#include "FS.h"
#include "SD.h"
#include <SPI.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <WiFi.h>
#include <NTPClient.h>
#include <WiFiUdp.h>


uint64_t uS_TO_S_FACTOR = 1000000;
uint64_t TIME_TO_SLEEP = 600;
const char* ssid  = "나우커피2G";
const char* password = "dee01dc173";
#define SD_CS 3
RTC_DATA_ATTR int readingID = 0;

String dataMessage;
#define ONE_WIRE_BUS 21
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);
float temperature;
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP);

String formattedDate;
String dayStamp;
String timesStamp;

void setup() {
  Serial.begin(115200);
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected.");
  timeClient.begin();
  timeClient.setTimeOffset(3600);
  SD.begin(SD_CS);
  if(!SD.begin(SD_CS)){
    Serial.println("Card Mount Failed");
    return;
  }
  uint8_t cardType = SD.cardType();
  if(cardType == CARD_NONE) {
    Serial.println("No SD card attached");
    return;
  }
  Serial.println("Initializing SD card ...");
  if (!SD.begin(SD_CS)) {
    Serial.println("ERROR - SD card initialization failed!");
    return;
  }
  File file = SD.open("/data.txt");
  if(!file) {
    Serial.println("File doesn't exist");
    Serial.println("Creating file...");
    writeFile(SD, "/data.txt", "Reading ID, Data, Hour, Temperature \r\n");
  }
  else {
    Serial.println("File already exists");
  }
  file.close();
  esp_sleep_enable_timer_wakeup(TIME_TO_SLEEP * uS_TO_S_FACTOR);
  sensors.begin();
  getReadings();
  getTimeStamp();
  logSDCard();
  readingID++;
  Serial.println("DONE! Going to sleep now.");
  esp_deep_sleep_start();
}

void loop() {
}
void getReadings(){
  sensors.requestTemperatures();
  temperature = sensors.getTempCByIndex(0); 
  Serial.print("Temperature : ");
  Serial.println(temperature);
}
void getTimeStamp() {
  while(!timeClient.update()) {
    timeClient.forceUpdate();
  }
  formattedDate = timeClient.getFormattedDate();
  Serial.println(formattedDate);
  int splitT = formattedData.indexOf("T");
  dayStamp = formattedData.substring(0, splitT);
  Serial.println(dayStamp);
  timeStamp = formattedData.substring(splitT+1, formattedDate.length()-1);
  Serial.println(timeStamp);
}
void logSDCard() {
  dataMessage = String(readingID) + "," + String(dayStamp) + "," + String(timeStamp) + "," + 
                String(temperature) + "\r\n";
  Serial.print("Save data: ");
  Serial.println(dataMessage);
  appendFile(SD, "/data.txt", dataMessage.c_str());
}
void writeFile(fs::FS &fs, const char * path, const char * message) {
  Serial.printf("Writing file: %s\n", path);

  File file = fs.open(path, FILE_WRITE);
  if(!file) {
    Serial.println(("Failed to open file for writing"));
    return;
    }
  if(file.print(message)) {
    Serial.println("File written");
    } else {
    Serial.println("Write failed");
    }
    file.close();
  }
void appendFile(fs::FS &fs, const char * path, const char * message) {
  Serial.printf("Appending to file : %s\n", path);
  File file = fs.open(path, FILE_APPEND);
  if(!file) {
    Serial.println("Failed to open file for appending");
    return;
  }
  if(file.print(message)) {
    Serial.println("Message appended");
  } else {
    Serial.println("Append failed");
  }
  file.close();
}