import AVFoundation
import os.log

public enum AudioIntent {
    case voice
    case playback
}

public class AudioSessionHub {
    
    public static let shared = AudioSessionHub()
    
    private let logger = OSLog(subsystem: "com.yunqiinnovation.agent_service", category: "AudioSessionHub")
    private var currentIntent: AudioIntent?
    private let audioSession = AVAudioSession.sharedInstance()
    private var isInterrupted = false
    
    private init() {
        setupNotifications()
    }
    
    public func begin(_ intent: AudioIntent) {
        if intent == currentIntent && audioSession.isOtherAudioPlaying == false {
            return
        }
        
        currentIntent = intent
        
        do {
            switch intent {

            case .voice:
                try audioSession.setCategory(.playAndRecord, 
                                           mode: .voiceChat, 
                                           options: [.allowBluetooth, .mixWithOthers])
                
                // 如果有蓝牙HFP设备，强制设置为首选输入
                if let bluetoothInput = audioSession.availableInputs?.first(where: { $0.portType == .bluetoothHFP }) {
                    try audioSession.setPreferredInput(bluetoothInput)
                    os_log("已设置蓝牙HFP为首选输入: %{public}@", log: logger, type: .info, bluetoothInput.portName)
                }
                
            case .playback:
                try audioSession.setCategory(.playback, 
                                            mode: .default, 
                                            options: [.allowBluetooth, .mixWithOthers])
                
            }
            
            try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
            
            os_log("音频会话已设置为：%{public}@", log: logger, type: .debug, String(describing: intent))
            
            // 输出当前音频路由信息
            let hasBluetoothDevice = hasBluetoothAudioDevice()
            let hasBluetoothMic = hasBluetoothMicrophone()
            let currentInput = getCurrentInputDevice()
            
            os_log("蓝牙音频设备状态: %{public}@", log: logger, type: .info, hasBluetoothDevice ? "已连接" : "未连接")
            os_log("蓝牙麦克风状态: %{public}@", log: logger, type: .info, hasBluetoothMic ? "已连接" : "未连接")
            os_log("当前输入设备: %{public}@", log: logger, type: .info, currentInput)
            
            if hasBluetoothDevice {
                os_log("%{public}@", log: logger, type: .debug, getCurrentAudioRoute())
            }
        } catch {
            os_log("设置音频会话失败：%{public}@", log: logger, type: .error, error.localizedDescription)
        }
    }
    
    public func appWillEnterForeground() {
        if let intent = currentIntent {
            begin(intent)
        }
    }
    
    public func appDidEnterBackground() {
        do {
            try audioSession.setActive(false, options: .notifyOthersOnDeactivation)
            os_log("音频会话已释放（应用进入后台）", log: logger, type: .debug)
        } catch {
            os_log("释放音频会话失败：%{public}@", log: logger, type: .error, error.localizedDescription)
        }
    }
    
    /// 获取当前音频路由信息
    public func getCurrentAudioRoute() -> String {
        let currentRoute = audioSession.currentRoute
        var routeInfo = "当前音频路由:\n"
        
        // 输出设备
        routeInfo += "输出设备:\n"
        for output in currentRoute.outputs {
            routeInfo += "  - \(output.portName) (\(output.portType.rawValue))\n"
        }
        
        // 输入设备
        routeInfo += "输入设备:\n"
        for input in currentRoute.inputs {
            routeInfo += "  - \(input.portName) (\(input.portType.rawValue))\n"
        }
        
        return routeInfo
    }
    
    /// 检查是否有蓝牙音频设备连接
    public func hasBluetoothAudioDevice() -> Bool {
        let currentRoute = audioSession.currentRoute
        
        // 检查输出设备
        for output in currentRoute.outputs {
            if output.portType == .bluetoothA2DP || 
               output.portType == .bluetoothHFP || 
               output.portType == .bluetoothLE {
                return true
            }
        }
        
        // 检查输入设备（这是关键！）
        for input in currentRoute.inputs {
            if input.portType == .bluetoothHFP {
                return true
            }
        }
        
        return false
    }
    
    /// 检查是否有蓝牙麦克风作为输入设备
    public func hasBluetoothMicrophone() -> Bool {
        let currentRoute = audioSession.currentRoute
        
        for input in currentRoute.inputs {
            if input.portType == .bluetoothHFP {
                return true
            }
        }
        
        return false
    }
    
    /// 获取当前输入设备信息
    public func getCurrentInputDevice() -> String {
        let currentRoute = audioSession.currentRoute
        
        if let input = currentRoute.inputs.first {
            return "\(input.portName) (\(input.portType.rawValue))"
        }
        
        return "无输入设备"
    }
    
    private func setupNotifications() {
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(handleAudioSessionInterruption),
            name: AVAudioSession.interruptionNotification,
            object: nil
        )
        
        NotificationCenter.default.addObserver(
            self,
            selector: #selector(handleAudioRouteChange),
            name: AVAudioSession.routeChangeNotification,
            object: nil
        )
    }
    
    /// 处理音频中断
    @objc private func handleAudioSessionInterruption(notification: Notification) {
        guard let userInfo = notification.userInfo,
              let typeValue = userInfo[AVAudioSessionInterruptionTypeKey] as? UInt,
              let type = AVAudioSession.InterruptionType(rawValue: typeValue) else {
            return
        }
        
        switch type {
        case .began:
            // 中断开始
            isInterrupted = true
            os_log("音频会话被中断", log: logger, type: .debug)
            
        case .ended:
            // 中断结束
            isInterrupted = false
            
            // 检查是否应该恢复
            if let optionsValue = userInfo[AVAudioSessionInterruptionOptionKey] as? UInt {
                let options = AVAudioSession.InterruptionOptions(rawValue: optionsValue)
                if options.contains(.shouldResume), let intent = currentIntent {
                    // 恢复之前的音频意图
                    begin(intent)
                    os_log("音频会话中断结束，已恢复", log: logger, type: .debug)
                }
            }
            
        @unknown default:
            os_log("未知的音频中断类型: %{public}@", log: logger, type: .error, "\(type)")
        }
    }
    
    /// 处理音频路由变化
    @objc private func handleAudioRouteChange(notification: Notification) {
        guard let userInfo = notification.userInfo,
              let reasonValue = userInfo[AVAudioSessionRouteChangeReasonKey] as? UInt,
              let reason = AVAudioSession.RouteChangeReason(rawValue: reasonValue) else {
            return
        }
        
        switch reason {
        case .newDeviceAvailable:
            os_log("新音频设备已连接", log: logger, type: .info)
            os_log("%{public}@", log: logger, type: .debug, getCurrentAudioRoute())
            
            // 重新应用当前意图以确保正确路由
            if let intent = currentIntent {
                begin(intent)
            }
            
        case .oldDeviceUnavailable:
            os_log("音频设备已断开", log: logger, type: .info)
            os_log("%{public}@", log: logger, type: .debug, getCurrentAudioRoute())
            
            // 重新应用当前意图以确保正确路由
            if let intent = currentIntent {
                begin(intent)
            }
            
        case .categoryChange:
            os_log("音频类别已变化", log: logger, type: .info)
            
        default:
            break
        }
    }
    
    deinit {
        NotificationCenter.default.removeObserver(self)
    }
}