/* eslint-disable max-classes-per-file */
// Modified for Iris
// Original source https://github.com/badaix/snapcast
const Flac = require('libflacjs/dist/libflac.js');

// declare window.webkitAudioContext for the ts compiler
interface Window {
  webkitAudioContext: typeof AudioContext
}

function setCookie(key: string, value: string, exdays: number = -1) {
  let d = new Date();
  if (exdays < 0)
      exdays = 10 * 365;
  d.setTime(d.getTime() + (exdays * 24 * 60 * 60 * 1000));
  let expires = "expires=" + d.toUTCString();
  document.cookie = key + "=" + value + ";" + expires + ";sameSite=Strict;path=/";
}


function getPersistentValue(key: string, defaultValue: string = ""): string {
  if (!!window.localStorage) {
      const value = window.localStorage.getItem(key);
      if (value !== null) {
          return value;
      }
      window.localStorage.setItem(key, defaultValue);
      return defaultValue;
  }
  // Fallback to cookies if localStorage is not available.
  let name = key + "=";
  let decodedCookie = decodeURIComponent(document.cookie);
  let ca = decodedCookie.split(';');
  for (let c of ca) {
      c = c.trimLeft();
      if (c.indexOf(name) == 0) {
          return c.substring(name.length, c.length);
      }
  }
  setCookie(key, defaultValue);
  return defaultValue;
}

function getChromeVersion(): number | null {
  const raw = navigator.userAgent.match(/Chrom(e|ium)\/([0-9]+)\./);
  return raw ? parseInt(raw[2]) : null;
}

function uuidv4(): string {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
      var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
      return v.toString(16);
  });
}


class Tv {
  constructor(sec: number, usec: number) {
      this.sec = sec;
      this.usec = usec;
  }

  setMilliseconds(ms: number) {
      this.sec = Math.floor(ms / 1000);
      this.usec = Math.floor(ms * 1000) % 1000000;
  }

  getMilliseconds(): number {
      return this.sec * 1000 + this.usec / 1000;
  }

  sec: number = 0;
  usec: number = 0;
}


class BaseMessage {
  constructor(_buffer?: ArrayBuffer) {
  }

  deserialize(buffer: ArrayBuffer) {
      let view = new DataView(buffer);
      this.type = view.getUint16(0, true);
      this.id = view.getUint16(2, true);
      this.refersTo = view.getUint16(4, true);
      this.received = new Tv(view.getInt32(6, true), view.getInt32(10, true));
      this.sent = new Tv(view.getInt32(14, true), view.getInt32(18, true));
      this.size = view.getUint32(22, true);
  }

  serialize(): ArrayBuffer {
      this.size = 26 + this.getSize();
      let buffer = new ArrayBuffer(this.size);
      let view = new DataView(buffer);
      view.setUint16(0, this.type, true);
      view.setUint16(2, this.id, true);
      view.setUint16(4, this.refersTo, true);
      view.setInt32(6, this.sent.sec, true);
      view.setInt32(10, this.sent.usec, true);
      view.setInt32(14, this.received.sec, true);
      view.setInt32(18, this.received.usec, true);
      view.setUint32(22, this.size, true);
      return buffer;
  }

  getSize() {
      return 0;
  }

  type: number = 0;
  id: number = 0;
  refersTo: number = 0;
  received: Tv = new Tv(0, 0);
  sent: Tv = new Tv(0, 0);
  size: number = 0;
}


class CodecMessage extends BaseMessage {
  constructor(buffer?: ArrayBuffer) {
      super(buffer);
      this.payload = new ArrayBuffer(0);
      if (buffer) {
          this.deserialize(buffer);
      }
      this.type = 1;
  }

  deserialize(buffer: ArrayBuffer) {
      super.deserialize(buffer);
      let view = new DataView(buffer);
      let codecSize = view.getInt32(26, true);
      let decoder = new TextDecoder("utf-8");
      this.codec = decoder.decode(buffer.slice(30, 30 + codecSize));
      let payloadSize = view.getInt32(30 + codecSize, true);
      // console.log("payload size: " + payloadSize);
      this.payload = buffer.slice(34 + codecSize, 34 + codecSize + payloadSize);
      // console.log("payload: " + this.payload);
  }

  codec: string = "";
  payload: ArrayBuffer;
}


class TimeMessage extends BaseMessage {
  constructor(buffer?: ArrayBuffer) {
      super(buffer);
      if (buffer) {
          this.deserialize(buffer);
      }
      this.type = 4;
  }

  deserialize(buffer: ArrayBuffer) {
      super.deserialize(buffer);
      let view = new DataView(buffer);
      this.latency = new Tv(view.getInt32(26, true), view.getInt32(30, true));
  }

  serialize(): ArrayBuffer {
      let buffer = super.serialize();
      let view = new DataView(buffer);
      view.setInt32(26, this.latency.sec, true);
      view.setInt32(30, this.latency.usec, true);
      return buffer;
  }

  getSize() {
      return 8;
  }

  latency: Tv = new Tv(0, 0);
}


class JsonMessage extends BaseMessage {
  constructor(buffer?: ArrayBuffer) {
      super(buffer);
      if (buffer) {
          this.deserialize(buffer);
      }
  }

  deserialize(buffer: ArrayBuffer) {
      super.deserialize(buffer);
      let view = new DataView(buffer);
      let size = view.getUint32(26, true);
      let decoder = new TextDecoder();
      this.json = JSON.parse(decoder.decode(buffer.slice(30, 30 + size)));
  }

  serialize(): ArrayBuffer {
      let buffer = super.serialize();
      let view = new DataView(buffer);
      let jsonStr = JSON.stringify(this.json);
      view.setUint32(26, jsonStr.length, true);
      let encoder = new TextEncoder();
      let encoded = encoder.encode(jsonStr);
      for (let i = 0; i < encoded.length; ++i)
          view.setUint8(30 + i, encoded[i]);
      return buffer;
  }

  getSize() {
      let encoder = new TextEncoder();
      let encoded = encoder.encode(JSON.stringify(this.json));
      return encoded.length + 4;
      // return JSON.stringify(this.json).length;
  }

  json: any;
}


class HelloMessage extends JsonMessage {
  constructor(buffer?: ArrayBuffer) {
      super(buffer);
      if (buffer) {
          this.deserialize(buffer);
      }
      this.type = 5;
  }

  deserialize(buffer: ArrayBuffer) {
      super.deserialize(buffer);
      this.mac = this.json["MAC"];
      this.hostname = this.json["HostName"];
      this.version = this.json["Version"];
      this.clientName = this.json["ClientName"];
      this.os = this.json["OS"];
      this.arch = this.json["Arch"];
      this.instance = this.json["Instance"];
      this.uniqueId = this.json["ID"];
      this.snapStreamProtocolVersion = this.json["SnapStreamProtocolVersion"];
  }

  serialize(): ArrayBuffer {
      this.json = { "MAC": this.mac, "HostName": this.hostname, "Version": this.version, "ClientName": this.clientName, "OS": this.os, "Arch": this.arch, "Instance": this.instance, "ID": this.uniqueId, "SnapStreamProtocolVersion": this.snapStreamProtocolVersion };
      return super.serialize();
  }

  mac: string = "";
  hostname: string = "";
  version: string = "0.1.0";
  clientName = "Snapweb";
  os: string = "";
  arch: string = "web";
  instance: number = 1;
  uniqueId: string = "";
  snapStreamProtocolVersion: number = 2;
}


class ServerSettingsMessage extends JsonMessage {
  constructor(buffer?: ArrayBuffer) {
      super(buffer);
      if (buffer) {
          this.deserialize(buffer);
      }
      this.type = 3;
  }

  deserialize(buffer: ArrayBuffer) {
      super.deserialize(buffer);
      this.bufferMs = this.json["bufferMs"];
      this.latency = this.json["latency"];
      this.volumePercent = this.json["volume"];
      this.muted = this.json["muted"];
  }

  serialize(): ArrayBuffer {
      this.json = { "bufferMs": this.bufferMs, "latency": this.latency, "volume": this.volumePercent, "muted": this.muted };
      return super.serialize();
  }

  bufferMs: number = 0;
  latency: number = 0;
  volumePercent: number = 0;
  muted: boolean = false;
}


class PcmChunkMessage extends BaseMessage {
  constructor(buffer: ArrayBuffer, sampleFormat: SampleFormat) {
      super(buffer);
      this.deserialize(buffer);
      this.sampleFormat = sampleFormat;
      this.type = 2;
  }

  deserialize(buffer: ArrayBuffer) {
      super.deserialize(buffer);
      let view = new DataView(buffer);
      this.timestamp = new Tv(view.getInt32(26, true), view.getInt32(30, true));
      // this.payloadSize = view.getUint32(34, true);
      this.payload = buffer.slice(38);//, this.payloadSize + 38));// , this.payloadSize);
      // // console.log("ts: " + this.timestamp.sec + " " + this.timestamp.usec + ", payload: " + this.payloadSize + ", len: " + this.payload.byteLength);
  }

  readFrames(frames: number): ArrayBuffer {
      let frameCnt = frames;
      let frameSize = this.sampleFormat.frameSize();
      if (this.idx + frames > this.payloadSize() / frameSize)
          frameCnt = (this.payloadSize() / frameSize) - this.idx;
      let begin = this.idx * frameSize;
      this.idx += frameCnt;
      let end = begin + frameCnt * frameSize;
      // // console.log("readFrames: " + frames + ", result: " + frameCnt + ", begin: " + begin + ", end: " + end + ", payload: " + this.payload.byteLength);
      return this.payload.slice(begin, end);
  }

  getFrameCount(): number {
      return (this.payloadSize() / this.sampleFormat.frameSize());
  }

  isEndOfChunk(): boolean {
      return this.idx >= this.getFrameCount();
  }

  startMs(): number {
      return this.timestamp.getMilliseconds() + 1000 * (this.idx / this.sampleFormat.rate);
  }

  duration(): number {
      return 1000 * ((this.getFrameCount() - this.idx) / this.sampleFormat.rate);
  }

  payloadSize(): number {
      return this.payload.byteLength;
  }

  clearPayload(): void {
      this.payload = new ArrayBuffer(0);
  }

  addPayload(buffer: ArrayBuffer) {
      let payload = new ArrayBuffer(this.payload.byteLength + buffer.byteLength);
      let view = new DataView(payload);
      let viewOld = new DataView(this.payload);
      let viewNew = new DataView(buffer);
      for (let i = 0; i < viewOld.byteLength; ++i) {
          view.setInt8(i, viewOld.getInt8(i));
      }
      for (let i = 0; i < viewNew.byteLength; ++i) {
          view.setInt8(i + viewOld.byteLength, viewNew.getInt8(i));
      }
      this.payload = payload;
  }

  timestamp: Tv = new Tv(0, 0);
  // payloadSize: number = 0;
  payload: ArrayBuffer = new ArrayBuffer(0);
  idx: number = 0;
  sampleFormat: SampleFormat;
}


class AudioStream {
  constructor(public timeProvider: TimeProvider, public sampleFormat: SampleFormat, public bufferMs: number) {
  }

  chunks: Array<PcmChunkMessage> = new Array<PcmChunkMessage>();

  setVolume(percent: number, muted: boolean) {
      // let base = 10;
      this.volume = percent / 100; // (Math.pow(base, percent / 100) - 1) / (base - 1);
      // console.log("setVolume: " + percent + " => " + this.volume + ", muted: " + this.muted);
      this.muted = muted;
  }

  addChunk(chunk: PcmChunkMessage) {
      this.chunks.push(chunk);
      // let oldest = this.timeProvider.serverNow() - this.chunks[0].timestamp.getMilliseconds();
      // let newest = this.timeProvider.serverNow() - this.chunks[this.chunks.length - 1].timestamp.getMilliseconds();
      // // console.debug("chunks: " + this.chunks.length + ", oldest: " + oldest.toFixed(2) + ", newest: " + newest.toFixed(2));

      while (this.chunks.length > 0) {
          let age = this.timeProvider.serverNow() - this.chunks[0].timestamp.getMilliseconds();
          // todo: consider buffer ms
          if (age > 5000 + this.bufferMs) {
              this.chunks.shift();
              // console.log("Dropping old chunk: " + age.toFixed(2) + ", left: " + this.chunks.length);
          }
          else
              break;
      }
  }

  getNextBuffer(buffer: AudioBuffer, playTimeMs: number) {
      if (!this.chunk) {
          this.chunk = this.chunks.shift()
      }
      // let age = this.timeProvider.serverTime(this.playTime * 1000) - startMs;
      let frames = buffer.length;
      // // console.debug("getNextBuffer: " + frames + ", play time: " + playTimeMs.toFixed(2));
      let left = new Float32Array(frames);
      let right = new Float32Array(frames);
      let read = 0;
      let pos = 0;
      // let volume = this.muted ? 0 : this.volume;
      let serverPlayTimeMs = this.timeProvider.serverTime(playTimeMs);
      if (this.chunk) {
          let age = serverPlayTimeMs - this.chunk.startMs();// - 500;
          let reqChunkDuration = frames / this.sampleFormat.msRate();
          let secs = Math.floor(Date.now() / 1000);
          if (this.lastLog != secs) {
              this.lastLog = secs;
              // console.log("age: " + age.toFixed(2) + ", req: " + reqChunkDuration);
          }
          if (age < -reqChunkDuration) {
              // console.log("age: " + age.toFixed(2) + " < req: " + reqChunkDuration * -1 + ", chunk.startMs: " + this.chunk.startMs().toFixed(2) + ", timestamp: " + this.chunk.timestamp.getMilliseconds().toFixed(2));
              // console.log("Chunk too young, returning silence");
          } else {
              if (Math.abs(age) > 5) {
                  // We are 5ms apart, do a hard sync, i.e. don't play faster/slower, 
                  // but seek to the desired position instead
                  while (this.chunk && age > this.chunk.duration()) {
                      // console.log("Chunk too old, dropping (age: " + age.toFixed(2) + " > " + this.chunk.duration().toFixed(2) + ")");
                      this.chunk = this.chunks.shift();
                      if (!this.chunk)
                          break;
                      age = serverPlayTimeMs - (this.chunk as PcmChunkMessage).startMs();
                  }
                  if (this.chunk) {
                      if (age > 0) {
                          // console.log("Fast forwarding " + age.toFixed(2) + "ms");
                          this.chunk.readFrames(Math.floor(age * this.chunk.sampleFormat.msRate()));
                      }
                      else if (age < 0) {
                          // console.log("Playing silence " + -age.toFixed(2) + "ms");
                          let silentFrames = Math.floor(-age * this.chunk.sampleFormat.msRate());
                          left.fill(0, 0, silentFrames);
                          right.fill(0, 0, silentFrames);
                          read = silentFrames;
                          pos = silentFrames;
                      }
                      age = 0;
                  }
              }
              // else if (age > 0.1) {
              //     let rate = age * 0.0005;
              //     rate = 1.0 - Math.min(rate, 0.0005);
              //     // console.debug("Age > 0, rate: " + rate);
              //     // we are late (age > 0), this means we are not playing fast enough
              //     // => the real sample rate seems to be lower, we have to drop some frames
              //     this.setRealSampleRate(this.sampleFormat.rate * rate); // 0.9999);    
              // }
              // else if (age < -0.1) {
              //     let rate = -age * 0.0005;
              //     rate = 1.0 + Math.min(rate, 0.0005);
              //     // console.debug("Age < 0, rate: " + rate);
              //     // we are early (age > 0), this means we are playing too fast
              //     // => the real sample rate seems to be higher, we have to insert some frames
              //     this.setRealSampleRate(this.sampleFormat.rate * rate); // 0.9999);    
              // }
              // else {
              //     this.setRealSampleRate(this.sampleFormat.rate);
              // }


              let addFrames = 0;
              let everyN = 0;
              if (age > 0.1) {
                  addFrames = Math.ceil(age); // / 5);
              } else if (age < -0.1) {
                  addFrames = Math.floor(age); // / 5);
              }
              // addFrames = -2;
              let readFrames = frames + addFrames - read;
              if (addFrames != 0)
                  everyN = Math.ceil((frames + addFrames - read) / (Math.abs(addFrames) + 1));

              // addFrames = 0;
              // // console.debug("frames: " + frames + ", readFrames: " + readFrames + ", addFrames: " + addFrames + ", everyN: " + everyN);
              while ((read < readFrames) && this.chunk) {
                  let pcmChunk = this.chunk as PcmChunkMessage;
                  let pcmBuffer = pcmChunk.readFrames(readFrames - read);
                  let payload = new Int16Array(pcmBuffer);
                  // // console.debug("readFrames: " + (frames - read) + ", read: " + pcmBuffer.byteLength + ", payload: " + payload.length);
                  // read += (pcmBuffer.byteLength / this.sampleFormat.frameSize());
                  for (let i = 0; i < payload.length; i += 2) {
                      read++;
                      left[pos] = (payload[i] / 32768); // * volume;
                      right[pos] = (payload[i + 1] / 32768); // * volume;
                      if ((everyN != 0) && (read % everyN == 0)) {
                          if (addFrames > 0) {
                              pos--;
                          } else {
                              left[pos + 1] = left[pos];
                              right[pos + 1] = right[pos];
                              pos++;
                              // // console.log("Add: " + pos);
                          }
                      }
                      pos++;
                  }
                  if (pcmChunk.isEndOfChunk()) {
                      this.chunk = this.chunks.shift();
                  }
              }
              if (addFrames != 0)
                  // console.debug("Pos: " + pos + ", frames: " + frames + ", add: " + addFrames + ", everyN: " + everyN);
              if (read == readFrames)
                  read = frames;
          }
      }

      if (read < frames) {
          // console.log("Failed to get chunk, read: " + read + "/" + frames + ", chunks left: " + this.chunks.length);
          left.fill(0, pos);
          right.fill(0, pos);
      }

      // copyToChannel is not supported by Safari
      buffer.getChannelData(0).set(left);
      buffer.getChannelData(1).set(right);
  }


  // setRealSampleRate(sampleRate: number) {
  //     if (sampleRate == this.sampleFormat.rate) {
  //         this.correctAfterXFrames = 0;
  //     }
  //     else {
  //         this.correctAfterXFrames = Math.ceil((this.sampleFormat.rate / sampleRate) / (this.sampleFormat.rate / sampleRate - 1.));
  //         // console.debug("setRealSampleRate: " + sampleRate + ", correct after X: " + this.correctAfterXFrames);
  //     }
  // }


  chunk?: PcmChunkMessage = undefined;
  volume: number = 1;
  muted: boolean = false;
  lastLog: number = 0;
  // correctAfterXFrames: number = 0;
}


class TimeProvider {
  constructor(ctx: AudioContext | undefined = undefined) {
      if (ctx) {
          this.setAudioContext(ctx);
      }
  }

  setAudioContext(ctx: AudioContext) {
      this.ctx = ctx;
      this.reset();
  }

  reset() {
      this.diffBuffer.length = 0;
      this.diff = 0;
  }

  setDiff(c2s: number, s2c: number) {
      if (this.now() == 0) {
          this.reset()
      } else {
          if (this.diffBuffer.push((c2s - s2c) / 2) > 100)
              this.diffBuffer.shift();
          let sorted = [...this.diffBuffer];
          sorted.sort()
          this.diff = sorted[Math.floor(sorted.length / 2)];
      }
      // // console.debug("c2s: " + c2s.toFixed(2) + ", s2c: " + s2c.toFixed(2) + ", diff: " + this.diff.toFixed(2) + ", now: " + this.now().toFixed(2) + ", server.now: " + this.serverNow().toFixed(2) + ", win.now: " + window.performance.now().toFixed(2));
      // // console.log("now: " + this.now() + "\t" + this.now() + "\t" + this.now());
  }

  now() {
      if (!this.ctx) {
          return window.performance.now();
      } else {
          // Use the more accurate getOutputTimestamp if available, fallback to ctx.currentTime otherwise.
          const contextTime = !!this.ctx.getOutputTimestamp ? this.ctx.getOutputTimestamp().contextTime : undefined;
          return (contextTime !== undefined ? contextTime : this.ctx.currentTime) * 1000;
      }
  }

  nowSec() {
      return this.now() / 1000;
  }

  serverNow() {
      return this.serverTime(this.now());
  }

  serverTime(localTimeMs: number) {
      return localTimeMs + this.diff;
  }

  diffBuffer: Array<number> = new Array<number>();
  diff: number = 0;
  ctx: AudioContext | undefined;
}


class SampleFormat {
  rate: number = 48000;
  channels: number = 2;
  bits: number = 16;

  public msRate(): number {
      return this.rate / 1000;
  }

  public toString(): string {
      return this.rate + ":" + this.bits + ":" + this.channels;
  }

  public sampleSize(): number {
      if (this.bits == 24) {
          return 4;
      }
      return this.bits / 8;
  }

  public frameSize(): number {
      return this.channels * this.sampleSize();
  }

  public durationMs(bytes: number) {
      return (bytes / this.frameSize()) * this.msRate();
  }
}


class Decoder {
  setHeader(_buffer: ArrayBuffer): SampleFormat | null {
      return new SampleFormat();
  }

  decode(_chunk: PcmChunkMessage): PcmChunkMessage | null {
      return null;
  }
}


class OpusDecoder extends Decoder {
  setHeader(buffer: ArrayBuffer): SampleFormat | null {
      let view = new DataView(buffer);
      let ID_OPUS = 0x4F505553;
      if (buffer.byteLength < 12) {
          // console.error("Opus header too small: " + buffer.byteLength);
          return null;
      } else if (view.getUint32(0, true) != ID_OPUS) {
          // console.error("Opus header too small: " + buffer.byteLength);
          return null;
      }

      let format = new SampleFormat();
      format.rate = view.getUint32(4, true);
      format.bits = view.getUint16(8, true);
      format.channels = view.getUint16(10, true);
      // console.log("Opus samplerate: " + format.toString());
      return format;
  }

  decode(_chunk: PcmChunkMessage): PcmChunkMessage | null {
      return null;
  }
}


class FlacDecoder extends Decoder {
  constructor() {
      super();
      this.decoder = Flac.create_libflac_decoder(true);
      if (this.decoder) {
          let init_status = Flac.init_decoder_stream(this.decoder, this.read_callback_fn.bind(this), this.write_callback_fn.bind(this), this.error_callback_fn.bind(this), this.metadata_callback_fn.bind(this), false);
          // console.log("Flac init: " + init_status);
          Flac.setOptions(this.decoder, { analyseSubframes: true, analyseResiduals: true });
      }
      this.sampleFormat = new SampleFormat();
      this.flacChunk = new ArrayBuffer(0);
      // this.pcmChunk  = new PcmChunkMessage();

      // Flac.setOptions(this.decoder, {analyseSubframes: analyse_frames, analyseResiduals: analyse_residuals});
      // flac_ok &= init_status == 0;
      // // console.log("flac init     : " + flac_ok);//DEBUG
  }

  decode(chunk: PcmChunkMessage): PcmChunkMessage | null {
      // // console.log("Flac decode: " + chunk.payload.byteLength);
      this.flacChunk = chunk.payload.slice(0);
      this.pcmChunk = chunk;
      this.pcmChunk!.clearPayload();
      this.cacheInfo = { cachedBlocks: 0, isCachedChunk: true };
      // // console.log("Flac len: " + this.flacChunk.byteLength);
      while (this.flacChunk.byteLength && Flac.FLAC__stream_decoder_process_single(this.decoder)) {
          Flac.FLAC__stream_decoder_get_state(this.decoder);
          // let state = Flac.FLAC__stream_decoder_get_state(this.decoder);
          // // console.log("State: " + state);
      }
      // // console.log("Pcm payload: " + this.pcmChunk!.payloadSize());
      if (this.cacheInfo.cachedBlocks > 0) {
          let diffMs = this.cacheInfo.cachedBlocks / this.sampleFormat.msRate();
          // // console.log("Cached: " + this.cacheInfo.cachedBlocks + ", " + diffMs + "ms");
          this.pcmChunk!.timestamp.setMilliseconds(this.pcmChunk!.timestamp.getMilliseconds() - diffMs);
      }
      return this.pcmChunk!;
  }

  read_callback_fn(bufferSize: number): Flac.ReadResult | Flac.CompletedReadResult {
      // // console.log('  decode read callback, buffer bytes max=', bufferSize);
      if (this.header) {
          // console.log("  header: " + this.header.byteLength);
          let data = new Uint8Array(this.header);
          this.header = null;
          return { buffer: data, readDataLength: data.byteLength, error: false };
      } else if (this.flacChunk) {
          // // console.log("  flacChunk: " + this.flacChunk.byteLength);
          // a fresh read => next call to write will not be from cached data
          this.cacheInfo.isCachedChunk = false;
          let data = new Uint8Array(this.flacChunk.slice(0, Math.min(bufferSize, this.flacChunk.byteLength)));
          this.flacChunk = this.flacChunk.slice(data.byteLength);
          return { buffer: data, readDataLength: data.byteLength, error: false };
      }
      return { buffer: new Uint8Array(0), readDataLength: 0, error: false };
  }

  write_callback_fn(data: Array<Uint8Array>, frameInfo: Flac.BlockMetadata) {
      // // console.log("  write frame metadata: " + frameInfo + ", len: " + data.length);
      if (this.cacheInfo.isCachedChunk) {
          // there was no call to read, so it's some cached data
          this.cacheInfo.cachedBlocks += frameInfo.blocksize;
      }
      let payload = new ArrayBuffer((frameInfo.bitsPerSample / 8) * frameInfo.channels * frameInfo.blocksize);
      let view = new DataView(payload);
      for (let channel: number = 0; channel < frameInfo.channels; ++channel) {
          let channelData = new DataView(data[channel].buffer, 0, data[channel].buffer.byteLength);
          // // console.log("channelData: " + channelData.byteLength + ", blocksize: " + frameInfo.blocksize);
          for (let i: number = 0; i < frameInfo.blocksize; ++i) {
              view.setInt16(2 * (frameInfo.channels * i + channel), channelData.getInt16(2 * i, true), true);
          }
      }
      this.pcmChunk!.addPayload(payload);
      // // console.log("write: " + payload.byteLength + ", len: " + this.pcmChunk!.payloadSize());
  }

  /** @memberOf decode */
  metadata_callback_fn(data: any) {
      // console.info('meta data: ', data);
      // let view = new DataView(data);
      this.sampleFormat.rate = data.sampleRate;
      this.sampleFormat.channels = data.channels;
      this.sampleFormat.bits = data.bitsPerSample;
      // console.log("metadata_callback_fn, sampleformat: " + this.sampleFormat.toString());
  }

  /** @memberOf decode */
  error_callback_fn(err: any, errMsg: any) {
      // console.error('decode error callback', err, errMsg);
  }

  setHeader(buffer: ArrayBuffer): SampleFormat | null {
      this.header = buffer.slice(0);
      Flac.FLAC__stream_decoder_process_until_end_of_metadata(this.decoder);
      return this.sampleFormat;
  }

  sampleFormat: SampleFormat;
  decoder: number;
  header: ArrayBuffer | null = null;
  flacChunk: ArrayBuffer;
  pcmChunk?: PcmChunkMessage;

  cacheInfo: { isCachedChunk: boolean, cachedBlocks: number } = { isCachedChunk: false, cachedBlocks: 0 };
}


class PlayBuffer {
  constructor(buffer: AudioBuffer, playTime: number, source: AudioBufferSourceNode, destination: AudioNode) {
      this.buffer = buffer;
      this.playTime = playTime;
      this.source = source;
      this.source.buffer = this.buffer;
      this.source.connect(destination);
      this.onended = (_playBuffer: PlayBuffer) => { };
  }

  public onended: (playBuffer: PlayBuffer) => void

  start() {
      this.source.onended = () => {
          this.onended(this);
      }
      this.source.start(this.playTime);
  }

  buffer: AudioBuffer;
  playTime: number;
  source: AudioBufferSourceNode;
  num: number = 0;
}


class PcmDecoder extends Decoder {
  setHeader(buffer: ArrayBuffer): SampleFormat | null {
      let sampleFormat = new SampleFormat();
      let view = new DataView(buffer);
      sampleFormat.channels = view.getUint16(22, true);
      sampleFormat.rate = view.getUint32(24, true);
      sampleFormat.bits = view.getUint16(34, true);
      return sampleFormat;
  }

  decode(chunk: PcmChunkMessage): PcmChunkMessage | null {
      return chunk;
  }
}


class SnapStream {
  constructor(baseUrl: string) {
      this.baseUrl = baseUrl;
      this.timeProvider = new TimeProvider();

      if (this.setupAudioContext()) {
          this.connect();
      } else {
          alert("Sorry, but the Web Audio API is not supported by your browser");
      }
  }

  private setupAudioContext(): boolean {
      let AudioContext = window.AudioContext // Default
          || window.webkitAudioContext // Safari and old versions of Chrome
          || false;

      if (AudioContext) {
          let options: AudioContextOptions | undefined;
          options = { latencyHint: "playback", sampleRate: this.sampleFormat ? this.sampleFormat.rate : undefined };

          const chromeVersion = getChromeVersion();
          if ((chromeVersion !== null && chromeVersion < 55) || !window.AudioContext) {
              // Some older browsers won't decode the stream if options are provided.
              options = undefined;
          }

          this.ctx = new AudioContext(options);
          this.gainNode = this.ctx.createGain();
          this.gainNode.connect(this.ctx.destination);
      } else {
          // Web Audio API is not supported
          return false;
      }
      return true;
  }

  private connect() {
      this.streamsocket = new WebSocket(this.baseUrl + '/stream');
      this.streamsocket.binaryType = "arraybuffer";
      this.streamsocket.onmessage = (ev) => this.onMessage(ev);

      this.streamsocket.onopen = () => {
          // console.log("on open");
          let hello = new HelloMessage();

          hello.mac = "00:00:00:00:00:00";
          hello.arch = "web";
          hello.os = navigator.platform;
          hello.hostname = "Snapweb client";
          hello.uniqueId = getPersistentValue("uniqueId", uuidv4());
          this.sendMessage(hello);
          this.syncTime();
          this.syncHandle = window.setInterval(() => this.syncTime(), 1000);
      }
      this.streamsocket.onerror = (ev) => { console.error('error:', ev); };
      this.streamsocket.onclose = () => {
          window.clearInterval(this.syncHandle);
          // console.info('connection lost, reconnecting in 1s');
          setTimeout(() => this.connect(), 1000);
      }
  }

  private onMessage(msg: MessageEvent) {
      let view = new DataView(msg.data);
      let type = view.getUint16(0, true);
      if (type == 1) {
          let codec = new CodecMessage(msg.data);
          // console.log("Codec: " + codec.codec);
          if (codec.codec == "flac") {
              this.decoder = new FlacDecoder();
          } else if (codec.codec == "pcm") {
              this.decoder = new PcmDecoder();
          } else if (codec.codec == "opus") {
              this.decoder = new OpusDecoder();
              alert("Codec not supported: " + codec.codec);
          } else {
              alert("Codec not supported: " + codec.codec);
          }
          if (this.decoder) {
              this.sampleFormat = this.decoder.setHeader(codec.payload)!;
              // console.log("Sampleformat: " + this.sampleFormat.toString());
              if ((this.sampleFormat.channels != 2) || (this.sampleFormat.bits != 16)) {
                  alert("Stream must be stereo with 16 bit depth, actual format: " + this.sampleFormat.toString());
              } else {
                  if (this.bufferDurationMs != 0) {
                      this.bufferFrameCount = Math.floor(this.bufferDurationMs * this.sampleFormat.msRate());
                  }

                  if (window.AudioContext) {
                      // we are not using webkitAudioContext, so it's safe to setup a new AudioContext with the new samplerate
                      // since this code is not triggered by direct user input, we cannt create a webkitAudioContext here
                      this.stopAudio();
                      this.setupAudioContext();
                  }

                  this.ctx.resume();
                  this.timeProvider.setAudioContext(this.ctx);
                  this.gainNode.gain.value = this.serverSettings!.muted ? 0 : this.serverSettings!.volumePercent / 100;
                  // this.timeProvider = new TimeProvider(this.ctx);
                  this.stream = new AudioStream(this.timeProvider, this.sampleFormat, this.bufferMs);
                  this.latency = (this.ctx.baseLatency !== undefined ? this.ctx.baseLatency : 0) + (this.ctx.outputLatency !== undefined ? this.ctx.outputLatency : 0)
                  // console.log("Base latency: " + this.ctx.baseLatency + ", output latency: " + this.ctx.outputLatency + ", latency: " + this.latency);
                  this.play();
              }
          }
      } else if (type == 2) {
          let pcmChunk = new PcmChunkMessage(msg.data, this.sampleFormat as SampleFormat);
          if (this.decoder) {
              let decoded = this.decoder.decode(pcmChunk);
              if (decoded) {
                  this.stream!.addChunk(decoded);
              }
          }
      } else if (type == 3) {
          this.serverSettings = new ServerSettingsMessage(msg.data);
          this.gainNode.gain.value = this.serverSettings.muted ? 0 : this.serverSettings.volumePercent / 100;
          this.bufferMs = this.serverSettings.bufferMs - this.serverSettings.latency;
          // console.log("ServerSettings bufferMs: " + this.serverSettings.bufferMs + ", latency: " + this.serverSettings.latency + ", volume: " + this.serverSettings.volumePercent + ", muted: " + this.serverSettings.muted);
      } else if (type == 4) {
          if (this.timeProvider) {
              let time = new TimeMessage(msg.data);
              this.timeProvider.setDiff(time.latency.getMilliseconds(), this.timeProvider.now() - time.sent.getMilliseconds());
          }
          // // console.log("Time sec: " + time.latency.sec + ", usec: " + time.latency.usec + ", diff: " + this.timeProvider.diff);
      } else {
          // console.info("Message not handled, type: " + type);
      }
  }

  private sendMessage(msg: BaseMessage) {
      msg.sent = new Tv(0, 0);
      msg.sent.setMilliseconds(this.timeProvider.now());
      msg.id = ++this.msgId;
      if (this.streamsocket.readyState == this.streamsocket.OPEN) {
          this.streamsocket.send(msg.serialize());
      }
  }

  private syncTime() {
      let t = new TimeMessage();
      t.latency.setMilliseconds(this.timeProvider.now());
      this.sendMessage(t);
      // // console.log("prepareSource median: " + Math.round(this.median * 10) / 10);
  }

  private stopAudio() {
      // if (this.ctx) {
      //     this.ctx.close();
      // }
      this.ctx.suspend();
      while (this.audioBuffers.length > 0) {
          let buffer = this.audioBuffers.pop();
          buffer!.onended = () => { };
          buffer!.source.stop();
      }
      while (this.freeBuffers.length > 0) {
          this.freeBuffers.pop();
      }
  }

  public stop() {
      window.clearInterval(this.syncHandle);
      this.stopAudio();
      if ([WebSocket.OPEN, WebSocket.CONNECTING].includes(this.streamsocket.readyState)) {
          this.streamsocket.onclose = () => { };
          this.streamsocket.close();
      }
  }

  public play() {
      this.playTime = this.timeProvider.nowSec() + 0.1;
      for (let i = 1; i <= this.audioBufferCount; ++i) {
          this.playNext();
      }
  }

  public playNext() {
      let buffer = this.freeBuffers.pop() || this.ctx!.createBuffer(this.sampleFormat!.channels, this.bufferFrameCount, this.sampleFormat!.rate);
      let playTimeMs = (this.playTime + this.latency) * 1000 - this.bufferMs;
      this.stream!.getNextBuffer(buffer, playTimeMs);

      let source = this.ctx!.createBufferSource();
      let playBuffer = new PlayBuffer(buffer, this.playTime, source, this.gainNode!);
      this.audioBuffers.push(playBuffer);
      playBuffer.num = ++this.bufferNum;
      playBuffer.onended = (buffer: PlayBuffer) => {
          // let diff = this.timeProvider.nowSec() - buffer.playTime;
          this.freeBuffers.push(this.audioBuffers.splice(this.audioBuffers.indexOf(buffer), 1)[0].buffer);
          // // console.debug("PlayBuffer " + playBuffer.num + " ended after: " + (diff * 1000) + ", in flight: " + this.audioBuffers.length);
          this.playNext();
      }
      playBuffer.start();
      this.playTime += this.bufferFrameCount / (this.sampleFormat as SampleFormat).rate;
  }

  baseUrl: string;
  streamsocket!: WebSocket;
  playTime: number = 0;
  msgId: number = 0;
  bufferDurationMs: number = 80; // 0;
  bufferFrameCount: number = 3844; // 9600; // 2400;//8192;
  syncHandle: number = -1;
  // ageBuffer: Array<number>;
  audioBuffers: Array<PlayBuffer> = new Array<PlayBuffer>();
  freeBuffers: Array<AudioBuffer> = new Array<AudioBuffer>();

  timeProvider: TimeProvider;
  stream: AudioStream | undefined;
  ctx!: AudioContext; // | undefined;
  gainNode!: GainNode;
  serverSettings: ServerSettingsMessage | undefined;
  decoder: Decoder | undefined;
  sampleFormat: SampleFormat | undefined;

  // median: number = 0;
  audioBufferCount: number = 3;
  bufferMs: number = 1000;
  bufferNum: number = 0;

  latency: number = 0;
}

export {
  SnapStream,
}

export default {
  SnapStream,
};