XCGLogger loggly

LogglyDestination.swift

//
//  LogglyDestination.swift
//  qminder-tv
//
//  Created by Kristaps Grinbergs on 03/01/2018.
//  Copyright © 2018 Qminder. All rights reserved.
//

import Foundation

import XCGLogger

open class LogglyDestination: BaseQueuedDestination {
  
  /// Loggly URL
  fileprivate let logglyUrlString = "http://logs-01.loggly.com/bulk/KEY/tag/TAG/"
  
  /// Max entries before sending to loggly
  fileprivate let maxEntriesInBuffer = 5
  
  /// Loggly queue
  fileprivate let logglyQueue = DispatchQueue(label: "logglyQueue")
  
  /// Message buffer
  fileprivate var buffer: [String] = [String]()
  
  /// Observer
  fileprivate var observer: NSObjectProtocol?
  
  /// Background task identifier
  fileprivate var backgroundTaskIdentifier: UIBackgroundTaskIdentifier = UIBackgroundTaskInvalid
  
  /// Standard fields to send to loggly
  fileprivate lazy var standardFields: [String: Any] = {
    var dict = [String: Any]()
    
    dict["lang"] = Locale.preferredLanguages[0]
    
    if let infodict = Bundle.main.infoDictionary {
      if let appname = infodict["CFBundleName"] {
        dict["appname"] = appname
      }
      if let build = infodict["CFBundleVersion"] {
        dict["build"] = build
      }
      
      if let version = infodict["CFBundleShortVersionString"] {
        dict["version"] = version
      }
    }
    
    dict["devicename"] = UIDevice.current.name
    dict["devicemodel"] = UIDevice.current.model
    dict["osversion"] = UIDevice.current.systemVersion
    dict["sessionid"] = String(arc4random_uniform(999999))
    
    return dict
  }()
  
  /**
   Init Logger
   
   - Parameters:
     - owner: XCGLogger
     - identifier: Identifier
  */
  public override init(owner: XCGLogger?, identifier: String) {
    super.init(owner: owner, identifier: identifier)
    
    observer = NotificationCenter.default.addObserver(forName: NSNotification.Name(rawValue: "UIApplicationWillResignActiveNotification"),
                                                      object: nil, queue: nil, using: {[unowned self] _ in
      let tmpbuffer = self.buffer
      self.buffer = [String]()
      self.backgroundTaskIdentifier = UIApplication.shared.beginBackgroundTask(withName: "saveLogRecords") {
        self.endBackgroundTask()
      }
      self.sendLogsInBuffer(stringbuffer: tmpbuffer)
    })
  }
  
  /**
   End background task
  */
  private func endBackgroundTask() {
    if self.backgroundTaskIdentifier != UIBackgroundTaskInvalid {
      UIApplication.shared.endBackgroundTask(self.backgroundTaskIdentifier)
      self.backgroundTaskIdentifier = UIBackgroundTaskInvalid
      print("Ending background task")
    }
  }
  
  /**
   Send logs in bufer
   
   - Parameters:
     - stringbuffer: String buffer
  */
  private func sendLogsInBuffer(stringbuffer: [String]) {
    let allMessagesString = stringbuffer.joined(separator: "\n")
    if let allMessagesData = allMessagesString.data(using: .utf8) {
      guard let url = URL(string: logglyUrlString) else { return }
      var request = URLRequest(url: url)
      request.httpMethod = "POST"
      request.httpBody = allMessagesData
      
      let task = URLSession.shared.dataTask(with: request)
      task.resume()
    }
  }
  
  /**
   Write override
   
   - Parameters:
     - message: Log message
  */
  override open func write(message: String) {
    var msgDictionary = standardFields
    msgDictionary["message"] = message
    
    guard let jsonData = try? JSONSerialization.data(withJSONObject: msgDictionary, options: JSONSerialization.WritingOptions(rawValue: 0)) else { return }
    guard let jsonString = String(data: jsonData, encoding: .utf8) else { return }
    addLogMsgToBuffer(message: jsonString)
  }
  
  /**
   Add log message to buffer
   
   - Parameters:
     - message: Log message
  */
  private func addLogMsgToBuffer(message: String) {
    logglyQueue.async {
      self.buffer.append(message)
      if self.buffer.count > self.maxEntriesInBuffer {
        let tmpbuffer = self.buffer
        self.buffer = [String]()
        self.sendLogsInBuffer(stringbuffer: tmpbuffer)
      }
    }
  }
}