auto_switch_mic.swift

import AppKit
import CoreAudio
import ServiceManagement

// MARK: - Audio Helpers

func getInputDevices() -> [(name: String, id: AudioDeviceID)] {
    var propAddr = AudioObjectPropertyAddress(
        mSelector: kAudioHardwarePropertyDevices,
        mScope: kAudioObjectPropertyScopeGlobal,
        mElement: kAudioObjectPropertyElementMain
    )
    var dataSize: UInt32 = 0
    AudioObjectGetPropertyDataSize(AudioObjectID(kAudioObjectSystemObject), &propAddr, 0, nil, &dataSize)
    let count = Int(dataSize) / MemoryLayout<AudioDeviceID>.size
    var devices = [AudioDeviceID](repeating: 0, count: count)
    AudioObjectGetPropertyData(AudioObjectID(kAudioObjectSystemObject), &propAddr, 0, nil, &dataSize, &devices)

    var result: [(String, AudioDeviceID)] = []
    for device in devices {
        // Check if device has input channels
        var streamAddr = AudioObjectPropertyAddress(
            mSelector: kAudioDevicePropertyStreams,
            mScope: kAudioObjectPropertyScopeInput,
            mElement: kAudioObjectPropertyElementMain
        )
        var streamSize: UInt32 = 0
        AudioObjectGetPropertyDataSize(device, &streamAddr, 0, nil, &streamSize)
        if streamSize == 0 { continue }

        var nameAddr = AudioObjectPropertyAddress(
            mSelector: kAudioDevicePropertyDeviceNameCFString,
            mScope: kAudioObjectPropertyScopeGlobal,
            mElement: kAudioObjectPropertyElementMain
        )
        var name: CFString = "" as CFString
        var size = UInt32(MemoryLayout<CFString>.size)
        AudioObjectGetPropertyData(device, &nameAddr, 0, nil, &size, &name)
        result.append((name as String, device))
    }
    return result
}

func getDefaultInputDevice() -> AudioDeviceID {
    var addr = AudioObjectPropertyAddress(
        mSelector: kAudioHardwarePropertyDefaultInputDevice,
        mScope: kAudioObjectPropertyScopeGlobal,
        mElement: kAudioObjectPropertyElementMain
    )
    var deviceID: AudioDeviceID = 0
    var size = UInt32(MemoryLayout<AudioDeviceID>.size)
    AudioObjectGetPropertyData(AudioObjectID(kAudioObjectSystemObject), &addr, 0, nil, &size, &deviceID)
    return deviceID
}

func getDeviceName(_ deviceID: AudioDeviceID) -> String {
    var nameAddr = AudioObjectPropertyAddress(
        mSelector: kAudioDevicePropertyDeviceNameCFString,
        mScope: kAudioObjectPropertyScopeGlobal,
        mElement: kAudioObjectPropertyElementMain
    )
    var name: CFString = "" as CFString
    var size = UInt32(MemoryLayout<CFString>.size)
    AudioObjectGetPropertyData(deviceID, &nameAddr, 0, nil, &size, &name)
    return name as String
}

// MARK: - App Delegate

class AppDelegate: NSObject, NSApplicationDelegate, NSMenuDelegate {
    private var statusItem: NSStatusItem!
    private var listListenerAddr = AudioObjectPropertyAddress(
        mSelector: kAudioHardwarePropertyDevices,
        mScope: kAudioObjectPropertyScopeGlobal,
        mElement: kAudioObjectPropertyElementMain
    )
    private var defaultInputListenerAddr = AudioObjectPropertyAddress(
        mSelector: kAudioHardwarePropertyDefaultInputDevice,
        mScope: kAudioObjectPropertyScopeGlobal,
        mElement: kAudioObjectPropertyElementMain
    )

    var targetDeviceName: String {
        get { UserDefaults.standard.string(forKey: "targetDevice") ?? "Wireless Mic Rx" }
        set {
            UserDefaults.standard.set(newValue, forKey: "targetDevice")
            switchToTarget()
        }
    }

    var isEnabled: Bool {
        get { UserDefaults.standard.object(forKey: "isEnabled") as? Bool ?? true }
        set {
            UserDefaults.standard.set(newValue, forKey: "isEnabled")
            if newValue { switchToTarget() }
            updateIcon()
        }
    }

    // MARK: - Launch at Login

    var launchAtLogin: Bool {
        SMAppService.mainApp.status == .enabled
    }

    func setLaunchAtLogin(_ enabled: Bool) {
        do {
            if enabled {
                try SMAppService.mainApp.register()
                NSLog("Login item registered")
            } else {
                try SMAppService.mainApp.unregister()
                NSLog("Login item unregistered")
            }
        } catch {
            NSLog("Failed to update login item: %@", error.localizedDescription)
        }
    }

    func applicationDidFinishLaunching(_ notification: Notification) {
        // Migrate: remove old LaunchAgent plist if present
        let oldPlist = NSHomeDirectory() + "/Library/LaunchAgents/com.auto-switch-mic.plist"
        if FileManager.default.fileExists(atPath: oldPlist) {
            try? FileManager.default.removeItem(atPath: oldPlist)
            NSLog("Migrated: removed old LaunchAgent plist")
            setLaunchAtLogin(true)
        }

        statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)

        let menu = NSMenu()
        menu.delegate = self
        statusItem.menu = menu

        setupAudioListeners()
        if isEnabled { switchToTarget() }
        updateIcon()

        NSLog("auto_switch_mic running (menu bar mode), target: %@", targetDeviceName)
    }

    // MARK: - Menu

    func menuNeedsUpdate(_ menu: NSMenu) {
        menu.removeAllItems()

        let currentDefault = getDefaultInputDevice()
        let currentName = getDeviceName(currentDefault)

        // Current status
        let statusText = NSMenuItem(title: "当前输入: \(currentName)", action: nil, keyEquivalent: "")
        statusText.isEnabled = false
        menu.addItem(statusText)

        menu.addItem(NSMenuItem.separator())

        // Enable/disable
        let toggleItem = NSMenuItem(
            title: isEnabled ? "已启用自动切换" : "已停用自动切换",
            action: #selector(toggleEnabled),
            keyEquivalent: ""
        )
        toggleItem.target = self
        toggleItem.state = isEnabled ? .on : .off
        menu.addItem(toggleItem)

        // Launch at login
        let loginItem = NSMenuItem(
            title: "开机自动启动",
            action: #selector(toggleLaunchAtLogin),
            keyEquivalent: ""
        )
        loginItem.target = self
        loginItem.state = launchAtLogin ? .on : .off
        menu.addItem(loginItem)

        menu.addItem(NSMenuItem.separator())

        // Device list
        let header = NSMenuItem(title: "目标麦克风:", action: nil, keyEquivalent: "")
        header.isEnabled = false
        menu.addItem(header)

        let inputDevices = getInputDevices()
        if inputDevices.isEmpty {
            let noDevice = NSMenuItem(title: "  (无可用输入设备)", action: nil, keyEquivalent: "")
            noDevice.isEnabled = false
            menu.addItem(noDevice)
        } else {
            for (name, _) in inputDevices {
                let item = NSMenuItem(title: name, action: #selector(selectDevice(_:)), keyEquivalent: "")
                item.target = self
                item.representedObject = name
                item.indentationLevel = 1
                if name == targetDeviceName {
                    item.state = .on
                }
                menu.addItem(item)
            }
        }

        menu.addItem(NSMenuItem.separator())
        menu.addItem(NSMenuItem(title: "退出", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q"))
    }

    // MARK: - Actions

    @objc func toggleEnabled() {
        isEnabled = !isEnabled
    }

    @objc func toggleLaunchAtLogin() {
        setLaunchAtLogin(!launchAtLogin)
    }

    @objc func selectDevice(_ sender: NSMenuItem) {
        if let name = sender.representedObject as? String {
            targetDeviceName = name
        }
    }

    // MARK: - Icon

    func updateIcon() {
        guard let button = statusItem.button else { return }
        let symbolName: String
        if !isEnabled {
            symbolName = "mic.slash"
        } else if isTargetActive() {
            symbolName = "mic.fill"
        } else {
            symbolName = "mic"
        }
        if let img = NSImage(systemSymbolName: symbolName, accessibilityDescription: "Auto Switch Mic") {
            img.isTemplate = true
            button.image = img
        }
    }

    func isTargetActive() -> Bool {
        let current = getDefaultInputDevice()
        let name = getDeviceName(current)
        return name == targetDeviceName
    }

    // MARK: - Audio Monitoring

    func setupAudioListeners() {
        // Watch device list changes (plug/unplug)
        AudioObjectAddPropertyListenerBlock(
            AudioObjectID(kAudioObjectSystemObject),
            &listListenerAddr,
            nil
        ) { [weak self] _, _ in
            DispatchQueue.main.async {
                guard let self = self, self.isEnabled else { return }
                self.switchToTarget()
            }
        }

        // Watch default input device changes
        AudioObjectAddPropertyListenerBlock(
            AudioObjectID(kAudioObjectSystemObject),
            &defaultInputListenerAddr,
            nil
        ) { [weak self] _, _ in
            DispatchQueue.main.async {
                guard let self = self, self.isEnabled else { return }
                self.switchToTarget()
            }
        }
    }

    func switchToTarget() {
        let devices = getInputDevices()
        let currentDefault = getDefaultInputDevice()

        for (name, deviceID) in devices {
            if name == targetDeviceName {
                if deviceID == currentDefault {
                    NSLog("Already using: %@", name)
                    updateIcon()
                    return
                }
                var addr = AudioObjectPropertyAddress(
                    mSelector: kAudioHardwarePropertyDefaultInputDevice,
                    mScope: kAudioObjectPropertyScopeGlobal,
                    mElement: kAudioObjectPropertyElementMain
                )
                var id = deviceID
                AudioObjectSetPropertyData(
                    AudioObjectID(kAudioObjectSystemObject),
                    &addr, 0, nil,
                    UInt32(MemoryLayout<AudioDeviceID>.size), &id
                )
                NSLog("Switched input to: %@", name)
                updateIcon()
                return
            }
        }
        NSLog("Target device not found: %@", targetDeviceName)
        updateIcon()
    }
}

// MARK: - Main

let app = NSApplication.shared
let delegate = AppDelegate()
app.delegate = delegate
app.run()