import Foundation
import AVFoundation

/// 统一音频会话管理类
/// 用于统一管理所有组件的音频会话配置
@objc class AudioSessionManager: NSObject {
    // MARK: - 单例实现
    
    @objc static let shared = AudioSessionManager()
    
    // 音频会话
    private let audioSession = AVAudioSession.sharedInstance()
    
    // 是否已经配置过音频会话
    private var isConfigured = false
    
    // 当前配置类型
    private var currentCategory: AVAudioSession.Category = .playAndRecord
    private var currentMode: AVAudioSession.Mode = .default
    private var currentOptions: AVAudioSession.CategoryOptions = [.allowBluetooth, .allowBluetoothA2DP]
    
    // 私有初始化方法，确保只能通过shared访问
    private override init() {
        super.init()
        NSLog("[AudioSessionManager] 音频会话管理器已初始化")
    }
    
    // MARK: - 音频会话配置
    
    /// 在应用启动时调用一次性配置方法
    /// - Parameters:
    ///   - category: 音频会话类别
    ///   - mode: 音频会话模式
    ///   - options: 音频会话选项
    /// - Returns: 是否配置成功
    @objc func initialConfiguration(category: AVAudioSession.Category = .playAndRecord,
                                   mode: AVAudioSession.Mode = .default,
                                   options: AVAudioSession.CategoryOptions = [.allowBluetooth, .allowBluetoothA2DP]) -> Bool {
        if isConfigured {
            NSLog("[AudioSessionManager] 音频会话已经配置过，忽略初始化请求")
            return true
        }
        
        do {
            NSLog("[AudioSessionManager] 执行一次性音频会话配置: \(category)")
            try audioSession.setCategory(category, mode: mode, options: options)
            try audioSession.setActive(true)
            
            // 记录当前配置
            currentCategory = category
            currentMode = mode
            currentOptions = options
            isConfigured = true
            
            return true
        } catch {
            NSLog("[AudioSessionManager] 一次性配置音频会话失败: \(error.localizedDescription)")
            return false
        }
    }
    
    /// 配置音频会话，适用于语音识别和合成
    @objc func configureForVoiceProcessing() throws {
        if !applyConfigurationIfNeeded(category: .playAndRecord, 
                                      mode: .spokenAudio, 
                                      options: [.allowBluetooth, .allowBluetoothA2DP, .duckOthers]) {
            NSLog("[AudioSessionManager] 使用已存在的音频会话配置，跳过语音处理模式配置")
        }
    }
    
    /// 配置音频会话，适用于蓝牙耳机连接和监听
    @objc func configureForBluetoothHeadset() throws {
        if !applyConfigurationIfNeeded(category: .playAndRecord, 
                                      mode: .default, 
                                      options: [.allowBluetooth, .allowBluetoothA2DP]) {
            NSLog("[AudioSessionManager] 使用已存在的音频会话配置，跳过蓝牙耳机模式配置")
        }
    }
    
    /// 配置音频会话，适用于媒体播放和蓝牙媒体按钮
    @objc func configureForMediaPlayback() throws {
        if !applyConfigurationIfNeeded(category: .playback, 
                                      mode: .default, 
                                      options: [.allowBluetooth, .allowBluetoothA2DP]) {
            NSLog("[AudioSessionManager] 使用已存在的音频会话配置，跳过媒体播放模式配置")
        }
    }
    
    /// 配置自定义音频会话
    @objc func configure(category: AVAudioSession.Category, 
                         mode: AVAudioSession.Mode, 
                         options: AVAudioSession.CategoryOptions) throws {
        if !applyConfigurationIfNeeded(category: category, mode: mode, options: options) {
            NSLog("[AudioSessionManager] 使用已存在的音频会话配置，跳过自定义模式配置")
        }
    }
    
    /// 内部方法：如果尚未配置，应用新的配置
    private func applyConfigurationIfNeeded(category: AVAudioSession.Category, 
                                          mode: AVAudioSession.Mode, 
                                          options: AVAudioSession.CategoryOptions) -> Bool {
        // 如果已经配置过，不再重复配置
        if isConfigured {
            return false
        }
        
        do {
            NSLog("[AudioSessionManager] 应用音频会话配置: \(category)")
            try audioSession.setCategory(category, mode: mode, options: options)
            try audioSession.setActive(true)
            
            // 记录当前配置
            currentCategory = category
            currentMode = mode
            currentOptions = options
            isConfigured = true
            
            return true
        } catch {
            NSLog("[AudioSessionManager] 配置音频会话失败: \(error.localizedDescription)")
            return false
        }
    }
    
    /// 获取当前音频会话的配置信息
    @objc func getCurrentConfiguration() -> [String: Any] {
        return [
            "isConfigured": isConfigured,
            "category": "\(currentCategory)",
            "mode": "\(currentMode)"
        ]
    }
    
    /// 仅在特殊情况下使用：强制重新配置音频会话
    @objc func forceReconfigure() -> Bool {
        isConfigured = false
        
        do {
            NSLog("[AudioSessionManager] 强制重新配置音频会话")
            try audioSession.setCategory(currentCategory, mode: currentMode, options: currentOptions)
            try audioSession.setActive(true)
            isConfigured = true
            return true
        } catch {
            NSLog("[AudioSessionManager] 强制重新配置失败: \(error.localizedDescription)")
            return false
        }
    }
    
    /// 激活音频会话（如果已配置）
    @objc func activateSession() throws {
        if isConfigured {
            try audioSession.setActive(true)
        } else {
            NSLog("[AudioSessionManager] 警告: 尝试激活未配置的音频会话")
            // 应用默认配置并激活
            try applyConfigurationIfNeeded(category: .playAndRecord, 
                                         mode: .default, 
                                         options: [.allowBluetooth, .allowBluetoothA2DP])
        }
    }
    
    /// 停用音频会话（保留配置）
    @objc func deactivateSession() throws {
        try audioSession.setActive(false, options: .notifyOthersOnDeactivation)
    }
    
    /// 获取当前音频会话路由描述
    @objc func getCurrentRoute() -> AVAudioSessionRouteDescription {
        return audioSession.currentRoute
    }
    
    /// 添加路由变化监听器
    @objc func addRouteChangeListener(_ observer: Any, selector: Selector) {
        NotificationCenter.default.addObserver(
            observer,
            selector: selector,
            name: AVAudioSession.routeChangeNotification,
            object: nil
        )
    }
    
    /// 移除路由变化监听器
    @objc func removeRouteChangeListener(_ observer: Any) {
        NotificationCenter.default.removeObserver(
            observer,
            name: AVAudioSession.routeChangeNotification,
            object: nil
        )
    }
}