AudioPlayer

//
//  AudioPlayer.swift
//
//  Created by Andrei on 3/2/17.
//

import Foundation
import AVFoundation

public typealias CommonAction = () -> Void

@objc
class AudioPlayer: NSObject {
  
  var trackStopped: CommonAction?
  
  var audioPlayer: AVAudioPlayer?
  
  var audioEngine:AVAudioEngine?
  var audioFile:AVAudioFile?
  
  override init() {
    let fileURL = Bundle.main.url(forResource: "daffyduck1", withExtension: ".wav")!
    
    audioPlayer=try? AVAudioPlayer(contentsOf: fileURL as URL)
    audioPlayer?.enableRate=true
    
    audioEngine=AVAudioEngine()
    audioFile=try? AVAudioFile(forReading: fileURL as URL)
  }
  
  func stop() {
    trackStopped = nil
    audioPlayer?.stop()
  }
  
  func playsWith(rate: Float = 0) {
    audioPlayer?.stop()
    audioPlayer?.rate=0.5
    audioPlayer?.play()
  }
  
  func playsWith(pitch: Float = 0, trackStopped: CommonAction?) {
    guard let audioPlayer = audioPlayer, let audioEngine = audioEngine, let audioFile = audioFile else {
      return
    }
    
    self.trackStopped = trackStopped
    
    audioPlayer.stop()
    audioEngine.stop()
    audioEngine.reset()
    
    let audioNode=AVAudioPlayerNode()
    audioEngine.attach(audioNode)
    
    let audioPitch=AVAudioUnitTimePitch()
    audioPitch.pitch=pitch
    audioEngine.attach(audioPitch)
    
    audioEngine.connect(audioNode, to: audioPitch, format: nil)
    audioEngine.connect(audioPitch, to: audioEngine.outputNode, format: nil)
    
    audioNode.scheduleFile(audioFile, at: nil) { [weak self] in
      DispatchQueue.main.async {
        self?.trackStopped?()
        self?.trackStopped = nil
      }
    }
    
    try? audioEngine.start()
    audioNode.play()
  }
  
    func saveWithEffect() {
    let pitch = -800.0
    let rate = 0.5
    let reverb = 1.0
    let echo = 1.0
    
    // Initialize variables
    
    // These are global variables . if you want you can just  (let audioEngine = etc ..) init here these variables
    let audioEngine = AVAudioEngine()
    let audioPlayerNode = AVAudioPlayerNode()
    audioEngine.attach(audioPlayerNode)
    let playerB = AVAudioPlayerNode()
    
    audioEngine.attach(playerB)
    
    // Setting the pitch
    let pitchEffect = AVAudioUnitTimePitch()
    pitchEffect.pitch = Float(pitch)
    audioEngine.attach(pitchEffect)
    
    // Setting the platback-rate
    let playbackRateEffect = AVAudioUnitVarispeed()
    playbackRateEffect.rate = Float(rate)
    audioEngine.attach(playbackRateEffect)
    
    // Setting the reverb effect
    let reverbEffect = AVAudioUnitReverb()
    reverbEffect.loadFactoryPreset(AVAudioUnitReverbPreset.cathedral)
    reverbEffect.wetDryMix = Float(reverb)
    audioEngine.attach(reverbEffect)
    
    // Setting the echo effect on a specific interval
    let echoEffect = AVAudioUnitDelay()
    echoEffect.delayTime = TimeInterval(echo)
    audioEngine.attach(echoEffect)
    
    // Chain all these up, ending with the output
//    audioEngine.connect(audioPlayerNode, to: playbackRateEffect, format: nil)
//    audioEngine.connect(playbackRateEffect, to: pitchEffect, format: nil)
//    audioEngine.connect(pitchEffect, to: reverbEffect, format: nil)
//    audioEngine.connect(reverbEffect, to: echoEffect, format: nil)
//    audioEngine.connect(echoEffect, to: audioEngine.mainMixerNode, format: nil)

    audioEngine.connect(audioPlayerNode, to: pitchEffect, format: nil)
    audioEngine.connect(pitchEffect, to: audioEngine.mainMixerNode, format: nil)
    
    
    // Good practice to stop before starting
    audioPlayerNode.stop()
    
    audioPlayer?.stop()
    
    
    // audioFile here is our original audio
    audioPlayerNode.scheduleFile(audioFile!, at: nil, completionHandler: {[weak self] in
      print("Complete")
      self?.done = true
    })
    
    
    try! audioEngine.start()
    
    
    let dirPath=NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String
    
    let currentDateTime=Date()
    let formatter = DateFormatter()
    formatter.dateFormat="yyyyMMdd-HHmmss"
    let recordingName=formatter.string(from: currentDateTime)+".wav"
    
    let pathArray=[dirPath,recordingName]
    let tmpFileUrl = URL(string: pathArray.joined(separator: "/"))
    
    //Save the tmpFileUrl into global varibale to not lose it (not important if you want to do something else)
    print(tmpFileUrl!)
    
    do{
    print(audioFile!.fileFormat.settings)
    let newAudio = try! AVAudioFile(forWriting: tmpFileUrl!, settings: self.audioEngine!.outputNode.inputFormat(forBus: 0).settings)
      
    let length = self.audioFile?.length
      audioEngine.mainMixerNode.installTap(onBus: 0, bufferSize: 8192, format: self.audioEngine?.outputNode.inputFormat(forBus: 0)) {(buffer: AVAudioPCMBuffer!, time: AVAudioTime!) -> Void in
        print(newAudio.length)
        print("=====================")
        print(length!)
        print("**************************")
        do{
          //print(buffer)
          try newAudio.write(from: buffer)
        }catch _{
          print("Problem Writing Buffer")
        }
        if self.done == .some(true) {
          audioEngine.mainMixerNode.removeTap(onBus: 0)
        }
      }
    }catch _{
      print("Problem")
    }
    
    audioPlayerNode.play()
    
  }
}