using NAudio.Wave;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace IOTContainer.Common
{
    public class BaiduSpeech
    {
        private int deviceNumber = 0;    // 选择的录音设备下标。多个设备时可设置为用户选择
        private WaveIn waveIn;    // waveIn操作类
        private WaveFormat recordingFormat;    // 录音格式
        private WaveFileWriter writer;    // 录音文件操作类
        StringBuilder result = new StringBuilder();//存储最终识别的结果
        int totalLength = 0;//用来记录总的识别后的结果的长度，判断是否超过缓存最大值
        /// <summary>
        /// 单例模式
        /// </summary>
        public static BaiduSpeech baiduSpeech
        {
            get
            {
                if (_baiduSpeech == null)
                    _baiduSpeech = new BaiduSpeech();
                return _baiduSpeech;
            }
        }

        private static BaiduSpeech _baiduSpeech = new BaiduSpeech();

        private  BaiduSpeech() { }
        /// <summary>
        /// 录音信息初始化
        /// </summary>
        public void InitSpeech()
        {
            try
            {
                recordingFormat = new WaveFormat(16000, 16, 1);
                // 设置麦克风操作对象
                waveIn = new WaveIn();
                waveIn.DeviceNumber = deviceNumber;    // 设置使用的录音设备
                waveIn.DataAvailable += OnDataAviailable;        // 接收到音频数据时，写入文件
                waveIn.RecordingStopped += OnRecordingStopped;   // 录音结束时执行
                waveIn.WaveFormat = recordingFormat;
            }
            catch (Exception ex)
            {

                Log.MyLog.WriteLogFile("语音初始化失败："+ ex.ToString(), "BaiduSpeech");
            }
            
        }
        /// <summary>
        /// 开始录音
        /// </summary>
        /// <returns></returns>
        internal bool StartRecorder(string filename = "speech.wav")
        {
            try
            {
                totalLength = 0;
                // 设置文件操作类
                writer = new WaveFileWriter(filename, recordingFormat);
                result.Clear();
                // 开始录音
                waveIn.StartRecording();
            }
            catch (Exception ex)
            {
                //结束录音
                StopRecorder();
                Log.MyLog.WriteLogFile("录音失败：" + ex.ToString(), "BaiduSpeech");
            }
            return true;
        }
        /// <summary>
        /// 结束录音
        /// </summary>
        /// <returns></returns>
        internal bool StopRecorder()
        {
            waveIn.StopRecording();
            return true;
        }
        /// <summary>
        /// 录音回调函数，写入数据
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void OnDataAviailable(object sender, WaveInEventArgs e)
        {
            try
            {
                byte[] buffer = e.Buffer;
                int bytesRecorded = e.BytesRecorded;
                long maxFileLength = this.recordingFormat.AverageBytesPerSecond * 60;
                var toWrite = (int)Math.Min(maxFileLength - writer.Length, bytesRecorded);
                if (toWrite > 0)
                {
                    writer.Write(buffer, 0, bytesRecorded);                   
                }
            }
            catch (Exception ex)
            {

                Log.MyLog.WriteLogFile("录音写入失败：" + ex.ToString(), "BaiduSpeech");
            }
        }
        /// <summary>
        /// 录音结束回调函数
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void OnRecordingStopped(object sender, StoppedEventArgs e)
        {
            writer.Dispose();
            BaiduSpeechApi();
        }
        /// <summary>
        /// 百度语音识别
        /// </summary>
        private string BaiduSpeechApi()
        {
            try
            {
                var APP_ID = "";
                var API_KEY = "";
                var SECRET_KEY = "";

                var client = new Baidu.Aip.Speech.Asr(APP_ID, API_KEY, SECRET_KEY);
                client.Timeout = 30000;  // 修改超时时间
                var data = File.ReadAllBytes("speech.wav");
                // 可选参数
                var options = new Dictionary<string, object>
             {
                {"dev_pid", 1537}  //语音模型1536代表普通话，其他请查看官方文档
             };
                client.Timeout = 120000; // 若语音较长，建议设置更大的超时时间. ms
                var result = client.Recognize(data, "pcm", 16000, options);
                return JsonConvert.SerializeObject(result);
            }
            catch (Exception ex)
            {

                Log.MyLog.WriteLogFile("百度语音识别失败：" + ex.ToString(), "BaiduSpeech");
                return null;
            }
            
        }
    }
}