? audioSession.setCategory(.playAndRecord, mode: .voiceChat, options: [.allowBluetooth, .allowBluetoothA2DP])
        try? audioSession.setActive(true)
        notifyListeners("audioActivated", data: ["ok": true])
    }

    public func provider(_ provider: CXProvider, didDeactivate audioSession: AVAudioSession) {
        notifyListeners("audioDeactivated", data: ["ok": true])
    }
}