using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using UnityEngine;

public class MicroPhoneManager : MonoBehaviour {

  public int DeviceLength;
  /// <summary>
  /// 錄音頻率
  /// </summary>
  public string Frequency = "44100";
  public int Samplerate = 44100;
  /// <summary>
  /// 錄音時長
  /// </summary>
  public int MicSecond = 2;
  string infoLog = "";

  AudioSource _curAudioSource;

  AudioSource CurAudioSource
  {
    get
    {
      if (_curAudioSource == null)
      {
        _curAudioSource = gameObject.AddComponent<AudioSource>();
      }
      return _curAudioSource;
    }
  }

  #region ［public Way］

  /// <summary>
  /// 獲取麥克風設備
  /// </summary>
  public void GetMicrophoneDevice()
  {
    string[] mDevice = Microphone.devices;
    DeviceLength = mDevice.Length;
    if (DeviceLength == 0)
      ShowInfoLog("找不到麥克風設備！");
  }

  /// <summary>
  /// 開始錄音
  /// </summary>
  public void StartRecordAudio()
  {
    CurAudioSource.Stop();
    CurAudioSource.loop = false;
    CurAudioSource.mute = true;
    CurAudioSource.clip = Microphone.Start(null, true, MicSecond, int.Parse(Frequency));
    while (!(Microphone.GetPosition(null) > 0))
    {

    }
    CurAudioSource.Play();
    ShowInfoLog("開始錄音.....");
  }

  /// <summary>
  /// 停止錄音
  /// </summary>
  public void StopRecordAudio()
  {
    ShowInfoLog("結束錄音.....");
    if (!Microphone.IsRecording(null))
      return;
    Microphone.End(null);
    CurAudioSource.Stop();

  }
  /// <summary>s
  /// 回放錄音
  /// </summary>
  public void PlayRecordAudio()
  {
    if (Microphone.IsRecording(null))
      return;
    if (CurAudioSource.clip == null)
      return;
    CurAudioSource.mute = false;
    CurAudioSource.loop = false;
    CurAudioSource.Play();
    ShowInfoLog("播放錄音.....");
  }

  /// <summary>
  /// 打印錄音信息
  /// </summary>
  public void PrintRecordData()
  {
    if (Microphone.IsRecording(null))
      return;
    byte[] data = GetClipData();
    #region 用戶自由固定錄音時長
    int position = Microphone.GetPosition(null);
    var soundata = new float[CurAudioSource.clip.samples * CurAudioSource.clip.channels];
    CurAudioSource.clip.GetData(soundata, 0);

    var newdata = new float[position * CurAudioSource.clip.channels];
    for (int i = 0; i < newdata.Length; i++) {
      newdata[i] = soundata[i];
    }
    CurAudioSource.clip = AudioClip.Create(CurAudioSource.clip.name, position, CurAudioSource.clip.channels, CurAudioSource.clip.frequency, false);
    CurAudioSource.clip.SetData(newdata, 0);

    Microphone.End(null);
    #endregion
    using (FileStream fs = CreateEmpty(Application.persistentDataPath + "/dd.wav")) {
      ConvertAndWrite(fs, CurAudioSource.clip);
      WriteHeader(fs, CurAudioSource.clip);
    }

    string infoLog = "total length:" + data.Length + " time:" + CurAudioSource.time;
    ShowInfoLog(infoLog);
  }
  private void WriteHeader(FileStream stream, AudioClip clip)
  {
    int hz = clip.frequency;
    int channels = clip.channels;
    int samples = clip.samples;

    stream.Seek(0, SeekOrigin.Begin);

    Byte[] riff = System.Text.Encoding.UTF8.GetBytes("RIFF");
    stream.Write(riff, 0, 4);

    Byte[] chunkSize = BitConverter.GetBytes(stream.Length - 8);
    stream.Write(chunkSize, 0, 4);

    Byte[] wave = System.Text.Encoding.UTF8.GetBytes("WAVE");
    stream.Write(wave, 0, 4);

    Byte[] fmt = System.Text.Encoding.UTF8.GetBytes("fmt ");
    stream.Write(fmt, 0, 4);

    Byte[] subChunk1 = BitConverter.GetBytes(16);
    stream.Write(subChunk1, 0, 4);

    UInt16 two = 2;
    UInt16 one = 1;

    Byte[] audioFormat = BitConverter.GetBytes(one);
    stream.Write(audioFormat, 0, 2);

    Byte[] numChannels = BitConverter.GetBytes(channels);
    stream.Write(numChannels, 0, 2);

    Byte[] sampleRate = BitConverter.GetBytes(hz);
    stream.Write(sampleRate, 0, 4);

    Byte[] byteRate = BitConverter.GetBytes(hz * channels * 2); // sampleRate * bytesPerSample*number of channels, here 44100*2*2 
    stream.Write(byteRate, 0, 4);

    UInt16 blockAlign = (ushort)(channels * 2);
    stream.Write(BitConverter.GetBytes(blockAlign), 0, 2);

    UInt16 bps = 16;
    Byte[] bitsPerSample = BitConverter.GetBytes(bps);
    stream.Write(bitsPerSample, 0, 2);

    Byte[] datastring = System.Text.Encoding.UTF8.GetBytes("data");
    stream.Write(datastring, 0, 4);

    Byte[] subChunk2 = BitConverter.GetBytes(samples * channels * 2);
    stream.Write(subChunk2, 0, 4);

  }
  private FileStream CreateEmpty(string filepath)
  {
    FileStream fileStream = new FileStream(filepath, FileMode.Create);
    byte emptyByte = new byte();

    for (int i = 0; i < 44; i++) //preparing the header 
    {
      fileStream.WriteByte(emptyByte);
    }

    return fileStream;
  }
  private void ConvertAndWrite(FileStream fileStream, AudioClip clip)
  {

    float[] samples = new float[clip.samples];

    clip.GetData(samples, 0);

    Int16[] intData = new Int16[samples.Length];

    Byte[] bytesData = new Byte[samples.Length * 2];

    int rescaleFactor = 32767; //to convert float to Int16 

    for (int i = 0; i < samples.Length; i++)
    {
      intData[i] = (short)(samples[i] * rescaleFactor);
      Byte[] byteArr = new Byte[2];
      byteArr = BitConverter.GetBytes(intData[i]);
      byteArr.CopyTo(bytesData, i * 2);
    }
    fileStream.Write(bytesData, 0, bytesData.Length);
  }
  /// <summary>
  /// 獲取音頻數據
  /// </summary>
  /// <returns>The clip data.</returns>
  public byte[] GetClipData()
  {
    if (CurAudioSource.clip == null)
    {
      ShowInfoLog("缺少音頻資源！");
      return null;
    }

    float[] samples = new float[CurAudioSource.clip.samples];
    CurAudioSource.clip.GetData(samples, 0);

    byte[] outData = new byte[samples.Length * 2];
    int reScaleFactor = 32767;

    for (int i = 0; i < samples.Length; i++)
    {
      short tempShort = (short)(samples[i] * reScaleFactor);
      byte[] tempData = System.BitConverter.GetBytes(tempShort);

      outData[i * 2] = tempData[0];
      outData[i * 2 + 1] = tempData[1];
    }
    if (outData == null || outData.Length <= 0)
    {

      ShowInfoLog("獲取音頻數據失敗！");
      return null;
    }
    return outData;
  }

  #endregion


  void OnGUI()
  {

    if (DeviceLength == 0)
    {
      if (ShowGUIButton("獲取麥克風設備"))
      {
        GetMicrophoneDevice();
      }
    }
    else if (DeviceLength > 0)
    {
      GUILayout.Label("錄音頻率:");
      Frequency = GUILayout.TextField(Frequency, GUILayout.Width(Screen.width / 5), GUILayout.Height(Screen.height / 20));
      GUILayout.BeginVertical();

      if (ShowGUIButton("開始錄音"))
      {
        StartRecordAudio();
      }
      if (ShowGUIButton("結束錄音"))
      {
        StopRecordAudio();
      }
      if (ShowGUIButton("回放錄音"))
      {
        PlayRecordAudio();
      }
      if (ShowGUIButton("獲取錄音數據"))
      {
        PrintRecordData();
      }

      GUILayout.EndVertical();
    }
    GUILayout.Label(infoLog);

  }

  #region [Private Way]

  /// <summary>
  /// 顯示GUI 按鈕
  /// </summary>
  /// <returns><c>true</c>, if GUI button was shown, <c>false</c> otherwise.</returns>
  /// <param name="buttonName">Button name.</param>
  bool ShowGUIButton(string buttonName)
  {
    return GUILayout.Button(buttonName, GUILayout.Height(Screen.height / 20), GUILayout.Width(Screen.width / 5));
  }

  void ShowInfoLog(string info)
  {
    infoLog += info;
    infoLog += "\r\n";
  }

  #endregion
}