BizGaze_Remote/mobile/plugins/audio-route/ios/Sources/AudioRoutePlugin/AudioRoutePlugin.swift

import Foundation
import Capacitor
import AVFoundation

// Earpiece <-> speaker toggle for calls. Registered by cap sync as a real Capacitor plugin package, so it
// shows up as window.Capacitor.Plugins.AudioRoute (an app-embedded class gets stripped in release builds).
//
// STATE OF THE INVESTIGATION (from device telemetry):
//  * In a WKWebView the app does NOT own the AVAudioSession; WebKit's media process re-pins it while WebRTC
//    capture is active. overrideOutputAudioPort is a *transient* override (Apple QA1754) that any route/category
//    change resets, so we must re-assert on AVAudioSession.routeChangeNotification (debounced, mismatch-only, capped).
//  * For earpiece, override(.none) reverts to the mode default — the RECEIVER only if the mode is .voiceChat.
//    .videoChat implies .defaultToSpeaker => the default is the loudspeaker. So we pin .voiceChat before .none.
//  * OPEN QUESTION this build answers: telemetry showed mode already == .voiceChat when earpiece still landed on
//    Speaker, AND setSpeaker read the route SYNCHRONOUSLY right after the override (which can be stale). So this
//    build adds a reliable SETTLED probe: it re-reads the actual output port + mode at +0.4s and +1.2s after each
//    toggle, and stamps the live mode into every route-change log line. That tells us definitively whether WebKit
//    flips to .videoChat and where the route truly settles — i.e. whether the mode re-pin works or we've hit the
//    documented WKWebView ceiling (earpiece not reliably forceable on video calls).
@objc(AudioRoutePlugin)
public class AudioRoutePlugin: CAPPlugin, CAPBridgedPlugin {
    public let identifier = "AudioRoutePlugin"
    public let jsName = "AudioRoute"
    public let pluginMethods: [CAPPluginMethod] = [
        CAPPluginMethod(name: "setSpeaker", returnType: CAPPluginReturnPromise)
    ]

    // Bump on every native change so telemetry identifies the running binary unambiguously.
    private static let nativeTag = "1.0.5-settle"

    private var wantSpeaker = false          // desired output; source of truth, re-applied on route changes
    private var pending: DispatchWorkItem?   // debounced re-assert
    private var asserts = 0                   // re-assert count this toggle (capped, anti-thrash)
    private var routeLog: [String] = []       // reason->port/mode trail, returned to JS for diagnosis

    private let accessoryPorts: [AVAudioSession.Port] = [
        .bluetoothHFP, .bluetoothA2DP, .bluetoothLE, .headphones, .headsetMic, .usbAudio, .carAudio, .airPlay
    ]

    override public func load() {
        let session = AVAudioSession.sharedInstance()
        try? session.setCategory(.playAndRecord, mode: .voiceChat, options: [.allowBluetooth, .allowBluetoothA2DP])
        try? session.setActive(true)
        NotificationCenter.default.addObserver(self, selector: #selector(routeChanged(_:)),
                                               name: AVAudioSession.routeChangeNotification, object: nil)
    }

    deinit { NotificationCenter.default.removeObserver(self) }

    private func reasonName(_ r: UInt) -> String {
        switch r {
        case 1: return "newDev"; case 2: return "oldDev"; case 3: return "catChg"
        case 4: return "override"; case 6: return "wake"; case 7: return "noRoute"
        case 8: return "cfgChg"; default: return "unknown"
        }
    }

    private func modeShort(_ m: AVAudioSession.Mode) -> String {
        if m == .voiceChat { return "vc" }
        if m == .videoChat { return "vid" }
        if m == .default { return "def" }
        return "oth"
    }

    // Actual output port(s) + live mode — the ground-truth snapshot.
    private func snap() -> String {
        let s = AVAudioSession.sharedInstance()
        let outs = s.currentRoute.outputs.map { $0.portType.rawValue }
        return (outs.isEmpty ? "(none)" : outs.joined(separator: "+")) + "/" + modeShort(s.mode)
    }

    private func log(_ s: String) {
        routeLog.append(s)
        if routeLog.count > 18 { routeLog.removeFirst(routeLog.count - 18) }
    }

    @objc private func routeChanged(_ note: Notification) {
        let raw = (note.userInfo?[AVAudioSessionRouteChangeReasonKey] as? UInt) ?? 0
        log("\(reasonName(raw))>\(snap())")
        pending?.cancel()
        let work = DispatchWorkItem { [weak self] in self?.applyRoute() }
        pending = work
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.25, execute: work)
    }

    private func applyRoute() {
        guard asserts < 6 else { log("cap"); return }
        let s = AVAudioSession.sharedInstance()
        let outs = s.currentRoute.outputs
        let onSpeaker = outs.contains { $0.portType == .builtInSpeaker }
        let onAccessory = outs.contains { accessoryPorts.contains($0.portType) }
        if onAccessory && !wantSpeaker { log("skipAcc"); return }
        do {
            if wantSpeaker {
                if !onSpeaker { asserts += 1; try s.overrideOutputAudioPort(.speaker); log("assert>spk") }
            } else if onSpeaker {
                asserts += 1
                // .none reverts to the mode default; make that the RECEIVER by pinning .voiceChat first.
                if s.category != .playAndRecord {
                    try s.setCategory(.playAndRecord, mode: .voiceChat, options: [.allowBluetooth, .allowBluetoothA2DP])
                    log("repinCat")
                } else if s.mode != .voiceChat {
                    try s.setMode(.voiceChat); log("repinMode")
                }
                try s.overrideOutputAudioPort(.none)
                log("assert>rcv:\(snap())")
            }
        } catch { log("assertErr") }
    }

    // Re-read the SETTLED route a beat after the override, since the immediate read can be stale.
    private func scheduleSettleProbe() {
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.4) { [weak self] in self?.log("s4>\(self?.snap() ?? "")") }
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.2) { [weak self] in self?.log("s12>\(self?.snap() ?? "")") }
    }

    private func diag(_ applied: String) -> [String: Any] {
        let s = AVAudioSession.sharedInstance()
        return [
            "route": applied,
            "native": AudioRoutePlugin.nativeTag,
            "outputs": snap(),
            "category": s.category.rawValue,
            "opts": Int(s.categoryOptions.rawValue),
            "log": routeLog.joined(separator: ",")   // trail (incl. settled probes) since the previous toggle
        ]
    }

    @objc func setSpeaker(_ call: CAPPluginCall) {
        wantSpeaker = call.getBool("on") ?? true
        asserts = 0
        let s = AVAudioSession.sharedInstance()
        do {
            if !wantSpeaker && s.category == .playAndRecord && s.mode != .voiceChat {
                try s.setMode(.voiceChat)
            }
            try s.overrideOutputAudioPort(wantSpeaker ? .speaker : .none)
            scheduleSettleProbe()                     // settled reads land in the NEXT toggle's trail
            let out = diag(wantSpeaker ? "speaker" : "earpiece")
            routeLog.removeAll()
            call.resolve(out)
        } catch {
            call.reject(error.localizedDescription)
        }
    }
}