import Foundation
import os.log

/// iOS端的文件日志助手类，提供与Android端FileLogger类似的功能
class FileLogger {
    
    private static let logQueue = DispatchQueue(label: "com.yunqiinnovation.classic_bluetooth.logger", qos: .background)
    private static let dateFormatter: DateFormatter = {
        let formatter = DateFormatter()
        formatter.dateFormat = "yyyy-MM-dd HH:mm:ss.SSS"
        return formatter
    }()
    
    /// 日志类型
    enum LogLevel: String {
        case debug = "DEBUG"
        case info = "INFO"
        case warning = "WARNING"
        case error = "ERROR"
    }
    
    /// 输出调试日志
    /// - Parameters:
    ///   - tag: 标签
    ///   - message: 日志消息
    static func d(_ tag: String, _ message: String) {
        log(level: .debug, tag: tag, message: message)
    }
    
    /// 输出信息日志
    /// - Parameters:
    ///   - tag: 标签
    ///   - message: 日志消息
    static func i(_ tag: String, _ message: String) {
        log(level: .info, tag: tag, message: message)
    }
    
    /// 输出警告日志
    /// - Parameters:
    ///   - tag: 标签
    ///   - message: 日志消息
    static func w(_ tag: String, _ message: String) {
        log(level: .warning, tag: tag, message: message)
    }
    
    /// 输出错误日志
    /// - Parameters:
    ///   - tag: 标签
    ///   - message: 日志消息
    ///   - error: 可选的错误对象
    static func e(_ tag: String, _ message: String, _ error: Error? = nil) {
        var fullMessage = message
        if let error = error {
            fullMessage += " - Error: \(error.localizedDescription)"
        }
        log(level: .error, tag: tag, message: fullMessage)
    }
    
    /// 输出日志
    /// - Parameters:
    ///   - level: 日志级别
    ///   - tag: 标签
    ///   - message: 日志消息
    private static func log(level: LogLevel, tag: String, message: String) {
        let timestamp = dateFormatter.string(from: Date())
        let logMessage = "[\(timestamp)] [\(level.rawValue)] [\(tag)]: \(message)"
        
        // 输出到控制台
        print(logMessage)
        
        // 异步写入日志文件
        logQueue.async {
            writeToLogFile(logMessage)
        }
        
        // 使用系统日志
        if #available(iOS 10.0, *) {
            let osLog = OSLog(subsystem: "com.yunqiinnovation.classic_bluetooth", category: tag)
            let osLogType: OSLogType
            
            switch level {
            case .debug:
                osLogType = .debug
            case .info:
                osLogType = .info
            case .warning:
                osLogType = .default
            case .error:
                osLogType = .error
            }
            
            os_log("%{public}@", log: osLog, type: osLogType, message)
        }
    }
    
    /// 将日志写入文件
    /// - Parameter message: 日志消息
    private static func writeToLogFile(_ message: String) {
        guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
            return
        }
        
        let logDirectoryURL = documentsDirectory.appendingPathComponent("Logs")
        let dateString = DateFormatter().with { $0.dateFormat = "yyyy-MM-dd" }.string(from: Date())
        let logFileURL = logDirectoryURL.appendingPathComponent("bluetooth_\(dateString).log")
        
        do {
            // 创建日志文件夹
            try FileManager.default.createDirectory(at: logDirectoryURL, withIntermediateDirectories: true)
            
            // 如果文件不存在，创建文件
            if !FileManager.default.fileExists(atPath: logFileURL.path) {
                FileManager.default.createFile(atPath: logFileURL.path, contents: nil)
            }
            
            // 追加日志内容
            if let fileHandle = FileHandle(forWritingAtPath: logFileURL.path) {
                fileHandle.seekToEndOfFile()
                if let data = "\(message)\n".data(using: .utf8) {
                    fileHandle.write(data)
                }
                fileHandle.closeFile()
            }
        } catch {
            print("写入日志文件失败: \(error.localizedDescription)")
        }
    }
}

// MARK: - DateFormatter 扩展
extension DateFormatter {
    func with(_ block: (DateFormatter) -> Void) -> DateFormatter {
        block(self)
        return self
    }
}