/*
   程序：  Message Buffer
          基于Stream Buffer上实现的, 在传输的时候用4个字节记录了sent的内容大小
          这样子读取的话，也可以一次读取对应大小的数据
          所以很适合 串口 接收和发送数据，每次的大小不定，但是接受和发送的数据量需要相同
*/

//不要忘记include message_buffer.h
#include <freertos/message_buffer.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);

MessageBufferHandle_t xMessageBuffer = NULL;

void readGPS(void * pvParam) {
  size_t xBytesSent; //The number of bytes written to the message buffer.
  String gpsInfo;
  while (1) {
    gpsInfo = randomGPS(); //随机发送不同长度的信息
    xBytesSent = xMessageBufferSend( xMessageBuffer,
                                     ( void * ) &gpsInfo,
                                     sizeof( gpsInfo ),
                                     portMAX_DELAY );

    if ( xBytesSent != sizeof( gpsInfo ) )
    {
      Serial.println("危险: xMessageBufferSend 发送数据不完整");
    }
    vTaskDelay(3000);
  }
}

void showGPS(void * pvParam) {
  size_t xReceivedBytes;
  String gpsInfo;
  const size_t xMessageSizeMax = 100;
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("   GPS INFO"); //clear this line
  while (1) {
    xReceivedBytes = xMessageBufferReceive( xMessageBuffer,
                                            ( void * ) &gpsInfo,
                                            xMessageSizeMax, //This sets the maximum length of the message that can be received.
                                            portMAX_DELAY );

    if ( xReceivedBytes > 0 )
    {
      gpsDecoder(gpsInfo); //解码，并且显示到屏幕上
    }

    vTaskDelay(1000);
  }
}


void monitorTask (void * pvParam) { //对 streamBuffer进行监控
  size_t xAvailable, xUsed;
  bool isFull;
  while (1) {

    //Queries a stream buffer to see if it is full.
    if (xMessageBufferIsFull(xMessageBuffer) == pdTRUE) Serial.println("xMessageBuffer 已满");

    //Queries a stream buffer to see how much free space it contains
    xAvailable = xMessageBufferSpacesAvailable(xMessageBuffer);

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

    vTaskDelay(1000);

  }
}

void setup()
{
  Serial.begin(115200);
  const size_t xMessageBufferSizeBytes = 100;
  xMessageBuffer = xMessageBufferCreate( xMessageBufferSizeBytes );

  if ( xMessageBuffer == NULL )
  {
    Serial.println("Unable to Create Message Buffer");
  }
  else
  {
    xTaskCreate(readGPS, "Read GPX", 1024 * 4, NULL, 1, NULL);
    xTaskCreate(showGPS, "Show GPX", 1024 * 4, NULL, 1, NULL);
    xTaskCreate(monitorTask, "Monitor Message Buffer", 1024 * 8, NULL, 1, NULL); //对Stream Buffer进行监控

  }
}


void loop() {
  //   String gpsinfo = randomGPS();
  //   Serial.println(gpsinfo);
  //  gpsDecoder(gpsinfo);
  //   delay(1000);

}