//  _____ _
// |_   _| |_  _ _ ___ ___ _ __  __ _
//   | | | ' \| '_/ -_) -_) '  \/ _` |_
//   |_| |_||_|_| \___\___|_|_|_\__,_(_)
//
// Threema iOS Client
// Copyright (c) 2019-2020 Threema GmbH
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License, version 3,
// as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

import Foundation
import CocoaLumberjackSwift


/// Note: Add Log level for Swift in Build Settings - Preprocessor Macros for AdHoc and AppStore:
/// DD_LOG_LEVEL=0b0100011 (Error, Warning and Notice)

/// Swift method for logging Notice Log level
@inlinable
public func DDLogNotice(_ message: @autoclosure () -> String,
                        level: DDLogLevel = DDDefaultLogLevel,
                        context: Int = 0,
                        file: StaticString = #file,
                        function: StaticString = #function,
                        line: UInt = #line,
                        tag: Any? = nil,
                        asynchronous async: Bool = asyncLoggingEnabled,
                        ddlog: DDLog = .sharedInstance) {
    _DDLogMessage(message(), level: level, flag: DDLogFlag(rawValue: DDLogFlag.RawValue(DDLogFlagNotice)) , context: context, file: file, function: function, line: line, tag: tag, asynchronous: async, ddlog: ddlog)
}

@objc public class LogManager: NSObject {
    
    private static var isDebug: Bool = false
    
    @objc public static let debugLogFile: URL? = FileUtility.appDataDirectory?.appendingPathComponent("validation_log.txt")

    /// Log levels definition for Swift. Includes new Notice Log level at the end, to not break the standard Log levels like in <CocoaLumberjack/DDLog.h>
    public enum DDLogLevelCustom: UInt {
        case err     = 0b0000001
        case warn    = 0b0000010
        case info    = 0b0000100
        case verbose = 0b0001000
        case debug   = 0b0010000
        case notice  = 0b0100000
    }

    @objc public static func initializeGlobalLogger(debug: Bool) {
        isDebug = debug
        if isDebug {
            DDTTYLogger.sharedInstance?.logFormatter = LogFormatterCustom()
            DDLog.add(DDTTYLogger.sharedInstance as! DDLogger, with: LogManager.logLevel())
        }
        
        // Add Debug Logger is enabled by user
        if let validationLogging = UserSettings.shared()?.validationLogging,
            validationLogging {
            
            addFileLogger(debugLogFile)
        }
        else {
            removeFileLogger(debugLogFile)
        }
    }

    @objc public static func addFileLogger(_ logFile: URL?) {
        guard let logFile = logFile else {
            return
        }
        
        if let existingLogger = findFileLogger(logFile),
            existingLogger.count == 0 {
        
            let fileLogger: FileLoggerCustom = FileLoggerCustom(logFile: logFile)
            DDLog.add(fileLogger, with: logLevel())
        }
    }
    
    @objc public static func removeFileLogger(_ logFile: URL?) {
        guard let logFile = logFile else {
            return
        }
        
        if let existingLoggers = findFileLogger(logFile),
            existingLoggers.count > 0 {
            for logger in existingLoggers {
                DDLog.remove(logger)
            }
        }
    }
    
    @objc public static func deleteLogFile(_ logFile: URL?) {
        FileUtility.delete(fileUrl: logFile)
    }
    
    @objc public static func logFileSize(_ logFile: URL?) -> Int64 {
        guard let logFile = logFile else {
            return 0
        }
        
        return FileUtility.fileSizeInBytes(fileUrl: logFile) ?? 0
    }

    /**
     Get Log Level depence on debug environment or not.
     
     - Returns: Log Level
    */
    private static func logLevel() -> DDLogLevel {
        // Default log level is Error, Warning and Notice
        var ddLogLevel: DDLogLevel = DDLogLevel(rawValue: DDLogLevelCustom.err.rawValue | DDLogLevelCustom.warn.rawValue | DDLogLevelCustom.notice.rawValue)!
        if isDebug {
            ddLogLevel = .all
        }
        return ddLogLevel
    }

    /**
     Looking for existing file logger (FileLoggerCustom).
     
     - Parameters:
     - logFile: Log file path
     
     - Returns: Array of file loggers
    */
    private static func findFileLogger(_ logFile: URL?) -> [DDLogger]? {
        guard let logFile = logFile else {
            return nil
        }
        
        var fileLoggers: [DDLogger] = []
        for logger in DDLog.allLoggers {
            if let fileLogger = logger as? FileLoggerCustom,
                fileLogger.logFile == logFile {
                
                fileLoggers.append(logger)
            }
        }
        return fileLoggers
    }
}