#include "FS.h"
#include "FFat.h"
 
// USB Host CH341 库
#include "cdc_ch34x.h"
 
#include <DFRobot_NeoPixel.h>
 
class CH34XAsyncOper : public CDCAsyncOper
{
  public:
    uint8_t OnInit(CH34X *pch34x);
};
 
// 初始化 CH341 USB 转 UART芯片
uint8_t CH34XAsyncOper::OnInit(CH34X *pch34x)
{
  uint8_t rcode;
  LINE_CODING lc;
 
  // 通讯波特率 9600
  lc.dwDTERate = 9600;
  lc.bCharFormat = 0;
  lc.bParityType = 0;
  lc.bDataBits = 8;
  lc.bFlowControl = 0;
 
  rcode = pch34x->SetLineCoding(&lc);
 
  if (rcode)
    ErrorMessage<uint8_t>(PSTR("SetLineCoding"), rcode);
 
  return rcode;
}
 
USB Usb;
CH34XAsyncOper AsyncOper;
CH34X Ch34x(&Usb, &AsyncOper);
 
// 定义发给设备的读取命令
uint8_t readCMD[]={0x01,0x03,0x00,0x00,0x00,0x14,0x45,0xC5};
 
// 定时取得数据的计时器
unsigned long DataElsp=0;
 
// 按键计时器，只有超过特定时间才可以再次按下这样能够避免抖动
unsigned long ButtonElsp=0;
 
// 记录当前灯色，RED 表示正在记录，绿色表示未记录
byte CurrentColor;
 
// 文件名变量
String filePath = "/log.csv";
 
 
// 检查给定的文件名是否存在
bool checkFile(fs::FS &fs, const char * path) {
  Serial.printf("Check file: %s\r\n", path);
  File file = fs.open(path);
  if (!file || file.isDirectory()) {
    return false;
  }
  return true;
}
 
// 写入 message 到 path 给定的文件中， mode 是写入模式，有新建和追加两种模式
void writeFile(fs::FS &fs, const char * path, const char * message,char* mode) {
  // 新建的情况下显示文件名
  if (mode==FILE_WRITE) {
    Serial.printf("Writing file: %s\r\n", path); }
   
  //尝试打开文件，这样判断文件是否存在
  File file = fs.open(path, mode);
  if (!file) {
    Serial.println("- failed to open file for writing");
    return;
  }
   
  // 串口输出写入的数据
  file.print(message);
}
 
// 将 Data 给出的缓冲区中的第 num 个字符串转化为浮点数
float BufferToFloat(uint8_t num,uint8_t *Data){
  float   value;
  uint32_t *pValue; 
   
   pValue=(uint32_t *)&value;
  *pValue=((uint32_t) Data[3+num*4]) | 
          ((uint32_t) Data[4+num*4]<<8)| 
          ((uint32_t) Data[5+num*4]<<16)| 
          ((uint32_t) Data[6+num*4]<<24);
           
  return value;             
}
 
void setup() {
  Serial.begin(115200);
 
  // 打开 U盘
  if (!FFat.begin()) {
    Serial.println("FFat Mount Failed");
        FFat.format();
            Serial.println("Format");
    return;
  }
 
  RGB_LED.begin();
  // 低亮度 
  RGB_LED.setBrightness(DARK);
  // 初始为绿色
  CurrentColor=GREEN;
  RGB_LED.setColor(GREEN);
  RGB_LED.show();
  RGB_LED.show();
   
  // 设置 SET 按钮对应的 GPIO 为输入
  pinMode(D3,INPUT);
 
  if (Usb.Init() == -1)
    Serial.println("OSC did not start.");
 
  delay( 200 );
  Serial.println("Start....");
}
 
void loop() {
  // 距离上一次按键时间大于2秒
  if (millis()-ButtonElsp>2000UL) {
      if (digitalRead(D3)==LOW) {
          // 如果当前是绿灯，那么切换为红色，并且创建一个文件
       if (CurrentColor==GREEN) {
          Serial.println("Switch to Red");
          CurrentColor=RED;
          RGB_LED.setColor(CurrentColor);
          RGB_LED.show();
          RGB_LED.show();
           
          // 尝试创建文件名
          for(int i = 1; i < 20; i++){
                  char fileNameNum[4];
                  sprintf(fileNameNum,"%04d",i);
                  String nowFileName  = (char *)fileNameNum;
                  filePath = "/log"+nowFileName+".csv";
                  // 如果这个文件名不存在，那么就创建之
                  if (!checkFile(FFat, filePath.c_str() )) {
                          Serial.println("Create a log.csv file");
                          // 写入第一行
                          writeFile(FFat, filePath.c_str(), "Time(MS),Current(A),Voltage(V),Power(W)\r\n",FILE_WRITE);          
                          Serial.print(filePath.c_str());
                          Serial.println(" cteated!");
                          break;
                  }
          }
          Serial.println("Log begin...");
       } else
            //如果当前是红色，那么切换为绿灯
       {
        Serial.println("Switch to Green");
        CurrentColor=GREEN;
        RGB_LED.setColor(CurrentColor);
        RGB_LED.show();
        RGB_LED.show();        
        Serial.println("It is paused now.");
        }
     }
     // 按键重新计时 
     ButtonElsp=millis(); 
  }
 
  char s[20];
  uint8_t Buffer[64];
   
  Usb.Task();
 
  if (( Usb.getUsbTaskState() == USB_STATE_RUNNING ) &&
     (CurrentColor==RED) && (millis()-DataElsp>300UL)) {
      if (Ch34x.isReady()) {
          Serial.println("CH34X:Ready!");
 
          // 将命令拷贝到 Buffer 中
          for (uint8_t i=0;i<sizeof(readCMD);i++) {
              Buffer[i]=readCMD[i];
            }
          // 发送读取命令  
          Ch34x.SndData(sizeof(readCMD), Buffer);
           
          Serial.println("RDCMD");
          delay(2000);
           
          // 接收
          uint16_t size = sizeof(Buffer);
          Ch34x.RcvData(&size, Buffer);
          if (size > 0) {
            // 将接收到的数据写入文件
                // 写入时间信息,单位是 100ms
            itoa(millis() /100,s,10);      
            writeFile(FFat, filePath.c_str(), s,FILE_APPEND);
            writeFile(FFat, filePath.c_str(), "," ,FILE_APPEND);
            Serial.print("Time(s):");Serial.println(s);
                // 写入电流信息        
            dtostrf(BufferToFloat(1,Buffer),1,3,s);
            writeFile(FFat, filePath.c_str(), s ,FILE_APPEND);
            writeFile(FFat, filePath.c_str(), "," ,FILE_APPEND);
            Serial.print("Current(A):");Serial.println(s);
                // 写入电压信息  
            dtostrf(BufferToFloat(2,Buffer),1,3,s);
            writeFile(FFat, filePath.c_str(), s ,FILE_APPEND);
            writeFile(FFat, filePath.c_str(), "," ,FILE_APPEND);
            Serial.print("Voltage(V):");Serial.println(s);
                // 写入功率
            dtostrf(BufferToFloat(0,Buffer),1,3,s);
            writeFile(FFat, filePath.c_str(), s ,FILE_APPEND);
            writeFile(FFat, filePath.c_str(), "\r\n" ,FILE_APPEND);
            Serial.print("Power(W):");Serial.println(s);    
             
            // 重置取得数据的定时器
            DataElsp=millis();   
             
            } //if (size > 0)
            else {
              Serial.println("received 0");
              }
          } //if (Ch34x.isReady())
          else {
              Serial.println("CH34X:not ready.");
          }
      }; //stop
}