#include <freertos/stream_buffer.h>

StreamBufferHandle_t xStreamMusic = NULL;//创建一个Stream Buffer 的 handler

void downloadTask(void *pvParam)
{
  String music;
  size_t xBytesSent;//The number of tytes written to the stream buffer.

  while (1) {
    //模拟从网路上下载音乐，放一些随机的延迟
    for (int i = 0; i < random(20, 40); i++) vTaskDelay(1);
    music = randomMusic();//随机生成一些数据

    xBytesSent = xStreamBufferSend(xStreamMusic,
                                   (void *)&music,
                                   sizeof(music),
                                   portMAX_DELAY);

    if (xBytesSent != sizeof(music)) {
      Serial.println("警告：xStreamBufferSend 写入数据出错");//Optional
    }
    vTaskDelay(100);
  }
}

void playBackTask(void *pvParam)
{
  size_t xReceivedBytes;//The number of bytes read from the stream buffer.
  size_t xReadBytes = 8 * 10 - 1;
  String music;

  while (1) {
    xReceivedBytes = xStreamBufferReceive(xStreamMusic,
                                          (void *)&music,
                                          xReadBytes,
                                          portMAX_DELAY);
    if (xReceivedBytes > 0) {
      decode(music);
    }
  }
}

void monitorTask (void *pvParam)
{
  size_t xAvailable, xUsed;
  bool isFull;
  while (1) {
    //Queries a stream buffer to see if it is full.
    if (xStreamBufferIsFull(xStreamMusic) == pdTRUE)
      Serial.println("xStreamMusic is full");
    //Queries a stream buffer to see how much free space it contains
    xAvailable = xStreamBufferSpacesAvailable(xStreamMusic);

    char msg[40];
    sprintf(msg,"xStreamBuffer已使用 %d 字节",xUsed);
    Serial.println(msg);
    sprintf(msg,"xStreamBuffer可用空间为 %d 字节",xAvailable);
    Serial.println(msg);

    vTaskDelay(2000);
  }
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");

  //
  const size_t xStreamBufferSizeBytes = 540;
  //
  const size_t xTriggerLevel = 8;
  xStreamMusic = xStreamBufferCreate(xStreamBufferSizeBytes,xTriggerLevel);

  if(xStreamMusic == NULL){
    Serial.println("UNABLE TO CREATE STREAM BUFFER");
  }else{
    xTaskCreate(downloadTask,"Download Music",1024*8,NULL,1,NULL);//下载音乐
    xTaskCreate(playBackTask,"Playback Music",1024*8,NULL,1,NULL);//解码播放音乐
    xTaskCreate(monitorTask,"Monitor Stream Buffer",1024*8,NULL,1,NULL);//对Stream Buffer进行监控
  }
  vTaskDelete(NULL);//setup 和loop 这个loopback 任务没用了，自宫了
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}