/*
   程序：  使用Stream Buffer 对流媒体数据，在任务间进行传输
          流媒体，读和写的大小都没有任何的限制

          读和写的大小可以不一致， 比如写入100 bytes, 可以分成两次每次50 bytes读取出来

   注意：  适合于一个任务写，另外一个任务读
          不适合多任务读写

          如果必须要用在多任务的读写，请将内容放入CRITICAL SECTION
          可以使用 MUTEX 或者 TASK Notification
   公众号：孤独的二进制

   API:
*/

//不要忘记include stream_buffer.h
#include <freertos/stream_buffer.h>

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

void Download_Task(void *pvParam){
  String music;
  size_t xBytesSent;    //The number of bytes written to the stream buffer.
  while(1){
    // music = randomMusic();
    music = twinkleTwinkle();
    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 PlayBack_Task(void *pvParam)
{
  String music;
  size_t xBytesReceive;    //The number of bytes written to the stream buffer.
  size_t xReadBytes = 8*10-1;
  while(1)
  {
     xBytesReceive = xStreamBufferReceive(xStreamMusic,&music,xReadBytes,portMAX_DELAY);
     if(xBytesReceive > 0)
     {
       decode(music);
     }
  }
}

void Monitor_Task(void *pvParam)
{
  size_t xAvailable, xUsed;
  bool isFull;
  while(1)
  {
    if (xStreamBufferIsFull(xStreamMusic) == pdTRUE) Serial.println("xStreamMusic 已满");
    xUsed =  xStreamBufferBytesAvailable(xStreamMusic);
    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() {
  Serial.begin(115200);

  //Stream Buffer的最大尺寸，如果超出可能内存空间，那么创建Stream Buffer就会失败
  const size_t xStreamBufferSizeBytes = 540;
  //Trigger Level - Stream Buffer内数据超过这个数值，才会被读取
  const size_t xTriggerLevel = 8;
  xStreamMusic = xStreamBufferCreate(xStreamBufferSizeBytes, xTriggerLevel);

  if ( xStreamMusic == NULL )
  { //内存不过，无法创建Stream Buffer
    Serial.println("UNABLE TO CREATE STREAM BUFFER");
  }
  else
  {
    xTaskCreate(Download_Task, "Download Music", 1024 * 8, NULL, 1, NULL); //下载音乐
    xTaskCreate(PlayBack_Task, "Playback Music", 1024 * 8, NULL, 1, NULL); //解码播放音乐
    xTaskCreate(Monitor_Task, "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() {

}